From c433820971ffa854feda6adc17f5f24201354f11 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Tue, 19 May 2009 07:49:32 -0500 Subject: Move kernel/kgdb.c to kernel/debug/debug_core.c Move kgdb.c in preparation to separate the gdbstub from the debug core and exception handling. CC: Ingo Molnar Signed-off-by: Jason Wessel --- kernel/Makefile | 2 +- kernel/debug/Makefile | 6 + kernel/debug/debug_core.c | 1764 +++++++++++++++++++++++++++++++++++++++++++++ kernel/kgdb.c | 1764 --------------------------------------------- 4 files changed, 1771 insertions(+), 1765 deletions(-) create mode 100644 kernel/debug/Makefile create mode 100644 kernel/debug/debug_core.c delete mode 100644 kernel/kgdb.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 149e18ef1ab..057472fbc27 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -75,7 +75,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_GCOV_KERNEL) += gcov/ obj-$(CONFIG_AUDIT_TREE) += audit_tree.o obj-$(CONFIG_KPROBES) += kprobes.o -obj-$(CONFIG_KGDB) += kgdb.o +obj-$(CONFIG_KGDB) += debug/ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile new file mode 100644 index 00000000000..5d785041526 --- /dev/null +++ b/kernel/debug/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for the linux kernel debugger +# + +obj-$(CONFIG_KGDB) += debug_core.o + diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c new file mode 100644 index 00000000000..11f3515ca83 --- /dev/null +++ b/kernel/debug/debug_core.c @@ -0,0 +1,1764 @@ +/* + * KGDB stub. + * + * Maintainer: Jason Wessel + * + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002-2004 Timesys Corporation + * Copyright (C) 2003-2004 Amit S. Kale + * Copyright (C) 2004 Pavel Machek + * Copyright (C) 2004-2006 Tom Rini + * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2005-2008 Wind River Systems, Inc. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar + * + * Contributors at various stages not listed above: + * Jason Wessel ( jason.wessel@windriver.com ) + * George Anzinger + * Anurekh Saxena (anurekh.saxena@timesys.com) + * Lake Stevens Instrument Division (Glenn Engel) + * Jim Kingdon, Cygnus Support. + * + * Original KGDB stub: David Grothe , + * Tigran Aivazian + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +static int kgdb_break_asap; + +#define KGDB_MAX_THREAD_QUERY 17 +struct kgdb_state { + int ex_vector; + int signo; + int err_code; + int cpu; + int pass_exception; + unsigned long thr_query; + unsigned long threadid; + long kgdb_usethreadid; + struct pt_regs *linux_regs; +}; + +/* Exception state values */ +#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */ +#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */ +#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */ +#define DCPU_SSTEP 0x8 /* CPU is single stepping */ + +static struct debuggerinfo_struct { + void *debuggerinfo; + struct task_struct *task; + int exception_state; +} kgdb_info[NR_CPUS]; + +/** + * kgdb_connected - Is a host GDB connected to us? + */ +int kgdb_connected; +EXPORT_SYMBOL_GPL(kgdb_connected); + +/* All the KGDB handlers are installed */ +static int kgdb_io_module_registered; + +/* Guard for recursive entry */ +static int exception_level; + +static struct kgdb_io *kgdb_io_ops; +static DEFINE_SPINLOCK(kgdb_registration_lock); + +/* kgdb console driver is loaded */ +static int kgdb_con_registered; +/* determine if kgdb console output should be used */ +static int kgdb_use_con; + +static int __init opt_kgdb_con(char *str) +{ + kgdb_use_con = 1; + return 0; +} + +early_param("kgdbcon", opt_kgdb_con); + +module_param(kgdb_use_con, int, 0644); + +/* + * Holds information about breakpoints in a kernel. These breakpoints are + * added and removed by gdb. + */ +static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } +}; + +/* + * The CPU# of the active CPU, or -1 if none: + */ +atomic_t kgdb_active = ATOMIC_INIT(-1); + +/* + * We use NR_CPUs not PERCPU, in case kgdb is used to debug early + * bootup code (which might not have percpu set up yet): + */ +static atomic_t passive_cpu_wait[NR_CPUS]; +static atomic_t cpu_in_kgdb[NR_CPUS]; +atomic_t kgdb_setting_breakpoint; + +struct task_struct *kgdb_usethread; +struct task_struct *kgdb_contthread; + +int kgdb_single_step; +pid_t kgdb_sstep_pid; + +/* Our I/O buffers. */ +static char remcom_in_buffer[BUFMAX]; +static char remcom_out_buffer[BUFMAX]; + +/* Storage for the registers, in GDB format. */ +static unsigned long gdb_regs[(NUMREGBYTES + + sizeof(unsigned long) - 1) / + sizeof(unsigned long)]; + +/* to keep track of the CPU which is doing the single stepping*/ +atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); + +/* + * If you are debugging a problem where roundup (the collection of + * all other CPUs) is a problem [this should be extremely rare], + * then use the nokgdbroundup option to avoid roundup. In that case + * the other CPUs might interfere with your debugging context, so + * use this with care: + */ +static int kgdb_do_roundup = 1; + +static int __init opt_nokgdbroundup(char *str) +{ + kgdb_do_roundup = 0; + + return 0; +} + +early_param("nokgdbroundup", opt_nokgdbroundup); + +/* + * Finally, some KGDB code :-) + */ + +/* + * Weak aliases for breakpoint management, + * can be overriden by architectures when needed: + */ +int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) +{ + int err; + + err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); + if (err) + return err; + + return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, + BREAK_INSTR_SIZE); +} + +int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) +{ + return probe_kernel_write((char *)addr, + (char *)bundle, BREAK_INSTR_SIZE); +} + +int __weak kgdb_validate_break_address(unsigned long addr) +{ + char tmp_variable[BREAK_INSTR_SIZE]; + int err; + /* Validate setting the breakpoint and then removing it. In the + * remove fails, the kernel needs to emit a bad message because we + * are deep trouble not being able to put things back the way we + * found them. + */ + err = kgdb_arch_set_breakpoint(addr, tmp_variable); + if (err) + return err; + err = kgdb_arch_remove_breakpoint(addr, tmp_variable); + if (err) + printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " + "memory destroyed at: %lx", addr); + return err; +} + +unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int __weak kgdb_arch_init(void) +{ + return 0; +} + +int __weak kgdb_skipexception(int exception, struct pt_regs *regs) +{ + return 0; +} + +void __weak +kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) +{ + return; +} + +/** + * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +void __weak kgdb_disable_hw_debug(struct pt_regs *regs) +{ +} + +/* + * GDB remote protocol parser: + */ + +static int hex(char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return ch - 'a' + 10; + if ((ch >= '0') && (ch <= '9')) + return ch - '0'; + if ((ch >= 'A') && (ch <= 'F')) + return ch - 'A' + 10; + return -1; +} + +/* scan for the sequence $# */ +static void get_packet(char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int count; + char ch; + + do { + /* + * Spin and wait around for the start character, ignore all + * other characters: + */ + while ((ch = (kgdb_io_ops->read_char())) != '$') + /* nothing */; + + kgdb_connected = 1; + checksum = 0; + xmitcsum = -1; + + count = 0; + + /* + * now, read until a # or end of buffer is found: + */ + while (count < (BUFMAX - 1)) { + ch = kgdb_io_ops->read_char(); + if (ch == '#') + break; + checksum = checksum + ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + + if (ch == '#') { + xmitcsum = hex(kgdb_io_ops->read_char()) << 4; + xmitcsum += hex(kgdb_io_ops->read_char()); + + if (checksum != xmitcsum) + /* failed checksum */ + kgdb_io_ops->write_char('-'); + else + /* successful transfer */ + kgdb_io_ops->write_char('+'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + } + } while (checksum != xmitcsum); +} + +/* + * Send the packet in buffer. + * Check for gdb connection if asked for. + */ +static void put_packet(char *buffer) +{ + unsigned char checksum; + int count; + char ch; + + /* + * $#. + */ + while (1) { + kgdb_io_ops->write_char('$'); + checksum = 0; + count = 0; + + while ((ch = buffer[count])) { + kgdb_io_ops->write_char(ch); + checksum += ch; + count++; + } + + kgdb_io_ops->write_char('#'); + kgdb_io_ops->write_char(hex_asc_hi(checksum)); + kgdb_io_ops->write_char(hex_asc_lo(checksum)); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + + /* Now see what we get in reply. */ + ch = kgdb_io_ops->read_char(); + + if (ch == 3) + ch = kgdb_io_ops->read_char(); + + /* If we get an ACK, we are done. */ + if (ch == '+') + return; + + /* + * If we get the start of another packet, this means + * that GDB is attempting to reconnect. We will NAK + * the packet being sent, and stop trying to send this + * packet. + */ + if (ch == '$') { + kgdb_io_ops->write_char('-'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + return; + } + } +} + +/* + * Convert the memory pointed to by mem into hex, placing result in buf. + * Return a pointer to the last char put in buf (null). May return an error. + */ +int kgdb_mem2hex(char *mem, char *buf, int count) +{ + char *tmp; + int err; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory copy. Hex conversion will work against this one. + */ + tmp = buf + count; + + err = probe_kernel_read(tmp, mem, count); + if (!err) { + while (count > 0) { + buf = pack_hex_byte(buf, *tmp); + tmp++; + count--; + } + + *buf = 0; + } + + return err; +} + +/* + * Copy the binary array pointed to by buf into mem. Fix $, #, and + * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. + * The input buf is overwitten with the result to write to mem. + */ +static int kgdb_ebin2mem(char *buf, char *mem, int count) +{ + int size = 0; + char *c = buf; + + while (count-- > 0) { + c[size] = *buf++; + if (c[size] == 0x7d) + c[size] = *buf++ ^ 0x20; + size++; + } + + return probe_kernel_write(mem, c, size); +} + +/* + * Convert the hex array pointed to by buf into binary to be placed in mem. + * Return a pointer to the character AFTER the last byte written. + * May return an error. + */ +int kgdb_hex2mem(char *buf, char *mem, int count) +{ + char *tmp_raw; + char *tmp_hex; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory that is converted from hex. + */ + tmp_raw = buf + count * 2; + + tmp_hex = tmp_raw - 1; + while (tmp_hex >= buf) { + tmp_raw--; + *tmp_raw = hex(*tmp_hex--); + *tmp_raw |= hex(*tmp_hex--) << 4; + } + + return probe_kernel_write(mem, tmp_raw, count); +} + +/* + * While we find nice hex chars, build a long_val. + * Return number of chars processed. + */ +int kgdb_hex2long(char **ptr, unsigned long *long_val) +{ + int hex_val; + int num = 0; + int negate = 0; + + *long_val = 0; + + if (**ptr == '-') { + negate = 1; + (*ptr)++; + } + while (**ptr) { + hex_val = hex(**ptr); + if (hex_val < 0) + break; + + *long_val = (*long_val << 4) | hex_val; + num++; + (*ptr)++; + } + + if (negate) + *long_val = -*long_val; + + return num; +} + +/* Write memory due to an 'M' or 'X' packet. */ +static int write_mem_msg(int binary) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long addr; + unsigned long length; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && + kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { + if (binary) + err = kgdb_ebin2mem(ptr, (char *)addr, length); + else + err = kgdb_hex2mem(ptr, (char *)addr, length); + if (err) + return err; + if (CACHE_FLUSH_IS_SAFE) + flush_icache_range(addr, addr + length); + return 0; + } + + return -EINVAL; +} + +static void error_packet(char *pkt, int error) +{ + error = -error; + pkt[0] = 'E'; + pkt[1] = hex_asc[(error / 10)]; + pkt[2] = hex_asc[(error % 10)]; + pkt[3] = '\0'; +} + +/* + * Thread ID accessors. We represent a flat TID space to GDB, where + * the per CPU idle threads (which under Linux all have PID 0) are + * remapped to negative TIDs. + */ + +#define BUF_THREAD_ID_SIZE 16 + +static char *pack_threadid(char *pkt, unsigned char *id) +{ + char *limit; + + limit = pkt + BUF_THREAD_ID_SIZE; + while (pkt < limit) + pkt = pack_hex_byte(pkt, *id++); + + return pkt; +} + +static void int_to_threadref(unsigned char *id, int value) +{ + unsigned char *scan; + int i = 4; + + scan = (unsigned char *)id; + while (i--) + *scan++ = 0; + put_unaligned_be32(value, scan); +} + +static struct task_struct *getthread(struct pt_regs *regs, int tid) +{ + /* + * Non-positive TIDs are remapped to the cpu shadow information + */ + if (tid == 0 || tid == -1) + tid = -atomic_read(&kgdb_active) - 2; + if (tid < -1 && tid > -NR_CPUS - 2) { + if (kgdb_info[-tid - 2].task) + return kgdb_info[-tid - 2].task; + else + return idle_task(-tid - 2); + } + if (tid <= 0) { + printk(KERN_ERR "KGDB: Internal thread select error\n"); + dump_stack(); + return NULL; + } + + /* + * find_task_by_pid_ns() does not take the tasklist lock anymore + * but is nicely RCU locked - hence is a pretty resilient + * thing to use: + */ + return find_task_by_pid_ns(tid, &init_pid_ns); +} + +/* + * Some architectures need cache flushes when we set/clear a + * breakpoint: + */ +static void kgdb_flush_swbreak_addr(unsigned long addr) +{ + if (!CACHE_FLUSH_IS_SAFE) + return; + + if (current->mm && current->mm->mmap_cache) { + flush_cache_range(current->mm->mmap_cache, + addr, addr + BREAK_INSTR_SIZE); + } + /* Force flush instruction cache if it was outside the mm */ + flush_icache_range(addr, addr + BREAK_INSTR_SIZE); +} + +/* + * SW breakpoint management: + */ +static int kgdb_activate_sw_breakpoints(void) +{ + unsigned long addr; + int error; + int ret = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_SET) + continue; + + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_set_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) { + ret = error; + printk(KERN_INFO "KGDB: BP install failed: %lx", addr); + continue; + } + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_ACTIVE; + } + return ret; +} + +static int kgdb_set_sw_break(unsigned long addr) +{ + int err = kgdb_validate_break_address(addr); + int breakno = -1; + int i; + + if (err) + return err; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) + return -EEXIST; + } + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_REMOVED && + kgdb_break[i].bpt_addr == addr) { + breakno = i; + break; + } + } + + if (breakno == -1) { + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_UNDEFINED) { + breakno = i; + break; + } + } + } + + if (breakno == -1) + return -E2BIG; + + kgdb_break[breakno].state = BP_SET; + kgdb_break[breakno].type = BP_BREAKPOINT; + kgdb_break[breakno].bpt_addr = addr; + + return 0; +} + +static int kgdb_deactivate_sw_breakpoints(void) +{ + unsigned long addr; + int error; + int ret = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + continue; + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_remove_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) { + printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr); + ret = error; + } + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_SET; + } + return ret; +} + +static int kgdb_remove_sw_break(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) { + kgdb_break[i].state = BP_REMOVED; + return 0; + } + } + return -ENOENT; +} + +int kgdb_isremovedbreak(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_REMOVED) && + (kgdb_break[i].bpt_addr == addr)) + return 1; + } + return 0; +} + +static int remove_all_break(void) +{ + unsigned long addr; + int error; + int i; + + /* Clear memory breakpoints. */ + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + goto setundefined; + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_remove_breakpoint(addr, + kgdb_break[i].saved_instr); + if (error) + printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", + addr); +setundefined: + kgdb_break[i].state = BP_UNDEFINED; + } + + /* Clear hardware breakpoints. */ + if (arch_kgdb_ops.remove_all_hw_break) + arch_kgdb_ops.remove_all_hw_break(); + + return 0; +} + +/* + * Remap normal tasks to their real PID, + * CPU shadow threads are mapped to -CPU - 2 + */ +static inline int shadow_pid(int realpid) +{ + if (realpid) + return realpid; + + return -raw_smp_processor_id() - 2; +} + +static char gdbmsgbuf[BUFMAX + 1]; + +static void kgdb_msg_write(const char *s, int len) +{ + char *bufptr; + int wcount; + int i; + + /* 'O'utput */ + gdbmsgbuf[0] = 'O'; + + /* Fill and send buffers... */ + while (len > 0) { + bufptr = gdbmsgbuf + 1; + + /* Calculate how many this time */ + if ((len << 1) > (BUFMAX - 2)) + wcount = (BUFMAX - 2) >> 1; + else + wcount = len; + + /* Pack in hex chars */ + for (i = 0; i < wcount; i++) + bufptr = pack_hex_byte(bufptr, s[i]); + *bufptr = '\0'; + + /* Move up */ + s += wcount; + len -= wcount; + + /* Write packet */ + put_packet(gdbmsgbuf); + } +} + +/* + * Return true if there is a valid kgdb I/O module. Also if no + * debugger is attached a message can be printed to the console about + * waiting for the debugger to attach. + * + * The print_wait argument is only to be true when called from inside + * the core kgdb_handle_exception, because it will wait for the + * debugger to attach. + */ +static int kgdb_io_ready(int print_wait) +{ + if (!kgdb_io_ops) + return 0; + if (kgdb_connected) + return 1; + if (atomic_read(&kgdb_setting_breakpoint)) + return 1; + if (print_wait) + printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); + return 1; +} + +/* + * All the functions that start with gdb_cmd are the various + * operations to implement the handlers for the gdbserial protocol + * where KGDB is communicating with an external debugger + */ + +/* Handle the '?' status packets */ +static void gdb_cmd_status(struct kgdb_state *ks) +{ + /* + * We know that this packet is only sent + * during initial connect. So to be safe, + * we clear out our breakpoints now in case + * GDB is reconnecting. + */ + remove_all_break(); + + remcom_out_buffer[0] = 'S'; + pack_hex_byte(&remcom_out_buffer[1], ks->signo); +} + +/* Handle the 'g' get registers request */ +static void gdb_cmd_getregs(struct kgdb_state *ks) +{ + struct task_struct *thread; + void *local_debuggerinfo; + int i; + + thread = kgdb_usethread; + if (!thread) { + thread = kgdb_info[ks->cpu].task; + local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; + } else { + local_debuggerinfo = NULL; + for_each_online_cpu(i) { + /* + * Try to find the task on some other + * or possibly this node if we do not + * find the matching task then we try + * to approximate the results. + */ + if (thread == kgdb_info[i].task) + local_debuggerinfo = kgdb_info[i].debuggerinfo; + } + } + + /* + * All threads that don't have debuggerinfo should be + * in schedule() sleeping, since all other CPUs + * are in kgdb_wait, and thus have debuggerinfo. + */ + if (local_debuggerinfo) { + pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); + } else { + /* + * Pull stuff saved during switch_to; nothing + * else is accessible (or even particularly + * relevant). + * + * This should be enough for a stack trace. + */ + sleeping_thread_to_gdb_regs(gdb_regs, thread); + } + kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); +} + +/* Handle the 'G' set registers request */ +static void gdb_cmd_setregs(struct kgdb_state *ks) +{ + kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); + + if (kgdb_usethread && kgdb_usethread != current) { + error_packet(remcom_out_buffer, -EINVAL); + } else { + gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); + strcpy(remcom_out_buffer, "OK"); + } +} + +/* Handle the 'm' memory read bytes */ +static void gdb_cmd_memread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long length; + unsigned long addr; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && + kgdb_hex2long(&ptr, &length) > 0) { + err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); + if (err) + error_packet(remcom_out_buffer, err); + } else { + error_packet(remcom_out_buffer, -EINVAL); + } +} + +/* Handle the 'M' memory write bytes */ +static void gdb_cmd_memwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(0); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'X' memory binary write bytes */ +static void gdb_cmd_binwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(1); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'D' or 'k', detach or kill packets */ +static void gdb_cmd_detachkill(struct kgdb_state *ks) +{ + int error; + + /* The detach case */ + if (remcom_in_buffer[0] == 'D') { + error = remove_all_break(); + if (error < 0) { + error_packet(remcom_out_buffer, error); + } else { + strcpy(remcom_out_buffer, "OK"); + kgdb_connected = 0; + } + put_packet(remcom_out_buffer); + } else { + /* + * Assume the kill case, with no exit code checking, + * trying to force detach the debugger: + */ + remove_all_break(); + kgdb_connected = 0; + } +} + +/* Handle the 'R' reboot packets */ +static int gdb_cmd_reboot(struct kgdb_state *ks) +{ + /* For now, only honor R0 */ + if (strcmp(remcom_in_buffer, "R0") == 0) { + printk(KERN_CRIT "Executing emergency reboot\n"); + strcpy(remcom_out_buffer, "OK"); + put_packet(remcom_out_buffer); + + /* + * Execution should not return from + * machine_emergency_restart() + */ + machine_emergency_restart(); + kgdb_connected = 0; + + return 1; + } + return 0; +} + +/* Handle the 'q' query packets */ +static void gdb_cmd_query(struct kgdb_state *ks) +{ + struct task_struct *g; + struct task_struct *p; + unsigned char thref[8]; + char *ptr; + int i; + int cpu; + int finished = 0; + + switch (remcom_in_buffer[1]) { + case 's': + case 'f': + if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + + i = 0; + remcom_out_buffer[0] = 'm'; + ptr = remcom_out_buffer + 1; + if (remcom_in_buffer[1] == 'f') { + /* Each cpu is a shadow thread */ + for_each_online_cpu(cpu) { + ks->thr_query = 0; + int_to_threadref(thref, -cpu - 2); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + i++; + } + } + + do_each_thread(g, p) { + if (i >= ks->thr_query && !finished) { + int_to_threadref(thref, p->pid); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + ks->thr_query++; + if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) + finished = 1; + } + i++; + } while_each_thread(g, p); + + *(--ptr) = '\0'; + break; + + case 'C': + /* Current thread id */ + strcpy(remcom_out_buffer, "QC"); + ks->threadid = shadow_pid(current->pid); + int_to_threadref(thref, ks->threadid); + pack_threadid(remcom_out_buffer + 2, thref); + break; + case 'T': + if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + ks->threadid = 0; + ptr = remcom_in_buffer + 17; + kgdb_hex2long(&ptr, &ks->threadid); + if (!getthread(ks->linux_regs, ks->threadid)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + if ((int)ks->threadid > 0) { + kgdb_mem2hex(getthread(ks->linux_regs, + ks->threadid)->comm, + remcom_out_buffer, 16); + } else { + static char tmpstr[23 + BUF_THREAD_ID_SIZE]; + + sprintf(tmpstr, "shadowCPU%d", + (int)(-ks->threadid - 2)); + kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); + } + break; + } +} + +/* Handle the 'H' task query packets */ +static void gdb_cmd_task(struct kgdb_state *ks) +{ + struct task_struct *thread; + char *ptr; + + switch (remcom_in_buffer[1]) { + case 'g': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_usethread = thread; + ks->kgdb_usethreadid = ks->threadid; + strcpy(remcom_out_buffer, "OK"); + break; + case 'c': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + if (!ks->threadid) { + kgdb_contthread = NULL; + } else { + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_contthread = thread; + } + strcpy(remcom_out_buffer, "OK"); + break; + } +} + +/* Handle the 'T' thread query packets */ +static void gdb_cmd_thread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + struct task_struct *thread; + + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (thread) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, -EINVAL); +} + +/* Handle the 'z' or 'Z' breakpoint remove or set packets */ +static void gdb_cmd_break(struct kgdb_state *ks) +{ + /* + * Since GDB-5.3, it's been drafted that '0' is a software + * breakpoint, '1' is a hardware breakpoint, so let's do that. + */ + char *bpt_type = &remcom_in_buffer[1]; + char *ptr = &remcom_in_buffer[2]; + unsigned long addr; + unsigned long length; + int error = 0; + + if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { + /* Unsupported */ + if (*bpt_type > '4') + return; + } else { + if (*bpt_type != '0' && *bpt_type != '1') + /* Unsupported. */ + return; + } + + /* + * Test if this is a hardware breakpoint, and + * if we support it: + */ + if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) + /* Unsupported. */ + return; + + if (*(ptr++) != ',') { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (!kgdb_hex2long(&ptr, &addr)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (*(ptr++) != ',' || + !kgdb_hex2long(&ptr, &length)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + + if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') + error = kgdb_set_sw_break(addr); + else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') + error = kgdb_remove_sw_break(addr); + else if (remcom_in_buffer[0] == 'Z') + error = arch_kgdb_ops.set_hw_breakpoint(addr, + (int)length, *bpt_type - '0'); + else if (remcom_in_buffer[0] == 'z') + error = arch_kgdb_ops.remove_hw_breakpoint(addr, + (int) length, *bpt_type - '0'); + + if (error == 0) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, error); +} + +/* Handle the 'C' signal / exception passing packets */ +static int gdb_cmd_exception_pass(struct kgdb_state *ks) +{ + /* C09 == pass exception + * C15 == detach kgdb, pass exception + */ + if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'c'; + + } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'D'; + remove_all_break(); + kgdb_connected = 0; + return 1; + + } else { + kgdb_msg_write("KGDB only knows signal 9 (pass)" + " and 15 (pass and disconnect)\n" + "Executing a continue without signal passing\n", 0); + remcom_in_buffer[0] = 'c'; + } + + /* Indicate fall through */ + return -1; +} + +/* + * This function performs all gdbserial command procesing + */ +static int gdb_serial_stub(struct kgdb_state *ks) +{ + int error = 0; + int tmp; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + if (kgdb_connected) { + unsigned char thref[8]; + char *ptr; + + /* Reply to host that an exception has occurred */ + ptr = remcom_out_buffer; + *ptr++ = 'T'; + ptr = pack_hex_byte(ptr, ks->signo); + ptr += strlen(strcpy(ptr, "thread:")); + int_to_threadref(thref, shadow_pid(current->pid)); + ptr = pack_threadid(ptr, thref); + *ptr++ = ';'; + put_packet(remcom_out_buffer); + } + + kgdb_usethread = kgdb_info[ks->cpu].task; + ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); + ks->pass_exception = 0; + + while (1) { + error = 0; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + get_packet(remcom_in_buffer); + + switch (remcom_in_buffer[0]) { + case '?': /* gdbserial status */ + gdb_cmd_status(ks); + break; + case 'g': /* return the value of the CPU registers */ + gdb_cmd_getregs(ks); + break; + case 'G': /* set the value of the CPU registers - return OK */ + gdb_cmd_setregs(ks); + break; + case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + gdb_cmd_memread(ks); + break; + case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_memwrite(ks); + break; + case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_binwrite(ks); + break; + /* kill or detach. KGDB should treat this like a + * continue. + */ + case 'D': /* Debugger detach */ + case 'k': /* Debugger detach via kill */ + gdb_cmd_detachkill(ks); + goto default_handle; + case 'R': /* Reboot */ + if (gdb_cmd_reboot(ks)) + goto default_handle; + break; + case 'q': /* query command */ + gdb_cmd_query(ks); + break; + case 'H': /* task related */ + gdb_cmd_task(ks); + break; + case 'T': /* Query thread status */ + gdb_cmd_thread(ks); + break; + case 'z': /* Break point remove */ + case 'Z': /* Break point set */ + gdb_cmd_break(ks); + break; + case 'C': /* Exception passing */ + tmp = gdb_cmd_exception_pass(ks); + if (tmp > 0) + goto default_handle; + if (tmp == 0) + break; + /* Fall through on tmp < 0 */ + case 'c': /* Continue packet */ + case 's': /* Single step packet */ + if (kgdb_contthread && kgdb_contthread != current) { + /* Can't switch threads in kgdb */ + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_activate_sw_breakpoints(); + /* Fall through to default processing */ + default: +default_handle: + error = kgdb_arch_handle_exception(ks->ex_vector, + ks->signo, + ks->err_code, + remcom_in_buffer, + remcom_out_buffer, + ks->linux_regs); + /* + * Leave cmd processing on error, detach, + * kill, continue, or single step. + */ + if (error >= 0 || remcom_in_buffer[0] == 'D' || + remcom_in_buffer[0] == 'k') { + error = 0; + goto kgdb_exit; + } + + } + + /* reply to the request */ + put_packet(remcom_out_buffer); + } + +kgdb_exit: + if (ks->pass_exception) + error = 1; + return error; +} + +static int kgdb_reenter_check(struct kgdb_state *ks) +{ + unsigned long addr; + + if (atomic_read(&kgdb_active) != raw_smp_processor_id()) + return 0; + + /* Panic on recursive debugger calls: */ + exception_level++; + addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); + kgdb_deactivate_sw_breakpoints(); + + /* + * If the break point removed ok at the place exception + * occurred, try to recover and print a warning to the end + * user because the user planted a breakpoint in a place that + * KGDB needs in order to function. + */ + if (kgdb_remove_sw_break(addr) == 0) { + exception_level = 0; + kgdb_skipexception(ks->ex_vector, ks->linux_regs); + kgdb_activate_sw_breakpoints(); + printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", + addr); + WARN_ON_ONCE(1); + + return 1; + } + remove_all_break(); + kgdb_skipexception(ks->ex_vector, ks->linux_regs); + + if (exception_level > 1) { + dump_stack(); + panic("Recursive entry to debugger"); + } + + printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); + dump_stack(); + panic("Recursive entry to debugger"); + + return 1; +} + +static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs) +{ + unsigned long flags; + int sstep_tries = 100; + int error = 0; + int i, cpu; + int trace_on = 0; +acquirelock: + /* + * Interrupts will be restored by the 'trap return' code, except when + * single stepping. + */ + local_irq_save(flags); + + cpu = ks->cpu; + kgdb_info[cpu].debuggerinfo = regs; + kgdb_info[cpu].task = current; + /* + * Make sure the above info reaches the primary CPU before + * our cpu_in_kgdb[] flag setting does: + */ + atomic_inc(&cpu_in_kgdb[cpu]); + + /* + * CPU will loop if it is a slave or request to become a kgdb + * master cpu and acquire the kgdb_active lock: + */ + while (1) { + if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { + if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu) + break; + } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { + if (!atomic_read(&passive_cpu_wait[cpu])) + goto return_normal; + } else { +return_normal: + /* Return to normal operation by executing any + * hw breakpoint fixup. + */ + if (arch_kgdb_ops.correct_hw_break) + arch_kgdb_ops.correct_hw_break(); + if (trace_on) + tracing_on(); + atomic_dec(&cpu_in_kgdb[cpu]); + touch_softlockup_watchdog_sync(); + clocksource_touch_watchdog(); + local_irq_restore(flags); + return 0; + } + cpu_relax(); + } + + /* + * For single stepping, try to only enter on the processor + * that was single stepping. To gaurd against a deadlock, the + * kernel will only try for the value of sstep_tries before + * giving up and continuing on. + */ + if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && + (kgdb_info[cpu].task && + kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) { + atomic_set(&kgdb_active, -1); + touch_softlockup_watchdog_sync(); + clocksource_touch_watchdog(); + local_irq_restore(flags); + + goto acquirelock; + } + + if (!kgdb_io_ready(1)) { + error = 1; + goto kgdb_restore; /* No I/O connection, so resume the system */ + } + + /* + * Don't enter if we have hit a removed breakpoint. + */ + if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) + goto kgdb_restore; + + /* Call the I/O driver's pre_exception routine */ + if (kgdb_io_ops->pre_exception) + kgdb_io_ops->pre_exception(); + + kgdb_disable_hw_debug(ks->linux_regs); + + /* + * Get the passive CPU lock which will hold all the non-primary + * CPU in a spin state while the debugger is active + */ + if (!kgdb_single_step) { + for (i = 0; i < NR_CPUS; i++) + atomic_inc(&passive_cpu_wait[i]); + } + +#ifdef CONFIG_SMP + /* Signal the other CPUs to enter kgdb_wait() */ + if ((!kgdb_single_step) && kgdb_do_roundup) + kgdb_roundup_cpus(flags); +#endif + + /* + * Wait for the other CPUs to be notified and be waiting for us: + */ + for_each_online_cpu(i) { + while (!atomic_read(&cpu_in_kgdb[i])) + cpu_relax(); + } + + /* + * At this point the primary processor is completely + * in the debugger and all secondary CPUs are quiescent + */ + kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); + kgdb_deactivate_sw_breakpoints(); + kgdb_single_step = 0; + kgdb_contthread = current; + exception_level = 0; + trace_on = tracing_is_on(); + if (trace_on) + tracing_off(); + + /* Talk to debugger with gdbserial protocol */ + error = gdb_serial_stub(ks); + + /* Call the I/O driver's post_exception routine */ + if (kgdb_io_ops->post_exception) + kgdb_io_ops->post_exception(); + + atomic_dec(&cpu_in_kgdb[ks->cpu]); + + if (!kgdb_single_step) { + for (i = NR_CPUS-1; i >= 0; i--) + atomic_dec(&passive_cpu_wait[i]); + /* + * Wait till all the CPUs have quit + * from the debugger. + */ + for_each_online_cpu(i) { + while (atomic_read(&cpu_in_kgdb[i])) + cpu_relax(); + } + } + +kgdb_restore: + if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { + int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step); + if (kgdb_info[sstep_cpu].task) + kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid; + else + kgdb_sstep_pid = 0; + } + if (trace_on) + tracing_on(); + /* Free kgdb_active */ + atomic_set(&kgdb_active, -1); + touch_softlockup_watchdog_sync(); + clocksource_touch_watchdog(); + local_irq_restore(flags); + + return error; +} + +/* + * kgdb_handle_exception() - main entry point from a kernel exception + * + * Locking hierarchy: + * interface locks, if any (begin_session) + * kgdb lock (kgdb_active) + */ +int +kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) +{ + struct kgdb_state kgdb_var; + struct kgdb_state *ks = &kgdb_var; + int ret; + + ks->cpu = raw_smp_processor_id(); + ks->ex_vector = evector; + ks->signo = signo; + ks->ex_vector = evector; + ks->err_code = ecode; + ks->kgdb_usethreadid = 0; + ks->linux_regs = regs; + + if (kgdb_reenter_check(ks)) + return 0; /* Ouch, double exception ! */ + kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER; + ret = kgdb_cpu_enter(ks, regs); + kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER; + return ret; +} + +int kgdb_nmicallback(int cpu, void *regs) +{ +#ifdef CONFIG_SMP + struct kgdb_state kgdb_var; + struct kgdb_state *ks = &kgdb_var; + + memset(ks, 0, sizeof(struct kgdb_state)); + ks->cpu = cpu; + ks->linux_regs = regs; + + if (!atomic_read(&cpu_in_kgdb[cpu]) && + atomic_read(&kgdb_active) != -1 && + atomic_read(&kgdb_active) != cpu) { + kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE; + kgdb_cpu_enter(ks, regs); + kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE; + return 0; + } +#endif + return 1; +} + +static void kgdb_console_write(struct console *co, const char *s, + unsigned count) +{ + unsigned long flags; + + /* If we're debugging, or KGDB has not connected, don't try + * and print. */ + if (!kgdb_connected || atomic_read(&kgdb_active) != -1) + return; + + local_irq_save(flags); + kgdb_msg_write(s, count); + local_irq_restore(flags); +} + +static struct console kgdbcons = { + .name = "kgdb", + .write = kgdb_console_write, + .flags = CON_PRINTBUFFER | CON_ENABLED, + .index = -1, +}; + +#ifdef CONFIG_MAGIC_SYSRQ +static void sysrq_handle_gdb(int key, struct tty_struct *tty) +{ + if (!kgdb_io_ops) { + printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); + return; + } + if (!kgdb_connected) + printk(KERN_CRIT "Entering KGDB\n"); + + kgdb_breakpoint(); +} + +static struct sysrq_key_op sysrq_gdb_op = { + .handler = sysrq_handle_gdb, + .help_msg = "debug(G)", + .action_msg = "DEBUG", +}; +#endif + +static void kgdb_register_callbacks(void) +{ + if (!kgdb_io_module_registered) { + kgdb_io_module_registered = 1; + kgdb_arch_init(); +#ifdef CONFIG_MAGIC_SYSRQ + register_sysrq_key('g', &sysrq_gdb_op); +#endif + if (kgdb_use_con && !kgdb_con_registered) { + register_console(&kgdbcons); + kgdb_con_registered = 1; + } + } +} + +static void kgdb_unregister_callbacks(void) +{ + /* + * When this routine is called KGDB should unregister from the + * panic handler and clean up, making sure it is not handling any + * break exceptions at the time. + */ + if (kgdb_io_module_registered) { + kgdb_io_module_registered = 0; + kgdb_arch_exit(); +#ifdef CONFIG_MAGIC_SYSRQ + unregister_sysrq_key('g', &sysrq_gdb_op); +#endif + if (kgdb_con_registered) { + unregister_console(&kgdbcons); + kgdb_con_registered = 0; + } + } +} + +static void kgdb_initial_breakpoint(void) +{ + kgdb_break_asap = 0; + + printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); + kgdb_breakpoint(); +} + +/** + * kgdb_register_io_module - register KGDB IO module + * @new_kgdb_io_ops: the io ops vector + * + * Register it with the KGDB core. + */ +int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) +{ + int err; + + spin_lock(&kgdb_registration_lock); + + if (kgdb_io_ops) { + spin_unlock(&kgdb_registration_lock); + + printk(KERN_ERR "kgdb: Another I/O driver is already " + "registered with KGDB.\n"); + return -EBUSY; + } + + if (new_kgdb_io_ops->init) { + err = new_kgdb_io_ops->init(); + if (err) { + spin_unlock(&kgdb_registration_lock); + return err; + } + } + + kgdb_io_ops = new_kgdb_io_ops; + + spin_unlock(&kgdb_registration_lock); + + printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", + new_kgdb_io_ops->name); + + /* Arm KGDB now. */ + kgdb_register_callbacks(); + + if (kgdb_break_asap) + kgdb_initial_breakpoint(); + + return 0; +} +EXPORT_SYMBOL_GPL(kgdb_register_io_module); + +/** + * kkgdb_unregister_io_module - unregister KGDB IO module + * @old_kgdb_io_ops: the io ops vector + * + * Unregister it with the KGDB core. + */ +void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) +{ + BUG_ON(kgdb_connected); + + /* + * KGDB is no longer able to communicate out, so + * unregister our callbacks and reset state. + */ + kgdb_unregister_callbacks(); + + spin_lock(&kgdb_registration_lock); + + WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); + kgdb_io_ops = NULL; + + spin_unlock(&kgdb_registration_lock); + + printk(KERN_INFO + "kgdb: Unregistered I/O driver %s, debugger disabled.\n", + old_kgdb_io_ops->name); +} +EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); + +/** + * kgdb_breakpoint - generate breakpoint exception + * + * This function will generate a breakpoint exception. It is used at the + * beginning of a program to sync up with a debugger and can be used + * otherwise as a quick means to stop program execution and "break" into + * the debugger. + */ +void kgdb_breakpoint(void) +{ + atomic_inc(&kgdb_setting_breakpoint); + wmb(); /* Sync point before breakpoint */ + arch_kgdb_breakpoint(); + wmb(); /* Sync point after breakpoint */ + atomic_dec(&kgdb_setting_breakpoint); +} +EXPORT_SYMBOL_GPL(kgdb_breakpoint); + +static int __init opt_kgdb_wait(char *str) +{ + kgdb_break_asap = 1; + + if (kgdb_io_module_registered) + kgdb_initial_breakpoint(); + + return 0; +} + +early_param("kgdbwait", opt_kgdb_wait); diff --git a/kernel/kgdb.c b/kernel/kgdb.c deleted file mode 100644 index 11f3515ca83..00000000000 --- a/kernel/kgdb.c +++ /dev/null @@ -1,1764 +0,0 @@ -/* - * KGDB stub. - * - * Maintainer: Jason Wessel - * - * Copyright (C) 2000-2001 VERITAS Software Corporation. - * Copyright (C) 2002-2004 Timesys Corporation - * Copyright (C) 2003-2004 Amit S. Kale - * Copyright (C) 2004 Pavel Machek - * Copyright (C) 2004-2006 Tom Rini - * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. - * Copyright (C) 2005-2008 Wind River Systems, Inc. - * Copyright (C) 2007 MontaVista Software, Inc. - * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar - * - * Contributors at various stages not listed above: - * Jason Wessel ( jason.wessel@windriver.com ) - * George Anzinger - * Anurekh Saxena (anurekh.saxena@timesys.com) - * Lake Stevens Instrument Division (Glenn Engel) - * Jim Kingdon, Cygnus Support. - * - * Original KGDB stub: David Grothe , - * Tigran Aivazian - * - * This file is licensed under the terms of the GNU General Public License - * version 2. This program is licensed "as is" without any warranty of any - * kind, whether express or implied. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include - -static int kgdb_break_asap; - -#define KGDB_MAX_THREAD_QUERY 17 -struct kgdb_state { - int ex_vector; - int signo; - int err_code; - int cpu; - int pass_exception; - unsigned long thr_query; - unsigned long threadid; - long kgdb_usethreadid; - struct pt_regs *linux_regs; -}; - -/* Exception state values */ -#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */ -#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */ -#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */ -#define DCPU_SSTEP 0x8 /* CPU is single stepping */ - -static struct debuggerinfo_struct { - void *debuggerinfo; - struct task_struct *task; - int exception_state; -} kgdb_info[NR_CPUS]; - -/** - * kgdb_connected - Is a host GDB connected to us? - */ -int kgdb_connected; -EXPORT_SYMBOL_GPL(kgdb_connected); - -/* All the KGDB handlers are installed */ -static int kgdb_io_module_registered; - -/* Guard for recursive entry */ -static int exception_level; - -static struct kgdb_io *kgdb_io_ops; -static DEFINE_SPINLOCK(kgdb_registration_lock); - -/* kgdb console driver is loaded */ -static int kgdb_con_registered; -/* determine if kgdb console output should be used */ -static int kgdb_use_con; - -static int __init opt_kgdb_con(char *str) -{ - kgdb_use_con = 1; - return 0; -} - -early_param("kgdbcon", opt_kgdb_con); - -module_param(kgdb_use_con, int, 0644); - -/* - * Holds information about breakpoints in a kernel. These breakpoints are - * added and removed by gdb. - */ -static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { - [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } -}; - -/* - * The CPU# of the active CPU, or -1 if none: - */ -atomic_t kgdb_active = ATOMIC_INIT(-1); - -/* - * We use NR_CPUs not PERCPU, in case kgdb is used to debug early - * bootup code (which might not have percpu set up yet): - */ -static atomic_t passive_cpu_wait[NR_CPUS]; -static atomic_t cpu_in_kgdb[NR_CPUS]; -atomic_t kgdb_setting_breakpoint; - -struct task_struct *kgdb_usethread; -struct task_struct *kgdb_contthread; - -int kgdb_single_step; -pid_t kgdb_sstep_pid; - -/* Our I/O buffers. */ -static char remcom_in_buffer[BUFMAX]; -static char remcom_out_buffer[BUFMAX]; - -/* Storage for the registers, in GDB format. */ -static unsigned long gdb_regs[(NUMREGBYTES + - sizeof(unsigned long) - 1) / - sizeof(unsigned long)]; - -/* to keep track of the CPU which is doing the single stepping*/ -atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); - -/* - * If you are debugging a problem where roundup (the collection of - * all other CPUs) is a problem [this should be extremely rare], - * then use the nokgdbroundup option to avoid roundup. In that case - * the other CPUs might interfere with your debugging context, so - * use this with care: - */ -static int kgdb_do_roundup = 1; - -static int __init opt_nokgdbroundup(char *str) -{ - kgdb_do_roundup = 0; - - return 0; -} - -early_param("nokgdbroundup", opt_nokgdbroundup); - -/* - * Finally, some KGDB code :-) - */ - -/* - * Weak aliases for breakpoint management, - * can be overriden by architectures when needed: - */ -int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) -{ - int err; - - err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); - if (err) - return err; - - return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, - BREAK_INSTR_SIZE); -} - -int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) -{ - return probe_kernel_write((char *)addr, - (char *)bundle, BREAK_INSTR_SIZE); -} - -int __weak kgdb_validate_break_address(unsigned long addr) -{ - char tmp_variable[BREAK_INSTR_SIZE]; - int err; - /* Validate setting the breakpoint and then removing it. In the - * remove fails, the kernel needs to emit a bad message because we - * are deep trouble not being able to put things back the way we - * found them. - */ - err = kgdb_arch_set_breakpoint(addr, tmp_variable); - if (err) - return err; - err = kgdb_arch_remove_breakpoint(addr, tmp_variable); - if (err) - printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " - "memory destroyed at: %lx", addr); - return err; -} - -unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) -{ - return instruction_pointer(regs); -} - -int __weak kgdb_arch_init(void) -{ - return 0; -} - -int __weak kgdb_skipexception(int exception, struct pt_regs *regs) -{ - return 0; -} - -void __weak -kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) -{ - return; -} - -/** - * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. - * @regs: Current &struct pt_regs. - * - * This function will be called if the particular architecture must - * disable hardware debugging while it is processing gdb packets or - * handling exception. - */ -void __weak kgdb_disable_hw_debug(struct pt_regs *regs) -{ -} - -/* - * GDB remote protocol parser: - */ - -static int hex(char ch) -{ - if ((ch >= 'a') && (ch <= 'f')) - return ch - 'a' + 10; - if ((ch >= '0') && (ch <= '9')) - return ch - '0'; - if ((ch >= 'A') && (ch <= 'F')) - return ch - 'A' + 10; - return -1; -} - -/* scan for the sequence $# */ -static void get_packet(char *buffer) -{ - unsigned char checksum; - unsigned char xmitcsum; - int count; - char ch; - - do { - /* - * Spin and wait around for the start character, ignore all - * other characters: - */ - while ((ch = (kgdb_io_ops->read_char())) != '$') - /* nothing */; - - kgdb_connected = 1; - checksum = 0; - xmitcsum = -1; - - count = 0; - - /* - * now, read until a # or end of buffer is found: - */ - while (count < (BUFMAX - 1)) { - ch = kgdb_io_ops->read_char(); - if (ch == '#') - break; - checksum = checksum + ch; - buffer[count] = ch; - count = count + 1; - } - buffer[count] = 0; - - if (ch == '#') { - xmitcsum = hex(kgdb_io_ops->read_char()) << 4; - xmitcsum += hex(kgdb_io_ops->read_char()); - - if (checksum != xmitcsum) - /* failed checksum */ - kgdb_io_ops->write_char('-'); - else - /* successful transfer */ - kgdb_io_ops->write_char('+'); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - } - } while (checksum != xmitcsum); -} - -/* - * Send the packet in buffer. - * Check for gdb connection if asked for. - */ -static void put_packet(char *buffer) -{ - unsigned char checksum; - int count; - char ch; - - /* - * $#. - */ - while (1) { - kgdb_io_ops->write_char('$'); - checksum = 0; - count = 0; - - while ((ch = buffer[count])) { - kgdb_io_ops->write_char(ch); - checksum += ch; - count++; - } - - kgdb_io_ops->write_char('#'); - kgdb_io_ops->write_char(hex_asc_hi(checksum)); - kgdb_io_ops->write_char(hex_asc_lo(checksum)); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - - /* Now see what we get in reply. */ - ch = kgdb_io_ops->read_char(); - - if (ch == 3) - ch = kgdb_io_ops->read_char(); - - /* If we get an ACK, we are done. */ - if (ch == '+') - return; - - /* - * If we get the start of another packet, this means - * that GDB is attempting to reconnect. We will NAK - * the packet being sent, and stop trying to send this - * packet. - */ - if (ch == '$') { - kgdb_io_ops->write_char('-'); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - return; - } - } -} - -/* - * Convert the memory pointed to by mem into hex, placing result in buf. - * Return a pointer to the last char put in buf (null). May return an error. - */ -int kgdb_mem2hex(char *mem, char *buf, int count) -{ - char *tmp; - int err; - - /* - * We use the upper half of buf as an intermediate buffer for the - * raw memory copy. Hex conversion will work against this one. - */ - tmp = buf + count; - - err = probe_kernel_read(tmp, mem, count); - if (!err) { - while (count > 0) { - buf = pack_hex_byte(buf, *tmp); - tmp++; - count--; - } - - *buf = 0; - } - - return err; -} - -/* - * Copy the binary array pointed to by buf into mem. Fix $, #, and - * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. - * The input buf is overwitten with the result to write to mem. - */ -static int kgdb_ebin2mem(char *buf, char *mem, int count) -{ - int size = 0; - char *c = buf; - - while (count-- > 0) { - c[size] = *buf++; - if (c[size] == 0x7d) - c[size] = *buf++ ^ 0x20; - size++; - } - - return probe_kernel_write(mem, c, size); -} - -/* - * Convert the hex array pointed to by buf into binary to be placed in mem. - * Return a pointer to the character AFTER the last byte written. - * May return an error. - */ -int kgdb_hex2mem(char *buf, char *mem, int count) -{ - char *tmp_raw; - char *tmp_hex; - - /* - * We use the upper half of buf as an intermediate buffer for the - * raw memory that is converted from hex. - */ - tmp_raw = buf + count * 2; - - tmp_hex = tmp_raw - 1; - while (tmp_hex >= buf) { - tmp_raw--; - *tmp_raw = hex(*tmp_hex--); - *tmp_raw |= hex(*tmp_hex--) << 4; - } - - return probe_kernel_write(mem, tmp_raw, count); -} - -/* - * While we find nice hex chars, build a long_val. - * Return number of chars processed. - */ -int kgdb_hex2long(char **ptr, unsigned long *long_val) -{ - int hex_val; - int num = 0; - int negate = 0; - - *long_val = 0; - - if (**ptr == '-') { - negate = 1; - (*ptr)++; - } - while (**ptr) { - hex_val = hex(**ptr); - if (hex_val < 0) - break; - - *long_val = (*long_val << 4) | hex_val; - num++; - (*ptr)++; - } - - if (negate) - *long_val = -*long_val; - - return num; -} - -/* Write memory due to an 'M' or 'X' packet. */ -static int write_mem_msg(int binary) -{ - char *ptr = &remcom_in_buffer[1]; - unsigned long addr; - unsigned long length; - int err; - - if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && - kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { - if (binary) - err = kgdb_ebin2mem(ptr, (char *)addr, length); - else - err = kgdb_hex2mem(ptr, (char *)addr, length); - if (err) - return err; - if (CACHE_FLUSH_IS_SAFE) - flush_icache_range(addr, addr + length); - return 0; - } - - return -EINVAL; -} - -static void error_packet(char *pkt, int error) -{ - error = -error; - pkt[0] = 'E'; - pkt[1] = hex_asc[(error / 10)]; - pkt[2] = hex_asc[(error % 10)]; - pkt[3] = '\0'; -} - -/* - * Thread ID accessors. We represent a flat TID space to GDB, where - * the per CPU idle threads (which under Linux all have PID 0) are - * remapped to negative TIDs. - */ - -#define BUF_THREAD_ID_SIZE 16 - -static char *pack_threadid(char *pkt, unsigned char *id) -{ - char *limit; - - limit = pkt + BUF_THREAD_ID_SIZE; - while (pkt < limit) - pkt = pack_hex_byte(pkt, *id++); - - return pkt; -} - -static void int_to_threadref(unsigned char *id, int value) -{ - unsigned char *scan; - int i = 4; - - scan = (unsigned char *)id; - while (i--) - *scan++ = 0; - put_unaligned_be32(value, scan); -} - -static struct task_struct *getthread(struct pt_regs *regs, int tid) -{ - /* - * Non-positive TIDs are remapped to the cpu shadow information - */ - if (tid == 0 || tid == -1) - tid = -atomic_read(&kgdb_active) - 2; - if (tid < -1 && tid > -NR_CPUS - 2) { - if (kgdb_info[-tid - 2].task) - return kgdb_info[-tid - 2].task; - else - return idle_task(-tid - 2); - } - if (tid <= 0) { - printk(KERN_ERR "KGDB: Internal thread select error\n"); - dump_stack(); - return NULL; - } - - /* - * find_task_by_pid_ns() does not take the tasklist lock anymore - * but is nicely RCU locked - hence is a pretty resilient - * thing to use: - */ - return find_task_by_pid_ns(tid, &init_pid_ns); -} - -/* - * Some architectures need cache flushes when we set/clear a - * breakpoint: - */ -static void kgdb_flush_swbreak_addr(unsigned long addr) -{ - if (!CACHE_FLUSH_IS_SAFE) - return; - - if (current->mm && current->mm->mmap_cache) { - flush_cache_range(current->mm->mmap_cache, - addr, addr + BREAK_INSTR_SIZE); - } - /* Force flush instruction cache if it was outside the mm */ - flush_icache_range(addr, addr + BREAK_INSTR_SIZE); -} - -/* - * SW breakpoint management: - */ -static int kgdb_activate_sw_breakpoints(void) -{ - unsigned long addr; - int error; - int ret = 0; - int i; - - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state != BP_SET) - continue; - - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_set_breakpoint(addr, - kgdb_break[i].saved_instr); - if (error) { - ret = error; - printk(KERN_INFO "KGDB: BP install failed: %lx", addr); - continue; - } - - kgdb_flush_swbreak_addr(addr); - kgdb_break[i].state = BP_ACTIVE; - } - return ret; -} - -static int kgdb_set_sw_break(unsigned long addr) -{ - int err = kgdb_validate_break_address(addr); - int breakno = -1; - int i; - - if (err) - return err; - - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if ((kgdb_break[i].state == BP_SET) && - (kgdb_break[i].bpt_addr == addr)) - return -EEXIST; - } - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state == BP_REMOVED && - kgdb_break[i].bpt_addr == addr) { - breakno = i; - break; - } - } - - if (breakno == -1) { - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state == BP_UNDEFINED) { - breakno = i; - break; - } - } - } - - if (breakno == -1) - return -E2BIG; - - kgdb_break[breakno].state = BP_SET; - kgdb_break[breakno].type = BP_BREAKPOINT; - kgdb_break[breakno].bpt_addr = addr; - - return 0; -} - -static int kgdb_deactivate_sw_breakpoints(void) -{ - unsigned long addr; - int error; - int ret = 0; - int i; - - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state != BP_ACTIVE) - continue; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); - if (error) { - printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr); - ret = error; - } - - kgdb_flush_swbreak_addr(addr); - kgdb_break[i].state = BP_SET; - } - return ret; -} - -static int kgdb_remove_sw_break(unsigned long addr) -{ - int i; - - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if ((kgdb_break[i].state == BP_SET) && - (kgdb_break[i].bpt_addr == addr)) { - kgdb_break[i].state = BP_REMOVED; - return 0; - } - } - return -ENOENT; -} - -int kgdb_isremovedbreak(unsigned long addr) -{ - int i; - - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if ((kgdb_break[i].state == BP_REMOVED) && - (kgdb_break[i].bpt_addr == addr)) - return 1; - } - return 0; -} - -static int remove_all_break(void) -{ - unsigned long addr; - int error; - int i; - - /* Clear memory breakpoints. */ - for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state != BP_ACTIVE) - goto setundefined; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); - if (error) - printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", - addr); -setundefined: - kgdb_break[i].state = BP_UNDEFINED; - } - - /* Clear hardware breakpoints. */ - if (arch_kgdb_ops.remove_all_hw_break) - arch_kgdb_ops.remove_all_hw_break(); - - return 0; -} - -/* - * Remap normal tasks to their real PID, - * CPU shadow threads are mapped to -CPU - 2 - */ -static inline int shadow_pid(int realpid) -{ - if (realpid) - return realpid; - - return -raw_smp_processor_id() - 2; -} - -static char gdbmsgbuf[BUFMAX + 1]; - -static void kgdb_msg_write(const char *s, int len) -{ - char *bufptr; - int wcount; - int i; - - /* 'O'utput */ - gdbmsgbuf[0] = 'O'; - - /* Fill and send buffers... */ - while (len > 0) { - bufptr = gdbmsgbuf + 1; - - /* Calculate how many this time */ - if ((len << 1) > (BUFMAX - 2)) - wcount = (BUFMAX - 2) >> 1; - else - wcount = len; - - /* Pack in hex chars */ - for (i = 0; i < wcount; i++) - bufptr = pack_hex_byte(bufptr, s[i]); - *bufptr = '\0'; - - /* Move up */ - s += wcount; - len -= wcount; - - /* Write packet */ - put_packet(gdbmsgbuf); - } -} - -/* - * Return true if there is a valid kgdb I/O module. Also if no - * debugger is attached a message can be printed to the console about - * waiting for the debugger to attach. - * - * The print_wait argument is only to be true when called from inside - * the core kgdb_handle_exception, because it will wait for the - * debugger to attach. - */ -static int kgdb_io_ready(int print_wait) -{ - if (!kgdb_io_ops) - return 0; - if (kgdb_connected) - return 1; - if (atomic_read(&kgdb_setting_breakpoint)) - return 1; - if (print_wait) - printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); - return 1; -} - -/* - * All the functions that start with gdb_cmd are the various - * operations to implement the handlers for the gdbserial protocol - * where KGDB is communicating with an external debugger - */ - -/* Handle the '?' status packets */ -static void gdb_cmd_status(struct kgdb_state *ks) -{ - /* - * We know that this packet is only sent - * during initial connect. So to be safe, - * we clear out our breakpoints now in case - * GDB is reconnecting. - */ - remove_all_break(); - - remcom_out_buffer[0] = 'S'; - pack_hex_byte(&remcom_out_buffer[1], ks->signo); -} - -/* Handle the 'g' get registers request */ -static void gdb_cmd_getregs(struct kgdb_state *ks) -{ - struct task_struct *thread; - void *local_debuggerinfo; - int i; - - thread = kgdb_usethread; - if (!thread) { - thread = kgdb_info[ks->cpu].task; - local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; - } else { - local_debuggerinfo = NULL; - for_each_online_cpu(i) { - /* - * Try to find the task on some other - * or possibly this node if we do not - * find the matching task then we try - * to approximate the results. - */ - if (thread == kgdb_info[i].task) - local_debuggerinfo = kgdb_info[i].debuggerinfo; - } - } - - /* - * All threads that don't have debuggerinfo should be - * in schedule() sleeping, since all other CPUs - * are in kgdb_wait, and thus have debuggerinfo. - */ - if (local_debuggerinfo) { - pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); - } else { - /* - * Pull stuff saved during switch_to; nothing - * else is accessible (or even particularly - * relevant). - * - * This should be enough for a stack trace. - */ - sleeping_thread_to_gdb_regs(gdb_regs, thread); - } - kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); -} - -/* Handle the 'G' set registers request */ -static void gdb_cmd_setregs(struct kgdb_state *ks) -{ - kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); - - if (kgdb_usethread && kgdb_usethread != current) { - error_packet(remcom_out_buffer, -EINVAL); - } else { - gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); - strcpy(remcom_out_buffer, "OK"); - } -} - -/* Handle the 'm' memory read bytes */ -static void gdb_cmd_memread(struct kgdb_state *ks) -{ - char *ptr = &remcom_in_buffer[1]; - unsigned long length; - unsigned long addr; - int err; - - if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && - kgdb_hex2long(&ptr, &length) > 0) { - err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); - if (err) - error_packet(remcom_out_buffer, err); - } else { - error_packet(remcom_out_buffer, -EINVAL); - } -} - -/* Handle the 'M' memory write bytes */ -static void gdb_cmd_memwrite(struct kgdb_state *ks) -{ - int err = write_mem_msg(0); - - if (err) - error_packet(remcom_out_buffer, err); - else - strcpy(remcom_out_buffer, "OK"); -} - -/* Handle the 'X' memory binary write bytes */ -static void gdb_cmd_binwrite(struct kgdb_state *ks) -{ - int err = write_mem_msg(1); - - if (err) - error_packet(remcom_out_buffer, err); - else - strcpy(remcom_out_buffer, "OK"); -} - -/* Handle the 'D' or 'k', detach or kill packets */ -static void gdb_cmd_detachkill(struct kgdb_state *ks) -{ - int error; - - /* The detach case */ - if (remcom_in_buffer[0] == 'D') { - error = remove_all_break(); - if (error < 0) { - error_packet(remcom_out_buffer, error); - } else { - strcpy(remcom_out_buffer, "OK"); - kgdb_connected = 0; - } - put_packet(remcom_out_buffer); - } else { - /* - * Assume the kill case, with no exit code checking, - * trying to force detach the debugger: - */ - remove_all_break(); - kgdb_connected = 0; - } -} - -/* Handle the 'R' reboot packets */ -static int gdb_cmd_reboot(struct kgdb_state *ks) -{ - /* For now, only honor R0 */ - if (strcmp(remcom_in_buffer, "R0") == 0) { - printk(KERN_CRIT "Executing emergency reboot\n"); - strcpy(remcom_out_buffer, "OK"); - put_packet(remcom_out_buffer); - - /* - * Execution should not return from - * machine_emergency_restart() - */ - machine_emergency_restart(); - kgdb_connected = 0; - - return 1; - } - return 0; -} - -/* Handle the 'q' query packets */ -static void gdb_cmd_query(struct kgdb_state *ks) -{ - struct task_struct *g; - struct task_struct *p; - unsigned char thref[8]; - char *ptr; - int i; - int cpu; - int finished = 0; - - switch (remcom_in_buffer[1]) { - case 's': - case 'f': - if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - - i = 0; - remcom_out_buffer[0] = 'm'; - ptr = remcom_out_buffer + 1; - if (remcom_in_buffer[1] == 'f') { - /* Each cpu is a shadow thread */ - for_each_online_cpu(cpu) { - ks->thr_query = 0; - int_to_threadref(thref, -cpu - 2); - pack_threadid(ptr, thref); - ptr += BUF_THREAD_ID_SIZE; - *(ptr++) = ','; - i++; - } - } - - do_each_thread(g, p) { - if (i >= ks->thr_query && !finished) { - int_to_threadref(thref, p->pid); - pack_threadid(ptr, thref); - ptr += BUF_THREAD_ID_SIZE; - *(ptr++) = ','; - ks->thr_query++; - if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) - finished = 1; - } - i++; - } while_each_thread(g, p); - - *(--ptr) = '\0'; - break; - - case 'C': - /* Current thread id */ - strcpy(remcom_out_buffer, "QC"); - ks->threadid = shadow_pid(current->pid); - int_to_threadref(thref, ks->threadid); - pack_threadid(remcom_out_buffer + 2, thref); - break; - case 'T': - if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - ks->threadid = 0; - ptr = remcom_in_buffer + 17; - kgdb_hex2long(&ptr, &ks->threadid); - if (!getthread(ks->linux_regs, ks->threadid)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - if ((int)ks->threadid > 0) { - kgdb_mem2hex(getthread(ks->linux_regs, - ks->threadid)->comm, - remcom_out_buffer, 16); - } else { - static char tmpstr[23 + BUF_THREAD_ID_SIZE]; - - sprintf(tmpstr, "shadowCPU%d", - (int)(-ks->threadid - 2)); - kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); - } - break; - } -} - -/* Handle the 'H' task query packets */ -static void gdb_cmd_task(struct kgdb_state *ks) -{ - struct task_struct *thread; - char *ptr; - - switch (remcom_in_buffer[1]) { - case 'g': - ptr = &remcom_in_buffer[2]; - kgdb_hex2long(&ptr, &ks->threadid); - thread = getthread(ks->linux_regs, ks->threadid); - if (!thread && ks->threadid > 0) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_usethread = thread; - ks->kgdb_usethreadid = ks->threadid; - strcpy(remcom_out_buffer, "OK"); - break; - case 'c': - ptr = &remcom_in_buffer[2]; - kgdb_hex2long(&ptr, &ks->threadid); - if (!ks->threadid) { - kgdb_contthread = NULL; - } else { - thread = getthread(ks->linux_regs, ks->threadid); - if (!thread && ks->threadid > 0) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_contthread = thread; - } - strcpy(remcom_out_buffer, "OK"); - break; - } -} - -/* Handle the 'T' thread query packets */ -static void gdb_cmd_thread(struct kgdb_state *ks) -{ - char *ptr = &remcom_in_buffer[1]; - struct task_struct *thread; - - kgdb_hex2long(&ptr, &ks->threadid); - thread = getthread(ks->linux_regs, ks->threadid); - if (thread) - strcpy(remcom_out_buffer, "OK"); - else - error_packet(remcom_out_buffer, -EINVAL); -} - -/* Handle the 'z' or 'Z' breakpoint remove or set packets */ -static void gdb_cmd_break(struct kgdb_state *ks) -{ - /* - * Since GDB-5.3, it's been drafted that '0' is a software - * breakpoint, '1' is a hardware breakpoint, so let's do that. - */ - char *bpt_type = &remcom_in_buffer[1]; - char *ptr = &remcom_in_buffer[2]; - unsigned long addr; - unsigned long length; - int error = 0; - - if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { - /* Unsupported */ - if (*bpt_type > '4') - return; - } else { - if (*bpt_type != '0' && *bpt_type != '1') - /* Unsupported. */ - return; - } - - /* - * Test if this is a hardware breakpoint, and - * if we support it: - */ - if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) - /* Unsupported. */ - return; - - if (*(ptr++) != ',') { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - if (!kgdb_hex2long(&ptr, &addr)) { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - if (*(ptr++) != ',' || - !kgdb_hex2long(&ptr, &length)) { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - - if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') - error = kgdb_set_sw_break(addr); - else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') - error = kgdb_remove_sw_break(addr); - else if (remcom_in_buffer[0] == 'Z') - error = arch_kgdb_ops.set_hw_breakpoint(addr, - (int)length, *bpt_type - '0'); - else if (remcom_in_buffer[0] == 'z') - error = arch_kgdb_ops.remove_hw_breakpoint(addr, - (int) length, *bpt_type - '0'); - - if (error == 0) - strcpy(remcom_out_buffer, "OK"); - else - error_packet(remcom_out_buffer, error); -} - -/* Handle the 'C' signal / exception passing packets */ -static int gdb_cmd_exception_pass(struct kgdb_state *ks) -{ - /* C09 == pass exception - * C15 == detach kgdb, pass exception - */ - if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { - - ks->pass_exception = 1; - remcom_in_buffer[0] = 'c'; - - } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { - - ks->pass_exception = 1; - remcom_in_buffer[0] = 'D'; - remove_all_break(); - kgdb_connected = 0; - return 1; - - } else { - kgdb_msg_write("KGDB only knows signal 9 (pass)" - " and 15 (pass and disconnect)\n" - "Executing a continue without signal passing\n", 0); - remcom_in_buffer[0] = 'c'; - } - - /* Indicate fall through */ - return -1; -} - -/* - * This function performs all gdbserial command procesing - */ -static int gdb_serial_stub(struct kgdb_state *ks) -{ - int error = 0; - int tmp; - - /* Clear the out buffer. */ - memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); - - if (kgdb_connected) { - unsigned char thref[8]; - char *ptr; - - /* Reply to host that an exception has occurred */ - ptr = remcom_out_buffer; - *ptr++ = 'T'; - ptr = pack_hex_byte(ptr, ks->signo); - ptr += strlen(strcpy(ptr, "thread:")); - int_to_threadref(thref, shadow_pid(current->pid)); - ptr = pack_threadid(ptr, thref); - *ptr++ = ';'; - put_packet(remcom_out_buffer); - } - - kgdb_usethread = kgdb_info[ks->cpu].task; - ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); - ks->pass_exception = 0; - - while (1) { - error = 0; - - /* Clear the out buffer. */ - memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); - - get_packet(remcom_in_buffer); - - switch (remcom_in_buffer[0]) { - case '?': /* gdbserial status */ - gdb_cmd_status(ks); - break; - case 'g': /* return the value of the CPU registers */ - gdb_cmd_getregs(ks); - break; - case 'G': /* set the value of the CPU registers - return OK */ - gdb_cmd_setregs(ks); - break; - case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ - gdb_cmd_memread(ks); - break; - case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ - gdb_cmd_memwrite(ks); - break; - case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ - gdb_cmd_binwrite(ks); - break; - /* kill or detach. KGDB should treat this like a - * continue. - */ - case 'D': /* Debugger detach */ - case 'k': /* Debugger detach via kill */ - gdb_cmd_detachkill(ks); - goto default_handle; - case 'R': /* Reboot */ - if (gdb_cmd_reboot(ks)) - goto default_handle; - break; - case 'q': /* query command */ - gdb_cmd_query(ks); - break; - case 'H': /* task related */ - gdb_cmd_task(ks); - break; - case 'T': /* Query thread status */ - gdb_cmd_thread(ks); - break; - case 'z': /* Break point remove */ - case 'Z': /* Break point set */ - gdb_cmd_break(ks); - break; - case 'C': /* Exception passing */ - tmp = gdb_cmd_exception_pass(ks); - if (tmp > 0) - goto default_handle; - if (tmp == 0) - break; - /* Fall through on tmp < 0 */ - case 'c': /* Continue packet */ - case 's': /* Single step packet */ - if (kgdb_contthread && kgdb_contthread != current) { - /* Can't switch threads in kgdb */ - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_activate_sw_breakpoints(); - /* Fall through to default processing */ - default: -default_handle: - error = kgdb_arch_handle_exception(ks->ex_vector, - ks->signo, - ks->err_code, - remcom_in_buffer, - remcom_out_buffer, - ks->linux_regs); - /* - * Leave cmd processing on error, detach, - * kill, continue, or single step. - */ - if (error >= 0 || remcom_in_buffer[0] == 'D' || - remcom_in_buffer[0] == 'k') { - error = 0; - goto kgdb_exit; - } - - } - - /* reply to the request */ - put_packet(remcom_out_buffer); - } - -kgdb_exit: - if (ks->pass_exception) - error = 1; - return error; -} - -static int kgdb_reenter_check(struct kgdb_state *ks) -{ - unsigned long addr; - - if (atomic_read(&kgdb_active) != raw_smp_processor_id()) - return 0; - - /* Panic on recursive debugger calls: */ - exception_level++; - addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); - kgdb_deactivate_sw_breakpoints(); - - /* - * If the break point removed ok at the place exception - * occurred, try to recover and print a warning to the end - * user because the user planted a breakpoint in a place that - * KGDB needs in order to function. - */ - if (kgdb_remove_sw_break(addr) == 0) { - exception_level = 0; - kgdb_skipexception(ks->ex_vector, ks->linux_regs); - kgdb_activate_sw_breakpoints(); - printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", - addr); - WARN_ON_ONCE(1); - - return 1; - } - remove_all_break(); - kgdb_skipexception(ks->ex_vector, ks->linux_regs); - - if (exception_level > 1) { - dump_stack(); - panic("Recursive entry to debugger"); - } - - printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); - dump_stack(); - panic("Recursive entry to debugger"); - - return 1; -} - -static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs) -{ - unsigned long flags; - int sstep_tries = 100; - int error = 0; - int i, cpu; - int trace_on = 0; -acquirelock: - /* - * Interrupts will be restored by the 'trap return' code, except when - * single stepping. - */ - local_irq_save(flags); - - cpu = ks->cpu; - kgdb_info[cpu].debuggerinfo = regs; - kgdb_info[cpu].task = current; - /* - * Make sure the above info reaches the primary CPU before - * our cpu_in_kgdb[] flag setting does: - */ - atomic_inc(&cpu_in_kgdb[cpu]); - - /* - * CPU will loop if it is a slave or request to become a kgdb - * master cpu and acquire the kgdb_active lock: - */ - while (1) { - if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { - if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu) - break; - } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { - if (!atomic_read(&passive_cpu_wait[cpu])) - goto return_normal; - } else { -return_normal: - /* Return to normal operation by executing any - * hw breakpoint fixup. - */ - if (arch_kgdb_ops.correct_hw_break) - arch_kgdb_ops.correct_hw_break(); - if (trace_on) - tracing_on(); - atomic_dec(&cpu_in_kgdb[cpu]); - touch_softlockup_watchdog_sync(); - clocksource_touch_watchdog(); - local_irq_restore(flags); - return 0; - } - cpu_relax(); - } - - /* - * For single stepping, try to only enter on the processor - * that was single stepping. To gaurd against a deadlock, the - * kernel will only try for the value of sstep_tries before - * giving up and continuing on. - */ - if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && - (kgdb_info[cpu].task && - kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) { - atomic_set(&kgdb_active, -1); - touch_softlockup_watchdog_sync(); - clocksource_touch_watchdog(); - local_irq_restore(flags); - - goto acquirelock; - } - - if (!kgdb_io_ready(1)) { - error = 1; - goto kgdb_restore; /* No I/O connection, so resume the system */ - } - - /* - * Don't enter if we have hit a removed breakpoint. - */ - if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) - goto kgdb_restore; - - /* Call the I/O driver's pre_exception routine */ - if (kgdb_io_ops->pre_exception) - kgdb_io_ops->pre_exception(); - - kgdb_disable_hw_debug(ks->linux_regs); - - /* - * Get the passive CPU lock which will hold all the non-primary - * CPU in a spin state while the debugger is active - */ - if (!kgdb_single_step) { - for (i = 0; i < NR_CPUS; i++) - atomic_inc(&passive_cpu_wait[i]); - } - -#ifdef CONFIG_SMP - /* Signal the other CPUs to enter kgdb_wait() */ - if ((!kgdb_single_step) && kgdb_do_roundup) - kgdb_roundup_cpus(flags); -#endif - - /* - * Wait for the other CPUs to be notified and be waiting for us: - */ - for_each_online_cpu(i) { - while (!atomic_read(&cpu_in_kgdb[i])) - cpu_relax(); - } - - /* - * At this point the primary processor is completely - * in the debugger and all secondary CPUs are quiescent - */ - kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); - kgdb_deactivate_sw_breakpoints(); - kgdb_single_step = 0; - kgdb_contthread = current; - exception_level = 0; - trace_on = tracing_is_on(); - if (trace_on) - tracing_off(); - - /* Talk to debugger with gdbserial protocol */ - error = gdb_serial_stub(ks); - - /* Call the I/O driver's post_exception routine */ - if (kgdb_io_ops->post_exception) - kgdb_io_ops->post_exception(); - - atomic_dec(&cpu_in_kgdb[ks->cpu]); - - if (!kgdb_single_step) { - for (i = NR_CPUS-1; i >= 0; i--) - atomic_dec(&passive_cpu_wait[i]); - /* - * Wait till all the CPUs have quit - * from the debugger. - */ - for_each_online_cpu(i) { - while (atomic_read(&cpu_in_kgdb[i])) - cpu_relax(); - } - } - -kgdb_restore: - if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { - int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step); - if (kgdb_info[sstep_cpu].task) - kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid; - else - kgdb_sstep_pid = 0; - } - if (trace_on) - tracing_on(); - /* Free kgdb_active */ - atomic_set(&kgdb_active, -1); - touch_softlockup_watchdog_sync(); - clocksource_touch_watchdog(); - local_irq_restore(flags); - - return error; -} - -/* - * kgdb_handle_exception() - main entry point from a kernel exception - * - * Locking hierarchy: - * interface locks, if any (begin_session) - * kgdb lock (kgdb_active) - */ -int -kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) -{ - struct kgdb_state kgdb_var; - struct kgdb_state *ks = &kgdb_var; - int ret; - - ks->cpu = raw_smp_processor_id(); - ks->ex_vector = evector; - ks->signo = signo; - ks->ex_vector = evector; - ks->err_code = ecode; - ks->kgdb_usethreadid = 0; - ks->linux_regs = regs; - - if (kgdb_reenter_check(ks)) - return 0; /* Ouch, double exception ! */ - kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER; - ret = kgdb_cpu_enter(ks, regs); - kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER; - return ret; -} - -int kgdb_nmicallback(int cpu, void *regs) -{ -#ifdef CONFIG_SMP - struct kgdb_state kgdb_var; - struct kgdb_state *ks = &kgdb_var; - - memset(ks, 0, sizeof(struct kgdb_state)); - ks->cpu = cpu; - ks->linux_regs = regs; - - if (!atomic_read(&cpu_in_kgdb[cpu]) && - atomic_read(&kgdb_active) != -1 && - atomic_read(&kgdb_active) != cpu) { - kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE; - kgdb_cpu_enter(ks, regs); - kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE; - return 0; - } -#endif - return 1; -} - -static void kgdb_console_write(struct console *co, const char *s, - unsigned count) -{ - unsigned long flags; - - /* If we're debugging, or KGDB has not connected, don't try - * and print. */ - if (!kgdb_connected || atomic_read(&kgdb_active) != -1) - return; - - local_irq_save(flags); - kgdb_msg_write(s, count); - local_irq_restore(flags); -} - -static struct console kgdbcons = { - .name = "kgdb", - .write = kgdb_console_write, - .flags = CON_PRINTBUFFER | CON_ENABLED, - .index = -1, -}; - -#ifdef CONFIG_MAGIC_SYSRQ -static void sysrq_handle_gdb(int key, struct tty_struct *tty) -{ - if (!kgdb_io_ops) { - printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); - return; - } - if (!kgdb_connected) - printk(KERN_CRIT "Entering KGDB\n"); - - kgdb_breakpoint(); -} - -static struct sysrq_key_op sysrq_gdb_op = { - .handler = sysrq_handle_gdb, - .help_msg = "debug(G)", - .action_msg = "DEBUG", -}; -#endif - -static void kgdb_register_callbacks(void) -{ - if (!kgdb_io_module_registered) { - kgdb_io_module_registered = 1; - kgdb_arch_init(); -#ifdef CONFIG_MAGIC_SYSRQ - register_sysrq_key('g', &sysrq_gdb_op); -#endif - if (kgdb_use_con && !kgdb_con_registered) { - register_console(&kgdbcons); - kgdb_con_registered = 1; - } - } -} - -static void kgdb_unregister_callbacks(void) -{ - /* - * When this routine is called KGDB should unregister from the - * panic handler and clean up, making sure it is not handling any - * break exceptions at the time. - */ - if (kgdb_io_module_registered) { - kgdb_io_module_registered = 0; - kgdb_arch_exit(); -#ifdef CONFIG_MAGIC_SYSRQ - unregister_sysrq_key('g', &sysrq_gdb_op); -#endif - if (kgdb_con_registered) { - unregister_console(&kgdbcons); - kgdb_con_registered = 0; - } - } -} - -static void kgdb_initial_breakpoint(void) -{ - kgdb_break_asap = 0; - - printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); - kgdb_breakpoint(); -} - -/** - * kgdb_register_io_module - register KGDB IO module - * @new_kgdb_io_ops: the io ops vector - * - * Register it with the KGDB core. - */ -int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) -{ - int err; - - spin_lock(&kgdb_registration_lock); - - if (kgdb_io_ops) { - spin_unlock(&kgdb_registration_lock); - - printk(KERN_ERR "kgdb: Another I/O driver is already " - "registered with KGDB.\n"); - return -EBUSY; - } - - if (new_kgdb_io_ops->init) { - err = new_kgdb_io_ops->init(); - if (err) { - spin_unlock(&kgdb_registration_lock); - return err; - } - } - - kgdb_io_ops = new_kgdb_io_ops; - - spin_unlock(&kgdb_registration_lock); - - printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", - new_kgdb_io_ops->name); - - /* Arm KGDB now. */ - kgdb_register_callbacks(); - - if (kgdb_break_asap) - kgdb_initial_breakpoint(); - - return 0; -} -EXPORT_SYMBOL_GPL(kgdb_register_io_module); - -/** - * kkgdb_unregister_io_module - unregister KGDB IO module - * @old_kgdb_io_ops: the io ops vector - * - * Unregister it with the KGDB core. - */ -void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) -{ - BUG_ON(kgdb_connected); - - /* - * KGDB is no longer able to communicate out, so - * unregister our callbacks and reset state. - */ - kgdb_unregister_callbacks(); - - spin_lock(&kgdb_registration_lock); - - WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); - kgdb_io_ops = NULL; - - spin_unlock(&kgdb_registration_lock); - - printk(KERN_INFO - "kgdb: Unregistered I/O driver %s, debugger disabled.\n", - old_kgdb_io_ops->name); -} -EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); - -/** - * kgdb_breakpoint - generate breakpoint exception - * - * This function will generate a breakpoint exception. It is used at the - * beginning of a program to sync up with a debugger and can be used - * otherwise as a quick means to stop program execution and "break" into - * the debugger. - */ -void kgdb_breakpoint(void) -{ - atomic_inc(&kgdb_setting_breakpoint); - wmb(); /* Sync point before breakpoint */ - arch_kgdb_breakpoint(); - wmb(); /* Sync point after breakpoint */ - atomic_dec(&kgdb_setting_breakpoint); -} -EXPORT_SYMBOL_GPL(kgdb_breakpoint); - -static int __init opt_kgdb_wait(char *str) -{ - kgdb_break_asap = 1; - - if (kgdb_io_module_registered) - kgdb_initial_breakpoint(); - - return 0; -} - -early_param("kgdbwait", opt_kgdb_wait); -- cgit v1.2.3-70-g09d2 From 53197fc49549240f6c6a963b2713a4cd9517964b Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 2 Apr 2010 11:48:03 -0500 Subject: Separate the gdbstub from the debug core Split the former kernel/kgdb.c into debug_core.c which contains the kernel debugger exception logic and to the gdbstub.c which contains the logic for allowing gdb to talk to the debug core. This also created a private include file called debug_core.h which contains all the definitions to glue the debug_core to any other debugger connections. CC: Ingo Molnar Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 1 + kernel/debug/Makefile | 3 +- kernel/debug/debug_core.c | 994 ++-------------------------------------------- kernel/debug/debug_core.h | 55 +++ kernel/debug/gdbstub.c | 934 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 1030 insertions(+), 957 deletions(-) create mode 100644 kernel/debug/debug_core.h create mode 100644 kernel/debug/gdbstub.c (limited to 'kernel') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 19ec41a183f..4830142ec33 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -264,6 +264,7 @@ extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); +extern struct kgdb_io *dbg_io_ops; extern int kgdb_hex2long(char **ptr, unsigned long *long_val); extern int kgdb_mem2hex(char *mem, char *buf, int count); diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile index 5d785041526..fd4dc6e7782 100644 --- a/kernel/debug/Makefile +++ b/kernel/debug/Makefile @@ -2,5 +2,4 @@ # Makefile for the linux kernel debugger # -obj-$(CONFIG_KGDB) += debug_core.o - +obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 11f3515ca83..7e03969330b 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -1,5 +1,5 @@ /* - * KGDB stub. + * Kernel Debug Core * * Maintainer: Jason Wessel * @@ -9,7 +9,7 @@ * Copyright (C) 2004 Pavel Machek * Copyright (C) 2004-2006 Tom Rini * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. - * Copyright (C) 2005-2008 Wind River Systems, Inc. + * Copyright (C) 2005-2009 Wind River Systems, Inc. * Copyright (C) 2007 MontaVista Software, Inc. * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar * @@ -37,7 +37,6 @@ #include #include #include -#include #include #include #include @@ -52,34 +51,12 @@ #include #include #include -#include -static int kgdb_break_asap; - -#define KGDB_MAX_THREAD_QUERY 17 -struct kgdb_state { - int ex_vector; - int signo; - int err_code; - int cpu; - int pass_exception; - unsigned long thr_query; - unsigned long threadid; - long kgdb_usethreadid; - struct pt_regs *linux_regs; -}; +#include "debug_core.h" -/* Exception state values */ -#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */ -#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */ -#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */ -#define DCPU_SSTEP 0x8 /* CPU is single stepping */ +static int kgdb_break_asap; -static struct debuggerinfo_struct { - void *debuggerinfo; - struct task_struct *task; - int exception_state; -} kgdb_info[NR_CPUS]; +struct debuggerinfo_struct kgdb_info[NR_CPUS]; /** * kgdb_connected - Is a host GDB connected to us? @@ -93,7 +70,7 @@ static int kgdb_io_module_registered; /* Guard for recursive entry */ static int exception_level; -static struct kgdb_io *kgdb_io_ops; +struct kgdb_io *dbg_io_ops; static DEFINE_SPINLOCK(kgdb_registration_lock); /* kgdb console driver is loaded */ @@ -136,16 +113,7 @@ struct task_struct *kgdb_usethread; struct task_struct *kgdb_contthread; int kgdb_single_step; -pid_t kgdb_sstep_pid; - -/* Our I/O buffers. */ -static char remcom_in_buffer[BUFMAX]; -static char remcom_out_buffer[BUFMAX]; - -/* Storage for the registers, in GDB format. */ -static unsigned long gdb_regs[(NUMREGBYTES + - sizeof(unsigned long) - 1) / - sizeof(unsigned long)]; +static pid_t kgdb_sstep_pid; /* to keep track of the CPU which is doing the single stepping*/ atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); @@ -246,324 +214,6 @@ void __weak kgdb_disable_hw_debug(struct pt_regs *regs) { } -/* - * GDB remote protocol parser: - */ - -static int hex(char ch) -{ - if ((ch >= 'a') && (ch <= 'f')) - return ch - 'a' + 10; - if ((ch >= '0') && (ch <= '9')) - return ch - '0'; - if ((ch >= 'A') && (ch <= 'F')) - return ch - 'A' + 10; - return -1; -} - -/* scan for the sequence $# */ -static void get_packet(char *buffer) -{ - unsigned char checksum; - unsigned char xmitcsum; - int count; - char ch; - - do { - /* - * Spin and wait around for the start character, ignore all - * other characters: - */ - while ((ch = (kgdb_io_ops->read_char())) != '$') - /* nothing */; - - kgdb_connected = 1; - checksum = 0; - xmitcsum = -1; - - count = 0; - - /* - * now, read until a # or end of buffer is found: - */ - while (count < (BUFMAX - 1)) { - ch = kgdb_io_ops->read_char(); - if (ch == '#') - break; - checksum = checksum + ch; - buffer[count] = ch; - count = count + 1; - } - buffer[count] = 0; - - if (ch == '#') { - xmitcsum = hex(kgdb_io_ops->read_char()) << 4; - xmitcsum += hex(kgdb_io_ops->read_char()); - - if (checksum != xmitcsum) - /* failed checksum */ - kgdb_io_ops->write_char('-'); - else - /* successful transfer */ - kgdb_io_ops->write_char('+'); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - } - } while (checksum != xmitcsum); -} - -/* - * Send the packet in buffer. - * Check for gdb connection if asked for. - */ -static void put_packet(char *buffer) -{ - unsigned char checksum; - int count; - char ch; - - /* - * $#. - */ - while (1) { - kgdb_io_ops->write_char('$'); - checksum = 0; - count = 0; - - while ((ch = buffer[count])) { - kgdb_io_ops->write_char(ch); - checksum += ch; - count++; - } - - kgdb_io_ops->write_char('#'); - kgdb_io_ops->write_char(hex_asc_hi(checksum)); - kgdb_io_ops->write_char(hex_asc_lo(checksum)); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - - /* Now see what we get in reply. */ - ch = kgdb_io_ops->read_char(); - - if (ch == 3) - ch = kgdb_io_ops->read_char(); - - /* If we get an ACK, we are done. */ - if (ch == '+') - return; - - /* - * If we get the start of another packet, this means - * that GDB is attempting to reconnect. We will NAK - * the packet being sent, and stop trying to send this - * packet. - */ - if (ch == '$') { - kgdb_io_ops->write_char('-'); - if (kgdb_io_ops->flush) - kgdb_io_ops->flush(); - return; - } - } -} - -/* - * Convert the memory pointed to by mem into hex, placing result in buf. - * Return a pointer to the last char put in buf (null). May return an error. - */ -int kgdb_mem2hex(char *mem, char *buf, int count) -{ - char *tmp; - int err; - - /* - * We use the upper half of buf as an intermediate buffer for the - * raw memory copy. Hex conversion will work against this one. - */ - tmp = buf + count; - - err = probe_kernel_read(tmp, mem, count); - if (!err) { - while (count > 0) { - buf = pack_hex_byte(buf, *tmp); - tmp++; - count--; - } - - *buf = 0; - } - - return err; -} - -/* - * Copy the binary array pointed to by buf into mem. Fix $, #, and - * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. - * The input buf is overwitten with the result to write to mem. - */ -static int kgdb_ebin2mem(char *buf, char *mem, int count) -{ - int size = 0; - char *c = buf; - - while (count-- > 0) { - c[size] = *buf++; - if (c[size] == 0x7d) - c[size] = *buf++ ^ 0x20; - size++; - } - - return probe_kernel_write(mem, c, size); -} - -/* - * Convert the hex array pointed to by buf into binary to be placed in mem. - * Return a pointer to the character AFTER the last byte written. - * May return an error. - */ -int kgdb_hex2mem(char *buf, char *mem, int count) -{ - char *tmp_raw; - char *tmp_hex; - - /* - * We use the upper half of buf as an intermediate buffer for the - * raw memory that is converted from hex. - */ - tmp_raw = buf + count * 2; - - tmp_hex = tmp_raw - 1; - while (tmp_hex >= buf) { - tmp_raw--; - *tmp_raw = hex(*tmp_hex--); - *tmp_raw |= hex(*tmp_hex--) << 4; - } - - return probe_kernel_write(mem, tmp_raw, count); -} - -/* - * While we find nice hex chars, build a long_val. - * Return number of chars processed. - */ -int kgdb_hex2long(char **ptr, unsigned long *long_val) -{ - int hex_val; - int num = 0; - int negate = 0; - - *long_val = 0; - - if (**ptr == '-') { - negate = 1; - (*ptr)++; - } - while (**ptr) { - hex_val = hex(**ptr); - if (hex_val < 0) - break; - - *long_val = (*long_val << 4) | hex_val; - num++; - (*ptr)++; - } - - if (negate) - *long_val = -*long_val; - - return num; -} - -/* Write memory due to an 'M' or 'X' packet. */ -static int write_mem_msg(int binary) -{ - char *ptr = &remcom_in_buffer[1]; - unsigned long addr; - unsigned long length; - int err; - - if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && - kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { - if (binary) - err = kgdb_ebin2mem(ptr, (char *)addr, length); - else - err = kgdb_hex2mem(ptr, (char *)addr, length); - if (err) - return err; - if (CACHE_FLUSH_IS_SAFE) - flush_icache_range(addr, addr + length); - return 0; - } - - return -EINVAL; -} - -static void error_packet(char *pkt, int error) -{ - error = -error; - pkt[0] = 'E'; - pkt[1] = hex_asc[(error / 10)]; - pkt[2] = hex_asc[(error % 10)]; - pkt[3] = '\0'; -} - -/* - * Thread ID accessors. We represent a flat TID space to GDB, where - * the per CPU idle threads (which under Linux all have PID 0) are - * remapped to negative TIDs. - */ - -#define BUF_THREAD_ID_SIZE 16 - -static char *pack_threadid(char *pkt, unsigned char *id) -{ - char *limit; - - limit = pkt + BUF_THREAD_ID_SIZE; - while (pkt < limit) - pkt = pack_hex_byte(pkt, *id++); - - return pkt; -} - -static void int_to_threadref(unsigned char *id, int value) -{ - unsigned char *scan; - int i = 4; - - scan = (unsigned char *)id; - while (i--) - *scan++ = 0; - put_unaligned_be32(value, scan); -} - -static struct task_struct *getthread(struct pt_regs *regs, int tid) -{ - /* - * Non-positive TIDs are remapped to the cpu shadow information - */ - if (tid == 0 || tid == -1) - tid = -atomic_read(&kgdb_active) - 2; - if (tid < -1 && tid > -NR_CPUS - 2) { - if (kgdb_info[-tid - 2].task) - return kgdb_info[-tid - 2].task; - else - return idle_task(-tid - 2); - } - if (tid <= 0) { - printk(KERN_ERR "KGDB: Internal thread select error\n"); - dump_stack(); - return NULL; - } - - /* - * find_task_by_pid_ns() does not take the tasklist lock anymore - * but is nicely RCU locked - hence is a pretty resilient - * thing to use: - */ - return find_task_by_pid_ns(tid, &init_pid_ns); -} - /* * Some architectures need cache flushes when we set/clear a * breakpoint: @@ -584,7 +234,7 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) /* * SW breakpoint management: */ -static int kgdb_activate_sw_breakpoints(void) +int dbg_activate_sw_breakpoints(void) { unsigned long addr; int error; @@ -610,7 +260,7 @@ static int kgdb_activate_sw_breakpoints(void) return ret; } -static int kgdb_set_sw_break(unsigned long addr) +int dbg_set_sw_break(unsigned long addr) { int err = kgdb_validate_break_address(addr); int breakno = -1; @@ -675,7 +325,7 @@ static int kgdb_deactivate_sw_breakpoints(void) return ret; } -static int kgdb_remove_sw_break(unsigned long addr) +int dbg_remove_sw_break(unsigned long addr) { int i; @@ -701,7 +351,7 @@ int kgdb_isremovedbreak(unsigned long addr) return 0; } -static int remove_all_break(void) +int dbg_remove_all_break(void) { unsigned long addr; int error; @@ -728,53 +378,6 @@ setundefined: return 0; } -/* - * Remap normal tasks to their real PID, - * CPU shadow threads are mapped to -CPU - 2 - */ -static inline int shadow_pid(int realpid) -{ - if (realpid) - return realpid; - - return -raw_smp_processor_id() - 2; -} - -static char gdbmsgbuf[BUFMAX + 1]; - -static void kgdb_msg_write(const char *s, int len) -{ - char *bufptr; - int wcount; - int i; - - /* 'O'utput */ - gdbmsgbuf[0] = 'O'; - - /* Fill and send buffers... */ - while (len > 0) { - bufptr = gdbmsgbuf + 1; - - /* Calculate how many this time */ - if ((len << 1) > (BUFMAX - 2)) - wcount = (BUFMAX - 2) >> 1; - else - wcount = len; - - /* Pack in hex chars */ - for (i = 0; i < wcount; i++) - bufptr = pack_hex_byte(bufptr, s[i]); - *bufptr = '\0'; - - /* Move up */ - s += wcount; - len -= wcount; - - /* Write packet */ - put_packet(gdbmsgbuf); - } -} - /* * Return true if there is a valid kgdb I/O module. Also if no * debugger is attached a message can be printed to the console about @@ -786,7 +389,7 @@ static void kgdb_msg_write(const char *s, int len) */ static int kgdb_io_ready(int print_wait) { - if (!kgdb_io_ops) + if (!dbg_io_ops) return 0; if (kgdb_connected) return 1; @@ -797,525 +400,6 @@ static int kgdb_io_ready(int print_wait) return 1; } -/* - * All the functions that start with gdb_cmd are the various - * operations to implement the handlers for the gdbserial protocol - * where KGDB is communicating with an external debugger - */ - -/* Handle the '?' status packets */ -static void gdb_cmd_status(struct kgdb_state *ks) -{ - /* - * We know that this packet is only sent - * during initial connect. So to be safe, - * we clear out our breakpoints now in case - * GDB is reconnecting. - */ - remove_all_break(); - - remcom_out_buffer[0] = 'S'; - pack_hex_byte(&remcom_out_buffer[1], ks->signo); -} - -/* Handle the 'g' get registers request */ -static void gdb_cmd_getregs(struct kgdb_state *ks) -{ - struct task_struct *thread; - void *local_debuggerinfo; - int i; - - thread = kgdb_usethread; - if (!thread) { - thread = kgdb_info[ks->cpu].task; - local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; - } else { - local_debuggerinfo = NULL; - for_each_online_cpu(i) { - /* - * Try to find the task on some other - * or possibly this node if we do not - * find the matching task then we try - * to approximate the results. - */ - if (thread == kgdb_info[i].task) - local_debuggerinfo = kgdb_info[i].debuggerinfo; - } - } - - /* - * All threads that don't have debuggerinfo should be - * in schedule() sleeping, since all other CPUs - * are in kgdb_wait, and thus have debuggerinfo. - */ - if (local_debuggerinfo) { - pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); - } else { - /* - * Pull stuff saved during switch_to; nothing - * else is accessible (or even particularly - * relevant). - * - * This should be enough for a stack trace. - */ - sleeping_thread_to_gdb_regs(gdb_regs, thread); - } - kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); -} - -/* Handle the 'G' set registers request */ -static void gdb_cmd_setregs(struct kgdb_state *ks) -{ - kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); - - if (kgdb_usethread && kgdb_usethread != current) { - error_packet(remcom_out_buffer, -EINVAL); - } else { - gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); - strcpy(remcom_out_buffer, "OK"); - } -} - -/* Handle the 'm' memory read bytes */ -static void gdb_cmd_memread(struct kgdb_state *ks) -{ - char *ptr = &remcom_in_buffer[1]; - unsigned long length; - unsigned long addr; - int err; - - if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && - kgdb_hex2long(&ptr, &length) > 0) { - err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); - if (err) - error_packet(remcom_out_buffer, err); - } else { - error_packet(remcom_out_buffer, -EINVAL); - } -} - -/* Handle the 'M' memory write bytes */ -static void gdb_cmd_memwrite(struct kgdb_state *ks) -{ - int err = write_mem_msg(0); - - if (err) - error_packet(remcom_out_buffer, err); - else - strcpy(remcom_out_buffer, "OK"); -} - -/* Handle the 'X' memory binary write bytes */ -static void gdb_cmd_binwrite(struct kgdb_state *ks) -{ - int err = write_mem_msg(1); - - if (err) - error_packet(remcom_out_buffer, err); - else - strcpy(remcom_out_buffer, "OK"); -} - -/* Handle the 'D' or 'k', detach or kill packets */ -static void gdb_cmd_detachkill(struct kgdb_state *ks) -{ - int error; - - /* The detach case */ - if (remcom_in_buffer[0] == 'D') { - error = remove_all_break(); - if (error < 0) { - error_packet(remcom_out_buffer, error); - } else { - strcpy(remcom_out_buffer, "OK"); - kgdb_connected = 0; - } - put_packet(remcom_out_buffer); - } else { - /* - * Assume the kill case, with no exit code checking, - * trying to force detach the debugger: - */ - remove_all_break(); - kgdb_connected = 0; - } -} - -/* Handle the 'R' reboot packets */ -static int gdb_cmd_reboot(struct kgdb_state *ks) -{ - /* For now, only honor R0 */ - if (strcmp(remcom_in_buffer, "R0") == 0) { - printk(KERN_CRIT "Executing emergency reboot\n"); - strcpy(remcom_out_buffer, "OK"); - put_packet(remcom_out_buffer); - - /* - * Execution should not return from - * machine_emergency_restart() - */ - machine_emergency_restart(); - kgdb_connected = 0; - - return 1; - } - return 0; -} - -/* Handle the 'q' query packets */ -static void gdb_cmd_query(struct kgdb_state *ks) -{ - struct task_struct *g; - struct task_struct *p; - unsigned char thref[8]; - char *ptr; - int i; - int cpu; - int finished = 0; - - switch (remcom_in_buffer[1]) { - case 's': - case 'f': - if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - - i = 0; - remcom_out_buffer[0] = 'm'; - ptr = remcom_out_buffer + 1; - if (remcom_in_buffer[1] == 'f') { - /* Each cpu is a shadow thread */ - for_each_online_cpu(cpu) { - ks->thr_query = 0; - int_to_threadref(thref, -cpu - 2); - pack_threadid(ptr, thref); - ptr += BUF_THREAD_ID_SIZE; - *(ptr++) = ','; - i++; - } - } - - do_each_thread(g, p) { - if (i >= ks->thr_query && !finished) { - int_to_threadref(thref, p->pid); - pack_threadid(ptr, thref); - ptr += BUF_THREAD_ID_SIZE; - *(ptr++) = ','; - ks->thr_query++; - if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) - finished = 1; - } - i++; - } while_each_thread(g, p); - - *(--ptr) = '\0'; - break; - - case 'C': - /* Current thread id */ - strcpy(remcom_out_buffer, "QC"); - ks->threadid = shadow_pid(current->pid); - int_to_threadref(thref, ks->threadid); - pack_threadid(remcom_out_buffer + 2, thref); - break; - case 'T': - if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - ks->threadid = 0; - ptr = remcom_in_buffer + 17; - kgdb_hex2long(&ptr, &ks->threadid); - if (!getthread(ks->linux_regs, ks->threadid)) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - if ((int)ks->threadid > 0) { - kgdb_mem2hex(getthread(ks->linux_regs, - ks->threadid)->comm, - remcom_out_buffer, 16); - } else { - static char tmpstr[23 + BUF_THREAD_ID_SIZE]; - - sprintf(tmpstr, "shadowCPU%d", - (int)(-ks->threadid - 2)); - kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); - } - break; - } -} - -/* Handle the 'H' task query packets */ -static void gdb_cmd_task(struct kgdb_state *ks) -{ - struct task_struct *thread; - char *ptr; - - switch (remcom_in_buffer[1]) { - case 'g': - ptr = &remcom_in_buffer[2]; - kgdb_hex2long(&ptr, &ks->threadid); - thread = getthread(ks->linux_regs, ks->threadid); - if (!thread && ks->threadid > 0) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_usethread = thread; - ks->kgdb_usethreadid = ks->threadid; - strcpy(remcom_out_buffer, "OK"); - break; - case 'c': - ptr = &remcom_in_buffer[2]; - kgdb_hex2long(&ptr, &ks->threadid); - if (!ks->threadid) { - kgdb_contthread = NULL; - } else { - thread = getthread(ks->linux_regs, ks->threadid); - if (!thread && ks->threadid > 0) { - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_contthread = thread; - } - strcpy(remcom_out_buffer, "OK"); - break; - } -} - -/* Handle the 'T' thread query packets */ -static void gdb_cmd_thread(struct kgdb_state *ks) -{ - char *ptr = &remcom_in_buffer[1]; - struct task_struct *thread; - - kgdb_hex2long(&ptr, &ks->threadid); - thread = getthread(ks->linux_regs, ks->threadid); - if (thread) - strcpy(remcom_out_buffer, "OK"); - else - error_packet(remcom_out_buffer, -EINVAL); -} - -/* Handle the 'z' or 'Z' breakpoint remove or set packets */ -static void gdb_cmd_break(struct kgdb_state *ks) -{ - /* - * Since GDB-5.3, it's been drafted that '0' is a software - * breakpoint, '1' is a hardware breakpoint, so let's do that. - */ - char *bpt_type = &remcom_in_buffer[1]; - char *ptr = &remcom_in_buffer[2]; - unsigned long addr; - unsigned long length; - int error = 0; - - if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { - /* Unsupported */ - if (*bpt_type > '4') - return; - } else { - if (*bpt_type != '0' && *bpt_type != '1') - /* Unsupported. */ - return; - } - - /* - * Test if this is a hardware breakpoint, and - * if we support it: - */ - if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) - /* Unsupported. */ - return; - - if (*(ptr++) != ',') { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - if (!kgdb_hex2long(&ptr, &addr)) { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - if (*(ptr++) != ',' || - !kgdb_hex2long(&ptr, &length)) { - error_packet(remcom_out_buffer, -EINVAL); - return; - } - - if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') - error = kgdb_set_sw_break(addr); - else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') - error = kgdb_remove_sw_break(addr); - else if (remcom_in_buffer[0] == 'Z') - error = arch_kgdb_ops.set_hw_breakpoint(addr, - (int)length, *bpt_type - '0'); - else if (remcom_in_buffer[0] == 'z') - error = arch_kgdb_ops.remove_hw_breakpoint(addr, - (int) length, *bpt_type - '0'); - - if (error == 0) - strcpy(remcom_out_buffer, "OK"); - else - error_packet(remcom_out_buffer, error); -} - -/* Handle the 'C' signal / exception passing packets */ -static int gdb_cmd_exception_pass(struct kgdb_state *ks) -{ - /* C09 == pass exception - * C15 == detach kgdb, pass exception - */ - if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { - - ks->pass_exception = 1; - remcom_in_buffer[0] = 'c'; - - } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { - - ks->pass_exception = 1; - remcom_in_buffer[0] = 'D'; - remove_all_break(); - kgdb_connected = 0; - return 1; - - } else { - kgdb_msg_write("KGDB only knows signal 9 (pass)" - " and 15 (pass and disconnect)\n" - "Executing a continue without signal passing\n", 0); - remcom_in_buffer[0] = 'c'; - } - - /* Indicate fall through */ - return -1; -} - -/* - * This function performs all gdbserial command procesing - */ -static int gdb_serial_stub(struct kgdb_state *ks) -{ - int error = 0; - int tmp; - - /* Clear the out buffer. */ - memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); - - if (kgdb_connected) { - unsigned char thref[8]; - char *ptr; - - /* Reply to host that an exception has occurred */ - ptr = remcom_out_buffer; - *ptr++ = 'T'; - ptr = pack_hex_byte(ptr, ks->signo); - ptr += strlen(strcpy(ptr, "thread:")); - int_to_threadref(thref, shadow_pid(current->pid)); - ptr = pack_threadid(ptr, thref); - *ptr++ = ';'; - put_packet(remcom_out_buffer); - } - - kgdb_usethread = kgdb_info[ks->cpu].task; - ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); - ks->pass_exception = 0; - - while (1) { - error = 0; - - /* Clear the out buffer. */ - memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); - - get_packet(remcom_in_buffer); - - switch (remcom_in_buffer[0]) { - case '?': /* gdbserial status */ - gdb_cmd_status(ks); - break; - case 'g': /* return the value of the CPU registers */ - gdb_cmd_getregs(ks); - break; - case 'G': /* set the value of the CPU registers - return OK */ - gdb_cmd_setregs(ks); - break; - case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ - gdb_cmd_memread(ks); - break; - case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ - gdb_cmd_memwrite(ks); - break; - case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ - gdb_cmd_binwrite(ks); - break; - /* kill or detach. KGDB should treat this like a - * continue. - */ - case 'D': /* Debugger detach */ - case 'k': /* Debugger detach via kill */ - gdb_cmd_detachkill(ks); - goto default_handle; - case 'R': /* Reboot */ - if (gdb_cmd_reboot(ks)) - goto default_handle; - break; - case 'q': /* query command */ - gdb_cmd_query(ks); - break; - case 'H': /* task related */ - gdb_cmd_task(ks); - break; - case 'T': /* Query thread status */ - gdb_cmd_thread(ks); - break; - case 'z': /* Break point remove */ - case 'Z': /* Break point set */ - gdb_cmd_break(ks); - break; - case 'C': /* Exception passing */ - tmp = gdb_cmd_exception_pass(ks); - if (tmp > 0) - goto default_handle; - if (tmp == 0) - break; - /* Fall through on tmp < 0 */ - case 'c': /* Continue packet */ - case 's': /* Single step packet */ - if (kgdb_contthread && kgdb_contthread != current) { - /* Can't switch threads in kgdb */ - error_packet(remcom_out_buffer, -EINVAL); - break; - } - kgdb_activate_sw_breakpoints(); - /* Fall through to default processing */ - default: -default_handle: - error = kgdb_arch_handle_exception(ks->ex_vector, - ks->signo, - ks->err_code, - remcom_in_buffer, - remcom_out_buffer, - ks->linux_regs); - /* - * Leave cmd processing on error, detach, - * kill, continue, or single step. - */ - if (error >= 0 || remcom_in_buffer[0] == 'D' || - remcom_in_buffer[0] == 'k') { - error = 0; - goto kgdb_exit; - } - - } - - /* reply to the request */ - put_packet(remcom_out_buffer); - } - -kgdb_exit: - if (ks->pass_exception) - error = 1; - return error; -} - static int kgdb_reenter_check(struct kgdb_state *ks) { unsigned long addr; @@ -1334,17 +418,17 @@ static int kgdb_reenter_check(struct kgdb_state *ks) * user because the user planted a breakpoint in a place that * KGDB needs in order to function. */ - if (kgdb_remove_sw_break(addr) == 0) { + if (dbg_remove_sw_break(addr) == 0) { exception_level = 0; kgdb_skipexception(ks->ex_vector, ks->linux_regs); - kgdb_activate_sw_breakpoints(); + dbg_activate_sw_breakpoints(); printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", addr); WARN_ON_ONCE(1); return 1; } - remove_all_break(); + dbg_remove_all_break(); kgdb_skipexception(ks->ex_vector, ks->linux_regs); if (exception_level > 1) { @@ -1430,7 +514,7 @@ return_normal: if (!kgdb_io_ready(1)) { error = 1; - goto kgdb_restore; /* No I/O connection, so resume the system */ + goto kgdb_restore; /* No I/O connection, resume the system */ } /* @@ -1440,8 +524,8 @@ return_normal: goto kgdb_restore; /* Call the I/O driver's pre_exception routine */ - if (kgdb_io_ops->pre_exception) - kgdb_io_ops->pre_exception(); + if (dbg_io_ops->pre_exception) + dbg_io_ops->pre_exception(); kgdb_disable_hw_debug(ks->linux_regs); @@ -1485,8 +569,8 @@ return_normal: error = gdb_serial_stub(ks); /* Call the I/O driver's post_exception routine */ - if (kgdb_io_ops->post_exception) - kgdb_io_ops->post_exception(); + if (dbg_io_ops->post_exception) + dbg_io_ops->post_exception(); atomic_dec(&cpu_in_kgdb[ks->cpu]); @@ -1585,7 +669,7 @@ static void kgdb_console_write(struct console *co, const char *s, return; local_irq_save(flags); - kgdb_msg_write(s, count); + gdbstub_msg_write(s, count); local_irq_restore(flags); } @@ -1597,9 +681,9 @@ static struct console kgdbcons = { }; #ifdef CONFIG_MAGIC_SYSRQ -static void sysrq_handle_gdb(int key, struct tty_struct *tty) +static void sysrq_handle_dbg(int key, struct tty_struct *tty) { - if (!kgdb_io_ops) { + if (!dbg_io_ops) { printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); return; } @@ -1609,8 +693,8 @@ static void sysrq_handle_gdb(int key, struct tty_struct *tty) kgdb_breakpoint(); } -static struct sysrq_key_op sysrq_gdb_op = { - .handler = sysrq_handle_gdb, +static struct sysrq_key_op sysrq_dbg_op = { + .handler = sysrq_handle_dbg, .help_msg = "debug(G)", .action_msg = "DEBUG", }; @@ -1622,7 +706,7 @@ static void kgdb_register_callbacks(void) kgdb_io_module_registered = 1; kgdb_arch_init(); #ifdef CONFIG_MAGIC_SYSRQ - register_sysrq_key('g', &sysrq_gdb_op); + register_sysrq_key('g', &sysrq_dbg_op); #endif if (kgdb_use_con && !kgdb_con_registered) { register_console(&kgdbcons); @@ -1642,7 +726,7 @@ static void kgdb_unregister_callbacks(void) kgdb_io_module_registered = 0; kgdb_arch_exit(); #ifdef CONFIG_MAGIC_SYSRQ - unregister_sysrq_key('g', &sysrq_gdb_op); + unregister_sysrq_key('g', &sysrq_dbg_op); #endif if (kgdb_con_registered) { unregister_console(&kgdbcons); @@ -1661,17 +745,17 @@ static void kgdb_initial_breakpoint(void) /** * kgdb_register_io_module - register KGDB IO module - * @new_kgdb_io_ops: the io ops vector + * @new_dbg_io_ops: the io ops vector * * Register it with the KGDB core. */ -int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) +int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops) { int err; spin_lock(&kgdb_registration_lock); - if (kgdb_io_ops) { + if (dbg_io_ops) { spin_unlock(&kgdb_registration_lock); printk(KERN_ERR "kgdb: Another I/O driver is already " @@ -1679,20 +763,20 @@ int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) return -EBUSY; } - if (new_kgdb_io_ops->init) { - err = new_kgdb_io_ops->init(); + if (new_dbg_io_ops->init) { + err = new_dbg_io_ops->init(); if (err) { spin_unlock(&kgdb_registration_lock); return err; } } - kgdb_io_ops = new_kgdb_io_ops; + dbg_io_ops = new_dbg_io_ops; spin_unlock(&kgdb_registration_lock); printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", - new_kgdb_io_ops->name); + new_dbg_io_ops->name); /* Arm KGDB now. */ kgdb_register_callbacks(); @@ -1706,11 +790,11 @@ EXPORT_SYMBOL_GPL(kgdb_register_io_module); /** * kkgdb_unregister_io_module - unregister KGDB IO module - * @old_kgdb_io_ops: the io ops vector + * @old_dbg_io_ops: the io ops vector * * Unregister it with the KGDB core. */ -void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) +void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops) { BUG_ON(kgdb_connected); @@ -1722,14 +806,14 @@ void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) spin_lock(&kgdb_registration_lock); - WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); - kgdb_io_ops = NULL; + WARN_ON_ONCE(dbg_io_ops != old_dbg_io_ops); + dbg_io_ops = NULL; spin_unlock(&kgdb_registration_lock); printk(KERN_INFO "kgdb: Unregistered I/O driver %s, debugger disabled.\n", - old_kgdb_io_ops->name); + old_dbg_io_ops->name); } EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h new file mode 100644 index 00000000000..db554f9be51 --- /dev/null +++ b/kernel/debug/debug_core.h @@ -0,0 +1,55 @@ +/* + * Created by: Jason Wessel + * + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#ifndef _DEBUG_CORE_H_ +#define _DEBUG_CORE_H_ +/* + * These are the private implementation headers between the kernel + * debugger core and the debugger front end code. + */ + +/* kernel debug core data structures */ +struct kgdb_state { + int ex_vector; + int signo; + int err_code; + int cpu; + int pass_exception; + unsigned long thr_query; + unsigned long threadid; + long kgdb_usethreadid; + struct pt_regs *linux_regs; +}; + +/* Exception state values */ +#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */ +#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */ +#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */ +#define DCPU_SSTEP 0x8 /* CPU is single stepping */ + +struct debuggerinfo_struct { + void *debuggerinfo; + struct task_struct *task; + int exception_state; +}; + +extern struct debuggerinfo_struct kgdb_info[]; + +/* kernel debug core break point routines */ +extern int dbg_remove_all_break(void); +extern int dbg_set_sw_break(unsigned long addr); +extern int dbg_remove_sw_break(unsigned long addr); +extern int dbg_activate_sw_breakpoints(void); + +/* gdbstub interface functions */ +extern int gdb_serial_stub(struct kgdb_state *ks); +extern void gdbstub_msg_write(const char *s, int len); + +#endif /* _DEBUG_CORE_H_ */ diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c new file mode 100644 index 00000000000..ccdf0929f12 --- /dev/null +++ b/kernel/debug/gdbstub.c @@ -0,0 +1,934 @@ +/* + * Kernel Debug Core + * + * Maintainer: Jason Wessel + * + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002-2004 Timesys Corporation + * Copyright (C) 2003-2004 Amit S. Kale + * Copyright (C) 2004 Pavel Machek + * Copyright (C) 2004-2006 Tom Rini + * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2005-2009 Wind River Systems, Inc. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar + * + * Contributors at various stages not listed above: + * Jason Wessel ( jason.wessel@windriver.com ) + * George Anzinger + * Anurekh Saxena (anurekh.saxena@timesys.com) + * Lake Stevens Instrument Division (Glenn Engel) + * Jim Kingdon, Cygnus Support. + * + * Original KGDB stub: David Grothe , + * Tigran Aivazian + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include "debug_core.h" + +#define KGDB_MAX_THREAD_QUERY 17 + +/* Our I/O buffers. */ +static char remcom_in_buffer[BUFMAX]; +static char remcom_out_buffer[BUFMAX]; + +/* Storage for the registers, in GDB format. */ +static unsigned long gdb_regs[(NUMREGBYTES + + sizeof(unsigned long) - 1) / + sizeof(unsigned long)]; + +/* + * GDB remote protocol parser: + */ + +static int hex(char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return ch - 'a' + 10; + if ((ch >= '0') && (ch <= '9')) + return ch - '0'; + if ((ch >= 'A') && (ch <= 'F')) + return ch - 'A' + 10; + return -1; +} + +/* scan for the sequence $# */ +static void get_packet(char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int count; + char ch; + + do { + /* + * Spin and wait around for the start character, ignore all + * other characters: + */ + while ((ch = (dbg_io_ops->read_char())) != '$') + /* nothing */; + + kgdb_connected = 1; + checksum = 0; + xmitcsum = -1; + + count = 0; + + /* + * now, read until a # or end of buffer is found: + */ + while (count < (BUFMAX - 1)) { + ch = dbg_io_ops->read_char(); + if (ch == '#') + break; + checksum = checksum + ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + + if (ch == '#') { + xmitcsum = hex(dbg_io_ops->read_char()) << 4; + xmitcsum += hex(dbg_io_ops->read_char()); + + if (checksum != xmitcsum) + /* failed checksum */ + dbg_io_ops->write_char('-'); + else + /* successful transfer */ + dbg_io_ops->write_char('+'); + if (dbg_io_ops->flush) + dbg_io_ops->flush(); + } + } while (checksum != xmitcsum); +} + +/* + * Send the packet in buffer. + * Check for gdb connection if asked for. + */ +static void put_packet(char *buffer) +{ + unsigned char checksum; + int count; + char ch; + + /* + * $#. + */ + while (1) { + dbg_io_ops->write_char('$'); + checksum = 0; + count = 0; + + while ((ch = buffer[count])) { + dbg_io_ops->write_char(ch); + checksum += ch; + count++; + } + + dbg_io_ops->write_char('#'); + dbg_io_ops->write_char(hex_asc_hi(checksum)); + dbg_io_ops->write_char(hex_asc_lo(checksum)); + if (dbg_io_ops->flush) + dbg_io_ops->flush(); + + /* Now see what we get in reply. */ + ch = dbg_io_ops->read_char(); + + if (ch == 3) + ch = dbg_io_ops->read_char(); + + /* If we get an ACK, we are done. */ + if (ch == '+') + return; + + /* + * If we get the start of another packet, this means + * that GDB is attempting to reconnect. We will NAK + * the packet being sent, and stop trying to send this + * packet. + */ + if (ch == '$') { + dbg_io_ops->write_char('-'); + if (dbg_io_ops->flush) + dbg_io_ops->flush(); + return; + } + } +} + +static char gdbmsgbuf[BUFMAX + 1]; + +void gdbstub_msg_write(const char *s, int len) +{ + char *bufptr; + int wcount; + int i; + + /* 'O'utput */ + gdbmsgbuf[0] = 'O'; + + /* Fill and send buffers... */ + while (len > 0) { + bufptr = gdbmsgbuf + 1; + + /* Calculate how many this time */ + if ((len << 1) > (BUFMAX - 2)) + wcount = (BUFMAX - 2) >> 1; + else + wcount = len; + + /* Pack in hex chars */ + for (i = 0; i < wcount; i++) + bufptr = pack_hex_byte(bufptr, s[i]); + *bufptr = '\0'; + + /* Move up */ + s += wcount; + len -= wcount; + + /* Write packet */ + put_packet(gdbmsgbuf); + } +} + +/* + * Convert the memory pointed to by mem into hex, placing result in + * buf. Return a pointer to the last char put in buf (null). May + * return an error. + */ +int kgdb_mem2hex(char *mem, char *buf, int count) +{ + char *tmp; + int err; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory copy. Hex conversion will work against this one. + */ + tmp = buf + count; + + err = probe_kernel_read(tmp, mem, count); + if (!err) { + while (count > 0) { + buf = pack_hex_byte(buf, *tmp); + tmp++; + count--; + } + + *buf = 0; + } + + return err; +} + +/* + * Convert the hex array pointed to by buf into binary to be placed in + * mem. Return a pointer to the character AFTER the last byte + * written. May return an error. + */ +int kgdb_hex2mem(char *buf, char *mem, int count) +{ + char *tmp_raw; + char *tmp_hex; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory that is converted from hex. + */ + tmp_raw = buf + count * 2; + + tmp_hex = tmp_raw - 1; + while (tmp_hex >= buf) { + tmp_raw--; + *tmp_raw = hex(*tmp_hex--); + *tmp_raw |= hex(*tmp_hex--) << 4; + } + + return probe_kernel_write(mem, tmp_raw, count); +} + +/* + * While we find nice hex chars, build a long_val. + * Return number of chars processed. + */ +int kgdb_hex2long(char **ptr, unsigned long *long_val) +{ + int hex_val; + int num = 0; + int negate = 0; + + *long_val = 0; + + if (**ptr == '-') { + negate = 1; + (*ptr)++; + } + while (**ptr) { + hex_val = hex(**ptr); + if (hex_val < 0) + break; + + *long_val = (*long_val << 4) | hex_val; + num++; + (*ptr)++; + } + + if (negate) + *long_val = -*long_val; + + return num; +} + +/* + * Copy the binary array pointed to by buf into mem. Fix $, #, and + * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. + * The input buf is overwitten with the result to write to mem. + */ +static int kgdb_ebin2mem(char *buf, char *mem, int count) +{ + int size = 0; + char *c = buf; + + while (count-- > 0) { + c[size] = *buf++; + if (c[size] == 0x7d) + c[size] = *buf++ ^ 0x20; + size++; + } + + return probe_kernel_write(mem, c, size); +} + +/* Write memory due to an 'M' or 'X' packet. */ +static int write_mem_msg(int binary) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long addr; + unsigned long length; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && + kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { + if (binary) + err = kgdb_ebin2mem(ptr, (char *)addr, length); + else + err = kgdb_hex2mem(ptr, (char *)addr, length); + if (err) + return err; + if (CACHE_FLUSH_IS_SAFE) + flush_icache_range(addr, addr + length); + return 0; + } + + return -EINVAL; +} + +static void error_packet(char *pkt, int error) +{ + error = -error; + pkt[0] = 'E'; + pkt[1] = hex_asc[(error / 10)]; + pkt[2] = hex_asc[(error % 10)]; + pkt[3] = '\0'; +} + +/* + * Thread ID accessors. We represent a flat TID space to GDB, where + * the per CPU idle threads (which under Linux all have PID 0) are + * remapped to negative TIDs. + */ + +#define BUF_THREAD_ID_SIZE 16 + +static char *pack_threadid(char *pkt, unsigned char *id) +{ + char *limit; + + limit = pkt + BUF_THREAD_ID_SIZE; + while (pkt < limit) + pkt = pack_hex_byte(pkt, *id++); + + return pkt; +} + +static void int_to_threadref(unsigned char *id, int value) +{ + unsigned char *scan; + int i = 4; + + scan = (unsigned char *)id; + while (i--) + *scan++ = 0; + put_unaligned_be32(value, scan); +} + +static struct task_struct *getthread(struct pt_regs *regs, int tid) +{ + /* + * Non-positive TIDs are remapped to the cpu shadow information + */ + if (tid == 0 || tid == -1) + tid = -atomic_read(&kgdb_active) - 2; + if (tid < -1 && tid > -NR_CPUS - 2) { + if (kgdb_info[-tid - 2].task) + return kgdb_info[-tid - 2].task; + else + return idle_task(-tid - 2); + } + if (tid <= 0) { + printk(KERN_ERR "KGDB: Internal thread select error\n"); + dump_stack(); + return NULL; + } + + /* + * find_task_by_pid_ns() does not take the tasklist lock anymore + * but is nicely RCU locked - hence is a pretty resilient + * thing to use: + */ + return find_task_by_pid_ns(tid, &init_pid_ns); +} + + +/* + * Remap normal tasks to their real PID, + * CPU shadow threads are mapped to -CPU - 2 + */ +static inline int shadow_pid(int realpid) +{ + if (realpid) + return realpid; + + return -raw_smp_processor_id() - 2; +} + +/* + * All the functions that start with gdb_cmd are the various + * operations to implement the handlers for the gdbserial protocol + * where KGDB is communicating with an external debugger + */ + +/* Handle the '?' status packets */ +static void gdb_cmd_status(struct kgdb_state *ks) +{ + /* + * We know that this packet is only sent + * during initial connect. So to be safe, + * we clear out our breakpoints now in case + * GDB is reconnecting. + */ + dbg_remove_all_break(); + + remcom_out_buffer[0] = 'S'; + pack_hex_byte(&remcom_out_buffer[1], ks->signo); +} + +/* Handle the 'g' get registers request */ +static void gdb_cmd_getregs(struct kgdb_state *ks) +{ + struct task_struct *thread; + void *local_debuggerinfo; + int i; + + thread = kgdb_usethread; + if (!thread) { + thread = kgdb_info[ks->cpu].task; + local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; + } else { + local_debuggerinfo = NULL; + for_each_online_cpu(i) { + /* + * Try to find the task on some other + * or possibly this node if we do not + * find the matching task then we try + * to approximate the results. + */ + if (thread == kgdb_info[i].task) + local_debuggerinfo = kgdb_info[i].debuggerinfo; + } + } + + /* + * All threads that don't have debuggerinfo should be + * in schedule() sleeping, since all other CPUs + * are in kgdb_wait, and thus have debuggerinfo. + */ + if (local_debuggerinfo) { + pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); + } else { + /* + * Pull stuff saved during switch_to; nothing + * else is accessible (or even particularly + * relevant). + * + * This should be enough for a stack trace. + */ + sleeping_thread_to_gdb_regs(gdb_regs, thread); + } + kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); +} + +/* Handle the 'G' set registers request */ +static void gdb_cmd_setregs(struct kgdb_state *ks) +{ + kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); + + if (kgdb_usethread && kgdb_usethread != current) { + error_packet(remcom_out_buffer, -EINVAL); + } else { + gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); + strcpy(remcom_out_buffer, "OK"); + } +} + +/* Handle the 'm' memory read bytes */ +static void gdb_cmd_memread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long length; + unsigned long addr; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && + kgdb_hex2long(&ptr, &length) > 0) { + err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); + if (err) + error_packet(remcom_out_buffer, err); + } else { + error_packet(remcom_out_buffer, -EINVAL); + } +} + +/* Handle the 'M' memory write bytes */ +static void gdb_cmd_memwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(0); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'X' memory binary write bytes */ +static void gdb_cmd_binwrite(struct kgdb_state *ks) +{ + int err = write_mem_msg(1); + + if (err) + error_packet(remcom_out_buffer, err); + else + strcpy(remcom_out_buffer, "OK"); +} + +/* Handle the 'D' or 'k', detach or kill packets */ +static void gdb_cmd_detachkill(struct kgdb_state *ks) +{ + int error; + + /* The detach case */ + if (remcom_in_buffer[0] == 'D') { + error = dbg_remove_all_break(); + if (error < 0) { + error_packet(remcom_out_buffer, error); + } else { + strcpy(remcom_out_buffer, "OK"); + kgdb_connected = 0; + } + put_packet(remcom_out_buffer); + } else { + /* + * Assume the kill case, with no exit code checking, + * trying to force detach the debugger: + */ + dbg_remove_all_break(); + kgdb_connected = 0; + } +} + +/* Handle the 'R' reboot packets */ +static int gdb_cmd_reboot(struct kgdb_state *ks) +{ + /* For now, only honor R0 */ + if (strcmp(remcom_in_buffer, "R0") == 0) { + printk(KERN_CRIT "Executing emergency reboot\n"); + strcpy(remcom_out_buffer, "OK"); + put_packet(remcom_out_buffer); + + /* + * Execution should not return from + * machine_emergency_restart() + */ + machine_emergency_restart(); + kgdb_connected = 0; + + return 1; + } + return 0; +} + +/* Handle the 'q' query packets */ +static void gdb_cmd_query(struct kgdb_state *ks) +{ + struct task_struct *g; + struct task_struct *p; + unsigned char thref[8]; + char *ptr; + int i; + int cpu; + int finished = 0; + + switch (remcom_in_buffer[1]) { + case 's': + case 'f': + if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + + i = 0; + remcom_out_buffer[0] = 'm'; + ptr = remcom_out_buffer + 1; + if (remcom_in_buffer[1] == 'f') { + /* Each cpu is a shadow thread */ + for_each_online_cpu(cpu) { + ks->thr_query = 0; + int_to_threadref(thref, -cpu - 2); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + i++; + } + } + + do_each_thread(g, p) { + if (i >= ks->thr_query && !finished) { + int_to_threadref(thref, p->pid); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + ks->thr_query++; + if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) + finished = 1; + } + i++; + } while_each_thread(g, p); + + *(--ptr) = '\0'; + break; + + case 'C': + /* Current thread id */ + strcpy(remcom_out_buffer, "QC"); + ks->threadid = shadow_pid(current->pid); + int_to_threadref(thref, ks->threadid); + pack_threadid(remcom_out_buffer + 2, thref); + break; + case 'T': + if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + ks->threadid = 0; + ptr = remcom_in_buffer + 17; + kgdb_hex2long(&ptr, &ks->threadid); + if (!getthread(ks->linux_regs, ks->threadid)) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + if ((int)ks->threadid > 0) { + kgdb_mem2hex(getthread(ks->linux_regs, + ks->threadid)->comm, + remcom_out_buffer, 16); + } else { + static char tmpstr[23 + BUF_THREAD_ID_SIZE]; + + sprintf(tmpstr, "shadowCPU%d", + (int)(-ks->threadid - 2)); + kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); + } + break; + } +} + +/* Handle the 'H' task query packets */ +static void gdb_cmd_task(struct kgdb_state *ks) +{ + struct task_struct *thread; + char *ptr; + + switch (remcom_in_buffer[1]) { + case 'g': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_usethread = thread; + ks->kgdb_usethreadid = ks->threadid; + strcpy(remcom_out_buffer, "OK"); + break; + case 'c': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &ks->threadid); + if (!ks->threadid) { + kgdb_contthread = NULL; + } else { + thread = getthread(ks->linux_regs, ks->threadid); + if (!thread && ks->threadid > 0) { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_contthread = thread; + } + strcpy(remcom_out_buffer, "OK"); + break; + } +} + +/* Handle the 'T' thread query packets */ +static void gdb_cmd_thread(struct kgdb_state *ks) +{ + char *ptr = &remcom_in_buffer[1]; + struct task_struct *thread; + + kgdb_hex2long(&ptr, &ks->threadid); + thread = getthread(ks->linux_regs, ks->threadid); + if (thread) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, -EINVAL); +} + +/* Handle the 'z' or 'Z' breakpoint remove or set packets */ +static void gdb_cmd_break(struct kgdb_state *ks) +{ + /* + * Since GDB-5.3, it's been drafted that '0' is a software + * breakpoint, '1' is a hardware breakpoint, so let's do that. + */ + char *bpt_type = &remcom_in_buffer[1]; + char *ptr = &remcom_in_buffer[2]; + unsigned long addr; + unsigned long length; + int error = 0; + + if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { + /* Unsupported */ + if (*bpt_type > '4') + return; + } else { + if (*bpt_type != '0' && *bpt_type != '1') + /* Unsupported. */ + return; + } + + /* + * Test if this is a hardware breakpoint, and + * if we support it: + */ + if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) + /* Unsupported. */ + return; + + if (*(ptr++) != ',') { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (!kgdb_hex2long(&ptr, &addr)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + if (*(ptr++) != ',' || + !kgdb_hex2long(&ptr, &length)) { + error_packet(remcom_out_buffer, -EINVAL); + return; + } + + if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') + error = dbg_set_sw_break(addr); + else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') + error = dbg_remove_sw_break(addr); + else if (remcom_in_buffer[0] == 'Z') + error = arch_kgdb_ops.set_hw_breakpoint(addr, + (int)length, *bpt_type - '0'); + else if (remcom_in_buffer[0] == 'z') + error = arch_kgdb_ops.remove_hw_breakpoint(addr, + (int) length, *bpt_type - '0'); + + if (error == 0) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, error); +} + +/* Handle the 'C' signal / exception passing packets */ +static int gdb_cmd_exception_pass(struct kgdb_state *ks) +{ + /* C09 == pass exception + * C15 == detach kgdb, pass exception + */ + if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'c'; + + } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { + + ks->pass_exception = 1; + remcom_in_buffer[0] = 'D'; + dbg_remove_all_break(); + kgdb_connected = 0; + return 1; + + } else { + gdbstub_msg_write("KGDB only knows signal 9 (pass)" + " and 15 (pass and disconnect)\n" + "Executing a continue without signal passing\n", 0); + remcom_in_buffer[0] = 'c'; + } + + /* Indicate fall through */ + return -1; +} + +/* + * This function performs all gdbserial command procesing + */ +int gdb_serial_stub(struct kgdb_state *ks) +{ + int error = 0; + int tmp; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + if (kgdb_connected) { + unsigned char thref[8]; + char *ptr; + + /* Reply to host that an exception has occurred */ + ptr = remcom_out_buffer; + *ptr++ = 'T'; + ptr = pack_hex_byte(ptr, ks->signo); + ptr += strlen(strcpy(ptr, "thread:")); + int_to_threadref(thref, shadow_pid(current->pid)); + ptr = pack_threadid(ptr, thref); + *ptr++ = ';'; + put_packet(remcom_out_buffer); + } + + kgdb_usethread = kgdb_info[ks->cpu].task; + ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); + ks->pass_exception = 0; + + while (1) { + error = 0; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + get_packet(remcom_in_buffer); + + switch (remcom_in_buffer[0]) { + case '?': /* gdbserial status */ + gdb_cmd_status(ks); + break; + case 'g': /* return the value of the CPU registers */ + gdb_cmd_getregs(ks); + break; + case 'G': /* set the value of the CPU registers - return OK */ + gdb_cmd_setregs(ks); + break; + case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + gdb_cmd_memread(ks); + break; + case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_memwrite(ks); + break; + case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ + gdb_cmd_binwrite(ks); + break; + /* kill or detach. KGDB should treat this like a + * continue. + */ + case 'D': /* Debugger detach */ + case 'k': /* Debugger detach via kill */ + gdb_cmd_detachkill(ks); + goto default_handle; + case 'R': /* Reboot */ + if (gdb_cmd_reboot(ks)) + goto default_handle; + break; + case 'q': /* query command */ + gdb_cmd_query(ks); + break; + case 'H': /* task related */ + gdb_cmd_task(ks); + break; + case 'T': /* Query thread status */ + gdb_cmd_thread(ks); + break; + case 'z': /* Break point remove */ + case 'Z': /* Break point set */ + gdb_cmd_break(ks); + break; + case 'C': /* Exception passing */ + tmp = gdb_cmd_exception_pass(ks); + if (tmp > 0) + goto default_handle; + if (tmp == 0) + break; + /* Fall through on tmp < 0 */ + case 'c': /* Continue packet */ + case 's': /* Single step packet */ + if (kgdb_contthread && kgdb_contthread != current) { + /* Can't switch threads in kgdb */ + error_packet(remcom_out_buffer, -EINVAL); + break; + } + dbg_activate_sw_breakpoints(); + /* Fall through to default processing */ + default: +default_handle: + error = kgdb_arch_handle_exception(ks->ex_vector, + ks->signo, + ks->err_code, + remcom_in_buffer, + remcom_out_buffer, + ks->linux_regs); + /* + * Leave cmd processing on error, detach, + * kill, continue, or single step. + */ + if (error >= 0 || remcom_in_buffer[0] == 'D' || + remcom_in_buffer[0] == 'k') { + error = 0; + goto kgdb_exit; + } + + } + + /* reply to the request */ + put_packet(remcom_out_buffer); + } + +kgdb_exit: + if (ks->pass_exception) + error = 1; + return error; +} -- cgit v1.2.3-70-g09d2 From 5d5314d6795f3c1c0f415348ff8c51f7de042b77 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:20 -0500 Subject: kdb: core for kgdb back end (1 of 2) This patch contains only the kdb core. Because the change set was large, it was split. The next patch in the series includes the instrumentation into the core kernel which are mainly helper functions for kdb. This work is directly derived from kdb v4.4 found at: ftp://oss.sgi.com/projects/kdb/download/v4.4/ The kdb internals have been re-organized to make them mostly platform independent and to connect everything to the debug core which is used by gdbstub (which has long been known as kgdb). The original version of kdb was 58,000 lines worth of changes to support x86. From that implementation only the kdb shell, and basic commands for memory access, runcontrol, lsmod, and dmesg where carried forward. This is a generic implementation which aims to cover all the current architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and blackfin. More archictectures can be added by implementing the architecture specific kgdb functions. [mort@sgi.com: Compile fix with hugepages enabled] [mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_] [mort@sgi.com: fix new line after printing registers] [mort@sgi.com: Remove the concept of global vs. local breakpoints] [mort@sgi.com: Rework kdb_si_swapinfo to use more generic name] [mort@sgi.com: fix the information dump macros, remove 'arch' from the names] [sfr@canb.auug.org.au: include fixup to include linux/slab.h] CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel Signed-off-by: Martin Hicks --- include/linux/kdb.h | 113 ++ kernel/debug/Makefile | 1 + kernel/debug/kdb/.gitignore | 1 + kernel/debug/kdb/Makefile | 24 + kernel/debug/kdb/kdb_bp.c | 564 ++++++++ kernel/debug/kdb/kdb_bt.c | 208 +++ kernel/debug/kdb/kdb_cmds | 35 + kernel/debug/kdb/kdb_debugger.c | 159 +++ kernel/debug/kdb/kdb_io.c | 789 +++++++++++ kernel/debug/kdb/kdb_main.c | 2845 +++++++++++++++++++++++++++++++++++++++ kernel/debug/kdb/kdb_private.h | 301 +++++ kernel/debug/kdb/kdb_support.c | 927 +++++++++++++ 12 files changed, 5967 insertions(+) create mode 100644 include/linux/kdb.h create mode 100644 kernel/debug/kdb/.gitignore create mode 100644 kernel/debug/kdb/Makefile create mode 100644 kernel/debug/kdb/kdb_bp.c create mode 100644 kernel/debug/kdb/kdb_bt.c create mode 100644 kernel/debug/kdb/kdb_cmds create mode 100644 kernel/debug/kdb/kdb_debugger.c create mode 100644 kernel/debug/kdb/kdb_io.c create mode 100644 kernel/debug/kdb/kdb_main.c create mode 100644 kernel/debug/kdb/kdb_private.h create mode 100644 kernel/debug/kdb/kdb_support.c (limited to 'kernel') diff --git a/include/linux/kdb.h b/include/linux/kdb.h new file mode 100644 index 00000000000..4d93790faec --- /dev/null +++ b/include/linux/kdb.h @@ -0,0 +1,113 @@ +#ifndef _KDB_H +#define _KDB_H + +/* + * Kernel Debugger Architecture Independent Global Headers + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2000-2007 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (C) 2000 Stephane Eranian + * Copyright (C) 2009 Jason Wessel + */ + +#ifdef CONFIG_KGDB_KDB +#include +#include +#include + +#define KDB_POLL_FUNC_MAX 5 + +/* + * kdb_initial_cpu is initialized to -1, and is set to the cpu + * number whenever the kernel debugger is entered. + */ +extern int kdb_initial_cpu; +extern atomic_t kdb_event; + +/* + * kdb_diemsg + * + * Contains a pointer to the last string supplied to the + * kernel 'die' panic function. + */ +extern const char *kdb_diemsg; + +#define KDB_FLAG_EARLYKDB (1 << 0) /* set from boot parameter kdb=early */ +#define KDB_FLAG_CATASTROPHIC (1 << 1) /* A catastrophic event has occurred */ +#define KDB_FLAG_CMD_INTERRUPT (1 << 2) /* Previous command was interrupted */ +#define KDB_FLAG_NOIPI (1 << 3) /* Do not send IPIs */ +#define KDB_FLAG_ONLY_DO_DUMP (1 << 4) /* Only do a dump, used when + * kdb is off */ +#define KDB_FLAG_NO_CONSOLE (1 << 5) /* No console is available, + * kdb is disabled */ +#define KDB_FLAG_NO_VT_CONSOLE (1 << 6) /* No VT console is available, do + * not use keyboard */ +#define KDB_FLAG_NO_I8042 (1 << 7) /* No i8042 chip is available, do + * not use keyboard */ + +extern int kdb_flags; /* Global flags, see kdb_state for per cpu state */ + +extern void kdb_save_flags(void); +extern void kdb_restore_flags(void); + +#define KDB_FLAG(flag) (kdb_flags & KDB_FLAG_##flag) +#define KDB_FLAG_SET(flag) ((void)(kdb_flags |= KDB_FLAG_##flag)) +#define KDB_FLAG_CLEAR(flag) ((void)(kdb_flags &= ~KDB_FLAG_##flag)) + +/* + * External entry point for the kernel debugger. The pt_regs + * at the time of entry are supplied along with the reason for + * entry to the kernel debugger. + */ + +typedef enum { + KDB_REASON_ENTER = 1, /* KDB_ENTER() trap/fault - regs valid */ + KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */ + KDB_REASON_BREAK, /* Breakpoint inst. - regs valid */ + KDB_REASON_DEBUG, /* Debug Fault - regs valid */ + KDB_REASON_OOPS, /* Kernel Oops - regs valid */ + KDB_REASON_SWITCH, /* CPU switch - regs valid*/ + KDB_REASON_KEYBOARD, /* Keyboard entry - regs valid */ + KDB_REASON_NMI, /* Non-maskable interrupt; regs valid */ + KDB_REASON_RECURSE, /* Recursive entry to kdb; + * regs probably valid */ + KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ +} kdb_reason_t; + +extern int kdb_printf(const char *, ...) + __attribute__ ((format (printf, 1, 2))); +typedef int (*kdb_printf_t)(const char *, ...) + __attribute__ ((format (printf, 1, 2))); + +extern void kdb_init(int level); + +/* Access to kdb specific polling devices */ +typedef int (*get_char_func)(void); +extern get_char_func kdb_poll_funcs[]; +extern int kdb_get_kbd_char(void); + +static inline +int kdb_process_cpu(const struct task_struct *p) +{ + unsigned int cpu = task_thread_info(p)->cpu; + if (cpu > num_possible_cpus()) + cpu = 0; + return cpu; +} + +/* kdb access to register set for stack dumping */ +extern struct pt_regs *kdb_current_regs; + +#else /* ! CONFIG_KGDB_KDB */ +#define kdb_printf(...) +#define kdb_init(x) +#endif /* CONFIG_KGDB_KDB */ +enum { + KDB_NOT_INITIALIZED, + KDB_INIT_EARLY, + KDB_INIT_FULL, +}; +#endif /* !_KDB_H */ diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile index fd4dc6e7782..a85edc33998 100644 --- a/kernel/debug/Makefile +++ b/kernel/debug/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o +obj-$(CONFIG_KGDB_KDB) += kdb/ diff --git a/kernel/debug/kdb/.gitignore b/kernel/debug/kdb/.gitignore new file mode 100644 index 00000000000..396d12eda9e --- /dev/null +++ b/kernel/debug/kdb/.gitignore @@ -0,0 +1 @@ +gen-kdb_cmds.c diff --git a/kernel/debug/kdb/Makefile b/kernel/debug/kdb/Makefile new file mode 100644 index 00000000000..d1e925eddbc --- /dev/null +++ b/kernel/debug/kdb/Makefile @@ -0,0 +1,24 @@ +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. +# Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. +# + +CCVERSION := $(shell $(CC) -v 2>&1 | sed -ne '$$p') +obj-y := kdb_io.o kdb_main.o kdb_support.o kdb_bt.o gen-kdb_cmds.o kdb_bp.o kdb_debugger.o + +clean-files := gen-kdb_cmds.c + +quiet_cmd_gen-kdb = GENKDB $@ + cmd_gen-kdb = $(AWK) 'BEGIN {print "\#include "; print "\#include "} \ + /^\#/{next} \ + /^[ \t]*$$/{next} \ + {gsub(/"/, "\\\"", $$0); \ + print "static __initdata char kdb_cmd" cmds++ "[] = \"" $$0 "\\n\";"} \ + END {print "extern char *kdb_cmds[]; char __initdata *kdb_cmds[] = {"; for (i = 0; i < cmds; ++i) {print " kdb_cmd" i ","}; print(" NULL\n};");}' \ + $(filter-out %/Makefile,$^) > $@# + +$(obj)/gen-kdb_cmds.c: $(src)/kdb_cmds $(src)/Makefile + $(call cmd,gen-kdb) diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c new file mode 100644 index 00000000000..75bd9b3ebbb --- /dev/null +++ b/kernel/debug/kdb/kdb_bp.c @@ -0,0 +1,564 @@ +/* + * Kernel Debugger Architecture Independent Breakpoint Handler + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "kdb_private.h" + +/* + * Table of kdb_breakpoints + */ +kdb_bp_t kdb_breakpoints[KDB_MAXBPT]; + +static void kdb_setsinglestep(struct pt_regs *regs) +{ + KDB_STATE_SET(DOING_SS); +} + +static char *kdb_rwtypes[] = { + "Instruction(i)", + "Instruction(Register)", + "Data Write", + "I/O", + "Data Access" +}; + +static char *kdb_bptype(kdb_bp_t *bp) +{ + if (bp->bp_type < 0 || bp->bp_type > 4) + return ""; + + return kdb_rwtypes[bp->bp_type]; +} + +static int kdb_parsebp(int argc, const char **argv, int *nextargp, kdb_bp_t *bp) +{ + int nextarg = *nextargp; + int diag; + + bp->bph_length = 1; + if ((argc + 1) != nextarg) { + if (strnicmp(argv[nextarg], "datar", sizeof("datar")) == 0) + bp->bp_type = BP_ACCESS_WATCHPOINT; + else if (strnicmp(argv[nextarg], "dataw", sizeof("dataw")) == 0) + bp->bp_type = BP_WRITE_WATCHPOINT; + else if (strnicmp(argv[nextarg], "inst", sizeof("inst")) == 0) + bp->bp_type = BP_HARDWARE_BREAKPOINT; + else + return KDB_ARGCOUNT; + + bp->bph_length = 1; + + nextarg++; + + if ((argc + 1) != nextarg) { + unsigned long len; + + diag = kdbgetularg((char *)argv[nextarg], + &len); + if (diag) + return diag; + + + if (len > 8) + return KDB_BADLENGTH; + + bp->bph_length = len; + nextarg++; + } + + if ((argc + 1) != nextarg) + return KDB_ARGCOUNT; + } + + *nextargp = nextarg; + return 0; +} + +static int _kdb_bp_remove(kdb_bp_t *bp) +{ + int ret = 1; + if (!bp->bp_installed) + return ret; + if (!bp->bp_type) + ret = dbg_remove_sw_break(bp->bp_addr); + else + ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr, + bp->bph_length, + bp->bp_type); + if (ret == 0) + bp->bp_installed = 0; + return ret; +} + +static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp) +{ + if (KDB_DEBUG(BP)) + kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs)); + + /* + * Setup single step + */ + kdb_setsinglestep(regs); + + /* + * Reset delay attribute + */ + bp->bp_delay = 0; + bp->bp_delayed = 1; +} + +static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp) +{ + int ret; + /* + * Install the breakpoint, if it is not already installed. + */ + + if (KDB_DEBUG(BP)) + kdb_printf("%s: bp_installed %d\n", + __func__, bp->bp_installed); + if (!KDB_STATE(SSBPT)) + bp->bp_delay = 0; + if (bp->bp_installed) + return 1; + if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) { + if (KDB_DEBUG(BP)) + kdb_printf("%s: delayed bp\n", __func__); + kdb_handle_bp(regs, bp); + return 0; + } + if (!bp->bp_type) + ret = dbg_set_sw_break(bp->bp_addr); + else + ret = arch_kgdb_ops.set_hw_breakpoint(bp->bp_addr, + bp->bph_length, + bp->bp_type); + if (ret == 0) { + bp->bp_installed = 1; + } else { + kdb_printf("%s: failed to set breakpoint at 0x%lx\n", + __func__, bp->bp_addr); + return 1; + } + return 0; +} + +/* + * kdb_bp_install + * + * Install kdb_breakpoints prior to returning from the + * kernel debugger. This allows the kdb_breakpoints to be set + * upon functions that are used internally by kdb, such as + * printk(). This function is only called once per kdb session. + */ +void kdb_bp_install(struct pt_regs *regs) +{ + int i; + + for (i = 0; i < KDB_MAXBPT; i++) { + kdb_bp_t *bp = &kdb_breakpoints[i]; + + if (KDB_DEBUG(BP)) { + kdb_printf("%s: bp %d bp_enabled %d\n", + __func__, i, bp->bp_enabled); + } + if (bp->bp_enabled) + _kdb_bp_install(regs, bp); + } +} + +/* + * kdb_bp_remove + * + * Remove kdb_breakpoints upon entry to the kernel debugger. + * + * Parameters: + * None. + * Outputs: + * None. + * Returns: + * None. + * Locking: + * None. + * Remarks: + */ +void kdb_bp_remove(void) +{ + int i; + + for (i = KDB_MAXBPT - 1; i >= 0; i--) { + kdb_bp_t *bp = &kdb_breakpoints[i]; + + if (KDB_DEBUG(BP)) { + kdb_printf("%s: bp %d bp_enabled %d\n", + __func__, i, bp->bp_enabled); + } + if (bp->bp_enabled) + _kdb_bp_remove(bp); + } +} + + +/* + * kdb_printbp + * + * Internal function to format and print a breakpoint entry. + * + * Parameters: + * None. + * Outputs: + * None. + * Returns: + * None. + * Locking: + * None. + * Remarks: + */ + +static void kdb_printbp(kdb_bp_t *bp, int i) +{ + kdb_printf("%s ", kdb_bptype(bp)); + kdb_printf("BP #%d at ", i); + kdb_symbol_print(bp->bp_addr, NULL, KDB_SP_DEFAULT); + + if (bp->bp_enabled) + kdb_printf("\n is enabled"); + else + kdb_printf("\n is disabled"); + + kdb_printf("\taddr at %016lx, hardtype=%d installed=%d\n", + bp->bp_addr, bp->bp_type, bp->bp_installed); + + kdb_printf("\n"); +} + +/* + * kdb_bp + * + * Handle the bp commands. + * + * [bp|bph] [DATAR|DATAW] + * + * Parameters: + * argc Count of arguments in argv + * argv Space delimited command line arguments + * Outputs: + * None. + * Returns: + * Zero for success, a kdb diagnostic if failure. + * Locking: + * None. + * Remarks: + * + * bp Set breakpoint on all cpus. Only use hardware assist if need. + * bph Set breakpoint on all cpus. Force hardware register + */ + +static int kdb_bp(int argc, const char **argv) +{ + int i, bpno; + kdb_bp_t *bp, *bp_check; + int diag; + int free; + char *symname = NULL; + long offset = 0ul; + int nextarg; + kdb_bp_t template = {0}; + + if (argc == 0) { + /* + * Display breakpoint table + */ + for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; + bpno++, bp++) { + if (bp->bp_free) + continue; + kdb_printbp(bp, bpno); + } + + return 0; + } + + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &template.bp_addr, + &offset, &symname); + if (diag) + return diag; + if (!template.bp_addr) + return KDB_BADINT; + + /* + * Find an empty bp structure to allocate + */ + free = KDB_MAXBPT; + for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) { + if (bp->bp_free) + break; + } + + if (bpno == KDB_MAXBPT) + return KDB_TOOMANYBPT; + + if (strcmp(argv[0], "bph") == 0) { + template.bp_type = BP_HARDWARE_BREAKPOINT; + diag = kdb_parsebp(argc, argv, &nextarg, &template); + if (diag) + return diag; + } else { + template.bp_type = BP_BREAKPOINT; + } + + /* + * Check for clashing breakpoints. + * + * Note, in this design we can't have hardware breakpoints + * enabled for both read and write on the same address. + */ + for (i = 0, bp_check = kdb_breakpoints; i < KDB_MAXBPT; + i++, bp_check++) { + if (!bp_check->bp_free && + bp_check->bp_addr == template.bp_addr) { + kdb_printf("You already have a breakpoint at " + kdb_bfd_vma_fmt0 "\n", template.bp_addr); + return KDB_DUPBPT; + } + } + + template.bp_enabled = 1; + + /* + * Actually allocate the breakpoint found earlier + */ + *bp = template; + bp->bp_free = 0; + + kdb_printbp(bp, bpno); + + return 0; +} + +/* + * kdb_bc + * + * Handles the 'bc', 'be', and 'bd' commands + * + * [bd|bc|be] + * [bd|bc|be] * + * + * Parameters: + * argc Count of arguments in argv + * argv Space delimited command line arguments + * Outputs: + * None. + * Returns: + * Zero for success, a kdb diagnostic for failure + * Locking: + * None. + * Remarks: + */ +static int kdb_bc(int argc, const char **argv) +{ + unsigned long addr; + kdb_bp_t *bp = NULL; + int lowbp = KDB_MAXBPT; + int highbp = 0; + int done = 0; + int i; + int diag = 0; + + int cmd; /* KDBCMD_B? */ +#define KDBCMD_BC 0 +#define KDBCMD_BE 1 +#define KDBCMD_BD 2 + + if (strcmp(argv[0], "be") == 0) + cmd = KDBCMD_BE; + else if (strcmp(argv[0], "bd") == 0) + cmd = KDBCMD_BD; + else + cmd = KDBCMD_BC; + + if (argc != 1) + return KDB_ARGCOUNT; + + if (strcmp(argv[1], "*") == 0) { + lowbp = 0; + highbp = KDB_MAXBPT; + } else { + diag = kdbgetularg(argv[1], &addr); + if (diag) + return diag; + + /* + * For addresses less than the maximum breakpoint number, + * assume that the breakpoint number is desired. + */ + if (addr < KDB_MAXBPT) { + bp = &kdb_breakpoints[addr]; + lowbp = highbp = addr; + highbp++; + } else { + for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; + i++, bp++) { + if (bp->bp_addr == addr) { + lowbp = highbp = i; + highbp++; + break; + } + } + } + } + + /* + * Now operate on the set of breakpoints matching the input + * criteria (either '*' for all, or an individual breakpoint). + */ + for (bp = &kdb_breakpoints[lowbp], i = lowbp; + i < highbp; + i++, bp++) { + if (bp->bp_free) + continue; + + done++; + + switch (cmd) { + case KDBCMD_BC: + bp->bp_enabled = 0; + + kdb_printf("Breakpoint %d at " + kdb_bfd_vma_fmt " cleared\n", + i, bp->bp_addr); + + bp->bp_addr = 0; + bp->bp_free = 1; + + break; + case KDBCMD_BE: + bp->bp_enabled = 1; + + kdb_printf("Breakpoint %d at " + kdb_bfd_vma_fmt " enabled", + i, bp->bp_addr); + + kdb_printf("\n"); + break; + case KDBCMD_BD: + if (!bp->bp_enabled) + break; + + bp->bp_enabled = 0; + + kdb_printf("Breakpoint %d at " + kdb_bfd_vma_fmt " disabled\n", + i, bp->bp_addr); + + break; + } + if (bp->bp_delay && (cmd == KDBCMD_BC || cmd == KDBCMD_BD)) { + bp->bp_delay = 0; + KDB_STATE_CLEAR(SSBPT); + } + } + + return (!done) ? KDB_BPTNOTFOUND : 0; +} + +/* + * kdb_ss + * + * Process the 'ss' (Single Step) and 'ssb' (Single Step to Branch) + * commands. + * + * ss + * ssb + * + * Parameters: + * argc Argument count + * argv Argument vector + * Outputs: + * None. + * Returns: + * KDB_CMD_SS[B] for success, a kdb error if failure. + * Locking: + * None. + * Remarks: + * + * Set the arch specific option to trigger a debug trap after the next + * instruction. + * + * For 'ssb', set the trace flag in the debug trap handler + * after printing the current insn and return directly without + * invoking the kdb command processor, until a branch instruction + * is encountered. + */ + +static int kdb_ss(int argc, const char **argv) +{ + int ssb = 0; + + ssb = (strcmp(argv[0], "ssb") == 0); + if (argc != 0) + return KDB_ARGCOUNT; + /* + * Set trace flag and go. + */ + KDB_STATE_SET(DOING_SS); + if (ssb) { + KDB_STATE_SET(DOING_SSB); + return KDB_CMD_SSB; + } + return KDB_CMD_SS; +} + +/* Initialize the breakpoint table and register breakpoint commands. */ + +void __init kdb_initbptab(void) +{ + int i; + kdb_bp_t *bp; + + /* + * First time initialization. + */ + memset(&kdb_breakpoints, '\0', sizeof(kdb_breakpoints)); + + for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) + bp->bp_free = 1; + + kdb_register_repeat("bp", kdb_bp, "[]", + "Set/Display breakpoints", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("bl", kdb_bp, "[]", + "Display breakpoints", 0, KDB_REPEAT_NO_ARGS); + if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) + kdb_register_repeat("bph", kdb_bp, "[]", + "[datar [length]|dataw [length]] Set hw brk", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("bc", kdb_bc, "", + "Clear Breakpoint", 0, KDB_REPEAT_NONE); + kdb_register_repeat("be", kdb_bc, "", + "Enable Breakpoint", 0, KDB_REPEAT_NONE); + kdb_register_repeat("bd", kdb_bc, "", + "Disable Breakpoint", 0, KDB_REPEAT_NONE); + + kdb_register_repeat("ss", kdb_ss, "", + "Single Step", 1, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("ssb", kdb_ss, "", + "Single step to branch/call", 0, KDB_REPEAT_NO_ARGS); + /* + * Architecture dependent initialization. + */ +} diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c new file mode 100644 index 00000000000..483fa4e7aaa --- /dev/null +++ b/kernel/debug/kdb/kdb_bt.c @@ -0,0 +1,208 @@ +/* + * Kernel Debugger Architecture Independent Stack Traceback + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "kdb_private.h" + + +static void kdb_show_stack(struct task_struct *p, void *addr) +{ + int old_lvl = console_loglevel; + console_loglevel = 15; + kdb_set_current_task(p); + if (addr) { + show_stack((struct task_struct *)p, addr); + } else if (kdb_current_regs) { +#ifdef CONFIG_X86 + show_stack(p, &kdb_current_regs->sp); +#else + show_stack(p, NULL); +#endif + } else { + show_stack(p, NULL); + } + console_loglevel = old_lvl; +} + +/* + * kdb_bt + * + * This function implements the 'bt' command. Print a stack + * traceback. + * + * bt [] (addr-exp is for alternate stacks) + * btp Kernel stack for + * btt Kernel stack for task structure at + * + * bta [DRSTCZEUIMA] All useful processes, optionally + * filtered by state + * btc [] The current process on one cpu, + * default is all cpus + * + * bt refers to a address on the stack, that location + * is assumed to contain a return address. + * + * btt refers to the address of a struct task. + * + * Inputs: + * argc argument count + * argv argument vector + * Outputs: + * None. + * Returns: + * zero for success, a kdb diagnostic if error + * Locking: + * none. + * Remarks: + * Backtrack works best when the code uses frame pointers. But even + * without frame pointers we should get a reasonable trace. + * + * mds comes in handy when examining the stack to do a manual traceback or + * to get a starting point for bt . + */ + +static int +kdb_bt1(struct task_struct *p, unsigned long mask, + int argcount, int btaprompt) +{ + char buffer[2]; + if (kdb_getarea(buffer[0], (unsigned long)p) || + kdb_getarea(buffer[0], (unsigned long)(p+1)-1)) + return KDB_BADADDR; + if (!kdb_task_state(p, mask)) + return 0; + kdb_printf("Stack traceback for pid %d\n", p->pid); + kdb_ps1(p); + kdb_show_stack(p, NULL); + if (btaprompt) { + kdb_getstr(buffer, sizeof(buffer), + "Enter to end, to continue:"); + if (buffer[0] == 'q') { + kdb_printf("\n"); + return 1; + } + } + touch_nmi_watchdog(); + return 0; +} + +int +kdb_bt(int argc, const char **argv) +{ + int diag; + int argcount = 5; + int btaprompt = 1; + int nextarg; + unsigned long addr; + long offset; + + kdbgetintenv("BTARGS", &argcount); /* Arguments to print */ + kdbgetintenv("BTAPROMPT", &btaprompt); /* Prompt after each + * proc in bta */ + + if (strcmp(argv[0], "bta") == 0) { + struct task_struct *g, *p; + unsigned long cpu; + unsigned long mask = kdb_task_state_string(argc ? argv[1] : + NULL); + if (argc == 0) + kdb_ps_suppressed(); + /* Run the active tasks first */ + for_each_online_cpu(cpu) { + p = kdb_curr_task(cpu); + if (kdb_bt1(p, mask, argcount, btaprompt)) + return 0; + } + /* Now the inactive tasks */ + kdb_do_each_thread(g, p) { + if (task_curr(p)) + continue; + if (kdb_bt1(p, mask, argcount, btaprompt)) + return 0; + } kdb_while_each_thread(g, p); + } else if (strcmp(argv[0], "btp") == 0) { + struct task_struct *p; + unsigned long pid; + if (argc != 1) + return KDB_ARGCOUNT; + diag = kdbgetularg((char *)argv[1], &pid); + if (diag) + return diag; + p = find_task_by_pid_ns(pid, &init_pid_ns); + if (p) { + kdb_set_current_task(p); + return kdb_bt1(p, ~0UL, argcount, 0); + } + kdb_printf("No process with pid == %ld found\n", pid); + return 0; + } else if (strcmp(argv[0], "btt") == 0) { + if (argc != 1) + return KDB_ARGCOUNT; + diag = kdbgetularg((char *)argv[1], &addr); + if (diag) + return diag; + kdb_set_current_task((struct task_struct *)addr); + return kdb_bt1((struct task_struct *)addr, ~0UL, argcount, 0); + } else if (strcmp(argv[0], "btc") == 0) { + unsigned long cpu = ~0; + struct task_struct *save_current_task = kdb_current_task; + char buf[80]; + if (argc > 1) + return KDB_ARGCOUNT; + if (argc == 1) { + diag = kdbgetularg((char *)argv[1], &cpu); + if (diag) + return diag; + } + /* Recursive use of kdb_parse, do not use argv after + * this point */ + argv = NULL; + if (cpu != ~0) { + if (cpu >= num_possible_cpus() || !cpu_online(cpu)) { + kdb_printf("no process for cpu %ld\n", cpu); + return 0; + } + sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); + kdb_parse(buf); + return 0; + } + kdb_printf("btc: cpu status: "); + kdb_parse("cpu\n"); + for_each_online_cpu(cpu) { + sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); + kdb_parse(buf); + touch_nmi_watchdog(); + } + kdb_set_current_task(save_current_task); + return 0; + } else { + if (argc) { + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, + &offset, NULL); + if (diag) + return diag; + kdb_show_stack(kdb_current_task, (void *)addr); + return 0; + } else { + return kdb_bt1(kdb_current_task, ~0UL, argcount, 0); + } + } + + /* NOTREACHED */ + return 0; +} diff --git a/kernel/debug/kdb/kdb_cmds b/kernel/debug/kdb/kdb_cmds new file mode 100644 index 00000000000..56c88e4db30 --- /dev/null +++ b/kernel/debug/kdb/kdb_cmds @@ -0,0 +1,35 @@ +# Initial commands for kdb, alter to suit your needs. +# These commands are executed in kdb_init() context, no SMP, no +# processes. Commands that require process data (including stack or +# registers) are not reliable this early. set and bp commands should +# be safe. Global breakpoint commands affect each cpu as it is booted. + +# Standard debugging information for first level support, just type archkdb +# or archkdbcpu or archkdbshort at the kdb prompt. + +defcmd dumpcommon "" "Common kdb debugging" + set BTAPROMPT 0 + set LINES 10000 + -summary + -cpu + -ps + -dmesg 600 + -bt +endefcmd + +defcmd dumpall "" "First line debugging" + set BTSYMARG 1 + set BTARGS 9 + pid R + -dumpcommon + -bta +endefcmd + +defcmd dumpcpu "" "Same as dumpall but only tasks on cpus" + set BTSYMARG 1 + set BTARGS 9 + pid R + -dumpcommon + -btc +endefcmd + diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c new file mode 100644 index 00000000000..f024c0c4b8c --- /dev/null +++ b/kernel/debug/kdb/kdb_debugger.c @@ -0,0 +1,159 @@ +/* + * Created by: Jason Wessel + * + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include "kdb_private.h" +#include "../debug_core.h" + +/* + * KDB interface to KGDB internals + */ +get_char_func kdb_poll_funcs[] = { + dbg_io_get_char, + NULL, +}; + +int kdb_stub(struct kgdb_state *ks) +{ + int error = 0; + kdb_bp_t *bp; + unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); + kdb_reason_t reason = KDB_REASON_OOPS; + kdb_dbtrap_t db_result = KDB_DB_NOBPT; + int i; + + if (KDB_STATE(REENTRY)) { + reason = KDB_REASON_SWITCH; + KDB_STATE_CLEAR(REENTRY); + addr = instruction_pointer(ks->linux_regs); + } + ks->pass_exception = 0; + if (atomic_read(&kgdb_setting_breakpoint)) + reason = KDB_REASON_KEYBOARD; + + for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { + if ((bp->bp_enabled) && (bp->bp_addr == addr)) { + reason = KDB_REASON_BREAK; + db_result = KDB_DB_BPT; + if (addr != instruction_pointer(ks->linux_regs)) + kgdb_arch_set_pc(ks->linux_regs, addr); + break; + } + } + if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) { + for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { + if (bp->bp_free) + continue; + if (bp->bp_addr == addr) { + bp->bp_delay = 1; + bp->bp_delayed = 1; + /* + * SSBPT is set when the kernel debugger must single step a + * task in order to re-establish an instruction breakpoint + * which uses the instruction replacement mechanism. It is + * cleared by any action that removes the need to single-step + * the breakpoint. + */ + reason = KDB_REASON_BREAK; + db_result = KDB_DB_BPT; + KDB_STATE_SET(SSBPT); + break; + } + } + } + + if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 && + ks->signo == SIGTRAP) { + reason = KDB_REASON_SSTEP; + db_result = KDB_DB_BPT; + } + /* Set initial kdb state variables */ + KDB_STATE_CLEAR(KGDB_TRANS); + kdb_initial_cpu = ks->cpu; + kdb_current_task = kgdb_info[ks->cpu].task; + kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; + /* Remove any breakpoints as needed by kdb and clear single step */ + kdb_bp_remove(); + KDB_STATE_CLEAR(DOING_SS); + KDB_STATE_CLEAR(DOING_SSB); + /* zero out any offline cpu data */ + for_each_present_cpu(i) { + if (!cpu_online(i)) { + kgdb_info[i].debuggerinfo = NULL; + kgdb_info[i].task = NULL; + } + } + if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) { + ks->pass_exception = 1; + KDB_FLAG_SET(CATASTROPHIC); + } + kdb_initial_cpu = ks->cpu; + if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) { + KDB_STATE_CLEAR(SSBPT); + KDB_STATE_CLEAR(DOING_SS); + } else { + /* Start kdb main loop */ + error = kdb_main_loop(KDB_REASON_ENTER, reason, + ks->err_code, db_result, ks->linux_regs); + } + /* + * Upon exit from the kdb main loop setup break points and restart + * the system based on the requested continue state + */ + kdb_initial_cpu = -1; + kdb_current_task = NULL; + kdb_current_regs = NULL; + kdbnearsym_cleanup(); + if (error == KDB_CMD_KGDB) { + if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) { + /* + * This inteface glue which allows kdb to transition in into + * the gdb stub. In order to do this the '?' or '' gdb serial + * packet response is processed here. And then control is + * passed to the gdbstub. + */ + if (KDB_STATE(DOING_KGDB)) + gdbstub_state(ks, "?"); + else + gdbstub_state(ks, ""); + KDB_STATE_CLEAR(DOING_KGDB); + KDB_STATE_CLEAR(DOING_KGDB2); + } + return DBG_PASS_EVENT; + } + kdb_bp_install(ks->linux_regs); + dbg_activate_sw_breakpoints(); + /* Set the exit state to a single step or a continue */ + if (KDB_STATE(DOING_SS)) + gdbstub_state(ks, "s"); + else + gdbstub_state(ks, "c"); + + KDB_FLAG_CLEAR(CATASTROPHIC); + + /* Invoke arch specific exception handling prior to system resume */ + kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e"); + if (ks->pass_exception) + kgdb_info[ks->cpu].ret_state = 1; + if (error == KDB_CMD_CPU) { + KDB_STATE_SET(REENTRY); + /* + * Force clear the single step bit because kdb emulates this + * differently vs the gdbstub + */ + kgdb_single_step = 0; + dbg_deactivate_sw_breakpoints(); + return DBG_SWITCH_CPU_EVENT; + } + return kgdb_info[ks->cpu].ret_state; +} + diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c new file mode 100644 index 00000000000..9e3cec7a925 --- /dev/null +++ b/kernel/debug/kdb/kdb_io.c @@ -0,0 +1,789 @@ +/* + * Kernel Debugger Architecture Independent Console I/O handler + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "kdb_private.h" + +#define CMD_BUFLEN 256 +char kdb_prompt_str[CMD_BUFLEN]; + + +static void kgdb_transition_check(char *buffer) +{ + int slen = strlen(buffer); + if (strncmp(buffer, "$?#3f", slen) != 0 && + strncmp(buffer, "$qSupported#37", slen) != 0 && + strncmp(buffer, "+$qSupported#37", slen) != 0) { + KDB_STATE_SET(KGDB_TRANS); + kdb_printf("%s", buffer); + } +} + +static int kdb_read_get_key(char *buffer, size_t bufsize) +{ +#define ESCAPE_UDELAY 1000 +#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */ + char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */ + char *ped = escape_data; + int escape_delay = 0; + get_char_func *f, *f_escape = NULL; + int key; + + for (f = &kdb_poll_funcs[0]; ; ++f) { + if (*f == NULL) { + /* Reset NMI watchdog once per poll loop */ + touch_nmi_watchdog(); + f = &kdb_poll_funcs[0]; + } + if (escape_delay == 2) { + *ped = '\0'; + ped = escape_data; + --escape_delay; + } + if (escape_delay == 1) { + key = *ped++; + if (!*ped) + --escape_delay; + break; + } + key = (*f)(); + if (key == -1) { + if (escape_delay) { + udelay(ESCAPE_UDELAY); + --escape_delay; + } + continue; + } + if (bufsize <= 2) { + if (key == '\r') + key = '\n'; + *buffer++ = key; + *buffer = '\0'; + return -1; + } + if (escape_delay == 0 && key == '\e') { + escape_delay = ESCAPE_DELAY; + ped = escape_data; + f_escape = f; + } + if (escape_delay) { + *ped++ = key; + if (f_escape != f) { + escape_delay = 2; + continue; + } + if (ped - escape_data == 1) { + /* \e */ + continue; + } else if (ped - escape_data == 2) { + /* \e */ + if (key != '[') + escape_delay = 2; + continue; + } else if (ped - escape_data == 3) { + /* \e[ */ + int mapkey = 0; + switch (key) { + case 'A': /* \e[A, up arrow */ + mapkey = 16; + break; + case 'B': /* \e[B, down arrow */ + mapkey = 14; + break; + case 'C': /* \e[C, right arrow */ + mapkey = 6; + break; + case 'D': /* \e[D, left arrow */ + mapkey = 2; + break; + case '1': /* dropthrough */ + case '3': /* dropthrough */ + /* \e[<1,3,4>], may be home, del, end */ + case '4': + mapkey = -1; + break; + } + if (mapkey != -1) { + if (mapkey > 0) { + escape_data[0] = mapkey; + escape_data[1] = '\0'; + } + escape_delay = 2; + } + continue; + } else if (ped - escape_data == 4) { + /* \e[<1,3,4> */ + int mapkey = 0; + if (key == '~') { + switch (escape_data[2]) { + case '1': /* \e[1~, home */ + mapkey = 1; + break; + case '3': /* \e[3~, del */ + mapkey = 4; + break; + case '4': /* \e[4~, end */ + mapkey = 5; + break; + } + } + if (mapkey > 0) { + escape_data[0] = mapkey; + escape_data[1] = '\0'; + } + escape_delay = 2; + continue; + } + } + break; /* A key to process */ + } + return key; +} + +/* + * kdb_read + * + * This function reads a string of characters, terminated by + * a newline, or by reaching the end of the supplied buffer, + * from the current kernel debugger console device. + * Parameters: + * buffer - Address of character buffer to receive input characters. + * bufsize - size, in bytes, of the character buffer + * Returns: + * Returns a pointer to the buffer containing the received + * character string. This string will be terminated by a + * newline character. + * Locking: + * No locks are required to be held upon entry to this + * function. It is not reentrant - it relies on the fact + * that while kdb is running on only one "master debug" cpu. + * Remarks: + * + * The buffer size must be >= 2. A buffer size of 2 means that the caller only + * wants a single key. + * + * An escape key could be the start of a vt100 control sequence such as \e[D + * (left arrow) or it could be a character in its own right. The standard + * method for detecting the difference is to wait for 2 seconds to see if there + * are any other characters. kdb is complicated by the lack of a timer service + * (interrupts are off), by multiple input sources and by the need to sometimes + * return after just one key. Escape sequence processing has to be done as + * states in the polling loop. + */ + +static char *kdb_read(char *buffer, size_t bufsize) +{ + char *cp = buffer; + char *bufend = buffer+bufsize-2; /* Reserve space for newline + * and null byte */ + char *lastchar; + char *p_tmp; + char tmp; + static char tmpbuffer[CMD_BUFLEN]; + int len = strlen(buffer); + int len_tmp; + int tab = 0; + int count; + int i; + int diag, dtab_count; + int key; + + + diag = kdbgetintenv("DTABCOUNT", &dtab_count); + if (diag) + dtab_count = 30; + + if (len > 0) { + cp += len; + if (*(buffer+len-1) == '\n') + cp--; + } + + lastchar = cp; + *cp = '\0'; + kdb_printf("%s", buffer); +poll_again: + key = kdb_read_get_key(buffer, bufsize); + if (key == -1) + return buffer; + if (key != 9) + tab = 0; + switch (key) { + case 8: /* backspace */ + if (cp > buffer) { + if (cp < lastchar) { + memcpy(tmpbuffer, cp, lastchar - cp); + memcpy(cp-1, tmpbuffer, lastchar - cp); + } + *(--lastchar) = '\0'; + --cp; + kdb_printf("\b%s \r", cp); + tmp = *cp; + *cp = '\0'; + kdb_printf(kdb_prompt_str); + kdb_printf("%s", buffer); + *cp = tmp; + } + break; + case 13: /* enter */ + *lastchar++ = '\n'; + *lastchar++ = '\0'; + kdb_printf("\n"); + return buffer; + case 4: /* Del */ + if (cp < lastchar) { + memcpy(tmpbuffer, cp+1, lastchar - cp - 1); + memcpy(cp, tmpbuffer, lastchar - cp - 1); + *(--lastchar) = '\0'; + kdb_printf("%s \r", cp); + tmp = *cp; + *cp = '\0'; + kdb_printf(kdb_prompt_str); + kdb_printf("%s", buffer); + *cp = tmp; + } + break; + case 1: /* Home */ + if (cp > buffer) { + kdb_printf("\r"); + kdb_printf(kdb_prompt_str); + cp = buffer; + } + break; + case 5: /* End */ + if (cp < lastchar) { + kdb_printf("%s", cp); + cp = lastchar; + } + break; + case 2: /* Left */ + if (cp > buffer) { + kdb_printf("\b"); + --cp; + } + break; + case 14: /* Down */ + memset(tmpbuffer, ' ', + strlen(kdb_prompt_str) + (lastchar-buffer)); + *(tmpbuffer+strlen(kdb_prompt_str) + + (lastchar-buffer)) = '\0'; + kdb_printf("\r%s\r", tmpbuffer); + *lastchar = (char)key; + *(lastchar+1) = '\0'; + return lastchar; + case 6: /* Right */ + if (cp < lastchar) { + kdb_printf("%c", *cp); + ++cp; + } + break; + case 16: /* Up */ + memset(tmpbuffer, ' ', + strlen(kdb_prompt_str) + (lastchar-buffer)); + *(tmpbuffer+strlen(kdb_prompt_str) + + (lastchar-buffer)) = '\0'; + kdb_printf("\r%s\r", tmpbuffer); + *lastchar = (char)key; + *(lastchar+1) = '\0'; + return lastchar; + case 9: /* Tab */ + if (tab < 2) + ++tab; + p_tmp = buffer; + while (*p_tmp == ' ') + p_tmp++; + if (p_tmp > cp) + break; + memcpy(tmpbuffer, p_tmp, cp-p_tmp); + *(tmpbuffer + (cp-p_tmp)) = '\0'; + p_tmp = strrchr(tmpbuffer, ' '); + if (p_tmp) + ++p_tmp; + else + p_tmp = tmpbuffer; + len = strlen(p_tmp); + count = kallsyms_symbol_complete(p_tmp, + sizeof(tmpbuffer) - + (p_tmp - tmpbuffer)); + if (tab == 2 && count > 0) { + kdb_printf("\n%d symbols are found.", count); + if (count > dtab_count) { + count = dtab_count; + kdb_printf(" But only first %d symbols will" + " be printed.\nYou can change the" + " environment variable DTABCOUNT.", + count); + } + kdb_printf("\n"); + for (i = 0; i < count; i++) { + if (kallsyms_symbol_next(p_tmp, i) < 0) + break; + kdb_printf("%s ", p_tmp); + *(p_tmp + len) = '\0'; + } + if (i >= dtab_count) + kdb_printf("..."); + kdb_printf("\n"); + kdb_printf(kdb_prompt_str); + kdb_printf("%s", buffer); + } else if (tab != 2 && count > 0) { + len_tmp = strlen(p_tmp); + strncpy(p_tmp+len_tmp, cp, lastchar-cp+1); + len_tmp = strlen(p_tmp); + strncpy(cp, p_tmp+len, len_tmp-len + 1); + len = len_tmp - len; + kdb_printf("%s", cp); + cp += len; + lastchar += len; + } + kdb_nextline = 1; /* reset output line number */ + break; + default: + if (key >= 32 && lastchar < bufend) { + if (cp < lastchar) { + memcpy(tmpbuffer, cp, lastchar - cp); + memcpy(cp+1, tmpbuffer, lastchar - cp); + *++lastchar = '\0'; + *cp = key; + kdb_printf("%s\r", cp); + ++cp; + tmp = *cp; + *cp = '\0'; + kdb_printf(kdb_prompt_str); + kdb_printf("%s", buffer); + *cp = tmp; + } else { + *++lastchar = '\0'; + *cp++ = key; + /* The kgdb transition check will hide + * printed characters if we think that + * kgdb is connecting, until the check + * fails */ + if (!KDB_STATE(KGDB_TRANS)) + kgdb_transition_check(buffer); + else + kdb_printf("%c", key); + } + /* Special escape to kgdb */ + if (lastchar - buffer >= 5 && + strcmp(lastchar - 5, "$?#3f") == 0) { + strcpy(buffer, "kgdb"); + KDB_STATE_SET(DOING_KGDB); + return buffer; + } + if (lastchar - buffer >= 14 && + strcmp(lastchar - 14, "$qSupported#37") == 0) { + strcpy(buffer, "kgdb"); + KDB_STATE_SET(DOING_KGDB2); + return buffer; + } + } + break; + } + goto poll_again; +} + +/* + * kdb_getstr + * + * Print the prompt string and read a command from the + * input device. + * + * Parameters: + * buffer Address of buffer to receive command + * bufsize Size of buffer in bytes + * prompt Pointer to string to use as prompt string + * Returns: + * Pointer to command buffer. + * Locking: + * None. + * Remarks: + * For SMP kernels, the processor number will be + * substituted for %d, %x or %o in the prompt. + */ + +char *kdb_getstr(char *buffer, size_t bufsize, char *prompt) +{ + if (prompt && kdb_prompt_str != prompt) + strncpy(kdb_prompt_str, prompt, CMD_BUFLEN); + kdb_printf(kdb_prompt_str); + kdb_nextline = 1; /* Prompt and input resets line number */ + return kdb_read(buffer, bufsize); +} + +/* + * kdb_input_flush + * + * Get rid of any buffered console input. + * + * Parameters: + * none + * Returns: + * nothing + * Locking: + * none + * Remarks: + * Call this function whenever you want to flush input. If there is any + * outstanding input, it ignores all characters until there has been no + * data for approximately 1ms. + */ + +static void kdb_input_flush(void) +{ + get_char_func *f; + int res; + int flush_delay = 1; + while (flush_delay) { + flush_delay--; +empty: + touch_nmi_watchdog(); + for (f = &kdb_poll_funcs[0]; *f; ++f) { + res = (*f)(); + if (res != -1) { + flush_delay = 1; + goto empty; + } + } + if (flush_delay) + mdelay(1); + } +} + +/* + * kdb_printf + * + * Print a string to the output device(s). + * + * Parameters: + * printf-like format and optional args. + * Returns: + * 0 + * Locking: + * None. + * Remarks: + * use 'kdbcons->write()' to avoid polluting 'log_buf' with + * kdb output. + * + * If the user is doing a cmd args | grep srch + * then kdb_grepping_flag is set. + * In that case we need to accumulate full lines (ending in \n) before + * searching for the pattern. + */ + +static char kdb_buffer[256]; /* A bit too big to go on stack */ +static char *next_avail = kdb_buffer; +static int size_avail; +static int suspend_grep; + +/* + * search arg1 to see if it contains arg2 + * (kdmain.c provides flags for ^pat and pat$) + * + * return 1 for found, 0 for not found + */ +static int kdb_search_string(char *searched, char *searchfor) +{ + char firstchar, *cp; + int len1, len2; + + /* not counting the newline at the end of "searched" */ + len1 = strlen(searched)-1; + len2 = strlen(searchfor); + if (len1 < len2) + return 0; + if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) + return 0; + if (kdb_grep_leading) { + if (!strncmp(searched, searchfor, len2)) + return 1; + } else if (kdb_grep_trailing) { + if (!strncmp(searched+len1-len2, searchfor, len2)) + return 1; + } else { + firstchar = *searchfor; + cp = searched; + while ((cp = strchr(cp, firstchar))) { + if (!strncmp(cp, searchfor, len2)) + return 1; + cp++; + } + } + return 0; +} + +int kdb_printf(const char *fmt, ...) +{ + va_list ap; + int diag; + int linecount; + int logging, saved_loglevel = 0; + int got_printf_lock = 0; + int retlen = 0; + int fnd, len; + char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; + char *moreprompt = "more> "; + struct console *c = console_drivers; + static DEFINE_SPINLOCK(kdb_printf_lock); + unsigned long uninitialized_var(flags); + + preempt_disable(); + /* Serialize kdb_printf if multiple cpus try to write at once. + * But if any cpu goes recursive in kdb, just print the output, + * even if it is interleaved with any other text. + */ + if (!KDB_STATE(PRINTF_LOCK)) { + KDB_STATE_SET(PRINTF_LOCK); + spin_lock_irqsave(&kdb_printf_lock, flags); + got_printf_lock = 1; + atomic_inc(&kdb_event); + } else { + __acquire(kdb_printf_lock); + } + + diag = kdbgetintenv("LINES", &linecount); + if (diag || linecount <= 1) + linecount = 24; + + diag = kdbgetintenv("LOGGING", &logging); + if (diag) + logging = 0; + + if (!kdb_grepping_flag || suspend_grep) { + /* normally, every vsnprintf starts a new buffer */ + next_avail = kdb_buffer; + size_avail = sizeof(kdb_buffer); + } + va_start(ap, fmt); + vsnprintf(next_avail, size_avail, fmt, ap); + va_end(ap); + + /* + * If kdb_parse() found that the command was cmd xxx | grep yyy + * then kdb_grepping_flag is set, and kdb_grep_string contains yyy + * + * Accumulate the print data up to a newline before searching it. + * (vsnprintf does null-terminate the string that it generates) + */ + + /* skip the search if prints are temporarily unconditional */ + if (!suspend_grep && kdb_grepping_flag) { + cp = strchr(kdb_buffer, '\n'); + if (!cp) { + /* + * Special cases that don't end with newlines + * but should be written without one: + * The "[nn]kdb> " prompt should + * appear at the front of the buffer. + * + * The "[nn]more " prompt should also be + * (MOREPROMPT -> moreprompt) + * written * but we print that ourselves, + * we set the suspend_grep flag to make + * it unconditional. + * + */ + if (next_avail == kdb_buffer) { + /* + * these should occur after a newline, + * so they will be at the front of the + * buffer + */ + cp2 = kdb_buffer; + len = strlen(kdb_prompt_str); + if (!strncmp(cp2, kdb_prompt_str, len)) { + /* + * We're about to start a new + * command, so we can go back + * to normal mode. + */ + kdb_grepping_flag = 0; + goto kdb_printit; + } + } + /* no newline; don't search/write the buffer + until one is there */ + len = strlen(kdb_buffer); + next_avail = kdb_buffer + len; + size_avail = sizeof(kdb_buffer) - len; + goto kdb_print_out; + } + + /* + * The newline is present; print through it or discard + * it, depending on the results of the search. + */ + cp++; /* to byte after the newline */ + replaced_byte = *cp; /* remember what/where it was */ + cphold = cp; + *cp = '\0'; /* end the string for our search */ + + /* + * We now have a newline at the end of the string + * Only continue with this output if it contains the + * search string. + */ + fnd = kdb_search_string(kdb_buffer, kdb_grep_string); + if (!fnd) { + /* + * At this point the complete line at the start + * of kdb_buffer can be discarded, as it does + * not contain what the user is looking for. + * Shift the buffer left. + */ + *cphold = replaced_byte; + strcpy(kdb_buffer, cphold); + len = strlen(kdb_buffer); + next_avail = kdb_buffer + len; + size_avail = sizeof(kdb_buffer) - len; + goto kdb_print_out; + } + /* + * at this point the string is a full line and + * should be printed, up to the null. + */ + } +kdb_printit: + + /* + * Write to all consoles. + */ + retlen = strlen(kdb_buffer); + while (c) { + c->write(c, kdb_buffer, retlen); + touch_nmi_watchdog(); + c = c->next; + } + if (logging) { + saved_loglevel = console_loglevel; + console_loglevel = 0; + printk(KERN_INFO "%s", kdb_buffer); + } + + if (KDB_STATE(PAGER) && strchr(kdb_buffer, '\n')) + kdb_nextline++; + + /* check for having reached the LINES number of printed lines */ + if (kdb_nextline == linecount) { + char buf1[16] = ""; +#if defined(CONFIG_SMP) + char buf2[32]; +#endif + + /* Watch out for recursion here. Any routine that calls + * kdb_printf will come back through here. And kdb_read + * uses kdb_printf to echo on serial consoles ... + */ + kdb_nextline = 1; /* In case of recursion */ + + /* + * Pause until cr. + */ + moreprompt = kdbgetenv("MOREPROMPT"); + if (moreprompt == NULL) + moreprompt = "more> "; + +#if defined(CONFIG_SMP) + if (strchr(moreprompt, '%')) { + sprintf(buf2, moreprompt, get_cpu()); + put_cpu(); + moreprompt = buf2; + } +#endif + + kdb_input_flush(); + c = console_drivers; + + while (c) { + c->write(c, moreprompt, strlen(moreprompt)); + touch_nmi_watchdog(); + c = c->next; + } + + if (logging) + printk("%s", moreprompt); + + kdb_read(buf1, 2); /* '2' indicates to return + * immediately after getting one key. */ + kdb_nextline = 1; /* Really set output line 1 */ + + /* empty and reset the buffer: */ + kdb_buffer[0] = '\0'; + next_avail = kdb_buffer; + size_avail = sizeof(kdb_buffer); + if ((buf1[0] == 'q') || (buf1[0] == 'Q')) { + /* user hit q or Q */ + KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ + KDB_STATE_CLEAR(PAGER); + /* end of command output; back to normal mode */ + kdb_grepping_flag = 0; + kdb_printf("\n"); + } else if (buf1[0] == ' ') { + kdb_printf("\n"); + suspend_grep = 1; /* for this recursion */ + } else if (buf1[0] == '\n') { + kdb_nextline = linecount - 1; + kdb_printf("\r"); + suspend_grep = 1; /* for this recursion */ + } else if (buf1[0] && buf1[0] != '\n') { + /* user hit something other than enter */ + suspend_grep = 1; /* for this recursion */ + kdb_printf("\nOnly 'q' or 'Q' are processed at more " + "prompt, input ignored\n"); + } else if (kdb_grepping_flag) { + /* user hit enter */ + suspend_grep = 1; /* for this recursion */ + kdb_printf("\n"); + } + kdb_input_flush(); + } + + /* + * For grep searches, shift the printed string left. + * replaced_byte contains the character that was overwritten with + * the terminating null, and cphold points to the null. + * Then adjust the notion of available space in the buffer. + */ + if (kdb_grepping_flag && !suspend_grep) { + *cphold = replaced_byte; + strcpy(kdb_buffer, cphold); + len = strlen(kdb_buffer); + next_avail = kdb_buffer + len; + size_avail = sizeof(kdb_buffer) - len; + } + +kdb_print_out: + suspend_grep = 0; /* end of what may have been a recursive call */ + if (logging) + console_loglevel = saved_loglevel; + if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) { + got_printf_lock = 0; + spin_unlock_irqrestore(&kdb_printf_lock, flags); + KDB_STATE_CLEAR(PRINTF_LOCK); + atomic_dec(&kdb_event); + } else { + __release(kdb_printf_lock); + } + preempt_enable(); + return retlen; +} diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c new file mode 100644 index 00000000000..64ef9ac14ba --- /dev/null +++ b/kernel/debug/kdb/kdb_main.c @@ -0,0 +1,2845 @@ +/* + * Kernel Debugger Architecture Independent Main Code + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (C) 2000 Stephane Eranian + * Xscale (R) modifications copyright (C) 2003 Intel Corporation. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "kdb_private.h" + +#define GREP_LEN 256 +char kdb_grep_string[GREP_LEN]; +int kdb_grepping_flag; +EXPORT_SYMBOL(kdb_grepping_flag); +int kdb_grep_leading; +int kdb_grep_trailing; + +/* + * Kernel debugger state flags + */ +int kdb_flags; +atomic_t kdb_event; + +/* + * kdb_lock protects updates to kdb_initial_cpu. Used to + * single thread processors through the kernel debugger. + */ +int kdb_initial_cpu = -1; /* cpu number that owns kdb */ +int kdb_nextline = 1; +int kdb_state; /* General KDB state */ + +struct task_struct *kdb_current_task; +EXPORT_SYMBOL(kdb_current_task); +struct pt_regs *kdb_current_regs; + +const char *kdb_diemsg; +static int kdb_go_count; +#ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC +static unsigned int kdb_continue_catastrophic = + CONFIG_KDB_CONTINUE_CATASTROPHIC; +#else +static unsigned int kdb_continue_catastrophic; +#endif + +/* kdb_commands describes the available commands. */ +static kdbtab_t *kdb_commands; +#define KDB_BASE_CMD_MAX 50 +static int kdb_max_commands = KDB_BASE_CMD_MAX; +static kdbtab_t kdb_base_commands[50]; +#define for_each_kdbcmd(cmd, num) \ + for ((cmd) = kdb_base_commands, (num) = 0; \ + num < kdb_max_commands; \ + num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++, num++) + +typedef struct _kdbmsg { + int km_diag; /* kdb diagnostic */ + char *km_msg; /* Corresponding message text */ +} kdbmsg_t; + +#define KDBMSG(msgnum, text) \ + { KDB_##msgnum, text } + +static kdbmsg_t kdbmsgs[] = { + KDBMSG(NOTFOUND, "Command Not Found"), + KDBMSG(ARGCOUNT, "Improper argument count, see usage."), + KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, " + "8 is only allowed on 64 bit systems"), + KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"), + KDBMSG(NOTENV, "Cannot find environment variable"), + KDBMSG(NOENVVALUE, "Environment variable should have value"), + KDBMSG(NOTIMP, "Command not implemented"), + KDBMSG(ENVFULL, "Environment full"), + KDBMSG(ENVBUFFULL, "Environment buffer full"), + KDBMSG(TOOMANYBPT, "Too many breakpoints defined"), +#ifdef CONFIG_CPU_XSCALE + KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"), +#else + KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"), +#endif + KDBMSG(DUPBPT, "Duplicate breakpoint address"), + KDBMSG(BPTNOTFOUND, "Breakpoint not found"), + KDBMSG(BADMODE, "Invalid IDMODE"), + KDBMSG(BADINT, "Illegal numeric value"), + KDBMSG(INVADDRFMT, "Invalid symbolic address format"), + KDBMSG(BADREG, "Invalid register name"), + KDBMSG(BADCPUNUM, "Invalid cpu number"), + KDBMSG(BADLENGTH, "Invalid length field"), + KDBMSG(NOBP, "No Breakpoint exists"), + KDBMSG(BADADDR, "Invalid address"), +}; +#undef KDBMSG + +static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t); + + +/* + * Initial environment. This is all kept static and local to + * this file. We don't want to rely on the memory allocation + * mechanisms in the kernel, so we use a very limited allocate-only + * heap for new and altered environment variables. The entire + * environment is limited to a fixed number of entries (add more + * to __env[] if required) and a fixed amount of heap (add more to + * KDB_ENVBUFSIZE if required). + */ + +static char *__env[] = { +#if defined(CONFIG_SMP) + "PROMPT=[%d]kdb> ", + "MOREPROMPT=[%d]more> ", +#else + "PROMPT=kdb> ", + "MOREPROMPT=more> ", +#endif + "RADIX=16", + "MDCOUNT=8", /* lines of md output */ + "BTARGS=9", /* 9 possible args in bt */ + KDB_PLATFORM_ENV, + "DTABCOUNT=30", + "NOSECT=1", + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, + (char *)0, +}; + +static const int __nenv = (sizeof(__env) / sizeof(char *)); + +struct task_struct *kdb_curr_task(int cpu) +{ + struct task_struct *p = curr_task(cpu); +#ifdef _TIF_MCA_INIT + if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu)) + p = krp->p; +#endif + return p; +} + +/* + * kdbgetenv - This function will return the character string value of + * an environment variable. + * Parameters: + * match A character string representing an environment variable. + * Returns: + * NULL No environment variable matches 'match' + * char* Pointer to string value of environment variable. + */ +char *kdbgetenv(const char *match) +{ + char **ep = __env; + int matchlen = strlen(match); + int i; + + for (i = 0; i < __nenv; i++) { + char *e = *ep++; + + if (!e) + continue; + + if ((strncmp(match, e, matchlen) == 0) + && ((e[matchlen] == '\0') + || (e[matchlen] == '='))) { + char *cp = strchr(e, '='); + return cp ? ++cp : ""; + } + } + return NULL; +} + +/* + * kdballocenv - This function is used to allocate bytes for + * environment entries. + * Parameters: + * match A character string representing a numeric value + * Outputs: + * *value the unsigned long representation of the env variable 'match' + * Returns: + * Zero on success, a kdb diagnostic on failure. + * Remarks: + * We use a static environment buffer (envbuffer) to hold the values + * of dynamically generated environment variables (see kdb_set). Buffer + * space once allocated is never free'd, so over time, the amount of space + * (currently 512 bytes) will be exhausted if env variables are changed + * frequently. + */ +static char *kdballocenv(size_t bytes) +{ +#define KDB_ENVBUFSIZE 512 + static char envbuffer[KDB_ENVBUFSIZE]; + static int envbufsize; + char *ep = NULL; + + if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) { + ep = &envbuffer[envbufsize]; + envbufsize += bytes; + } + return ep; +} + +/* + * kdbgetulenv - This function will return the value of an unsigned + * long-valued environment variable. + * Parameters: + * match A character string representing a numeric value + * Outputs: + * *value the unsigned long represntation of the env variable 'match' + * Returns: + * Zero on success, a kdb diagnostic on failure. + */ +static int kdbgetulenv(const char *match, unsigned long *value) +{ + char *ep; + + ep = kdbgetenv(match); + if (!ep) + return KDB_NOTENV; + if (strlen(ep) == 0) + return KDB_NOENVVALUE; + + *value = simple_strtoul(ep, NULL, 0); + + return 0; +} + +/* + * kdbgetintenv - This function will return the value of an + * integer-valued environment variable. + * Parameters: + * match A character string representing an integer-valued env variable + * Outputs: + * *value the integer representation of the environment variable 'match' + * Returns: + * Zero on success, a kdb diagnostic on failure. + */ +int kdbgetintenv(const char *match, int *value) +{ + unsigned long val; + int diag; + + diag = kdbgetulenv(match, &val); + if (!diag) + *value = (int) val; + return diag; +} + +/* + * kdbgetularg - This function will convert a numeric string into an + * unsigned long value. + * Parameters: + * arg A character string representing a numeric value + * Outputs: + * *value the unsigned long represntation of arg. + * Returns: + * Zero on success, a kdb diagnostic on failure. + */ +int kdbgetularg(const char *arg, unsigned long *value) +{ + char *endp; + unsigned long val; + + val = simple_strtoul(arg, &endp, 0); + + if (endp == arg) { + /* + * Try base 16, for us folks too lazy to type the + * leading 0x... + */ + val = simple_strtoul(arg, &endp, 16); + if (endp == arg) + return KDB_BADINT; + } + + *value = val; + + return 0; +} + +/* + * kdb_set - This function implements the 'set' command. Alter an + * existing environment variable or create a new one. + */ +int kdb_set(int argc, const char **argv) +{ + int i; + char *ep; + size_t varlen, vallen; + + /* + * we can be invoked two ways: + * set var=value argv[1]="var", argv[2]="value" + * set var = value argv[1]="var", argv[2]="=", argv[3]="value" + * - if the latter, shift 'em down. + */ + if (argc == 3) { + argv[2] = argv[3]; + argc--; + } + + if (argc != 2) + return KDB_ARGCOUNT; + + /* + * Check for internal variables + */ + if (strcmp(argv[1], "KDBDEBUG") == 0) { + unsigned int debugflags; + char *cp; + + debugflags = simple_strtoul(argv[2], &cp, 0); + if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) { + kdb_printf("kdb: illegal debug flags '%s'\n", + argv[2]); + return 0; + } + kdb_flags = (kdb_flags & + ~(KDB_DEBUG_FLAG_MASK << KDB_DEBUG_FLAG_SHIFT)) + | (debugflags << KDB_DEBUG_FLAG_SHIFT); + + return 0; + } + + /* + * Tokenizer squashed the '=' sign. argv[1] is variable + * name, argv[2] = value. + */ + varlen = strlen(argv[1]); + vallen = strlen(argv[2]); + ep = kdballocenv(varlen + vallen + 2); + if (ep == (char *)0) + return KDB_ENVBUFFULL; + + sprintf(ep, "%s=%s", argv[1], argv[2]); + + ep[varlen+vallen+1] = '\0'; + + for (i = 0; i < __nenv; i++) { + if (__env[i] + && ((strncmp(__env[i], argv[1], varlen) == 0) + && ((__env[i][varlen] == '\0') + || (__env[i][varlen] == '=')))) { + __env[i] = ep; + return 0; + } + } + + /* + * Wasn't existing variable. Fit into slot. + */ + for (i = 0; i < __nenv-1; i++) { + if (__env[i] == (char *)0) { + __env[i] = ep; + return 0; + } + } + + return KDB_ENVFULL; +} + +static int kdb_check_regs(void) +{ + if (!kdb_current_regs) { + kdb_printf("No current kdb registers." + " You may need to select another task\n"); + return KDB_BADREG; + } + return 0; +} + +/* + * kdbgetaddrarg - This function is responsible for parsing an + * address-expression and returning the value of the expression, + * symbol name, and offset to the caller. + * + * The argument may consist of a numeric value (decimal or + * hexidecimal), a symbol name, a register name (preceeded by the + * percent sign), an environment variable with a numeric value + * (preceeded by a dollar sign) or a simple arithmetic expression + * consisting of a symbol name, +/-, and a numeric constant value + * (offset). + * Parameters: + * argc - count of arguments in argv + * argv - argument vector + * *nextarg - index to next unparsed argument in argv[] + * regs - Register state at time of KDB entry + * Outputs: + * *value - receives the value of the address-expression + * *offset - receives the offset specified, if any + * *name - receives the symbol name, if any + * *nextarg - index to next unparsed argument in argv[] + * Returns: + * zero is returned on success, a kdb diagnostic code is + * returned on error. + */ +int kdbgetaddrarg(int argc, const char **argv, int *nextarg, + unsigned long *value, long *offset, + char **name) +{ + unsigned long addr; + unsigned long off = 0; + int positive; + int diag; + int found = 0; + char *symname; + char symbol = '\0'; + char *cp; + kdb_symtab_t symtab; + + /* + * Process arguments which follow the following syntax: + * + * symbol | numeric-address [+/- numeric-offset] + * %register + * $environment-variable + */ + + if (*nextarg > argc) + return KDB_ARGCOUNT; + + symname = (char *)argv[*nextarg]; + + /* + * If there is no whitespace between the symbol + * or address and the '+' or '-' symbols, we + * remember the character and replace it with a + * null so the symbol/value can be properly parsed + */ + cp = strpbrk(symname, "+-"); + if (cp != NULL) { + symbol = *cp; + *cp++ = '\0'; + } + + if (symname[0] == '$') { + diag = kdbgetulenv(&symname[1], &addr); + if (diag) + return diag; + } else if (symname[0] == '%') { + diag = kdb_check_regs(); + if (diag) + return diag; + /* Implement register values with % at a later time as it is + * arch optional. + */ + return KDB_NOTIMP; + } else { + found = kdbgetsymval(symname, &symtab); + if (found) { + addr = symtab.sym_start; + } else { + diag = kdbgetularg(argv[*nextarg], &addr); + if (diag) + return diag; + } + } + + if (!found) + found = kdbnearsym(addr, &symtab); + + (*nextarg)++; + + if (name) + *name = symname; + if (value) + *value = addr; + if (offset && name && *name) + *offset = addr - symtab.sym_start; + + if ((*nextarg > argc) + && (symbol == '\0')) + return 0; + + /* + * check for +/- and offset + */ + + if (symbol == '\0') { + if ((argv[*nextarg][0] != '+') + && (argv[*nextarg][0] != '-')) { + /* + * Not our argument. Return. + */ + return 0; + } else { + positive = (argv[*nextarg][0] == '+'); + (*nextarg)++; + } + } else + positive = (symbol == '+'); + + /* + * Now there must be an offset! + */ + if ((*nextarg > argc) + && (symbol == '\0')) { + return KDB_INVADDRFMT; + } + + if (!symbol) { + cp = (char *)argv[*nextarg]; + (*nextarg)++; + } + + diag = kdbgetularg(cp, &off); + if (diag) + return diag; + + if (!positive) + off = -off; + + if (offset) + *offset += off; + + if (value) + *value += off; + + return 0; +} + +static void kdb_cmderror(int diag) +{ + int i; + + if (diag >= 0) { + kdb_printf("no error detected (diagnostic is %d)\n", diag); + return; + } + + for (i = 0; i < __nkdb_err; i++) { + if (kdbmsgs[i].km_diag == diag) { + kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg); + return; + } + } + + kdb_printf("Unknown diag %d\n", -diag); +} + +/* + * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd' + * command which defines one command as a set of other commands, + * terminated by endefcmd. kdb_defcmd processes the initial + * 'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for + * the following commands until 'endefcmd'. + * Inputs: + * argc argument count + * argv argument vector + * Returns: + * zero for success, a kdb diagnostic if error + */ +struct defcmd_set { + int count; + int usable; + char *name; + char *usage; + char *help; + char **command; +}; +static struct defcmd_set *defcmd_set; +static int defcmd_set_count; +static int defcmd_in_progress; + +/* Forward references */ +static int kdb_exec_defcmd(int argc, const char **argv); + +static int kdb_defcmd2(const char *cmdstr, const char *argv0) +{ + struct defcmd_set *s = defcmd_set + defcmd_set_count - 1; + char **save_command = s->command; + if (strcmp(argv0, "endefcmd") == 0) { + defcmd_in_progress = 0; + if (!s->count) + s->usable = 0; + if (s->usable) + kdb_register(s->name, kdb_exec_defcmd, + s->usage, s->help, 0); + return 0; + } + if (!s->usable) + return KDB_NOTIMP; + s->command = kmalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB); + if (!s->command) { + kdb_printf("Could not allocate new kdb_defcmd table for %s\n", + cmdstr); + s->usable = 0; + return KDB_NOTIMP; + } + memcpy(s->command, save_command, s->count * sizeof(*(s->command))); + s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB); + kfree(save_command); + return 0; +} + +static int kdb_defcmd(int argc, const char **argv) +{ + struct defcmd_set *save_defcmd_set = defcmd_set, *s; + if (defcmd_in_progress) { + kdb_printf("kdb: nested defcmd detected, assuming missing " + "endefcmd\n"); + kdb_defcmd2("endefcmd", "endefcmd"); + } + if (argc == 0) { + int i; + for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) { + kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name, + s->usage, s->help); + for (i = 0; i < s->count; ++i) + kdb_printf("%s", s->command[i]); + kdb_printf("endefcmd\n"); + } + return 0; + } + if (argc != 3) + return KDB_ARGCOUNT; + defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set), + GFP_KDB); + if (!defcmd_set) { + kdb_printf("Could not allocate new defcmd_set entry for %s\n", + argv[1]); + defcmd_set = save_defcmd_set; + return KDB_NOTIMP; + } + memcpy(defcmd_set, save_defcmd_set, + defcmd_set_count * sizeof(*defcmd_set)); + kfree(save_defcmd_set); + s = defcmd_set + defcmd_set_count; + memset(s, 0, sizeof(*s)); + s->usable = 1; + s->name = kdb_strdup(argv[1], GFP_KDB); + s->usage = kdb_strdup(argv[2], GFP_KDB); + s->help = kdb_strdup(argv[3], GFP_KDB); + if (s->usage[0] == '"') { + strcpy(s->usage, s->usage+1); + s->usage[strlen(s->usage)-1] = '\0'; + } + if (s->help[0] == '"') { + strcpy(s->help, s->help+1); + s->help[strlen(s->help)-1] = '\0'; + } + ++defcmd_set_count; + defcmd_in_progress = 1; + return 0; +} + +/* + * kdb_exec_defcmd - Execute the set of commands associated with this + * defcmd name. + * Inputs: + * argc argument count + * argv argument vector + * Returns: + * zero for success, a kdb diagnostic if error + */ +static int kdb_exec_defcmd(int argc, const char **argv) +{ + int i, ret; + struct defcmd_set *s; + if (argc != 0) + return KDB_ARGCOUNT; + for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) { + if (strcmp(s->name, argv[0]) == 0) + break; + } + if (i == defcmd_set_count) { + kdb_printf("kdb_exec_defcmd: could not find commands for %s\n", + argv[0]); + return KDB_NOTIMP; + } + for (i = 0; i < s->count; ++i) { + /* Recursive use of kdb_parse, do not use argv after + * this point */ + argv = NULL; + kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]); + ret = kdb_parse(s->command[i]); + if (ret) + return ret; + } + return 0; +} + +/* Command history */ +#define KDB_CMD_HISTORY_COUNT 32 +#define CMD_BUFLEN 200 /* kdb_printf: max printline + * size == 256 */ +static unsigned int cmd_head, cmd_tail; +static unsigned int cmdptr; +static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN]; +static char cmd_cur[CMD_BUFLEN]; + +/* + * The "str" argument may point to something like | grep xyz + */ +static void parse_grep(const char *str) +{ + int len; + char *cp = (char *)str, *cp2; + + /* sanity check: we should have been called with the \ first */ + if (*cp != '|') + return; + cp++; + while (isspace(*cp)) + cp++; + if (strncmp(cp, "grep ", 5)) { + kdb_printf("invalid 'pipe', see grephelp\n"); + return; + } + cp += 5; + while (isspace(*cp)) + cp++; + cp2 = strchr(cp, '\n'); + if (cp2) + *cp2 = '\0'; /* remove the trailing newline */ + len = strlen(cp); + if (len == 0) { + kdb_printf("invalid 'pipe', see grephelp\n"); + return; + } + /* now cp points to a nonzero length search string */ + if (*cp == '"') { + /* allow it be "x y z" by removing the "'s - there must + be two of them */ + cp++; + cp2 = strchr(cp, '"'); + if (!cp2) { + kdb_printf("invalid quoted string, see grephelp\n"); + return; + } + *cp2 = '\0'; /* end the string where the 2nd " was */ + } + kdb_grep_leading = 0; + if (*cp == '^') { + kdb_grep_leading = 1; + cp++; + } + len = strlen(cp); + kdb_grep_trailing = 0; + if (*(cp+len-1) == '$') { + kdb_grep_trailing = 1; + *(cp+len-1) = '\0'; + } + len = strlen(cp); + if (!len) + return; + if (len >= GREP_LEN) { + kdb_printf("search string too long\n"); + return; + } + strcpy(kdb_grep_string, cp); + kdb_grepping_flag++; + return; +} + +/* + * kdb_parse - Parse the command line, search the command table for a + * matching command and invoke the command function. This + * function may be called recursively, if it is, the second call + * will overwrite argv and cbuf. It is the caller's + * responsibility to save their argv if they recursively call + * kdb_parse(). + * Parameters: + * cmdstr The input command line to be parsed. + * regs The registers at the time kdb was entered. + * Returns: + * Zero for success, a kdb diagnostic if failure. + * Remarks: + * Limited to 20 tokens. + * + * Real rudimentary tokenization. Basically only whitespace + * is considered a token delimeter (but special consideration + * is taken of the '=' sign as used by the 'set' command). + * + * The algorithm used to tokenize the input string relies on + * there being at least one whitespace (or otherwise useless) + * character between tokens as the character immediately following + * the token is altered in-place to a null-byte to terminate the + * token string. + */ + +#define MAXARGC 20 + +int kdb_parse(const char *cmdstr) +{ + static char *argv[MAXARGC]; + static int argc; + static char cbuf[CMD_BUFLEN+2]; + char *cp; + char *cpp, quoted; + kdbtab_t *tp; + int i, escaped, ignore_errors = 0, check_grep; + + /* + * First tokenize the command string. + */ + cp = (char *)cmdstr; + kdb_grepping_flag = check_grep = 0; + + if (KDB_FLAG(CMD_INTERRUPT)) { + /* Previous command was interrupted, newline must not + * repeat the command */ + KDB_FLAG_CLEAR(CMD_INTERRUPT); + KDB_STATE_SET(PAGER); + argc = 0; /* no repeat */ + } + + if (*cp != '\n' && *cp != '\0') { + argc = 0; + cpp = cbuf; + while (*cp) { + /* skip whitespace */ + while (isspace(*cp)) + cp++; + if ((*cp == '\0') || (*cp == '\n') || + (*cp == '#' && !defcmd_in_progress)) + break; + /* special case: check for | grep pattern */ + if (*cp == '|') { + check_grep++; + break; + } + if (cpp >= cbuf + CMD_BUFLEN) { + kdb_printf("kdb_parse: command buffer " + "overflow, command ignored\n%s\n", + cmdstr); + return KDB_NOTFOUND; + } + if (argc >= MAXARGC - 1) { + kdb_printf("kdb_parse: too many arguments, " + "command ignored\n%s\n", cmdstr); + return KDB_NOTFOUND; + } + argv[argc++] = cpp; + escaped = 0; + quoted = '\0'; + /* Copy to next unquoted and unescaped + * whitespace or '=' */ + while (*cp && *cp != '\n' && + (escaped || quoted || !isspace(*cp))) { + if (cpp >= cbuf + CMD_BUFLEN) + break; + if (escaped) { + escaped = 0; + *cpp++ = *cp++; + continue; + } + if (*cp == '\\') { + escaped = 1; + ++cp; + continue; + } + if (*cp == quoted) + quoted = '\0'; + else if (*cp == '\'' || *cp == '"') + quoted = *cp; + *cpp = *cp++; + if (*cpp == '=' && !quoted) + break; + ++cpp; + } + *cpp++ = '\0'; /* Squash a ws or '=' character */ + } + } + if (!argc) + return 0; + if (check_grep) + parse_grep(cp); + if (defcmd_in_progress) { + int result = kdb_defcmd2(cmdstr, argv[0]); + if (!defcmd_in_progress) { + argc = 0; /* avoid repeat on endefcmd */ + *(argv[0]) = '\0'; + } + return result; + } + if (argv[0][0] == '-' && argv[0][1] && + (argv[0][1] < '0' || argv[0][1] > '9')) { + ignore_errors = 1; + ++argv[0]; + } + + for_each_kdbcmd(tp, i) { + if (tp->cmd_name) { + /* + * If this command is allowed to be abbreviated, + * check to see if this is it. + */ + + if (tp->cmd_minlen + && (strlen(argv[0]) <= tp->cmd_minlen)) { + if (strncmp(argv[0], + tp->cmd_name, + tp->cmd_minlen) == 0) { + break; + } + } + + if (strcmp(argv[0], tp->cmd_name) == 0) + break; + } + } + + /* + * If we don't find a command by this name, see if the first + * few characters of this match any of the known commands. + * e.g., md1c20 should match md. + */ + if (i == kdb_max_commands) { + for_each_kdbcmd(tp, i) { + if (tp->cmd_name) { + if (strncmp(argv[0], + tp->cmd_name, + strlen(tp->cmd_name)) == 0) { + break; + } + } + } + } + + if (i < kdb_max_commands) { + int result; + KDB_STATE_SET(CMD); + result = (*tp->cmd_func)(argc-1, (const char **)argv); + if (result && ignore_errors && result > KDB_CMD_GO) + result = 0; + KDB_STATE_CLEAR(CMD); + switch (tp->cmd_repeat) { + case KDB_REPEAT_NONE: + argc = 0; + if (argv[0]) + *(argv[0]) = '\0'; + break; + case KDB_REPEAT_NO_ARGS: + argc = 1; + if (argv[1]) + *(argv[1]) = '\0'; + break; + case KDB_REPEAT_WITH_ARGS: + break; + } + return result; + } + + /* + * If the input with which we were presented does not + * map to an existing command, attempt to parse it as an + * address argument and display the result. Useful for + * obtaining the address of a variable, or the nearest symbol + * to an address contained in a register. + */ + { + unsigned long value; + char *name = NULL; + long offset; + int nextarg = 0; + + if (kdbgetaddrarg(0, (const char **)argv, &nextarg, + &value, &offset, &name)) { + return KDB_NOTFOUND; + } + + kdb_printf("%s = ", argv[0]); + kdb_symbol_print(value, NULL, KDB_SP_DEFAULT); + kdb_printf("\n"); + return 0; + } +} + + +static int handle_ctrl_cmd(char *cmd) +{ +#define CTRL_P 16 +#define CTRL_N 14 + + /* initial situation */ + if (cmd_head == cmd_tail) + return 0; + switch (*cmd) { + case CTRL_P: + if (cmdptr != cmd_tail) + cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT; + strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN); + return 1; + case CTRL_N: + if (cmdptr != cmd_head) + cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT; + strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN); + return 1; + } + return 0; +} + +/* + * kdb_reboot - This function implements the 'reboot' command. Reboot + * the system immediately, or loop for ever on failure. + */ +static int kdb_reboot(int argc, const char **argv) +{ + emergency_restart(); + kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n"); + while (1) + cpu_relax(); + /* NOTREACHED */ + return 0; +} + +static void kdb_dumpregs(struct pt_regs *regs) +{ + int old_lvl = console_loglevel; + console_loglevel = 15; + show_regs(regs); + kdb_printf("\n"); + console_loglevel = old_lvl; +} + +void kdb_set_current_task(struct task_struct *p) +{ + kdb_current_task = p; + + if (kdb_task_has_cpu(p)) { + kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p)); + return; + } + kdb_current_regs = NULL; +} + +/* + * kdb_local - The main code for kdb. This routine is invoked on a + * specific processor, it is not global. The main kdb() routine + * ensures that only one processor at a time is in this routine. + * This code is called with the real reason code on the first + * entry to a kdb session, thereafter it is called with reason + * SWITCH, even if the user goes back to the original cpu. + * Inputs: + * reason The reason KDB was invoked + * error The hardware-defined error code + * regs The exception frame at time of fault/breakpoint. + * db_result Result code from the break or debug point. + * Returns: + * 0 KDB was invoked for an event which it wasn't responsible + * 1 KDB handled the event for which it was invoked. + * KDB_CMD_GO User typed 'go'. + * KDB_CMD_CPU User switched to another cpu. + * KDB_CMD_SS Single step. + * KDB_CMD_SSB Single step until branch. + */ +static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, + kdb_dbtrap_t db_result) +{ + char *cmdbuf; + int diag; + struct task_struct *kdb_current = + kdb_curr_task(raw_smp_processor_id()); + + KDB_DEBUG_STATE("kdb_local 1", reason); + kdb_go_count = 0; + if (reason == KDB_REASON_DEBUG) { + /* special case below */ + } else { + kdb_printf("\nEntering kdb (current=0x%p, pid %d) ", + kdb_current, kdb_current->pid); +#if defined(CONFIG_SMP) + kdb_printf("on processor %d ", raw_smp_processor_id()); +#endif + } + + switch (reason) { + case KDB_REASON_DEBUG: + { + /* + * If re-entering kdb after a single step + * command, don't print the message. + */ + switch (db_result) { + case KDB_DB_BPT: + kdb_printf("\nEntering kdb (0x%p, pid %d) ", + kdb_current, kdb_current->pid); +#if defined(CONFIG_SMP) + kdb_printf("on processor %d ", raw_smp_processor_id()); +#endif + kdb_printf("due to Debug @ " kdb_machreg_fmt "\n", + instruction_pointer(regs)); + break; + case KDB_DB_SSB: + /* + * In the midst of ssb command. Just return. + */ + KDB_DEBUG_STATE("kdb_local 3", reason); + return KDB_CMD_SSB; /* Continue with SSB command */ + + break; + case KDB_DB_SS: + break; + case KDB_DB_SSBPT: + KDB_DEBUG_STATE("kdb_local 4", reason); + return 1; /* kdba_db_trap did the work */ + default: + kdb_printf("kdb: Bad result from kdba_db_trap: %d\n", + db_result); + break; + } + + } + break; + case KDB_REASON_ENTER: + if (KDB_STATE(KEYBOARD)) + kdb_printf("due to Keyboard Entry\n"); + else + kdb_printf("due to KDB_ENTER()\n"); + break; + case KDB_REASON_KEYBOARD: + KDB_STATE_SET(KEYBOARD); + kdb_printf("due to Keyboard Entry\n"); + break; + case KDB_REASON_ENTER_SLAVE: + /* drop through, slaves only get released via cpu switch */ + case KDB_REASON_SWITCH: + kdb_printf("due to cpu switch\n"); + break; + case KDB_REASON_OOPS: + kdb_printf("Oops: %s\n", kdb_diemsg); + kdb_printf("due to oops @ " kdb_machreg_fmt "\n", + instruction_pointer(regs)); + kdb_dumpregs(regs); + break; + case KDB_REASON_NMI: + kdb_printf("due to NonMaskable Interrupt @ " + kdb_machreg_fmt "\n", + instruction_pointer(regs)); + kdb_dumpregs(regs); + break; + case KDB_REASON_SSTEP: + case KDB_REASON_BREAK: + kdb_printf("due to %s @ " kdb_machreg_fmt "\n", + reason == KDB_REASON_BREAK ? + "Breakpoint" : "SS trap", instruction_pointer(regs)); + /* + * Determine if this breakpoint is one that we + * are interested in. + */ + if (db_result != KDB_DB_BPT) { + kdb_printf("kdb: error return from kdba_bp_trap: %d\n", + db_result); + KDB_DEBUG_STATE("kdb_local 6", reason); + return 0; /* Not for us, dismiss it */ + } + break; + case KDB_REASON_RECURSE: + kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n", + instruction_pointer(regs)); + break; + default: + kdb_printf("kdb: unexpected reason code: %d\n", reason); + KDB_DEBUG_STATE("kdb_local 8", reason); + return 0; /* Not for us, dismiss it */ + } + + while (1) { + /* + * Initialize pager context. + */ + kdb_nextline = 1; + KDB_STATE_CLEAR(SUPPRESS); + + cmdbuf = cmd_cur; + *cmdbuf = '\0'; + *(cmd_hist[cmd_head]) = '\0'; + + if (KDB_FLAG(ONLY_DO_DUMP)) { + /* kdb is off but a catastrophic error requires a dump. + * Take the dump and reboot. + * Turn on logging so the kdb output appears in the log + * buffer in the dump. + */ + const char *setargs[] = { "set", "LOGGING", "1" }; + kdb_set(2, setargs); + kdb_reboot(0, NULL); + /*NOTREACHED*/ + } + +do_full_getstr: +#if defined(CONFIG_SMP) + snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"), + raw_smp_processor_id()); +#else + snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT")); +#endif + if (defcmd_in_progress) + strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN); + + /* + * Fetch command from keyboard + */ + cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str); + if (*cmdbuf != '\n') { + if (*cmdbuf < 32) { + if (cmdptr == cmd_head) { + strncpy(cmd_hist[cmd_head], cmd_cur, + CMD_BUFLEN); + *(cmd_hist[cmd_head] + + strlen(cmd_hist[cmd_head])-1) = '\0'; + } + if (!handle_ctrl_cmd(cmdbuf)) + *(cmd_cur+strlen(cmd_cur)-1) = '\0'; + cmdbuf = cmd_cur; + goto do_full_getstr; + } else { + strncpy(cmd_hist[cmd_head], cmd_cur, + CMD_BUFLEN); + } + + cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT; + if (cmd_head == cmd_tail) + cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT; + } + + cmdptr = cmd_head; + diag = kdb_parse(cmdbuf); + if (diag == KDB_NOTFOUND) { + kdb_printf("Unknown kdb command: '%s'\n", cmdbuf); + diag = 0; + } + if (diag == KDB_CMD_GO + || diag == KDB_CMD_CPU + || diag == KDB_CMD_SS + || diag == KDB_CMD_SSB + || diag == KDB_CMD_KGDB) + break; + + if (diag) + kdb_cmderror(diag); + } + KDB_DEBUG_STATE("kdb_local 9", diag); + return diag; +} + + +/* + * kdb_print_state - Print the state data for the current processor + * for debugging. + * Inputs: + * text Identifies the debug point + * value Any integer value to be printed, e.g. reason code. + */ +void kdb_print_state(const char *text, int value) +{ + kdb_printf("state: %s cpu %d value %d initial %d state %x\n", + text, raw_smp_processor_id(), value, kdb_initial_cpu, + kdb_state); +} + +/* + * kdb_main_loop - After initial setup and assignment of the + * controlling cpu, all cpus are in this loop. One cpu is in + * control and will issue the kdb prompt, the others will spin + * until 'go' or cpu switch. + * + * To get a consistent view of the kernel stacks for all + * processes, this routine is invoked from the main kdb code via + * an architecture specific routine. kdba_main_loop is + * responsible for making the kernel stacks consistent for all + * processes, there should be no difference between a blocked + * process and a running process as far as kdb is concerned. + * Inputs: + * reason The reason KDB was invoked + * error The hardware-defined error code + * reason2 kdb's current reason code. + * Initially error but can change + * acording to kdb state. + * db_result Result code from break or debug point. + * regs The exception frame at time of fault/breakpoint. + * should always be valid. + * Returns: + * 0 KDB was invoked for an event which it wasn't responsible + * 1 KDB handled the event for which it was invoked. + */ +int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error, + kdb_dbtrap_t db_result, struct pt_regs *regs) +{ + int result = 1; + /* Stay in kdb() until 'go', 'ss[b]' or an error */ + while (1) { + /* + * All processors except the one that is in control + * will spin here. + */ + KDB_DEBUG_STATE("kdb_main_loop 1", reason); + while (KDB_STATE(HOLD_CPU)) { + /* state KDB is turned off by kdb_cpu to see if the + * other cpus are still live, each cpu in this loop + * turns it back on. + */ + if (!KDB_STATE(KDB)) + KDB_STATE_SET(KDB); + } + + KDB_STATE_CLEAR(SUPPRESS); + KDB_DEBUG_STATE("kdb_main_loop 2", reason); + if (KDB_STATE(LEAVING)) + break; /* Another cpu said 'go' */ + /* Still using kdb, this processor is in control */ + result = kdb_local(reason2, error, regs, db_result); + KDB_DEBUG_STATE("kdb_main_loop 3", result); + + if (result == KDB_CMD_CPU) + break; + + if (result == KDB_CMD_SS) { + KDB_STATE_SET(DOING_SS); + break; + } + + if (result == KDB_CMD_SSB) { + KDB_STATE_SET(DOING_SS); + KDB_STATE_SET(DOING_SSB); + break; + } + + if (result == KDB_CMD_KGDB) { + if (!(KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2))) + kdb_printf("Entering please attach debugger " + "or use $D#44+ or $3#33\n"); + break; + } + if (result && result != 1 && result != KDB_CMD_GO) + kdb_printf("\nUnexpected kdb_local return code %d\n", + result); + KDB_DEBUG_STATE("kdb_main_loop 4", reason); + break; + } + if (KDB_STATE(DOING_SS)) + KDB_STATE_CLEAR(SSBPT); + + return result; +} + +/* + * kdb_mdr - This function implements the guts of the 'mdr', memory + * read command. + * mdr , + * Inputs: + * addr Start address + * count Number of bytes + * Returns: + * Always 0. Any errors are detected and printed by kdb_getarea. + */ +static int kdb_mdr(unsigned long addr, unsigned int count) +{ + unsigned char c; + while (count--) { + if (kdb_getarea(c, addr)) + return 0; + kdb_printf("%02x", c); + addr++; + } + kdb_printf("\n"); + return 0; +} + +/* + * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4', + * 'md8' 'mdr' and 'mds' commands. + * + * md|mds [ [ []]] + * mdWcN [ [ []]] + * where W = is the width (1, 2, 4 or 8) and N is the count. + * for eg., md1c20 reads 20 bytes, 1 at a time. + * mdr , + */ +static void kdb_md_line(const char *fmtstr, unsigned long addr, + int symbolic, int nosect, int bytesperword, + int num, int repeat, int phys) +{ + /* print just one line of data */ + kdb_symtab_t symtab; + char cbuf[32]; + char *c = cbuf; + int i; + unsigned long word; + + memset(cbuf, '\0', sizeof(cbuf)); + if (phys) + kdb_printf("phys " kdb_machreg_fmt0 " ", addr); + else + kdb_printf(kdb_machreg_fmt0 " ", addr); + + for (i = 0; i < num && repeat--; i++) { + if (phys) { + if (kdb_getphysword(&word, addr, bytesperword)) + break; + } else if (kdb_getword(&word, addr, bytesperword)) + break; + kdb_printf(fmtstr, word); + if (symbolic) + kdbnearsym(word, &symtab); + else + memset(&symtab, 0, sizeof(symtab)); + if (symtab.sym_name) { + kdb_symbol_print(word, &symtab, 0); + if (!nosect) { + kdb_printf("\n"); + kdb_printf(" %s %s " + kdb_machreg_fmt " " + kdb_machreg_fmt " " + kdb_machreg_fmt, symtab.mod_name, + symtab.sec_name, symtab.sec_start, + symtab.sym_start, symtab.sym_end); + } + addr += bytesperword; + } else { + union { + u64 word; + unsigned char c[8]; + } wc; + unsigned char *cp; +#ifdef __BIG_ENDIAN + cp = wc.c + 8 - bytesperword; +#else + cp = wc.c; +#endif + wc.word = word; +#define printable_char(c) \ + ({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; }) + switch (bytesperword) { + case 8: + *c++ = printable_char(*cp++); + *c++ = printable_char(*cp++); + *c++ = printable_char(*cp++); + *c++ = printable_char(*cp++); + addr += 4; + case 4: + *c++ = printable_char(*cp++); + *c++ = printable_char(*cp++); + addr += 2; + case 2: + *c++ = printable_char(*cp++); + addr++; + case 1: + *c++ = printable_char(*cp++); + addr++; + break; + } +#undef printable_char + } + } + kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1), + " ", cbuf); +} + +static int kdb_md(int argc, const char **argv) +{ + static unsigned long last_addr; + static int last_radix, last_bytesperword, last_repeat; + int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat; + int nosect = 0; + char fmtchar, fmtstr[64]; + unsigned long addr; + unsigned long word; + long offset = 0; + int symbolic = 0; + int valid = 0; + int phys = 0; + + kdbgetintenv("MDCOUNT", &mdcount); + kdbgetintenv("RADIX", &radix); + kdbgetintenv("BYTESPERWORD", &bytesperword); + + /* Assume 'md ' and start with environment values */ + repeat = mdcount * 16 / bytesperword; + + if (strcmp(argv[0], "mdr") == 0) { + if (argc != 2) + return KDB_ARGCOUNT; + valid = 1; + } else if (isdigit(argv[0][2])) { + bytesperword = (int)(argv[0][2] - '0'); + if (bytesperword == 0) { + bytesperword = last_bytesperword; + if (bytesperword == 0) + bytesperword = 4; + } + last_bytesperword = bytesperword; + repeat = mdcount * 16 / bytesperword; + if (!argv[0][3]) + valid = 1; + else if (argv[0][3] == 'c' && argv[0][4]) { + char *p; + repeat = simple_strtoul(argv[0] + 4, &p, 10); + mdcount = ((repeat * bytesperword) + 15) / 16; + valid = !*p; + } + last_repeat = repeat; + } else if (strcmp(argv[0], "md") == 0) + valid = 1; + else if (strcmp(argv[0], "mds") == 0) + valid = 1; + else if (strcmp(argv[0], "mdp") == 0) { + phys = valid = 1; + } + if (!valid) + return KDB_NOTFOUND; + + if (argc == 0) { + if (last_addr == 0) + return KDB_ARGCOUNT; + addr = last_addr; + radix = last_radix; + bytesperword = last_bytesperword; + repeat = last_repeat; + mdcount = ((repeat * bytesperword) + 15) / 16; + } + + if (argc) { + unsigned long val; + int diag, nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, + &offset, NULL); + if (diag) + return diag; + if (argc > nextarg+2) + return KDB_ARGCOUNT; + + if (argc >= nextarg) { + diag = kdbgetularg(argv[nextarg], &val); + if (!diag) { + mdcount = (int) val; + repeat = mdcount * 16 / bytesperword; + } + } + if (argc >= nextarg+1) { + diag = kdbgetularg(argv[nextarg+1], &val); + if (!diag) + radix = (int) val; + } + } + + if (strcmp(argv[0], "mdr") == 0) + return kdb_mdr(addr, mdcount); + + switch (radix) { + case 10: + fmtchar = 'd'; + break; + case 16: + fmtchar = 'x'; + break; + case 8: + fmtchar = 'o'; + break; + default: + return KDB_BADRADIX; + } + + last_radix = radix; + + if (bytesperword > KDB_WORD_SIZE) + return KDB_BADWIDTH; + + switch (bytesperword) { + case 8: + sprintf(fmtstr, "%%16.16l%c ", fmtchar); + break; + case 4: + sprintf(fmtstr, "%%8.8l%c ", fmtchar); + break; + case 2: + sprintf(fmtstr, "%%4.4l%c ", fmtchar); + break; + case 1: + sprintf(fmtstr, "%%2.2l%c ", fmtchar); + break; + default: + return KDB_BADWIDTH; + } + + last_repeat = repeat; + last_bytesperword = bytesperword; + + if (strcmp(argv[0], "mds") == 0) { + symbolic = 1; + /* Do not save these changes as last_*, they are temporary mds + * overrides. + */ + bytesperword = KDB_WORD_SIZE; + repeat = mdcount; + kdbgetintenv("NOSECT", &nosect); + } + + /* Round address down modulo BYTESPERWORD */ + + addr &= ~(bytesperword-1); + + while (repeat > 0) { + unsigned long a; + int n, z, num = (symbolic ? 1 : (16 / bytesperword)); + + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) { + if (phys) { + if (kdb_getphysword(&word, a, bytesperword) + || word) + break; + } else if (kdb_getword(&word, a, bytesperword) || word) + break; + } + n = min(num, repeat); + kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword, + num, repeat, phys); + addr += bytesperword * n; + repeat -= n; + z = (z + num - 1) / num; + if (z > 2) { + int s = num * (z-2); + kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0 + " zero suppressed\n", + addr, addr + bytesperword * s - 1); + addr += bytesperword * s; + repeat -= s; + } + } + last_addr = addr; + + return 0; +} + +/* + * kdb_mm - This function implements the 'mm' command. + * mm address-expression new-value + * Remarks: + * mm works on machine words, mmW works on bytes. + */ +static int kdb_mm(int argc, const char **argv) +{ + int diag; + unsigned long addr; + long offset = 0; + unsigned long contents; + int nextarg; + int width; + + if (argv[0][2] && !isdigit(argv[0][2])) + return KDB_NOTFOUND; + + if (argc < 2) + return KDB_ARGCOUNT; + + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); + if (diag) + return diag; + + if (nextarg > argc) + return KDB_ARGCOUNT; + diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL); + if (diag) + return diag; + + if (nextarg != argc + 1) + return KDB_ARGCOUNT; + + width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE); + diag = kdb_putword(addr, contents, width); + if (diag) + return diag; + + kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents); + + return 0; +} + +/* + * kdb_go - This function implements the 'go' command. + * go [address-expression] + */ +static int kdb_go(int argc, const char **argv) +{ + unsigned long addr; + int diag; + int nextarg; + long offset; + + if (argc == 1) { + if (raw_smp_processor_id() != kdb_initial_cpu) { + kdb_printf("go
must be issued from the " + "initial cpu, do cpu %d first\n", + kdb_initial_cpu); + return KDB_ARGCOUNT; + } + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, + &addr, &offset, NULL); + if (diag) + return diag; + } else if (argc) { + return KDB_ARGCOUNT; + } + + diag = KDB_CMD_GO; + if (KDB_FLAG(CATASTROPHIC)) { + kdb_printf("Catastrophic error detected\n"); + kdb_printf("kdb_continue_catastrophic=%d, ", + kdb_continue_catastrophic); + if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) { + kdb_printf("type go a second time if you really want " + "to continue\n"); + return 0; + } + if (kdb_continue_catastrophic == 2) { + kdb_printf("forcing reboot\n"); + kdb_reboot(0, NULL); + } + kdb_printf("attempting to continue\n"); + } + return diag; +} + +/* + * kdb_rd - This function implements the 'rd' command. + */ +static int kdb_rd(int argc, const char **argv) +{ + int diag = kdb_check_regs(); + if (diag) + return diag; + + kdb_dumpregs(kdb_current_regs); + return 0; +} + +/* + * kdb_rm - This function implements the 'rm' (register modify) command. + * rm register-name new-contents + * Remarks: + * Currently doesn't allow modification of control or + * debug registers. + */ +static int kdb_rm(int argc, const char **argv) +{ + int diag; + int ind = 0; + unsigned long contents; + + if (argc != 2) + return KDB_ARGCOUNT; + /* + * Allow presence or absence of leading '%' symbol. + */ + if (argv[1][0] == '%') + ind = 1; + + diag = kdbgetularg(argv[2], &contents); + if (diag) + return diag; + + diag = kdb_check_regs(); + if (diag) + return diag; + kdb_printf("ERROR: Register set currently not implemented\n"); + return 0; +} + +#if defined(CONFIG_MAGIC_SYSRQ) +/* + * kdb_sr - This function implements the 'sr' (SYSRQ key) command + * which interfaces to the soi-disant MAGIC SYSRQ functionality. + * sr + */ +static int kdb_sr(int argc, const char **argv) +{ + if (argc != 1) + return KDB_ARGCOUNT; + sysrq_toggle_support(1); + handle_sysrq(*argv[1], NULL); + + return 0; +} +#endif /* CONFIG_MAGIC_SYSRQ */ + +/* + * kdb_ef - This function implements the 'regs' (display exception + * frame) command. This command takes an address and expects to + * find an exception frame at that address, formats and prints + * it. + * regs address-expression + * Remarks: + * Not done yet. + */ +static int kdb_ef(int argc, const char **argv) +{ + int diag; + unsigned long addr; + long offset; + int nextarg; + + if (argc != 1) + return KDB_ARGCOUNT; + + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); + if (diag) + return diag; + show_regs((struct pt_regs *)addr); + return 0; +} + +#if defined(CONFIG_MODULES) +/* modules using other modules */ +struct module_use { + struct list_head list; + struct module *module_which_uses; +}; + +/* + * kdb_lsmod - This function implements the 'lsmod' command. Lists + * currently loaded kernel modules. + * Mostly taken from userland lsmod. + */ +static int kdb_lsmod(int argc, const char **argv) +{ + struct module *mod; + + if (argc != 0) + return KDB_ARGCOUNT; + + kdb_printf("Module Size modstruct Used by\n"); + list_for_each_entry(mod, kdb_modules, list) { + + kdb_printf("%-20s%8u 0x%p ", mod->name, + mod->core_size, (void *)mod); +#ifdef CONFIG_MODULE_UNLOAD + kdb_printf("%4d ", module_refcount(mod)); +#endif + if (mod->state == MODULE_STATE_GOING) + kdb_printf(" (Unloading)"); + else if (mod->state == MODULE_STATE_COMING) + kdb_printf(" (Loading)"); + else + kdb_printf(" (Live)"); + +#ifdef CONFIG_MODULE_UNLOAD + { + struct module_use *use; + kdb_printf(" [ "); + list_for_each_entry(use, &mod->modules_which_use_me, + list) + kdb_printf("%s ", use->module_which_uses->name); + kdb_printf("]\n"); + } +#endif + } + + return 0; +} + +#endif /* CONFIG_MODULES */ + +/* + * kdb_env - This function implements the 'env' command. Display the + * current environment variables. + */ + +static int kdb_env(int argc, const char **argv) +{ + int i; + + for (i = 0; i < __nenv; i++) { + if (__env[i]) + kdb_printf("%s\n", __env[i]); + } + + if (KDB_DEBUG(MASK)) + kdb_printf("KDBFLAGS=0x%x\n", kdb_flags); + + return 0; +} + +#ifdef CONFIG_PRINTK +/* + * kdb_dmesg - This function implements the 'dmesg' command to display + * the contents of the syslog buffer. + * dmesg [lines] [adjust] + */ +static int kdb_dmesg(int argc, const char **argv) +{ + char *syslog_data[4], *start, *end, c = '\0', *p; + int diag, logging, logsize, lines = 0, adjust = 0, n; + + if (argc > 2) + return KDB_ARGCOUNT; + if (argc) { + char *cp; + lines = simple_strtol(argv[1], &cp, 0); + if (*cp) + lines = 0; + if (argc > 1) { + adjust = simple_strtoul(argv[2], &cp, 0); + if (*cp || adjust < 0) + adjust = 0; + } + } + + /* disable LOGGING if set */ + diag = kdbgetintenv("LOGGING", &logging); + if (!diag && logging) { + const char *setargs[] = { "set", "LOGGING", "0" }; + kdb_set(2, setargs); + } + + /* syslog_data[0,1] physical start, end+1. syslog_data[2,3] + * logical start, end+1. */ + kdb_syslog_data(syslog_data); + if (syslog_data[2] == syslog_data[3]) + return 0; + logsize = syslog_data[1] - syslog_data[0]; + start = syslog_data[2]; + end = syslog_data[3]; +#define KDB_WRAP(p) (((p - syslog_data[0]) % logsize) + syslog_data[0]) + for (n = 0, p = start; p < end; ++p) { + c = *KDB_WRAP(p); + if (c == '\n') + ++n; + } + if (c != '\n') + ++n; + if (lines < 0) { + if (adjust >= n) + kdb_printf("buffer only contains %d lines, nothing " + "printed\n", n); + else if (adjust - lines >= n) + kdb_printf("buffer only contains %d lines, last %d " + "lines printed\n", n, n - adjust); + if (adjust) { + for (; start < end && adjust; ++start) { + if (*KDB_WRAP(start) == '\n') + --adjust; + } + if (start < end) + ++start; + } + for (p = start; p < end && lines; ++p) { + if (*KDB_WRAP(p) == '\n') + ++lines; + } + end = p; + } else if (lines > 0) { + int skip = n - (adjust + lines); + if (adjust >= n) { + kdb_printf("buffer only contains %d lines, " + "nothing printed\n", n); + skip = n; + } else if (skip < 0) { + lines += skip; + skip = 0; + kdb_printf("buffer only contains %d lines, first " + "%d lines printed\n", n, lines); + } + for (; start < end && skip; ++start) { + if (*KDB_WRAP(start) == '\n') + --skip; + } + for (p = start; p < end && lines; ++p) { + if (*KDB_WRAP(p) == '\n') + --lines; + } + end = p; + } + /* Do a line at a time (max 200 chars) to reduce protocol overhead */ + c = '\n'; + while (start != end) { + char buf[201]; + p = buf; + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + while (start < end && (c = *KDB_WRAP(start)) && + (p - buf) < sizeof(buf)-1) { + ++start; + *p++ = c; + if (c == '\n') + break; + } + *p = '\0'; + kdb_printf("%s", buf); + } + if (c != '\n') + kdb_printf("\n"); + + return 0; +} +#endif /* CONFIG_PRINTK */ +/* + * kdb_cpu - This function implements the 'cpu' command. + * cpu [] + * Returns: + * KDB_CMD_CPU for success, a kdb diagnostic if error + */ +static void kdb_cpu_status(void) +{ + int i, start_cpu, first_print = 1; + char state, prev_state = '?'; + + kdb_printf("Currently on cpu %d\n", raw_smp_processor_id()); + kdb_printf("Available cpus: "); + for (start_cpu = -1, i = 0; i < NR_CPUS; i++) { + if (!cpu_online(i)) { + state = 'F'; /* cpu is offline */ + } else { + state = ' '; /* cpu is responding to kdb */ + if (kdb_task_state_char(KDB_TSK(i)) == 'I') + state = 'I'; /* idle task */ + } + if (state != prev_state) { + if (prev_state != '?') { + if (!first_print) + kdb_printf(", "); + first_print = 0; + kdb_printf("%d", start_cpu); + if (start_cpu < i-1) + kdb_printf("-%d", i-1); + if (prev_state != ' ') + kdb_printf("(%c)", prev_state); + } + prev_state = state; + start_cpu = i; + } + } + /* print the trailing cpus, ignoring them if they are all offline */ + if (prev_state != 'F') { + if (!first_print) + kdb_printf(", "); + kdb_printf("%d", start_cpu); + if (start_cpu < i-1) + kdb_printf("-%d", i-1); + if (prev_state != ' ') + kdb_printf("(%c)", prev_state); + } + kdb_printf("\n"); +} + +static int kdb_cpu(int argc, const char **argv) +{ + unsigned long cpunum; + int diag; + + if (argc == 0) { + kdb_cpu_status(); + return 0; + } + + if (argc != 1) + return KDB_ARGCOUNT; + + diag = kdbgetularg(argv[1], &cpunum); + if (diag) + return diag; + + /* + * Validate cpunum + */ + if ((cpunum > NR_CPUS) || !cpu_online(cpunum)) + return KDB_BADCPUNUM; + + dbg_switch_cpu = cpunum; + + /* + * Switch to other cpu + */ + return KDB_CMD_CPU; +} + +/* The user may not realize that ps/bta with no parameters does not print idle + * or sleeping system daemon processes, so tell them how many were suppressed. + */ +void kdb_ps_suppressed(void) +{ + int idle = 0, daemon = 0; + unsigned long mask_I = kdb_task_state_string("I"), + mask_M = kdb_task_state_string("M"); + unsigned long cpu; + const struct task_struct *p, *g; + for_each_online_cpu(cpu) { + p = kdb_curr_task(cpu); + if (kdb_task_state(p, mask_I)) + ++idle; + } + kdb_do_each_thread(g, p) { + if (kdb_task_state(p, mask_M)) + ++daemon; + } kdb_while_each_thread(g, p); + if (idle || daemon) { + if (idle) + kdb_printf("%d idle process%s (state I)%s\n", + idle, idle == 1 ? "" : "es", + daemon ? " and " : ""); + if (daemon) + kdb_printf("%d sleeping system daemon (state M) " + "process%s", daemon, + daemon == 1 ? "" : "es"); + kdb_printf(" suppressed,\nuse 'ps A' to see all.\n"); + } +} + +/* + * kdb_ps - This function implements the 'ps' command which shows a + * list of the active processes. + * ps [DRSTCZEUIMA] All processes, optionally filtered by state + */ +void kdb_ps1(const struct task_struct *p) +{ + int cpu; + unsigned long tmp; + + if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long))) + return; + + cpu = kdb_process_cpu(p); + kdb_printf("0x%p %8d %8d %d %4d %c 0x%p %c%s\n", + (void *)p, p->pid, p->parent->pid, + kdb_task_has_cpu(p), kdb_process_cpu(p), + kdb_task_state_char(p), + (void *)(&p->thread), + p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ', + p->comm); + if (kdb_task_has_cpu(p)) { + if (!KDB_TSK(cpu)) { + kdb_printf(" Error: no saved data for this cpu\n"); + } else { + if (KDB_TSK(cpu) != p) + kdb_printf(" Error: does not match running " + "process table (0x%p)\n", KDB_TSK(cpu)); + } + } +} + +static int kdb_ps(int argc, const char **argv) +{ + struct task_struct *g, *p; + unsigned long mask, cpu; + + if (argc == 0) + kdb_ps_suppressed(); + kdb_printf("%-*s Pid Parent [*] cpu State %-*s Command\n", + (int)(2*sizeof(void *))+2, "Task Addr", + (int)(2*sizeof(void *))+2, "Thread"); + mask = kdb_task_state_string(argc ? argv[1] : NULL); + /* Run the active tasks first */ + for_each_online_cpu(cpu) { + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + p = kdb_curr_task(cpu); + if (kdb_task_state(p, mask)) + kdb_ps1(p); + } + kdb_printf("\n"); + /* Now the real tasks */ + kdb_do_each_thread(g, p) { + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + if (kdb_task_state(p, mask)) + kdb_ps1(p); + } kdb_while_each_thread(g, p); + + return 0; +} + +/* + * kdb_pid - This function implements the 'pid' command which switches + * the currently active process. + * pid [ | R] + */ +static int kdb_pid(int argc, const char **argv) +{ + struct task_struct *p; + unsigned long val; + int diag; + + if (argc > 1) + return KDB_ARGCOUNT; + + if (argc) { + if (strcmp(argv[1], "R") == 0) { + p = KDB_TSK(kdb_initial_cpu); + } else { + diag = kdbgetularg(argv[1], &val); + if (diag) + return KDB_BADINT; + + p = find_task_by_pid_ns((pid_t)val, &init_pid_ns); + if (!p) { + kdb_printf("No task with pid=%d\n", (pid_t)val); + return 0; + } + } + kdb_set_current_task(p); + } + kdb_printf("KDB current process is %s(pid=%d)\n", + kdb_current_task->comm, + kdb_current_task->pid); + + return 0; +} + +/* + * kdb_ll - This function implements the 'll' command which follows a + * linked list and executes an arbitrary command for each + * element. + */ +static int kdb_ll(int argc, const char **argv) +{ + int diag; + unsigned long addr; + long offset = 0; + unsigned long va; + unsigned long linkoffset; + int nextarg; + const char *command; + + if (argc != 3) + return KDB_ARGCOUNT; + + nextarg = 1; + diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); + if (diag) + return diag; + + diag = kdbgetularg(argv[2], &linkoffset); + if (diag) + return diag; + + /* + * Using the starting address as + * the first element in the list, and assuming that + * the list ends with a null pointer. + */ + + va = addr; + command = kdb_strdup(argv[3], GFP_KDB); + if (!command) { + kdb_printf("%s: cannot duplicate command\n", __func__); + return 0; + } + /* Recursive use of kdb_parse, do not use argv after this point */ + argv = NULL; + + while (va) { + char buf[80]; + + sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va); + diag = kdb_parse(buf); + if (diag) + return diag; + + addr = va + linkoffset; + if (kdb_getword(&va, addr, sizeof(va))) + return 0; + } + kfree(command); + + return 0; +} + +static int kdb_kgdb(int argc, const char **argv) +{ + return KDB_CMD_KGDB; +} + +/* + * kdb_help - This function implements the 'help' and '?' commands. + */ +static int kdb_help(int argc, const char **argv) +{ + kdbtab_t *kt; + int i; + + kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description"); + kdb_printf("-----------------------------" + "-----------------------------\n"); + for_each_kdbcmd(kt, i) { + if (kt->cmd_name) + kdb_printf("%-15.15s %-20.20s %s\n", kt->cmd_name, + kt->cmd_usage, kt->cmd_help); + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + } + return 0; +} + +/* + * kdb_kill - This function implements the 'kill' commands. + */ +static int kdb_kill(int argc, const char **argv) +{ + long sig, pid; + char *endp; + struct task_struct *p; + struct siginfo info; + + if (argc != 2) + return KDB_ARGCOUNT; + + sig = simple_strtol(argv[1], &endp, 0); + if (*endp) + return KDB_BADINT; + if (sig >= 0) { + kdb_printf("Invalid signal parameter.<-signal>\n"); + return 0; + } + sig = -sig; + + pid = simple_strtol(argv[2], &endp, 0); + if (*endp) + return KDB_BADINT; + if (pid <= 0) { + kdb_printf("Process ID must be large than 0.\n"); + return 0; + } + + /* Find the process. */ + p = find_task_by_pid_ns(pid, &init_pid_ns); + if (!p) { + kdb_printf("The specified process isn't found.\n"); + return 0; + } + p = p->group_leader; + info.si_signo = sig; + info.si_errno = 0; + info.si_code = SI_USER; + info.si_pid = pid; /* same capabilities as process being signalled */ + info.si_uid = 0; /* kdb has root authority */ + kdb_send_sig_info(p, &info); + return 0; +} + +struct kdb_tm { + int tm_sec; /* seconds */ + int tm_min; /* minutes */ + int tm_hour; /* hours */ + int tm_mday; /* day of the month */ + int tm_mon; /* month */ + int tm_year; /* year */ +}; + +static void kdb_gmtime(struct timespec *tv, struct kdb_tm *tm) +{ + /* This will work from 1970-2099, 2100 is not a leap year */ + static int mon_day[] = { 31, 29, 31, 30, 31, 30, 31, + 31, 30, 31, 30, 31 }; + memset(tm, 0, sizeof(*tm)); + tm->tm_sec = tv->tv_sec % (24 * 60 * 60); + tm->tm_mday = tv->tv_sec / (24 * 60 * 60) + + (2 * 365 + 1); /* shift base from 1970 to 1968 */ + tm->tm_min = tm->tm_sec / 60 % 60; + tm->tm_hour = tm->tm_sec / 60 / 60; + tm->tm_sec = tm->tm_sec % 60; + tm->tm_year = 68 + 4*(tm->tm_mday / (4*365+1)); + tm->tm_mday %= (4*365+1); + mon_day[1] = 29; + while (tm->tm_mday >= mon_day[tm->tm_mon]) { + tm->tm_mday -= mon_day[tm->tm_mon]; + if (++tm->tm_mon == 12) { + tm->tm_mon = 0; + ++tm->tm_year; + mon_day[1] = 28; + } + } + ++tm->tm_mday; +} + +/* + * Most of this code has been lifted from kernel/timer.c::sys_sysinfo(). + * I cannot call that code directly from kdb, it has an unconditional + * cli()/sti() and calls routines that take locks which can stop the debugger. + */ +static void kdb_sysinfo(struct sysinfo *val) +{ + struct timespec uptime; + do_posix_clock_monotonic_gettime(&uptime); + memset(val, 0, sizeof(*val)); + val->uptime = uptime.tv_sec; + val->loads[0] = avenrun[0]; + val->loads[1] = avenrun[1]; + val->loads[2] = avenrun[2]; + val->procs = nr_threads-1; + si_meminfo(val); + + return; +} + +/* + * kdb_summary - This function implements the 'summary' command. + */ +static int kdb_summary(int argc, const char **argv) +{ + struct kdb_tm tm; + struct sysinfo val; + + if (argc) + return KDB_ARGCOUNT; + + kdb_printf("sysname %s\n", init_uts_ns.name.sysname); + kdb_printf("release %s\n", init_uts_ns.name.release); + kdb_printf("version %s\n", init_uts_ns.name.version); + kdb_printf("machine %s\n", init_uts_ns.name.machine); + kdb_printf("nodename %s\n", init_uts_ns.name.nodename); + kdb_printf("domainname %s\n", init_uts_ns.name.domainname); + kdb_printf("ccversion %s\n", __stringify(CCVERSION)); + + kdb_gmtime(&xtime, &tm); + kdb_printf("date %04d-%02d-%02d %02d:%02d:%02d " + "tz_minuteswest %d\n", + 1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday, + tm.tm_hour, tm.tm_min, tm.tm_sec, + sys_tz.tz_minuteswest); + + kdb_sysinfo(&val); + kdb_printf("uptime "); + if (val.uptime > (24*60*60)) { + int days = val.uptime / (24*60*60); + val.uptime %= (24*60*60); + kdb_printf("%d day%s ", days, days == 1 ? "" : "s"); + } + kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60); + + /* lifted from fs/proc/proc_misc.c::loadavg_read_proc() */ + +#define LOAD_INT(x) ((x) >> FSHIFT) +#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100) + kdb_printf("load avg %ld.%02ld %ld.%02ld %ld.%02ld\n", + LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]), + LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]), + LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2])); +#undef LOAD_INT +#undef LOAD_FRAC + /* Display in kilobytes */ +#define K(x) ((x) << (PAGE_SHIFT - 10)) + kdb_printf("\nMemTotal: %8lu kB\nMemFree: %8lu kB\n" + "Buffers: %8lu kB\n", + val.totalram, val.freeram, val.bufferram); + return 0; +} + +/* + * kdb_per_cpu - This function implements the 'per_cpu' command. + */ +static int kdb_per_cpu(int argc, const char **argv) +{ + char buf[256], fmtstr[64]; + kdb_symtab_t symtab; + cpumask_t suppress = CPU_MASK_NONE; + int cpu, diag; + unsigned long addr, val, bytesperword = 0, whichcpu = ~0UL; + + if (argc < 1 || argc > 3) + return KDB_ARGCOUNT; + + snprintf(buf, sizeof(buf), "per_cpu__%s", argv[1]); + if (!kdbgetsymval(buf, &symtab)) { + kdb_printf("%s is not a per_cpu variable\n", argv[1]); + return KDB_BADADDR; + } + if (argc >= 2) { + diag = kdbgetularg(argv[2], &bytesperword); + if (diag) + return diag; + } + if (!bytesperword) + bytesperword = KDB_WORD_SIZE; + else if (bytesperword > KDB_WORD_SIZE) + return KDB_BADWIDTH; + sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword)); + if (argc >= 3) { + diag = kdbgetularg(argv[3], &whichcpu); + if (diag) + return diag; + if (!cpu_online(whichcpu)) { + kdb_printf("cpu %ld is not online\n", whichcpu); + return KDB_BADCPUNUM; + } + } + + /* Most architectures use __per_cpu_offset[cpu], some use + * __per_cpu_offset(cpu), smp has no __per_cpu_offset. + */ +#ifdef __per_cpu_offset +#define KDB_PCU(cpu) __per_cpu_offset(cpu) +#else +#ifdef CONFIG_SMP +#define KDB_PCU(cpu) __per_cpu_offset[cpu] +#else +#define KDB_PCU(cpu) 0 +#endif +#endif + + for_each_online_cpu(cpu) { + if (whichcpu != ~0UL && whichcpu != cpu) + continue; + addr = symtab.sym_start + KDB_PCU(cpu); + diag = kdb_getword(&val, addr, bytesperword); + if (diag) { + kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to " + "read, diag=%d\n", cpu, addr, diag); + continue; + } +#ifdef CONFIG_SMP + if (!val) { + cpu_set(cpu, suppress); + continue; + } +#endif /* CONFIG_SMP */ + kdb_printf("%5d ", cpu); + kdb_md_line(fmtstr, addr, + bytesperword == KDB_WORD_SIZE, + 1, bytesperword, 1, 1, 0); + } + if (cpus_weight(suppress) == 0) + return 0; + kdb_printf("Zero suppressed cpu(s):"); + for (cpu = first_cpu(suppress); cpu < num_possible_cpus(); + cpu = next_cpu(cpu, suppress)) { + kdb_printf(" %d", cpu); + if (cpu == num_possible_cpus() - 1 || + next_cpu(cpu, suppress) != cpu + 1) + continue; + while (cpu < num_possible_cpus() && + next_cpu(cpu, suppress) == cpu + 1) + ++cpu; + kdb_printf("-%d", cpu); + } + kdb_printf("\n"); + +#undef KDB_PCU + + return 0; +} + +/* + * display help for the use of cmd | grep pattern + */ +static int kdb_grep_help(int argc, const char **argv) +{ + kdb_printf("Usage of cmd args | grep pattern:\n"); + kdb_printf(" Any command's output may be filtered through an "); + kdb_printf("emulated 'pipe'.\n"); + kdb_printf(" 'grep' is just a key word.\n"); + kdb_printf(" The pattern may include a very limited set of " + "metacharacters:\n"); + kdb_printf(" pattern or ^pattern or pattern$ or ^pattern$\n"); + kdb_printf(" And if there are spaces in the pattern, you may " + "quote it:\n"); + kdb_printf(" \"pat tern\" or \"^pat tern\" or \"pat tern$\"" + " or \"^pat tern$\"\n"); + return 0; +} + +/* + * kdb_register_repeat - This function is used to register a kernel + * debugger command. + * Inputs: + * cmd Command name + * func Function to execute the command + * usage A simple usage string showing arguments + * help A simple help string describing command + * repeat Does the command auto repeat on enter? + * Returns: + * zero for success, one if a duplicate command. + */ +#define kdb_command_extend 50 /* arbitrary */ +int kdb_register_repeat(char *cmd, + kdb_func_t func, + char *usage, + char *help, + short minlen, + kdb_repeat_t repeat) +{ + int i; + kdbtab_t *kp; + + /* + * Brute force method to determine duplicates + */ + for_each_kdbcmd(kp, i) { + if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) { + kdb_printf("Duplicate kdb command registered: " + "%s, func %p help %s\n", cmd, func, help); + return 1; + } + } + + /* + * Insert command into first available location in table + */ + for_each_kdbcmd(kp, i) { + if (kp->cmd_name == NULL) + break; + } + + if (i >= kdb_max_commands) { + kdbtab_t *new = kmalloc((kdb_max_commands - KDB_BASE_CMD_MAX + + kdb_command_extend) * sizeof(*new), GFP_KDB); + if (!new) { + kdb_printf("Could not allocate new kdb_command " + "table\n"); + return 1; + } + if (kdb_commands) { + memcpy(new, kdb_commands, + kdb_max_commands * sizeof(*new)); + kfree(kdb_commands); + } + memset(new + kdb_max_commands, 0, + kdb_command_extend * sizeof(*new)); + kdb_commands = new; + kp = kdb_commands + kdb_max_commands; + kdb_max_commands += kdb_command_extend; + } + + kp->cmd_name = cmd; + kp->cmd_func = func; + kp->cmd_usage = usage; + kp->cmd_help = help; + kp->cmd_flags = 0; + kp->cmd_minlen = minlen; + kp->cmd_repeat = repeat; + + return 0; +} + +/* + * kdb_register - Compatibility register function for commands that do + * not need to specify a repeat state. Equivalent to + * kdb_register_repeat with KDB_REPEAT_NONE. + * Inputs: + * cmd Command name + * func Function to execute the command + * usage A simple usage string showing arguments + * help A simple help string describing command + * Returns: + * zero for success, one if a duplicate command. + */ +int kdb_register(char *cmd, + kdb_func_t func, + char *usage, + char *help, + short minlen) +{ + return kdb_register_repeat(cmd, func, usage, help, minlen, + KDB_REPEAT_NONE); +} + +/* + * kdb_unregister - This function is used to unregister a kernel + * debugger command. It is generally called when a module which + * implements kdb commands is unloaded. + * Inputs: + * cmd Command name + * Returns: + * zero for success, one command not registered. + */ +int kdb_unregister(char *cmd) +{ + int i; + kdbtab_t *kp; + + /* + * find the command. + */ + for (i = 0, kp = kdb_commands; i < kdb_max_commands; i++, kp++) { + if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) { + kp->cmd_name = NULL; + return 0; + } + } + + /* Couldn't find it. */ + return 1; +} + +/* Initialize the kdb command table. */ +static void __init kdb_inittab(void) +{ + int i; + kdbtab_t *kp; + + for_each_kdbcmd(kp, i) + kp->cmd_name = NULL; + + kdb_register_repeat("md", kdb_md, "", + "Display Memory Contents, also mdWcN, e.g. md8c1", 1, + KDB_REPEAT_NO_ARGS); + kdb_register_repeat("mdr", kdb_md, " ", + "Display Raw Memory", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("mdp", kdb_md, " ", + "Display Physical Memory", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("mds", kdb_md, "", + "Display Memory Symbolically", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("mm", kdb_mm, " ", + "Modify Memory Contents", 0, KDB_REPEAT_NO_ARGS); + kdb_register_repeat("go", kdb_go, "[]", + "Continue Execution", 1, KDB_REPEAT_NONE); + kdb_register_repeat("rd", kdb_rd, "", + "Display Registers", 0, KDB_REPEAT_NONE); + kdb_register_repeat("rm", kdb_rm, " ", + "Modify Registers", 0, KDB_REPEAT_NONE); + kdb_register_repeat("ef", kdb_ef, "", + "Display exception frame", 0, KDB_REPEAT_NONE); + kdb_register_repeat("bt", kdb_bt, "[]", + "Stack traceback", 1, KDB_REPEAT_NONE); + kdb_register_repeat("btp", kdb_bt, "", + "Display stack for process ", 0, KDB_REPEAT_NONE); + kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]", + "Display stack all processes", 0, KDB_REPEAT_NONE); + kdb_register_repeat("btc", kdb_bt, "", + "Backtrace current process on each cpu", 0, KDB_REPEAT_NONE); + kdb_register_repeat("btt", kdb_bt, "", + "Backtrace process given its struct task address", 0, + KDB_REPEAT_NONE); + kdb_register_repeat("ll", kdb_ll, " ", + "Execute cmd for each element in linked list", 0, KDB_REPEAT_NONE); + kdb_register_repeat("env", kdb_env, "", + "Show environment variables", 0, KDB_REPEAT_NONE); + kdb_register_repeat("set", kdb_set, "", + "Set environment variables", 0, KDB_REPEAT_NONE); + kdb_register_repeat("help", kdb_help, "", + "Display Help Message", 1, KDB_REPEAT_NONE); + kdb_register_repeat("?", kdb_help, "", + "Display Help Message", 0, KDB_REPEAT_NONE); + kdb_register_repeat("cpu", kdb_cpu, "", + "Switch to new cpu", 0, KDB_REPEAT_NONE); + kdb_register_repeat("kgdb", kdb_kgdb, "", + "Enter kgdb mode", 0, KDB_REPEAT_NONE); + kdb_register_repeat("ps", kdb_ps, "[|A]", + "Display active task list", 0, KDB_REPEAT_NONE); + kdb_register_repeat("pid", kdb_pid, "", + "Switch to another task", 0, KDB_REPEAT_NONE); + kdb_register_repeat("reboot", kdb_reboot, "", + "Reboot the machine immediately", 0, KDB_REPEAT_NONE); +#if defined(CONFIG_MODULES) + kdb_register_repeat("lsmod", kdb_lsmod, "", + "List loaded kernel modules", 0, KDB_REPEAT_NONE); +#endif +#if defined(CONFIG_MAGIC_SYSRQ) + kdb_register_repeat("sr", kdb_sr, "", + "Magic SysRq key", 0, KDB_REPEAT_NONE); +#endif +#if defined(CONFIG_PRINTK) + kdb_register_repeat("dmesg", kdb_dmesg, "[lines]", + "Display syslog buffer", 0, KDB_REPEAT_NONE); +#endif + kdb_register_repeat("defcmd", kdb_defcmd, "name \"usage\" \"help\"", + "Define a set of commands, down to endefcmd", 0, KDB_REPEAT_NONE); + kdb_register_repeat("kill", kdb_kill, "<-signal> ", + "Send a signal to a process", 0, KDB_REPEAT_NONE); + kdb_register_repeat("summary", kdb_summary, "", + "Summarize the system", 4, KDB_REPEAT_NONE); + kdb_register_repeat("per_cpu", kdb_per_cpu, "", + "Display per_cpu variables", 3, KDB_REPEAT_NONE); + kdb_register_repeat("grephelp", kdb_grep_help, "", + "Display help on | grep", 0, KDB_REPEAT_NONE); +} + +/* Execute any commands defined in kdb_cmds. */ +static void __init kdb_cmd_init(void) +{ + int i, diag; + for (i = 0; kdb_cmds[i]; ++i) { + diag = kdb_parse(kdb_cmds[i]); + if (diag) + kdb_printf("kdb command %s failed, kdb diag %d\n", + kdb_cmds[i], diag); + } + if (defcmd_in_progress) { + kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n"); + kdb_parse("endefcmd"); + } +} + +/* Intialize kdb_printf, breakpoint tables and kdb state */ +void __init kdb_init(int lvl) +{ + static int kdb_init_lvl = KDB_NOT_INITIALIZED; + int i; + + if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl) + return; + for (i = kdb_init_lvl; i < lvl; i++) { + switch (i) { + case KDB_NOT_INITIALIZED: + kdb_inittab(); /* Initialize Command Table */ + kdb_initbptab(); /* Initialize Breakpoints */ + break; + case KDB_INIT_EARLY: + kdb_cmd_init(); /* Build kdb_cmds tables */ + break; + } + } + kdb_init_lvl = lvl; +} diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h new file mode 100644 index 00000000000..69ed2eff3fe --- /dev/null +++ b/kernel/debug/kdb/kdb_private.h @@ -0,0 +1,301 @@ +#ifndef _KDBPRIVATE_H +#define _KDBPRIVATE_H + +/* + * Kernel Debugger Architecture Independent Private Headers + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include "../debug_core.h" + +/* Kernel Debugger Error codes. Must not overlap with command codes. */ +#define KDB_NOTFOUND (-1) +#define KDB_ARGCOUNT (-2) +#define KDB_BADWIDTH (-3) +#define KDB_BADRADIX (-4) +#define KDB_NOTENV (-5) +#define KDB_NOENVVALUE (-6) +#define KDB_NOTIMP (-7) +#define KDB_ENVFULL (-8) +#define KDB_ENVBUFFULL (-9) +#define KDB_TOOMANYBPT (-10) +#define KDB_TOOMANYDBREGS (-11) +#define KDB_DUPBPT (-12) +#define KDB_BPTNOTFOUND (-13) +#define KDB_BADMODE (-14) +#define KDB_BADINT (-15) +#define KDB_INVADDRFMT (-16) +#define KDB_BADREG (-17) +#define KDB_BADCPUNUM (-18) +#define KDB_BADLENGTH (-19) +#define KDB_NOBP (-20) +#define KDB_BADADDR (-21) + +/* Kernel Debugger Command codes. Must not overlap with error codes. */ +#define KDB_CMD_GO (-1001) +#define KDB_CMD_CPU (-1002) +#define KDB_CMD_SS (-1003) +#define KDB_CMD_SSB (-1004) +#define KDB_CMD_KGDB (-1005) +#define KDB_CMD_KGDB2 (-1006) + +/* Internal debug flags */ +#define KDB_DEBUG_FLAG_BP 0x0002 /* Breakpoint subsystem debug */ +#define KDB_DEBUG_FLAG_BB_SUMM 0x0004 /* Basic block analysis, summary only */ +#define KDB_DEBUG_FLAG_AR 0x0008 /* Activation record, generic */ +#define KDB_DEBUG_FLAG_ARA 0x0010 /* Activation record, arch specific */ +#define KDB_DEBUG_FLAG_BB 0x0020 /* All basic block analysis */ +#define KDB_DEBUG_FLAG_STATE 0x0040 /* State flags */ +#define KDB_DEBUG_FLAG_MASK 0xffff /* All debug flags */ +#define KDB_DEBUG_FLAG_SHIFT 16 /* Shift factor for dbflags */ + +#define KDB_DEBUG(flag) (kdb_flags & \ + (KDB_DEBUG_FLAG_##flag << KDB_DEBUG_FLAG_SHIFT)) +#define KDB_DEBUG_STATE(text, value) if (KDB_DEBUG(STATE)) \ + kdb_print_state(text, value) + +#if BITS_PER_LONG == 32 + +#define KDB_PLATFORM_ENV "BYTESPERWORD=4" + +#define kdb_machreg_fmt "0x%lx" +#define kdb_machreg_fmt0 "0x%08lx" +#define kdb_bfd_vma_fmt "0x%lx" +#define kdb_bfd_vma_fmt0 "0x%08lx" +#define kdb_elfw_addr_fmt "0x%x" +#define kdb_elfw_addr_fmt0 "0x%08x" +#define kdb_f_count_fmt "%d" + +#elif BITS_PER_LONG == 64 + +#define KDB_PLATFORM_ENV "BYTESPERWORD=8" + +#define kdb_machreg_fmt "0x%lx" +#define kdb_machreg_fmt0 "0x%016lx" +#define kdb_bfd_vma_fmt "0x%lx" +#define kdb_bfd_vma_fmt0 "0x%016lx" +#define kdb_elfw_addr_fmt "0x%x" +#define kdb_elfw_addr_fmt0 "0x%016x" +#define kdb_f_count_fmt "%ld" + +#endif + +/* + * KDB_MAXBPT describes the total number of breakpoints + * supported by this architecure. + */ +#define KDB_MAXBPT 16 + +/* Maximum number of arguments to a function */ +#define KDB_MAXARGS 16 + +typedef enum { + KDB_REPEAT_NONE = 0, /* Do not repeat this command */ + KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */ + KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */ +} kdb_repeat_t; + +typedef int (*kdb_func_t)(int, const char **); + +/* Symbol table format returned by kallsyms. */ +typedef struct __ksymtab { + unsigned long value; /* Address of symbol */ + const char *mod_name; /* Module containing symbol or + * "kernel" */ + unsigned long mod_start; + unsigned long mod_end; + const char *sec_name; /* Section containing symbol */ + unsigned long sec_start; + unsigned long sec_end; + const char *sym_name; /* Full symbol name, including + * any version */ + unsigned long sym_start; + unsigned long sym_end; + } kdb_symtab_t; +extern int kallsyms_symbol_next(char *prefix_name, int flag); +extern int kallsyms_symbol_complete(char *prefix_name, int max_len); + +/* Exported Symbols for kernel loadable modules to use. */ +extern int kdb_register(char *, kdb_func_t, char *, char *, short); +extern int kdb_register_repeat(char *, kdb_func_t, char *, char *, + short, kdb_repeat_t); +extern int kdb_unregister(char *); + +extern int kdb_getarea_size(void *, unsigned long, size_t); +extern int kdb_putarea_size(unsigned long, void *, size_t); + +/* + * Like get_user and put_user, kdb_getarea and kdb_putarea take variable + * names, not pointers. The underlying *_size functions take pointers. + */ +#define kdb_getarea(x, addr) kdb_getarea_size(&(x), addr, sizeof((x))) +#define kdb_putarea(addr, x) kdb_putarea_size(addr, &(x), sizeof((x))) + +extern int kdb_getphysword(unsigned long *word, + unsigned long addr, size_t size); +extern int kdb_getword(unsigned long *, unsigned long, size_t); +extern int kdb_putword(unsigned long, unsigned long, size_t); + +extern int kdbgetularg(const char *, unsigned long *); +extern int kdb_set(int, const char **); +extern char *kdbgetenv(const char *); +extern int kdbgetintenv(const char *, int *); +extern int kdbgetaddrarg(int, const char **, int*, unsigned long *, + long *, char **); +extern int kdbgetsymval(const char *, kdb_symtab_t *); +extern int kdbnearsym(unsigned long, kdb_symtab_t *); +extern void kdbnearsym_cleanup(void); +extern char *kdb_strdup(const char *str, gfp_t type); +extern void kdb_symbol_print(unsigned long, const kdb_symtab_t *, unsigned int); + +/* Routine for debugging the debugger state. */ +extern void kdb_print_state(const char *, int); + +extern int kdb_state; +#define KDB_STATE_KDB 0x00000001 /* Cpu is inside kdb */ +#define KDB_STATE_LEAVING 0x00000002 /* Cpu is leaving kdb */ +#define KDB_STATE_CMD 0x00000004 /* Running a kdb command */ +#define KDB_STATE_KDB_CONTROL 0x00000008 /* This cpu is under + * kdb control */ +#define KDB_STATE_HOLD_CPU 0x00000010 /* Hold this cpu inside kdb */ +#define KDB_STATE_DOING_SS 0x00000020 /* Doing ss command */ +#define KDB_STATE_DOING_SSB 0x00000040 /* Doing ssb command, + * DOING_SS is also set */ +#define KDB_STATE_SSBPT 0x00000080 /* Install breakpoint + * after one ss, independent of + * DOING_SS */ +#define KDB_STATE_REENTRY 0x00000100 /* Valid re-entry into kdb */ +#define KDB_STATE_SUPPRESS 0x00000200 /* Suppress error messages */ +#define KDB_STATE_PAGER 0x00000400 /* pager is available */ +#define KDB_STATE_GO_SWITCH 0x00000800 /* go is switching + * back to initial cpu */ +#define KDB_STATE_PRINTF_LOCK 0x00001000 /* Holds kdb_printf lock */ +#define KDB_STATE_WAIT_IPI 0x00002000 /* Waiting for kdb_ipi() NMI */ +#define KDB_STATE_RECURSE 0x00004000 /* Recursive entry to kdb */ +#define KDB_STATE_IP_ADJUSTED 0x00008000 /* Restart IP has been + * adjusted */ +#define KDB_STATE_GO1 0x00010000 /* go only releases one cpu */ +#define KDB_STATE_KEYBOARD 0x00020000 /* kdb entered via + * keyboard on this cpu */ +#define KDB_STATE_KEXEC 0x00040000 /* kexec issued */ +#define KDB_STATE_DOING_KGDB 0x00080000 /* kgdb enter now issued */ +#define KDB_STATE_DOING_KGDB2 0x00100000 /* kgdb enter now issued */ +#define KDB_STATE_KGDB_TRANS 0x00200000 /* Transition to kgdb */ +#define KDB_STATE_ARCH 0xff000000 /* Reserved for arch + * specific use */ + +#define KDB_STATE(flag) (kdb_state & KDB_STATE_##flag) +#define KDB_STATE_SET(flag) ((void)(kdb_state |= KDB_STATE_##flag)) +#define KDB_STATE_CLEAR(flag) ((void)(kdb_state &= ~KDB_STATE_##flag)) + +extern int kdb_nextline; /* Current number of lines displayed */ + +typedef struct _kdb_bp { + unsigned long bp_addr; /* Address breakpoint is present at */ + unsigned int bp_free:1; /* This entry is available */ + unsigned int bp_enabled:1; /* Breakpoint is active in register */ + unsigned int bp_type:4; /* Uses hardware register */ + unsigned int bp_installed:1; /* Breakpoint is installed */ + unsigned int bp_delay:1; /* Do delayed bp handling */ + unsigned int bp_delayed:1; /* Delayed breakpoint */ + unsigned int bph_length; /* HW break length */ +} kdb_bp_t; + +#ifdef CONFIG_KGDB_KDB +extern kdb_bp_t kdb_breakpoints[/* KDB_MAXBPT */]; + +/* The KDB shell command table */ +typedef struct _kdbtab { + char *cmd_name; /* Command name */ + kdb_func_t cmd_func; /* Function to execute command */ + char *cmd_usage; /* Usage String for this command */ + char *cmd_help; /* Help message for this command */ + short cmd_flags; /* Parsing flags */ + short cmd_minlen; /* Minimum legal # command + * chars required */ + kdb_repeat_t cmd_repeat; /* Does command auto repeat on enter? */ +} kdbtab_t; + +extern int kdb_bt(int, const char **); /* KDB display back trace */ + +/* KDB breakpoint management functions */ +extern void kdb_initbptab(void); +extern void kdb_bp_install(struct pt_regs *); +extern void kdb_bp_remove(void); + +typedef enum { + KDB_DB_BPT, /* Breakpoint */ + KDB_DB_SS, /* Single-step trap */ + KDB_DB_SSB, /* Single step to branch */ + KDB_DB_SSBPT, /* Single step over breakpoint */ + KDB_DB_NOBPT /* Spurious breakpoint */ +} kdb_dbtrap_t; + +extern int kdb_main_loop(kdb_reason_t, kdb_reason_t, + int, kdb_dbtrap_t, struct pt_regs *); + +/* Miscellaneous functions and data areas */ +extern int kdb_grepping_flag; +extern char kdb_grep_string[]; +extern int kdb_grep_leading; +extern int kdb_grep_trailing; +extern char *kdb_cmds[]; +extern void kdb_syslog_data(char *syslog_data[]); +extern unsigned long kdb_task_state_string(const char *); +extern char kdb_task_state_char (const struct task_struct *); +extern unsigned long kdb_task_state(const struct task_struct *p, + unsigned long mask); +extern void kdb_ps_suppressed(void); +extern void kdb_ps1(const struct task_struct *p); +extern int kdb_parse(const char *cmdstr); +extern void kdb_print_nameval(const char *name, unsigned long val); +extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info); +extern void kdb_meminfo_proc_show(void); +extern const char *kdb_walk_kallsyms(loff_t *pos); +extern char *kdb_getstr(char *, size_t, char *); + +/* Defines for kdb_symbol_print */ +#define KDB_SP_SPACEB 0x0001 /* Space before string */ +#define KDB_SP_SPACEA 0x0002 /* Space after string */ +#define KDB_SP_PAREN 0x0004 /* Parenthesis around string */ +#define KDB_SP_VALUE 0x0008 /* Print the value of the address */ +#define KDB_SP_SYMSIZE 0x0010 /* Print the size of the symbol */ +#define KDB_SP_NEWLINE 0x0020 /* Newline after string */ +#define KDB_SP_DEFAULT (KDB_SP_VALUE|KDB_SP_PAREN) + +#define KDB_TSK(cpu) kgdb_info[cpu].task +#define KDB_TSKREGS(cpu) kgdb_info[cpu].debuggerinfo + +extern struct task_struct *kdb_curr_task(int); + +#define kdb_task_has_cpu(p) (task_curr(p)) + +/* Simplify coexistence with NPTL */ +#define kdb_do_each_thread(g, p) do_each_thread(g, p) +#define kdb_while_each_thread(g, p) while_each_thread(g, p) + +#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL) + +extern void *debug_kmalloc(size_t size, gfp_t flags); +extern void debug_kfree(void *); +extern void debug_kusage(void); + +extern void kdb_set_current_task(struct task_struct *); +extern struct task_struct *kdb_current_task; +#ifdef CONFIG_MODULES +extern struct list_head *kdb_modules; +#endif /* CONFIG_MODULES */ + +extern char kdb_prompt_str[]; + +#define KDB_WORD_SIZE ((int)sizeof(unsigned long)) + +#endif /* CONFIG_KGDB_KDB */ +#endif /* !_KDBPRIVATE_H */ diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c new file mode 100644 index 00000000000..45344d5c53d --- /dev/null +++ b/kernel/debug/kdb/kdb_support.c @@ -0,0 +1,927 @@ +/* + * Kernel Debugger Architecture Independent Support Functions + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + * 03/02/13 added new 2.5 kallsyms + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "kdb_private.h" + +/* + * kdbgetsymval - Return the address of the given symbol. + * + * Parameters: + * symname Character string containing symbol name + * symtab Structure to receive results + * Returns: + * 0 Symbol not found, symtab zero filled + * 1 Symbol mapped to module/symbol/section, data in symtab + */ +int kdbgetsymval(const char *symname, kdb_symtab_t *symtab) +{ + if (KDB_DEBUG(AR)) + kdb_printf("kdbgetsymval: symname=%s, symtab=%p\n", symname, + symtab); + memset(symtab, 0, sizeof(*symtab)); + symtab->sym_start = kallsyms_lookup_name(symname); + if (symtab->sym_start) { + if (KDB_DEBUG(AR)) + kdb_printf("kdbgetsymval: returns 1, " + "symtab->sym_start=0x%lx\n", + symtab->sym_start); + return 1; + } + if (KDB_DEBUG(AR)) + kdb_printf("kdbgetsymval: returns 0\n"); + return 0; +} +EXPORT_SYMBOL(kdbgetsymval); + +static char *kdb_name_table[100]; /* arbitrary size */ + +/* + * kdbnearsym - Return the name of the symbol with the nearest address + * less than 'addr'. + * + * Parameters: + * addr Address to check for symbol near + * symtab Structure to receive results + * Returns: + * 0 No sections contain this address, symtab zero filled + * 1 Address mapped to module/symbol/section, data in symtab + * Remarks: + * 2.6 kallsyms has a "feature" where it unpacks the name into a + * string. If that string is reused before the caller expects it + * then the caller sees its string change without warning. To + * avoid cluttering up the main kdb code with lots of kdb_strdup, + * tests and kfree calls, kdbnearsym maintains an LRU list of the + * last few unique strings. The list is sized large enough to + * hold active strings, no kdb caller of kdbnearsym makes more + * than ~20 later calls before using a saved value. + */ +int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) +{ + int ret = 0; + unsigned long symbolsize; + unsigned long offset; +#define knt1_size 128 /* must be >= kallsyms table size */ + char *knt1 = NULL; + + if (KDB_DEBUG(AR)) + kdb_printf("kdbnearsym: addr=0x%lx, symtab=%p\n", addr, symtab); + memset(symtab, 0, sizeof(*symtab)); + + if (addr < 4096) + goto out; + knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC); + if (!knt1) { + kdb_printf("kdbnearsym: addr=0x%lx cannot kmalloc knt1\n", + addr); + goto out; + } + symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, + (char **)(&symtab->mod_name), knt1); + if (offset > 8*1024*1024) { + symtab->sym_name = NULL; + addr = offset = symbolsize = 0; + } + symtab->sym_start = addr - offset; + symtab->sym_end = symtab->sym_start + symbolsize; + ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; + + if (ret) { + int i; + /* Another 2.6 kallsyms "feature". Sometimes the sym_name is + * set but the buffer passed into kallsyms_lookup is not used, + * so it contains garbage. The caller has to work out which + * buffer needs to be saved. + * + * What was Rusty smoking when he wrote that code? + */ + if (symtab->sym_name != knt1) { + strncpy(knt1, symtab->sym_name, knt1_size); + knt1[knt1_size-1] = '\0'; + } + for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { + if (kdb_name_table[i] && + strcmp(kdb_name_table[i], knt1) == 0) + break; + } + if (i >= ARRAY_SIZE(kdb_name_table)) { + debug_kfree(kdb_name_table[0]); + memcpy(kdb_name_table, kdb_name_table+1, + sizeof(kdb_name_table[0]) * + (ARRAY_SIZE(kdb_name_table)-1)); + } else { + debug_kfree(knt1); + knt1 = kdb_name_table[i]; + memcpy(kdb_name_table+i, kdb_name_table+i+1, + sizeof(kdb_name_table[0]) * + (ARRAY_SIZE(kdb_name_table)-i-1)); + } + i = ARRAY_SIZE(kdb_name_table) - 1; + kdb_name_table[i] = knt1; + symtab->sym_name = kdb_name_table[i]; + knt1 = NULL; + } + + if (symtab->mod_name == NULL) + symtab->mod_name = "kernel"; + if (KDB_DEBUG(AR)) + kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, " + "symtab->mod_name=%p, symtab->sym_name=%p (%s)\n", ret, + symtab->sym_start, symtab->mod_name, symtab->sym_name, + symtab->sym_name); + +out: + debug_kfree(knt1); + return ret; +} + +void kdbnearsym_cleanup(void) +{ + int i; + for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { + if (kdb_name_table[i]) { + debug_kfree(kdb_name_table[i]); + kdb_name_table[i] = NULL; + } + } +} + +static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; + +/* + * kallsyms_symbol_complete + * + * Parameters: + * prefix_name prefix of a symbol name to lookup + * max_len maximum length that can be returned + * Returns: + * Number of symbols which match the given prefix. + * Notes: + * prefix_name is changed to contain the longest unique prefix that + * starts with this prefix (tab completion). + */ +int kallsyms_symbol_complete(char *prefix_name, int max_len) +{ + loff_t pos = 0; + int prefix_len = strlen(prefix_name), prev_len = 0; + int i, number = 0; + const char *name; + + while ((name = kdb_walk_kallsyms(&pos))) { + if (strncmp(name, prefix_name, prefix_len) == 0) { + strcpy(ks_namebuf, name); + /* Work out the longest name that matches the prefix */ + if (++number == 1) { + prev_len = min_t(int, max_len-1, + strlen(ks_namebuf)); + memcpy(ks_namebuf_prev, ks_namebuf, prev_len); + ks_namebuf_prev[prev_len] = '\0'; + continue; + } + for (i = 0; i < prev_len; i++) { + if (ks_namebuf[i] != ks_namebuf_prev[i]) { + prev_len = i; + ks_namebuf_prev[i] = '\0'; + break; + } + } + } + } + if (prev_len > prefix_len) + memcpy(prefix_name, ks_namebuf_prev, prev_len+1); + return number; +} + +/* + * kallsyms_symbol_next + * + * Parameters: + * prefix_name prefix of a symbol name to lookup + * flag 0 means search from the head, 1 means continue search. + * Returns: + * 1 if a symbol matches the given prefix. + * 0 if no string found + */ +int kallsyms_symbol_next(char *prefix_name, int flag) +{ + int prefix_len = strlen(prefix_name); + static loff_t pos; + const char *name; + + if (!flag) + pos = 0; + + while ((name = kdb_walk_kallsyms(&pos))) { + if (strncmp(name, prefix_name, prefix_len) == 0) { + strncpy(prefix_name, name, strlen(name)+1); + return 1; + } + } + return 0; +} + +/* + * kdb_symbol_print - Standard method for printing a symbol name and offset. + * Inputs: + * addr Address to be printed. + * symtab Address of symbol data, if NULL this routine does its + * own lookup. + * punc Punctuation for string, bit field. + * Remarks: + * The string and its punctuation is only printed if the address + * is inside the kernel, except that the value is always printed + * when requested. + */ +void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p, + unsigned int punc) +{ + kdb_symtab_t symtab, *symtab_p2; + if (symtab_p) { + symtab_p2 = (kdb_symtab_t *)symtab_p; + } else { + symtab_p2 = &symtab; + kdbnearsym(addr, symtab_p2); + } + if (!(symtab_p2->sym_name || (punc & KDB_SP_VALUE))) + return; + if (punc & KDB_SP_SPACEB) + kdb_printf(" "); + if (punc & KDB_SP_VALUE) + kdb_printf(kdb_machreg_fmt0, addr); + if (symtab_p2->sym_name) { + if (punc & KDB_SP_VALUE) + kdb_printf(" "); + if (punc & KDB_SP_PAREN) + kdb_printf("("); + if (strcmp(symtab_p2->mod_name, "kernel")) + kdb_printf("[%s]", symtab_p2->mod_name); + kdb_printf("%s", symtab_p2->sym_name); + if (addr != symtab_p2->sym_start) + kdb_printf("+0x%lx", addr - symtab_p2->sym_start); + if (punc & KDB_SP_SYMSIZE) + kdb_printf("/0x%lx", + symtab_p2->sym_end - symtab_p2->sym_start); + if (punc & KDB_SP_PAREN) + kdb_printf(")"); + } + if (punc & KDB_SP_SPACEA) + kdb_printf(" "); + if (punc & KDB_SP_NEWLINE) + kdb_printf("\n"); +} + +/* + * kdb_strdup - kdb equivalent of strdup, for disasm code. + * Inputs: + * str The string to duplicate. + * type Flags to kmalloc for the new string. + * Returns: + * Address of the new string, NULL if storage could not be allocated. + * Remarks: + * This is not in lib/string.c because it uses kmalloc which is not + * available when string.o is used in boot loaders. + */ +char *kdb_strdup(const char *str, gfp_t type) +{ + int n = strlen(str)+1; + char *s = kmalloc(n, type); + if (!s) + return NULL; + return strcpy(s, str); +} + +/* + * kdb_getarea_size - Read an area of data. The kdb equivalent of + * copy_from_user, with kdb messages for invalid addresses. + * Inputs: + * res Pointer to the area to receive the result. + * addr Address of the area to copy. + * size Size of the area. + * Returns: + * 0 for success, < 0 for error. + */ +int kdb_getarea_size(void *res, unsigned long addr, size_t size) +{ + int ret = probe_kernel_read((char *)res, (char *)addr, size); + if (ret) { + if (!KDB_STATE(SUPPRESS)) { + kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr); + KDB_STATE_SET(SUPPRESS); + } + ret = KDB_BADADDR; + } else { + KDB_STATE_CLEAR(SUPPRESS); + } + return ret; +} + +/* + * kdb_putarea_size - Write an area of data. The kdb equivalent of + * copy_to_user, with kdb messages for invalid addresses. + * Inputs: + * addr Address of the area to write to. + * res Pointer to the area holding the data. + * size Size of the area. + * Returns: + * 0 for success, < 0 for error. + */ +int kdb_putarea_size(unsigned long addr, void *res, size_t size) +{ + int ret = probe_kernel_read((char *)addr, (char *)res, size); + if (ret) { + if (!KDB_STATE(SUPPRESS)) { + kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr); + KDB_STATE_SET(SUPPRESS); + } + ret = KDB_BADADDR; + } else { + KDB_STATE_CLEAR(SUPPRESS); + } + return ret; +} + +/* + * kdb_getphys - Read data from a physical address. Validate the + * address is in range, use kmap_atomic() to get data + * similar to kdb_getarea() - but for phys addresses + * Inputs: + * res Pointer to the word to receive the result + * addr Physical address of the area to copy + * size Size of the area + * Returns: + * 0 for success, < 0 for error. + */ +static int kdb_getphys(void *res, unsigned long addr, size_t size) +{ + unsigned long pfn; + void *vaddr; + struct page *page; + + pfn = (addr >> PAGE_SHIFT); + if (!pfn_valid(pfn)) + return 1; + page = pfn_to_page(pfn); + vaddr = kmap_atomic(page, KM_KDB); + memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size); + kunmap_atomic(vaddr, KM_KDB); + + return 0; +} + +/* + * kdb_getphysword + * Inputs: + * word Pointer to the word to receive the result. + * addr Address of the area to copy. + * size Size of the area. + * Returns: + * 0 for success, < 0 for error. + */ +int kdb_getphysword(unsigned long *word, unsigned long addr, size_t size) +{ + int diag; + __u8 w1; + __u16 w2; + __u32 w4; + __u64 w8; + *word = 0; /* Default value if addr or size is invalid */ + + switch (size) { + case 1: + diag = kdb_getphys(&w1, addr, sizeof(w1)); + if (!diag) + *word = w1; + break; + case 2: + diag = kdb_getphys(&w2, addr, sizeof(w2)); + if (!diag) + *word = w2; + break; + case 4: + diag = kdb_getphys(&w4, addr, sizeof(w4)); + if (!diag) + *word = w4; + break; + case 8: + if (size <= sizeof(*word)) { + diag = kdb_getphys(&w8, addr, sizeof(w8)); + if (!diag) + *word = w8; + break; + } + /* drop through */ + default: + diag = KDB_BADWIDTH; + kdb_printf("kdb_getphysword: bad width %ld\n", (long) size); + } + return diag; +} + +/* + * kdb_getword - Read a binary value. Unlike kdb_getarea, this treats + * data as numbers. + * Inputs: + * word Pointer to the word to receive the result. + * addr Address of the area to copy. + * size Size of the area. + * Returns: + * 0 for success, < 0 for error. + */ +int kdb_getword(unsigned long *word, unsigned long addr, size_t size) +{ + int diag; + __u8 w1; + __u16 w2; + __u32 w4; + __u64 w8; + *word = 0; /* Default value if addr or size is invalid */ + switch (size) { + case 1: + diag = kdb_getarea(w1, addr); + if (!diag) + *word = w1; + break; + case 2: + diag = kdb_getarea(w2, addr); + if (!diag) + *word = w2; + break; + case 4: + diag = kdb_getarea(w4, addr); + if (!diag) + *word = w4; + break; + case 8: + if (size <= sizeof(*word)) { + diag = kdb_getarea(w8, addr); + if (!diag) + *word = w8; + break; + } + /* drop through */ + default: + diag = KDB_BADWIDTH; + kdb_printf("kdb_getword: bad width %ld\n", (long) size); + } + return diag; +} + +/* + * kdb_putword - Write a binary value. Unlike kdb_putarea, this + * treats data as numbers. + * Inputs: + * addr Address of the area to write to.. + * word The value to set. + * size Size of the area. + * Returns: + * 0 for success, < 0 for error. + */ +int kdb_putword(unsigned long addr, unsigned long word, size_t size) +{ + int diag; + __u8 w1; + __u16 w2; + __u32 w4; + __u64 w8; + switch (size) { + case 1: + w1 = word; + diag = kdb_putarea(addr, w1); + break; + case 2: + w2 = word; + diag = kdb_putarea(addr, w2); + break; + case 4: + w4 = word; + diag = kdb_putarea(addr, w4); + break; + case 8: + if (size <= sizeof(word)) { + w8 = word; + diag = kdb_putarea(addr, w8); + break; + } + /* drop through */ + default: + diag = KDB_BADWIDTH; + kdb_printf("kdb_putword: bad width %ld\n", (long) size); + } + return diag; +} + +/* + * kdb_task_state_string - Convert a string containing any of the + * letters DRSTCZEUIMA to a mask for the process state field and + * return the value. If no argument is supplied, return the mask + * that corresponds to environment variable PS, DRSTCZEU by + * default. + * Inputs: + * s String to convert + * Returns: + * Mask for process state. + * Notes: + * The mask folds data from several sources into a single long value, so + * be carefull not to overlap the bits. TASK_* bits are in the LSB, + * special cases like UNRUNNABLE are in the MSB. As of 2.6.10-rc1 there + * is no overlap between TASK_* and EXIT_* but that may not always be + * true, so EXIT_* bits are shifted left 16 bits before being stored in + * the mask. + */ + +/* unrunnable is < 0 */ +#define UNRUNNABLE (1UL << (8*sizeof(unsigned long) - 1)) +#define RUNNING (1UL << (8*sizeof(unsigned long) - 2)) +#define IDLE (1UL << (8*sizeof(unsigned long) - 3)) +#define DAEMON (1UL << (8*sizeof(unsigned long) - 4)) + +unsigned long kdb_task_state_string(const char *s) +{ + long res = 0; + if (!s) { + s = kdbgetenv("PS"); + if (!s) + s = "DRSTCZEU"; /* default value for ps */ + } + while (*s) { + switch (*s) { + case 'D': + res |= TASK_UNINTERRUPTIBLE; + break; + case 'R': + res |= RUNNING; + break; + case 'S': + res |= TASK_INTERRUPTIBLE; + break; + case 'T': + res |= TASK_STOPPED; + break; + case 'C': + res |= TASK_TRACED; + break; + case 'Z': + res |= EXIT_ZOMBIE << 16; + break; + case 'E': + res |= EXIT_DEAD << 16; + break; + case 'U': + res |= UNRUNNABLE; + break; + case 'I': + res |= IDLE; + break; + case 'M': + res |= DAEMON; + break; + case 'A': + res = ~0UL; + break; + default: + kdb_printf("%s: unknown flag '%c' ignored\n", + __func__, *s); + break; + } + ++s; + } + return res; +} + +/* + * kdb_task_state_char - Return the character that represents the task state. + * Inputs: + * p struct task for the process + * Returns: + * One character to represent the task state. + */ +char kdb_task_state_char (const struct task_struct *p) +{ + int cpu; + char state; + unsigned long tmp; + + if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long))) + return 'E'; + + cpu = kdb_process_cpu(p); + state = (p->state == 0) ? 'R' : + (p->state < 0) ? 'U' : + (p->state & TASK_UNINTERRUPTIBLE) ? 'D' : + (p->state & TASK_STOPPED) ? 'T' : + (p->state & TASK_TRACED) ? 'C' : + (p->exit_state & EXIT_ZOMBIE) ? 'Z' : + (p->exit_state & EXIT_DEAD) ? 'E' : + (p->state & TASK_INTERRUPTIBLE) ? 'S' : '?'; + if (p->pid == 0) { + /* Idle task. Is it really idle, apart from the kdb + * interrupt? */ + if (!kdb_task_has_cpu(p) || kgdb_info[cpu].irq_depth == 1) { + if (cpu != kdb_initial_cpu) + state = 'I'; /* idle task */ + } + } else if (!p->mm && state == 'S') { + state = 'M'; /* sleeping system daemon */ + } + return state; +} + +/* + * kdb_task_state - Return true if a process has the desired state + * given by the mask. + * Inputs: + * p struct task for the process + * mask mask from kdb_task_state_string to select processes + * Returns: + * True if the process matches at least one criteria defined by the mask. + */ +unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask) +{ + char state[] = { kdb_task_state_char(p), '\0' }; + return (mask & kdb_task_state_string(state)) != 0; +} + +/* + * kdb_print_nameval - Print a name and its value, converting the + * value to a symbol lookup if possible. + * Inputs: + * name field name to print + * val value of field + */ +void kdb_print_nameval(const char *name, unsigned long val) +{ + kdb_symtab_t symtab; + kdb_printf(" %-11.11s ", name); + if (kdbnearsym(val, &symtab)) + kdb_symbol_print(val, &symtab, + KDB_SP_VALUE|KDB_SP_SYMSIZE|KDB_SP_NEWLINE); + else + kdb_printf("0x%lx\n", val); +} + +/* Last ditch allocator for debugging, so we can still debug even when + * the GFP_ATOMIC pool has been exhausted. The algorithms are tuned + * for space usage, not for speed. One smallish memory pool, the free + * chain is always in ascending address order to allow coalescing, + * allocations are done in brute force best fit. + */ + +struct debug_alloc_header { + u32 next; /* offset of next header from start of pool */ + u32 size; + void *caller; +}; + +/* The memory returned by this allocator must be aligned, which means + * so must the header size. Do not assume that sizeof(struct + * debug_alloc_header) is a multiple of the alignment, explicitly + * calculate the overhead of this header, including the alignment. + * The rest of this code must not use sizeof() on any header or + * pointer to a header. + */ +#define dah_align 8 +#define dah_overhead ALIGN(sizeof(struct debug_alloc_header), dah_align) + +static u64 debug_alloc_pool_aligned[256*1024/dah_align]; /* 256K pool */ +static char *debug_alloc_pool = (char *)debug_alloc_pool_aligned; +static u32 dah_first, dah_first_call = 1, dah_used, dah_used_max; + +/* Locking is awkward. The debug code is called from all contexts, + * including non maskable interrupts. A normal spinlock is not safe + * in NMI context. Try to get the debug allocator lock, if it cannot + * be obtained after a second then give up. If the lock could not be + * previously obtained on this cpu then only try once. + * + * sparse has no annotation for "this function _sometimes_ acquires a + * lock", so fudge the acquire/release notation. + */ +static DEFINE_SPINLOCK(dap_lock); +static int get_dap_lock(void) + __acquires(dap_lock) +{ + static int dap_locked = -1; + int count; + if (dap_locked == smp_processor_id()) + count = 1; + else + count = 1000; + while (1) { + if (spin_trylock(&dap_lock)) { + dap_locked = -1; + return 1; + } + if (!count--) + break; + udelay(1000); + } + dap_locked = smp_processor_id(); + __acquire(dap_lock); + return 0; +} + +void *debug_kmalloc(size_t size, gfp_t flags) +{ + unsigned int rem, h_offset; + struct debug_alloc_header *best, *bestprev, *prev, *h; + void *p = NULL; + if (!get_dap_lock()) { + __release(dap_lock); /* we never actually got it */ + return NULL; + } + h = (struct debug_alloc_header *)(debug_alloc_pool + dah_first); + if (dah_first_call) { + h->size = sizeof(debug_alloc_pool_aligned) - dah_overhead; + dah_first_call = 0; + } + size = ALIGN(size, dah_align); + prev = best = bestprev = NULL; + while (1) { + if (h->size >= size && (!best || h->size < best->size)) { + best = h; + bestprev = prev; + if (h->size == size) + break; + } + if (!h->next) + break; + prev = h; + h = (struct debug_alloc_header *)(debug_alloc_pool + h->next); + } + if (!best) + goto out; + rem = best->size - size; + /* The pool must always contain at least one header */ + if (best->next == 0 && bestprev == NULL && rem < dah_overhead) + goto out; + if (rem >= dah_overhead) { + best->size = size; + h_offset = ((char *)best - debug_alloc_pool) + + dah_overhead + best->size; + h = (struct debug_alloc_header *)(debug_alloc_pool + h_offset); + h->size = rem - dah_overhead; + h->next = best->next; + } else + h_offset = best->next; + best->caller = __builtin_return_address(0); + dah_used += best->size; + dah_used_max = max(dah_used, dah_used_max); + if (bestprev) + bestprev->next = h_offset; + else + dah_first = h_offset; + p = (char *)best + dah_overhead; + memset(p, POISON_INUSE, best->size - 1); + *((char *)p + best->size - 1) = POISON_END; +out: + spin_unlock(&dap_lock); + return p; +} + +void debug_kfree(void *p) +{ + struct debug_alloc_header *h; + unsigned int h_offset; + if (!p) + return; + if ((char *)p < debug_alloc_pool || + (char *)p >= debug_alloc_pool + sizeof(debug_alloc_pool_aligned)) { + kfree(p); + return; + } + if (!get_dap_lock()) { + __release(dap_lock); /* we never actually got it */ + return; /* memory leak, cannot be helped */ + } + h = (struct debug_alloc_header *)((char *)p - dah_overhead); + memset(p, POISON_FREE, h->size - 1); + *((char *)p + h->size - 1) = POISON_END; + h->caller = NULL; + dah_used -= h->size; + h_offset = (char *)h - debug_alloc_pool; + if (h_offset < dah_first) { + h->next = dah_first; + dah_first = h_offset; + } else { + struct debug_alloc_header *prev; + unsigned int prev_offset; + prev = (struct debug_alloc_header *)(debug_alloc_pool + + dah_first); + while (1) { + if (!prev->next || prev->next > h_offset) + break; + prev = (struct debug_alloc_header *) + (debug_alloc_pool + prev->next); + } + prev_offset = (char *)prev - debug_alloc_pool; + if (prev_offset + dah_overhead + prev->size == h_offset) { + prev->size += dah_overhead + h->size; + memset(h, POISON_FREE, dah_overhead - 1); + *((char *)h + dah_overhead - 1) = POISON_END; + h = prev; + h_offset = prev_offset; + } else { + h->next = prev->next; + prev->next = h_offset; + } + } + if (h_offset + dah_overhead + h->size == h->next) { + struct debug_alloc_header *next; + next = (struct debug_alloc_header *) + (debug_alloc_pool + h->next); + h->size += dah_overhead + next->size; + h->next = next->next; + memset(next, POISON_FREE, dah_overhead - 1); + *((char *)next + dah_overhead - 1) = POISON_END; + } + spin_unlock(&dap_lock); +} + +void debug_kusage(void) +{ + struct debug_alloc_header *h_free, *h_used; +#ifdef CONFIG_IA64 + /* FIXME: using dah for ia64 unwind always results in a memory leak. + * Fix that memory leak first, then set debug_kusage_one_time = 1 for + * all architectures. + */ + static int debug_kusage_one_time; +#else + static int debug_kusage_one_time = 1; +#endif + if (!get_dap_lock()) { + __release(dap_lock); /* we never actually got it */ + return; + } + h_free = (struct debug_alloc_header *)(debug_alloc_pool + dah_first); + if (dah_first == 0 && + (h_free->size == sizeof(debug_alloc_pool_aligned) - dah_overhead || + dah_first_call)) + goto out; + if (!debug_kusage_one_time) + goto out; + debug_kusage_one_time = 0; + kdb_printf("%s: debug_kmalloc memory leak dah_first %d\n", + __func__, dah_first); + if (dah_first) { + h_used = (struct debug_alloc_header *)debug_alloc_pool; + kdb_printf("%s: h_used %p size %d\n", __func__, h_used, + h_used->size); + } + do { + h_used = (struct debug_alloc_header *) + ((char *)h_free + dah_overhead + h_free->size); + kdb_printf("%s: h_used %p size %d caller %p\n", + __func__, h_used, h_used->size, h_used->caller); + h_free = (struct debug_alloc_header *) + (debug_alloc_pool + h_free->next); + } while (h_free->next); + h_used = (struct debug_alloc_header *) + ((char *)h_free + dah_overhead + h_free->size); + if ((char *)h_used - debug_alloc_pool != + sizeof(debug_alloc_pool_aligned)) + kdb_printf("%s: h_used %p size %d caller %p\n", + __func__, h_used, h_used->size, h_used->caller); +out: + spin_unlock(&dap_lock); +} + +/* Maintain a small stack of kdb_flags to allow recursion without disturbing + * the global kdb state. + */ + +static int kdb_flags_stack[4], kdb_flags_index; + +void kdb_save_flags(void) +{ + BUG_ON(kdb_flags_index >= ARRAY_SIZE(kdb_flags_stack)); + kdb_flags_stack[kdb_flags_index++] = kdb_flags; +} + +void kdb_restore_flags(void) +{ + BUG_ON(kdb_flags_index <= 0); + kdb_flags = kdb_flags_stack[--kdb_flags_index]; +} -- cgit v1.2.3-70-g09d2 From 67fc4e0cb931d6b4ccf21248e4199b154478ecea Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:21 -0500 Subject: kdb: core for kgdb back end (2 of 2) This patch contains the hooks and instrumentation into kernel which live outside the kernel/debug directory, which the kdb core will call to run commands like lsmod, dmesg, bt etc... CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel Signed-off-by: Martin Hicks --- arch/arm/include/asm/kmap_types.h | 1 + arch/powerpc/include/asm/kmap_types.h | 1 + include/asm-generic/kmap_types.h | 3 ++- init/main.c | 2 ++ kernel/kallsyms.c | 21 ++++++++++++++++++ kernel/module.c | 4 ++++ kernel/printk.c | 16 ++++++++++++++ kernel/sched.c | 7 ++++-- kernel/signal.c | 40 +++++++++++++++++++++++++++++++++++ 9 files changed, 92 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/arch/arm/include/asm/kmap_types.h b/arch/arm/include/asm/kmap_types.h index c4b2ea3fbe4..e51b1e81df0 100644 --- a/arch/arm/include/asm/kmap_types.h +++ b/arch/arm/include/asm/kmap_types.h @@ -20,6 +20,7 @@ enum km_type { KM_SOFTIRQ1, KM_L1_CACHE, KM_L2_CACHE, + KM_KDB, KM_TYPE_NR }; diff --git a/arch/powerpc/include/asm/kmap_types.h b/arch/powerpc/include/asm/kmap_types.h index 916369575c9..bca8fdcd254 100644 --- a/arch/powerpc/include/asm/kmap_types.h +++ b/arch/powerpc/include/asm/kmap_types.h @@ -26,6 +26,7 @@ enum km_type { KM_SOFTIRQ1, KM_PPC_SYNC_PAGE, KM_PPC_SYNC_ICACHE, + KM_KDB, KM_TYPE_NR }; diff --git a/include/asm-generic/kmap_types.h b/include/asm-generic/kmap_types.h index e5f234a0854..97e807c8c81 100644 --- a/include/asm-generic/kmap_types.h +++ b/include/asm-generic/kmap_types.h @@ -28,7 +28,8 @@ KMAP_D(15) KM_UML_USERCOPY, KMAP_D(16) KM_IRQ_PTE, KMAP_D(17) KM_NMI, KMAP_D(18) KM_NMI_PTE, -KMAP_D(19) KM_TYPE_NR +KMAP_D(19) KM_KDB, +KMAP_D(20) KM_TYPE_NR }; #undef KMAP_D diff --git a/init/main.c b/init/main.c index 5c854027152..372771333d9 100644 --- a/init/main.c +++ b/init/main.c @@ -62,6 +62,7 @@ #include #include #include +#include #include #include #include @@ -675,6 +676,7 @@ asmlinkage void __init start_kernel(void) buffer_init(); key_init(); security_init(); + kdb_init(KDB_INIT_FULL); vfs_caches_init(totalram_pages); signals_init(); /* rootfs populating might need page-writeback */ diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 13aff293f4d..6f6d091b575 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include /* for cond_resched */ @@ -516,6 +517,26 @@ static int kallsyms_open(struct inode *inode, struct file *file) return ret; } +#ifdef CONFIG_KGDB_KDB +const char *kdb_walk_kallsyms(loff_t *pos) +{ + static struct kallsym_iter kdb_walk_kallsyms_iter; + if (*pos == 0) { + memset(&kdb_walk_kallsyms_iter, 0, + sizeof(kdb_walk_kallsyms_iter)); + reset_iter(&kdb_walk_kallsyms_iter, 0); + } + while (1) { + if (!update_iter(&kdb_walk_kallsyms_iter, *pos)) + return NULL; + ++*pos; + /* Some debugging symbols have no name. Ignore them. */ + if (kdb_walk_kallsyms_iter.name[0]) + return kdb_walk_kallsyms_iter.name; + } +} +#endif /* CONFIG_KGDB_KDB */ + static const struct file_operations kallsyms_operations = { .open = kallsyms_open, .read = seq_read, diff --git a/kernel/module.c b/kernel/module.c index e2564580f3f..b751f190247 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -77,6 +77,10 @@ DEFINE_MUTEX(module_mutex); EXPORT_SYMBOL_GPL(module_mutex); static LIST_HEAD(modules); +#ifdef CONFIG_KGDB_KDB +struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ +#endif /* CONFIG_KGDB_KDB */ + /* Block module loading/unloading? */ int modules_disabled = 0; diff --git a/kernel/printk.c b/kernel/printk.c index 75077ad0b53..9213b8b5bb4 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -413,6 +413,22 @@ SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len) return do_syslog(type, buf, len, SYSLOG_FROM_CALL); } +#ifdef CONFIG_KGDB_KDB +/* kdb dmesg command needs access to the syslog buffer. do_syslog() + * uses locks so it cannot be used during debugging. Just tell kdb + * where the start and end of the physical and logical logs are. This + * is equivalent to do_syslog(3). + */ +void kdb_syslog_data(char *syslog_data[4]) +{ + syslog_data[0] = log_buf; + syslog_data[1] = log_buf + log_buf_len; + syslog_data[2] = log_buf + log_end - + (logged_chars < log_buf_len ? logged_chars : log_buf_len); + syslog_data[3] = log_buf + log_end; +} +#endif /* CONFIG_KGDB_KDB */ + /* * Call the console drivers on a range of log_buf */ diff --git a/kernel/sched.c b/kernel/sched.c index 1d93cd0ae4d..a25c1324af5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7758,9 +7758,9 @@ void normalize_rt_tasks(void) #endif /* CONFIG_MAGIC_SYSRQ */ -#ifdef CONFIG_IA64 +#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) /* - * These functions are only useful for the IA64 MCA handling. + * These functions are only useful for the IA64 MCA handling, or kdb. * * They can only be called when the whole system has been * stopped - every CPU needs to be quiescent, and no scheduling @@ -7780,6 +7780,9 @@ struct task_struct *curr_task(int cpu) return cpu_curr(cpu); } +#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ + +#ifdef CONFIG_IA64 /** * set_curr_task - set the current task for a given cpu. * @cpu: the processor in question. diff --git a/kernel/signal.c b/kernel/signal.c index dbd7fe073c5..825a3f24ad7 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2735,3 +2735,43 @@ void __init signals_init(void) { sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); } + +#ifdef CONFIG_KGDB_KDB +#include +/* + * kdb_send_sig_info - Allows kdb to send signals without exposing + * signal internals. This function checks if the required locks are + * available before calling the main signal code, to avoid kdb + * deadlocks. + */ +void +kdb_send_sig_info(struct task_struct *t, struct siginfo *info) +{ + static struct task_struct *kdb_prev_t; + int sig, new_t; + if (!spin_trylock(&t->sighand->siglock)) { + kdb_printf("Can't do kill command now.\n" + "The sigmask lock is held somewhere else in " + "kernel, try again later\n"); + return; + } + spin_unlock(&t->sighand->siglock); + new_t = kdb_prev_t != t; + kdb_prev_t = t; + if (t->state != TASK_RUNNING && new_t) { + kdb_printf("Process is not RUNNING, sending a signal from " + "kdb risks deadlock\n" + "on the run queue locks. " + "The signal has _not_ been sent.\n" + "Reissue the kill command if you want to risk " + "the deadlock.\n"); + return; + } + sig = info->si_signo; + if (send_sig_info(sig, info, t)) + kdb_printf("Fail to deliver Signal %d to process %d.\n", + sig, t->pid); + else + kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); +} +#endif /* CONFIG_KGDB_KDB */ -- cgit v1.2.3-70-g09d2 From dcc7871128e99458ca86186b7bc8bf27ff0c47b5 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:21 -0500 Subject: kgdb: core changes to support kdb These are the minimum changes to the kgdb core in order to enable an API to connect a new front end (kdb) to the debug core. This patch introduces the dbg_kdb_mode variable controls where the user level I/O is routed. It will be routed to the gdbstub (kgdb) or to the kdb front end which is a simple shell available over the kgdboc connection. You can switch back and forth between kdb or the gdb stub mode of operation dynamically. From gdb stub mode you can blindly type "$3#33", or from the kdb mode you can enter "kgdb" to switch to the gdb stub. The logic in the debug core depends on kdb to look for the typical gdb connection sequences and return immediately with KGDB_PASS_EVENT if a gdb serial command sequence is detected. That should allow a reasonably seamless transition between kdb -> gdb without leaving the kernel exception state. The two gdb serial queries that kdb is responsible for detecting are the "?" and "qSupported" packets. CC: Ingo Molnar Signed-off-by: Jason Wessel Acked-by: Martin Hicks --- arch/arm/kernel/kgdb.c | 5 +++ arch/mips/kernel/kgdb.c | 5 +++ arch/powerpc/kernel/kgdb.c | 5 +++ arch/x86/kernel/kgdb.c | 5 +++ include/linux/kgdb.h | 11 ++++- kernel/debug/debug_core.c | 107 ++++++++++++++++++++++++++++++++++++++------- kernel/debug/debug_core.h | 24 ++++++++++ kernel/debug/gdbstub.c | 36 +++++++++++++++ lib/Kconfig.kgdb | 8 +++- 9 files changed, 186 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index a5b846b9895..c868a886411 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -98,6 +98,11 @@ sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) gdb_regs[_CPSR] = thread_regs->ARM_cpsr; } +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->ARM_pc = pc; +} + static int compiled_break; int kgdb_arch_handle_exception(int exception_vector, int signo, diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index 50c9bb88066..6ed4c83c869 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -180,6 +180,11 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) *(ptr++) = regs->cp0_epc; } +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->cp0_epc = pc; +} + /* * Calls linux_debug_hook before the kernel dies. If KGDB is enabled, * then try to fall into the debugger diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index 41bada0298c..c81e3de1306 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -309,6 +309,11 @@ void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); } +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->nip = pc; +} + /* * This function does PowerPC specific procesing for interfacing to gdb. */ diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index b2258ca9100..f95a2c0b915 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -690,6 +690,11 @@ unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) return instruction_pointer(regs); } +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) +{ + regs->ip = ip; +} + struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: */ .gdb_bpt_instr = { 0xcc }, diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 4830142ec33..5b37df00000 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -16,10 +16,12 @@ #include #include #include - #include +#ifdef CONFIG_HAVE_ARCH_KGDB #include +#endif +#ifdef CONFIG_KGDB struct pt_regs; /** @@ -262,6 +264,7 @@ extern struct kgdb_arch arch_kgdb_ops; extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); +extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); extern struct kgdb_io *dbg_io_ops; @@ -279,5 +282,9 @@ extern int kgdb_nmicallback(int cpu, void *regs); extern int kgdb_single_step; extern atomic_t kgdb_active; - +#define in_dbg_master() \ + (raw_smp_processor_id() == atomic_read(&kgdb_active)) +#else /* ! CONFIG_KGDB */ +#define in_dbg_master() (0) +#endif /* ! CONFIG_KGDB */ #endif /* _KGDB_H_ */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 7e03969330b..6e1fa829fde 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include #include @@ -77,6 +78,11 @@ static DEFINE_SPINLOCK(kgdb_registration_lock); static int kgdb_con_registered; /* determine if kgdb console output should be used */ static int kgdb_use_con; +/* Next cpu to become the master debug core */ +int dbg_switch_cpu; + +/* Use kdb or gdbserver mode */ +static int dbg_kdb_mode = 1; static int __init opt_kgdb_con(char *str) { @@ -100,6 +106,7 @@ static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { * The CPU# of the active CPU, or -1 if none: */ atomic_t kgdb_active = ATOMIC_INIT(-1); +EXPORT_SYMBOL_GPL(kgdb_active); /* * We use NR_CPUs not PERCPU, in case kgdb is used to debug early @@ -301,7 +308,7 @@ int dbg_set_sw_break(unsigned long addr) return 0; } -static int kgdb_deactivate_sw_breakpoints(void) +int dbg_deactivate_sw_breakpoints(void) { unsigned long addr; int error; @@ -395,8 +402,14 @@ static int kgdb_io_ready(int print_wait) return 1; if (atomic_read(&kgdb_setting_breakpoint)) return 1; - if (print_wait) + if (print_wait) { +#ifdef CONFIG_KGDB_KDB + if (!dbg_kdb_mode) + printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB\n"); +#else printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); +#endif + } return 1; } @@ -410,7 +423,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks) /* Panic on recursive debugger calls: */ exception_level++; addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); - kgdb_deactivate_sw_breakpoints(); + dbg_deactivate_sw_breakpoints(); /* * If the break point removed ok at the place exception @@ -443,11 +456,24 @@ static int kgdb_reenter_check(struct kgdb_state *ks) return 1; } +static void dbg_cpu_switch(int cpu, int next_cpu) +{ + /* Mark the cpu we are switching away from as a slave when it + * holds the kgdb_active token. This must be done so that the + * that all the cpus wait in for the debug core will not enter + * again as the master. */ + if (cpu == atomic_read(&kgdb_active)) { + kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE; + kgdb_info[cpu].exception_state &= ~DCPU_WANT_MASTER; + } + kgdb_info[next_cpu].exception_state |= DCPU_NEXT_MASTER; +} + static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs) { unsigned long flags; int sstep_tries = 100; - int error = 0; + int error; int i, cpu; int trace_on = 0; acquirelock: @@ -460,6 +486,8 @@ acquirelock: cpu = ks->cpu; kgdb_info[cpu].debuggerinfo = regs; kgdb_info[cpu].task = current; + kgdb_info[cpu].ret_state = 0; + kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT; /* * Make sure the above info reaches the primary CPU before * our cpu_in_kgdb[] flag setting does: @@ -471,7 +499,11 @@ acquirelock: * master cpu and acquire the kgdb_active lock: */ while (1) { - if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { +cpu_loop: + if (kgdb_info[cpu].exception_state & DCPU_NEXT_MASTER) { + kgdb_info[cpu].exception_state &= ~DCPU_NEXT_MASTER; + goto cpu_master_loop; + } else if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu) break; } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { @@ -513,7 +545,7 @@ return_normal: } if (!kgdb_io_ready(1)) { - error = 1; + kgdb_info[cpu].ret_state = 1; goto kgdb_restore; /* No I/O connection, resume the system */ } @@ -548,7 +580,7 @@ return_normal: * Wait for the other CPUs to be notified and be waiting for us: */ for_each_online_cpu(i) { - while (!atomic_read(&cpu_in_kgdb[i])) + while (kgdb_do_roundup && !atomic_read(&cpu_in_kgdb[i])) cpu_relax(); } @@ -557,7 +589,7 @@ return_normal: * in the debugger and all secondary CPUs are quiescent */ kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); - kgdb_deactivate_sw_breakpoints(); + dbg_deactivate_sw_breakpoints(); kgdb_single_step = 0; kgdb_contthread = current; exception_level = 0; @@ -565,8 +597,26 @@ return_normal: if (trace_on) tracing_off(); - /* Talk to debugger with gdbserial protocol */ - error = gdb_serial_stub(ks); + while (1) { +cpu_master_loop: + if (dbg_kdb_mode) { + kgdb_connected = 1; + error = kdb_stub(ks); + } else { + error = gdb_serial_stub(ks); + } + + if (error == DBG_PASS_EVENT) { + dbg_kdb_mode = !dbg_kdb_mode; + kgdb_connected = 0; + } else if (error == DBG_SWITCH_CPU_EVENT) { + dbg_cpu_switch(cpu, dbg_switch_cpu); + goto cpu_loop; + } else { + kgdb_info[cpu].ret_state = error; + break; + } + } /* Call the I/O driver's post_exception routine */ if (dbg_io_ops->post_exception) @@ -578,11 +628,16 @@ return_normal: for (i = NR_CPUS-1; i >= 0; i--) atomic_dec(&passive_cpu_wait[i]); /* - * Wait till all the CPUs have quit - * from the debugger. + * Wait till all the CPUs have quit from the debugger, + * but allow a CPU that hit an exception and is + * waiting to become the master to remain in the debug + * core. */ for_each_online_cpu(i) { - while (atomic_read(&cpu_in_kgdb[i])) + while (kgdb_do_roundup && + atomic_read(&cpu_in_kgdb[i]) && + !(kgdb_info[i].exception_state & + DCPU_WANT_MASTER)) cpu_relax(); } } @@ -603,7 +658,7 @@ kgdb_restore: clocksource_touch_watchdog(); local_irq_restore(flags); - return error; + return kgdb_info[cpu].ret_state; } /* @@ -632,7 +687,8 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) return 0; /* Ouch, double exception ! */ kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER; ret = kgdb_cpu_enter(ks, regs); - kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER; + kgdb_info[ks->cpu].exception_state &= ~(DCPU_WANT_MASTER | + DCPU_IS_SLAVE); return ret; } @@ -665,7 +721,7 @@ static void kgdb_console_write(struct console *co, const char *s, /* If we're debugging, or KGDB has not connected, don't try * and print. */ - if (!kgdb_connected || atomic_read(&kgdb_active) != -1) + if (!kgdb_connected || atomic_read(&kgdb_active) != -1 || dbg_kdb_mode) return; local_irq_save(flags); @@ -687,8 +743,14 @@ static void sysrq_handle_dbg(int key, struct tty_struct *tty) printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); return; } - if (!kgdb_connected) + if (!kgdb_connected) { +#ifdef CONFIG_KGDB_KDB + if (!dbg_kdb_mode) + printk(KERN_CRIT "KGDB or $3#33 for KDB\n"); +#else printk(KERN_CRIT "Entering KGDB\n"); +#endif + } kgdb_breakpoint(); } @@ -817,6 +879,16 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops) } EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); +int dbg_io_get_char(void) +{ + int ret = dbg_io_ops->read_char(); + if (!dbg_kdb_mode) + return ret; + if (ret == 127) + return 8; + return ret; +} + /** * kgdb_breakpoint - generate breakpoint exception * @@ -839,6 +911,7 @@ static int __init opt_kgdb_wait(char *str) { kgdb_break_asap = 1; + kdb_init(KDB_INIT_EARLY); if (kgdb_io_module_registered) kgdb_initial_breakpoint(); diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h index db554f9be51..44cf3de8cf9 100644 --- a/kernel/debug/debug_core.h +++ b/kernel/debug/debug_core.h @@ -38,6 +38,8 @@ struct debuggerinfo_struct { void *debuggerinfo; struct task_struct *task; int exception_state; + int ret_state; + int irq_depth; }; extern struct debuggerinfo_struct kgdb_info[]; @@ -47,9 +49,31 @@ extern int dbg_remove_all_break(void); extern int dbg_set_sw_break(unsigned long addr); extern int dbg_remove_sw_break(unsigned long addr); extern int dbg_activate_sw_breakpoints(void); +extern int dbg_deactivate_sw_breakpoints(void); + +/* polled character access to i/o module */ +extern int dbg_io_get_char(void); + +/* stub return value for switching between the gdbstub and kdb */ +#define DBG_PASS_EVENT -12345 +/* Switch from one cpu to another */ +#define DBG_SWITCH_CPU_EVENT -123456 +extern int dbg_switch_cpu; /* gdbstub interface functions */ extern int gdb_serial_stub(struct kgdb_state *ks); extern void gdbstub_msg_write(const char *s, int len); +/* gdbstub functions used for kdb <-> gdbstub transition */ +extern int gdbstub_state(struct kgdb_state *ks, char *cmd); + +#ifdef CONFIG_KGDB_KDB +extern int kdb_stub(struct kgdb_state *ks); +#else /* ! CONFIG_KGDB_KDB */ +static inline int kdb_stub(struct kgdb_state *ks) +{ + return DBG_PASS_EVENT; +} +#endif /* CONFIG_KGDB_KDB */ + #endif /* _DEBUG_CORE_H_ */ diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index ccdf0929f12..188203a1965 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -887,6 +887,13 @@ int gdb_serial_stub(struct kgdb_state *ks) case 'Z': /* Break point set */ gdb_cmd_break(ks); break; +#ifdef CONFIG_KGDB_KDB + case '3': /* Escape into back into kdb */ + if (remcom_in_buffer[1] == '\0') { + gdb_cmd_detachkill(ks); + return DBG_PASS_EVENT; + } +#endif case 'C': /* Exception passing */ tmp = gdb_cmd_exception_pass(ks); if (tmp > 0) @@ -932,3 +939,32 @@ kgdb_exit: error = 1; return error; } + +int gdbstub_state(struct kgdb_state *ks, char *cmd) +{ + int error; + + switch (cmd[0]) { + case 'e': + error = kgdb_arch_handle_exception(ks->ex_vector, + ks->signo, + ks->err_code, + remcom_in_buffer, + remcom_out_buffer, + ks->linux_regs); + return error; + case 's': + case 'c': + strcpy(remcom_in_buffer, cmd); + return 0; + case '?': + gdb_cmd_status(ks); + break; + case '\0': + strcpy(remcom_out_buffer, ""); + break; + } + dbg_io_ops->write_char('+'); + put_packet(remcom_out_buffer); + return 0; +} diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb index 9b5d1d7f2ef..78de43a5e90 100644 --- a/lib/Kconfig.kgdb +++ b/lib/Kconfig.kgdb @@ -3,7 +3,7 @@ config HAVE_ARCH_KGDB bool menuconfig KGDB - bool "KGDB: kernel debugging with remote gdb" + bool "KGDB: kernel debugger" depends on HAVE_ARCH_KGDB depends on DEBUG_KERNEL && EXPERIMENTAL help @@ -57,4 +57,10 @@ config KGDB_TESTS_BOOT_STRING information about other strings you could use beyond the default of V1F100. +config KGDB_KDB + bool "KGDB_KDB: include kdb frontend for kgdb" + default n + help + KDB frontend for kernel + endif # KGDB -- cgit v1.2.3-70-g09d2 From f5316b4aea024da9266d740322a5481657f6ce59 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:22 -0500 Subject: kgdb,8250,pl011: Return immediately from console poll The design of the kdb shell requires that every device that can provide input to kdb have a polling routine that exits immediately if there is no character available. This is required in order to get the page scrolling mechanism working. Changing the kernel debugger I/O API to require all polling character routines to exit immediately if there is no data allows the kernel debugger to process multiple input channels. NO_POLL_CHAR will be the return code to the polling routine when ever there is no character available. CC: linux-serial@vger.kernel.org Signed-off-by: Jason Wessel --- drivers/serial/8250.c | 4 ++-- drivers/serial/amba-pl011.c | 6 +++--- include/linux/kdb.h | 1 + include/linux/serial_core.h | 1 + kernel/debug/debug_core.c | 2 ++ kernel/debug/gdbstub.c | 37 +++++++++++++++++++++++++++++++------ kernel/debug/kdb/kdb_debugger.c | 10 ++++++++++ 7 files changed, 50 insertions(+), 11 deletions(-) (limited to 'kernel') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 2b1ea3d4c4f..891e1dd65f2 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1891,8 +1891,8 @@ static int serial8250_get_poll_char(struct uart_port *port) struct uart_8250_port *up = (struct uart_8250_port *)port; unsigned char lsr = serial_inp(up, UART_LSR); - while (!(lsr & UART_LSR_DR)) - lsr = serial_inp(up, UART_LSR); + if (!(lsr & UART_LSR_DR)) + return NO_POLL_CHAR; return serial_inp(up, UART_RX); } diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c index 743ebf5f16d..eb4cb480b93 100644 --- a/drivers/serial/amba-pl011.c +++ b/drivers/serial/amba-pl011.c @@ -342,9 +342,9 @@ static int pl010_get_poll_char(struct uart_port *port) struct uart_amba_port *uap = (struct uart_amba_port *)port; unsigned int status; - do { - status = readw(uap->port.membase + UART01x_FR); - } while (status & UART01x_FR_RXFE); + status = readw(uap->port.membase + UART01x_FR); + if (status & UART01x_FR_RXFE) + return NO_POLL_CHAR; return readw(uap->port.membase + UART01x_DR); } diff --git a/include/linux/kdb.h b/include/linux/kdb.h index 4d93790faec..d72fa390812 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -19,6 +19,7 @@ #include #define KDB_POLL_FUNC_MAX 5 +extern int kdb_poll_idx; /* * kdb_initial_cpu is initialized to -1, and is set to the cpu diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 78dd1e7120a..ad839963fa6 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -246,6 +246,7 @@ struct uart_ops { #endif }; +#define NO_POLL_CHAR 0x00ff0000 #define UART_CONFIG_TYPE (1 << 0) #define UART_CONFIG_IRQ (1 << 1) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 6e1fa829fde..1d71df66f3f 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -882,6 +882,8 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); int dbg_io_get_char(void) { int ret = dbg_io_ops->read_char(); + if (ret == NO_POLL_CHAR) + return -1; if (!dbg_kdb_mode) return ret; if (ret == 127) diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index 188203a1965..3c000490a7d 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -30,6 +30,7 @@ #include #include +#include #include #include #include @@ -62,6 +63,30 @@ static int hex(char ch) return -1; } +#ifdef CONFIG_KGDB_KDB +static int gdbstub_read_wait(void) +{ + int ret = -1; + int i; + + /* poll any additional I/O interfaces that are defined */ + while (ret < 0) + for (i = 0; kdb_poll_funcs[i] != NULL; i++) { + ret = kdb_poll_funcs[i](); + if (ret > 0) + break; + } + return ret; +} +#else +static int gdbstub_read_wait(void) +{ + int ret = dbg_io_ops->read_char(); + while (ret == NO_POLL_CHAR) + ret = dbg_io_ops->read_char(); + return ret; +} +#endif /* scan for the sequence $# */ static void get_packet(char *buffer) { @@ -75,7 +100,7 @@ static void get_packet(char *buffer) * Spin and wait around for the start character, ignore all * other characters: */ - while ((ch = (dbg_io_ops->read_char())) != '$') + while ((ch = (gdbstub_read_wait())) != '$') /* nothing */; kgdb_connected = 1; @@ -88,7 +113,7 @@ static void get_packet(char *buffer) * now, read until a # or end of buffer is found: */ while (count < (BUFMAX - 1)) { - ch = dbg_io_ops->read_char(); + ch = gdbstub_read_wait(); if (ch == '#') break; checksum = checksum + ch; @@ -98,8 +123,8 @@ static void get_packet(char *buffer) buffer[count] = 0; if (ch == '#') { - xmitcsum = hex(dbg_io_ops->read_char()) << 4; - xmitcsum += hex(dbg_io_ops->read_char()); + xmitcsum = hex(gdbstub_read_wait()) << 4; + xmitcsum += hex(gdbstub_read_wait()); if (checksum != xmitcsum) /* failed checksum */ @@ -144,10 +169,10 @@ static void put_packet(char *buffer) dbg_io_ops->flush(); /* Now see what we get in reply. */ - ch = dbg_io_ops->read_char(); + ch = gdbstub_read_wait(); if (ch == 3) - ch = dbg_io_ops->read_char(); + ch = gdbstub_read_wait(); /* If we get an ACK, we are done. */ if (ch == '+') diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index f024c0c4b8c..bf6e8270e95 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -20,7 +20,15 @@ get_char_func kdb_poll_funcs[] = { dbg_io_get_char, NULL, + NULL, + NULL, + NULL, + NULL, }; +EXPORT_SYMBOL_GPL(kdb_poll_funcs); + +int kdb_poll_idx = 1; +EXPORT_SYMBOL_GPL(kdb_poll_idx); int kdb_stub(struct kgdb_state *ks) { @@ -85,6 +93,7 @@ int kdb_stub(struct kgdb_state *ks) kdb_bp_remove(); KDB_STATE_CLEAR(DOING_SS); KDB_STATE_CLEAR(DOING_SSB); + KDB_STATE_SET(PAGER); /* zero out any offline cpu data */ for_each_present_cpu(i) { if (!cpu_online(i)) { @@ -112,6 +121,7 @@ int kdb_stub(struct kgdb_state *ks) kdb_initial_cpu = -1; kdb_current_task = NULL; kdb_current_regs = NULL; + KDB_STATE_CLEAR(PAGER); kdbnearsym_cleanup(); if (error == KDB_CMD_KGDB) { if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) { -- cgit v1.2.3-70-g09d2 From a0de055cf61338549b13079a5677ef2e1b6472ef Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:24 -0500 Subject: kgdb: gdb "monitor" -> kdb passthrough One of the driving forces behind integrating another front end (kdb) to the debug core is to allow front end commands to be accessible via gdb's monitor command. It is true that you could write gdb macros to get certain data, but you may want to just use gdb to access the commands that are available in the kdb front end. This patch implements the Rcmd gdb stub packet. In gdb you access this with the "monitor" command. For instance you could type "monitor help", "monitor lsmod" or "monitor ps A" etc... There is no error checking or command restrictions on what you can and cannot access at this point. Doing something like trying to set breakpoints with the monitor command is going to cause nothing but problems. Perhaps in the future only the commands that are actually known to work with the gdb monitor command will be available. Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 2 +- kernel/debug/debug_core.h | 2 ++ kernel/debug/gdbstub.c | 22 ++++++++++++++++++++++ kernel/debug/kdb/kdb_io.c | 13 +++++++++---- kernel/debug/kdb/kdb_private.h | 1 - 5 files changed, 34 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1d71df66f3f..1aed37b4c56 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -82,7 +82,7 @@ static int kgdb_use_con; int dbg_switch_cpu; /* Use kdb or gdbserver mode */ -static int dbg_kdb_mode = 1; +int dbg_kdb_mode = 1; static int __init opt_kgdb_con(char *str) { diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h index 44cf3de8cf9..c5d753d80f6 100644 --- a/kernel/debug/debug_core.h +++ b/kernel/debug/debug_core.h @@ -66,9 +66,11 @@ extern void gdbstub_msg_write(const char *s, int len); /* gdbstub functions used for kdb <-> gdbstub transition */ extern int gdbstub_state(struct kgdb_state *ks, char *cmd); +extern int dbg_kdb_mode; #ifdef CONFIG_KGDB_KDB extern int kdb_stub(struct kgdb_state *ks); +extern int kdb_parse(const char *cmdstr); #else /* ! CONFIG_KGDB_KDB */ static inline int kdb_stub(struct kgdb_state *ks) { diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index 3c000490a7d..4b17b326952 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -201,6 +201,9 @@ void gdbstub_msg_write(const char *s, int len) int wcount; int i; + if (len == 0) + len = strlen(s); + /* 'O'utput */ gdbmsgbuf[0] = 'O'; @@ -685,6 +688,25 @@ static void gdb_cmd_query(struct kgdb_state *ks) kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); } break; +#ifdef CONFIG_KGDB_KDB + case 'R': + if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) { + int len = strlen(remcom_in_buffer + 6); + + if ((len % 2) != 0) { + strcpy(remcom_out_buffer, "E01"); + break; + } + kgdb_hex2mem(remcom_in_buffer + 6, + remcom_out_buffer, len); + len = len / 2; + remcom_out_buffer[len++] = 0; + + kdb_parse(remcom_out_buffer); + strcpy(remcom_out_buffer, "OK"); + } + break; +#endif } } diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 9e3cec7a925..8339b291e8b 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include "kdb_private.h" @@ -669,10 +670,14 @@ kdb_printit: * Write to all consoles. */ retlen = strlen(kdb_buffer); - while (c) { - c->write(c, kdb_buffer, retlen); - touch_nmi_watchdog(); - c = c->next; + if (!dbg_kdb_mode && kgdb_connected) { + gdbstub_msg_write(kdb_buffer, retlen); + } else { + while (c) { + c->write(c, kdb_buffer, retlen); + touch_nmi_watchdog(); + c = c->next; + } } if (logging) { saved_loglevel = console_loglevel; diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 69ed2eff3fe..97d3ba69775 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -254,7 +254,6 @@ extern unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask); extern void kdb_ps_suppressed(void); extern void kdb_ps1(const struct task_struct *p); -extern int kdb_parse(const char *cmdstr); extern void kdb_print_nameval(const char *name, unsigned long val); extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info); extern void kdb_meminfo_proc_show(void); -- cgit v1.2.3-70-g09d2 From ada64e4c98eb5f04a9ca223c5ff9e7ac22ce6404 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:24 -0500 Subject: kgdboc,keyboard: Keyboard driver for kdb with kgdb This patch adds in the kdb PS/2 keyboard driver. This was mostly a direct port from the original kdb where I cleaned up the code against checkpatch.pl and added the glue to stitch it into kgdb. This patch also enables early kdb debug via kgdbwait and the keyboard. All the access to configure kdb using either a serial console or the keyboard is done via kgdboc. If you want to use only the keyboard and want to break in early you would add to your kernel command arguments: kgdboc=kbd kgdbwait If you wanted serial and or the keyboard access you could use: kgdboc=kbd,ttyS0 You can also configure kgdboc as a kernel module or at run time with the sysfs where you can activate and deactivate kgdb. Turn it on: echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc Turn it off: echo "" > /sys/module/kgdboc/parameters/kgdboc Signed-off-by: Jason Wessel Reviewed-by: Dmitry Torokhov --- Documentation/kernel-parameters.txt | 8 +- drivers/serial/kgdboc.c | 61 +++++++++-- kernel/debug/kdb/Makefile | 1 + kernel/debug/kdb/kdb_keyboard.c | 212 ++++++++++++++++++++++++++++++++++++ lib/Kconfig.kgdb | 7 ++ 5 files changed, 279 insertions(+), 10 deletions(-) create mode 100644 kernel/debug/kdb/kdb_keyboard.c (limited to 'kernel') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b12bacd252f..3845e3a84a5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1121,9 +1121,11 @@ and is between 256 and 4096 characters. It is defined in the file zone if it does not. kgdboc= [HW] kgdb over consoles. - Requires a tty driver that supports console polling. - (only serial supported for now) - Format: [,baud] + Requires a tty driver that supports console polling, + or a supported polling keyboard driver (non-usb). + Serial only format: [,baud] + keyboard only format: kbd + keyboard and serial format: kbd,[,baud] kmac= [MIPS] korina ethernet MAC address. Configure the RouterBoard 532 series on-chip diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c index eadc1ab6bbc..ecef6e1a599 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #define MAX_CONFIG_LEN 40 @@ -32,6 +33,40 @@ static struct kparam_string kps = { static struct tty_driver *kgdb_tty_driver; static int kgdb_tty_line; +#ifdef CONFIG_KDB_KEYBOARD +static int kgdboc_register_kbd(char **cptr) +{ + if (strncmp(*cptr, "kbd", 3) == 0) { + if (kdb_poll_idx < KDB_POLL_FUNC_MAX) { + kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char; + kdb_poll_idx++; + if (cptr[0][3] == ',') + *cptr += 4; + else + return 1; + } + } + return 0; +} + +static void kgdboc_unregister_kbd(void) +{ + int i; + + for (i = 0; i < kdb_poll_idx; i++) { + if (kdb_poll_funcs[i] == kdb_get_kbd_char) { + kdb_poll_idx--; + kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx]; + kdb_poll_funcs[kdb_poll_idx] = NULL; + i--; + } + } +} +#else /* ! CONFIG_KDB_KEYBOARD */ +#define kgdboc_register_kbd(x) 0 +#define kgdboc_unregister_kbd() +#endif /* ! CONFIG_KDB_KEYBOARD */ + static int kgdboc_option_setup(char *opt) { if (strlen(opt) > MAX_CONFIG_LEN) { @@ -45,25 +80,38 @@ static int kgdboc_option_setup(char *opt) __setup("kgdboc=", kgdboc_option_setup); +static void cleanup_kgdboc(void) +{ + kgdboc_unregister_kbd(); + if (configured == 1) + kgdb_unregister_io_module(&kgdboc_io_ops); +} + static int configure_kgdboc(void) { struct tty_driver *p; int tty_line = 0; int err; + char *cptr = config; err = kgdboc_option_setup(config); if (err || !strlen(config) || isspace(config[0])) goto noconfig; err = -ENODEV; + kgdb_tty_driver = NULL; + + if (kgdboc_register_kbd(&cptr)) + goto do_register; - p = tty_find_polling_driver(config, &tty_line); + p = tty_find_polling_driver(cptr, &tty_line); if (!p) goto noconfig; kgdb_tty_driver = p; kgdb_tty_line = tty_line; +do_register: err = kgdb_register_io_module(&kgdboc_io_ops); if (err) goto noconfig; @@ -75,6 +123,7 @@ static int configure_kgdboc(void) noconfig: config[0] = 0; configured = 0; + cleanup_kgdboc(); return err; } @@ -88,20 +137,18 @@ static int __init init_kgdboc(void) return configure_kgdboc(); } -static void cleanup_kgdboc(void) -{ - if (configured == 1) - kgdb_unregister_io_module(&kgdboc_io_ops); -} - static int kgdboc_get_char(void) { + if (!kgdb_tty_driver) + return -1; return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver, kgdb_tty_line); } static void kgdboc_put_char(u8 chr) { + if (!kgdb_tty_driver) + return; kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr); } diff --git a/kernel/debug/kdb/Makefile b/kernel/debug/kdb/Makefile index d1e925eddbc..d4fc58f4b88 100644 --- a/kernel/debug/kdb/Makefile +++ b/kernel/debug/kdb/Makefile @@ -8,6 +8,7 @@ CCVERSION := $(shell $(CC) -v 2>&1 | sed -ne '$$p') obj-y := kdb_io.o kdb_main.o kdb_support.o kdb_bt.o gen-kdb_cmds.o kdb_bp.o kdb_debugger.o +obj-$(CONFIG_KDB_KEYBOARD) += kdb_keyboard.o clean-files := gen-kdb_cmds.c diff --git a/kernel/debug/kdb/kdb_keyboard.c b/kernel/debug/kdb/kdb_keyboard.c new file mode 100644 index 00000000000..4bca634975c --- /dev/null +++ b/kernel/debug/kdb/kdb_keyboard.c @@ -0,0 +1,212 @@ +/* + * Kernel Debugger Architecture Dependent Console I/O handler + * + * This file is subject to the terms and conditions of the GNU General Public + * License. + * + * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include + +/* Keyboard Controller Registers on normal PCs. */ + +#define KBD_STATUS_REG 0x64 /* Status register (R) */ +#define KBD_DATA_REG 0x60 /* Keyboard data register (R/W) */ + +/* Status Register Bits */ + +#define KBD_STAT_OBF 0x01 /* Keyboard output buffer full */ +#define KBD_STAT_MOUSE_OBF 0x20 /* Mouse output buffer full */ + +static int kbd_exists; + +/* + * Check if the keyboard controller has a keypress for us. + * Some parts (Enter Release, LED change) are still blocking polled here, + * but hopefully they are all short. + */ +int kdb_get_kbd_char(void) +{ + int scancode, scanstatus; + static int shift_lock; /* CAPS LOCK state (0-off, 1-on) */ + static int shift_key; /* Shift next keypress */ + static int ctrl_key; + u_short keychar; + + if (KDB_FLAG(NO_I8042) || KDB_FLAG(NO_VT_CONSOLE) || + (inb(KBD_STATUS_REG) == 0xff && inb(KBD_DATA_REG) == 0xff)) { + kbd_exists = 0; + return -1; + } + kbd_exists = 1; + + if ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0) + return -1; + + /* + * Fetch the scancode + */ + scancode = inb(KBD_DATA_REG); + scanstatus = inb(KBD_STATUS_REG); + + /* + * Ignore mouse events. + */ + if (scanstatus & KBD_STAT_MOUSE_OBF) + return -1; + + /* + * Ignore release, trigger on make + * (except for shift keys, where we want to + * keep the shift state so long as the key is + * held down). + */ + + if (((scancode&0x7f) == 0x2a) || ((scancode&0x7f) == 0x36)) { + /* + * Next key may use shift table + */ + if ((scancode & 0x80) == 0) + shift_key = 1; + else + shift_key = 0; + return -1; + } + + if ((scancode&0x7f) == 0x1d) { + /* + * Left ctrl key + */ + if ((scancode & 0x80) == 0) + ctrl_key = 1; + else + ctrl_key = 0; + return -1; + } + + if ((scancode & 0x80) != 0) + return -1; + + scancode &= 0x7f; + + /* + * Translate scancode + */ + + if (scancode == 0x3a) { + /* + * Toggle caps lock + */ + shift_lock ^= 1; + +#ifdef KDB_BLINK_LED + kdb_toggleled(0x4); +#endif + return -1; + } + + if (scancode == 0x0e) { + /* + * Backspace + */ + return 8; + } + + /* Special Key */ + switch (scancode) { + case 0xF: /* Tab */ + return 9; + case 0x53: /* Del */ + return 4; + case 0x47: /* Home */ + return 1; + case 0x4F: /* End */ + return 5; + case 0x4B: /* Left */ + return 2; + case 0x48: /* Up */ + return 16; + case 0x50: /* Down */ + return 14; + case 0x4D: /* Right */ + return 6; + } + + if (scancode == 0xe0) + return -1; + + /* + * For Japanese 86/106 keyboards + * See comment in drivers/char/pc_keyb.c. + * - Masahiro Adegawa + */ + if (scancode == 0x73) + scancode = 0x59; + else if (scancode == 0x7d) + scancode = 0x7c; + + if (!shift_lock && !shift_key && !ctrl_key) { + keychar = plain_map[scancode]; + } else if ((shift_lock || shift_key) && key_maps[1]) { + keychar = key_maps[1][scancode]; + } else if (ctrl_key && key_maps[4]) { + keychar = key_maps[4][scancode]; + } else { + keychar = 0x0020; + kdb_printf("Unknown state/scancode (%d)\n", scancode); + } + keychar &= 0x0fff; + if (keychar == '\t') + keychar = ' '; + switch (KTYP(keychar)) { + case KT_LETTER: + case KT_LATIN: + if (isprint(keychar)) + break; /* printable characters */ + /* drop through */ + case KT_SPEC: + if (keychar == K_ENTER) + break; + /* drop through */ + default: + return -1; /* ignore unprintables */ + } + + if ((scancode & 0x7f) == 0x1c) { + /* + * enter key. All done. Absorb the release scancode. + */ + while ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0) + ; + + /* + * Fetch the scancode + */ + scancode = inb(KBD_DATA_REG); + scanstatus = inb(KBD_STATUS_REG); + + while (scanstatus & KBD_STAT_MOUSE_OBF) { + scancode = inb(KBD_DATA_REG); + scanstatus = inb(KBD_STATUS_REG); + } + + if (scancode != 0x9c) { + /* + * Wasn't an enter-release, why not? + */ + kdb_printf("kdb: expected enter got 0x%x status 0x%x\n", + scancode, scanstatus); + } + + return 13; + } + + return keychar & 0xff; +} +EXPORT_SYMBOL_GPL(kdb_get_kbd_char); diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb index 78de43a5e90..ee8ae7132f2 100644 --- a/lib/Kconfig.kgdb +++ b/lib/Kconfig.kgdb @@ -63,4 +63,11 @@ config KGDB_KDB help KDB frontend for kernel +config KDB_KEYBOARD + bool "KGDB_KDB: keyboard as input device" + depends on VT && KGDB_KDB + default n + help + KDB can use a PS/2 type keyboard for an input device + endif # KGDB -- cgit v1.2.3-70-g09d2 From 98ec1878cacb393975cba64f7392eece81716cb4 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 27 Apr 2009 10:58:06 -0500 Subject: kgdb: remove post_primary_code references Remove all the references to the kgdb_post_primary_code. This function serves no useful purpose because you can obtain the same information from the "struct kgdb_state *ks" from with in the debugger, if for some reason you want the data. Also remove the unintentional duplicate assignment for ks->ex_vector. Signed-off-by: Jason Wessel --- arch/x86/kernel/kgdb.c | 29 ----------------------------- include/linux/kgdb.h | 14 -------------- kernel/debug/debug_core.c | 8 -------- 3 files changed, 51 deletions(-) (limited to 'kernel') diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index f95a2c0b915..acba5716993 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -47,20 +47,8 @@ #include #include #include - #include -/* - * Put the error code here just in case the user cares: - */ -static int gdb_x86errcode; - -/* - * Likewise, the vector number here (since GDB only gets the signal - * number through the usual means, and that's not very specific): - */ -static int gdb_x86vector = -1; - /** * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs * @gdb_regs: A pointer to hold the registers in the order GDB wants. @@ -399,23 +387,6 @@ void kgdb_disable_hw_debug(struct pt_regs *regs) } } -/** - * kgdb_post_primary_code - Save error vector/code numbers. - * @regs: Original pt_regs. - * @e_vector: Original error vector. - * @err_code: Original error code. - * - * This is needed on architectures which support SMP and KGDB. - * This function is called after all the slave cpus have been put - * to a know spin state and the primary CPU has control over KGDB. - */ -void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) -{ - /* primary processor is completely in the debugger */ - gdb_x86vector = e_vector; - gdb_x86errcode = err_code; -} - #ifdef CONFIG_SMP /** * kgdb_roundup_cpus - Get other CPUs into a holding pattern diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 407edb1e0c4..406f6f9286f 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -35,20 +35,6 @@ struct pt_regs; */ extern int kgdb_skipexception(int exception, struct pt_regs *regs); -/** - * kgdb_post_primary_code - (optional) Save error vector/code numbers. - * @regs: Original pt_regs. - * @e_vector: Original error vector. - * @err_code: Original error code. - * - * This is usually needed on architectures which support SMP and - * KGDB. This function is called after all the secondary cpus have - * been put to a know spin state and the primary CPU has control over - * KGDB. - */ -extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, - int err_code); - /** * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook * @regs: Current &struct pt_regs. diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1aed37b4c56..88a83a22537 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -203,12 +203,6 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs) return 0; } -void __weak -kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) -{ - return; -} - /** * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. * @regs: Current &struct pt_regs. @@ -588,7 +582,6 @@ return_normal: * At this point the primary processor is completely * in the debugger and all secondary CPUs are quiescent */ - kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); dbg_deactivate_sw_breakpoints(); kgdb_single_step = 0; kgdb_contthread = current; @@ -678,7 +671,6 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) ks->cpu = raw_smp_processor_id(); ks->ex_vector = evector; ks->signo = signo; - ks->ex_vector = evector; ks->err_code = ecode; ks->kgdb_usethreadid = 0; ks->linux_regs = regs; -- cgit v1.2.3-70-g09d2 From f503b5ae53cb557ac351a668fcac1baab1cef0db Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:25 -0500 Subject: x86,kgdb: Add low level debug hook The only way the debugger can handle a trap in inside rcu_lock, notify_die, or atomic_notifier_call_chain without a triple fault is to have a low level "first opportunity handler" in the int3 exception handler. Generally this will be something the vast majority of folks will not need, but for those who need it, it is added as a kernel .config option called KGDB_LOW_LEVEL_TRAP. CC: Ingo Molnar CC: Thomas Gleixner CC: H. Peter Anvin CC: x86@kernel.org Signed-off-by: Jason Wessel --- arch/x86/include/asm/kgdb.h | 3 +++ arch/x86/kernel/kgdb.c | 22 +++++++++++++++++++++- arch/x86/kernel/traps.c | 6 ++++++ include/linux/kgdb.h | 1 + kernel/debug/debug_core.c | 2 +- lib/Kconfig.kgdb | 9 +++++++++ 6 files changed, 41 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/arch/x86/include/asm/kgdb.h b/arch/x86/include/asm/kgdb.h index e6c6c808489..006da3687cd 100644 --- a/arch/x86/include/asm/kgdb.h +++ b/arch/x86/include/asm/kgdb.h @@ -76,4 +76,7 @@ static inline void arch_kgdb_breakpoint(void) #define BREAK_INSTR_SIZE 1 #define CACHE_FLUSH_IS_SAFE 1 +extern int kgdb_ll_trap(int cmd, const char *str, + struct pt_regs *regs, long err, int trap, int sig); + #endif /* _ASM_X86_KGDB_H */ diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index acba5716993..95b89d4cb8f 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -538,7 +538,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd) return NOTIFY_DONE; } - if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) + if (kgdb_handle_exception(args->trapnr, args->signr, cmd, regs)) return NOTIFY_DONE; /* Must touch watchdog before return to normal operation */ @@ -546,6 +546,26 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd) return NOTIFY_STOP; } +#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP +int kgdb_ll_trap(int cmd, const char *str, + struct pt_regs *regs, long err, int trap, int sig) +{ + struct die_args args = { + .regs = regs, + .str = str, + .err = err, + .trapnr = trap, + .signr = sig, + + }; + + if (!kgdb_io_module_registered) + return NOTIFY_DONE; + + return __kgdb_notify(&args, cmd); +} +#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ + static int kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) { diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 02cfb9b8f5b..7eaad4c5110 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -451,6 +452,11 @@ void restart_nmi(void) /* May run on IST stack. */ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) { +#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP + if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) + == NOTIFY_STOP) + return; +#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ #ifdef CONFIG_KPROBES if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 406f6f9286f..19d1b29a269 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -60,6 +60,7 @@ struct uart_port; void kgdb_breakpoint(void); extern int kgdb_connected; +extern int kgdb_io_module_registered; extern atomic_t kgdb_setting_breakpoint; extern atomic_t kgdb_cpu_doing_single_step; diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 88a83a22537..375e42f0baf 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -66,7 +66,7 @@ int kgdb_connected; EXPORT_SYMBOL_GPL(kgdb_connected); /* All the KGDB handlers are installed */ -static int kgdb_io_module_registered; +int kgdb_io_module_registered; /* Guard for recursive entry */ static int exception_level; diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb index ee8ae7132f2..c56ccb4ad29 100644 --- a/lib/Kconfig.kgdb +++ b/lib/Kconfig.kgdb @@ -57,6 +57,15 @@ config KGDB_TESTS_BOOT_STRING information about other strings you could use beyond the default of V1F100. +config KGDB_LOW_LEVEL_TRAP + bool "KGDB: Allow debugging with traps in notifiers" + depends on X86 + default n + help + This will add an extra call back to kgdb for the breakpoint + exception handler on which will will allow kgdb to step + through a notify handler. + config KGDB_KDB bool "KGDB_KDB: include kdb frontend for kgdb" default n -- cgit v1.2.3-70-g09d2 From 1cee5e35f15d0893be1ba944f1aec8676e43ab76 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Wed, 3 Jun 2009 14:06:57 -0500 Subject: kgdb: Add the ability to schedule a breakpoint via a tasklet Some kgdb I/O modules require the ability to create a breakpoint tasklet, such as kgdboc and external modules such as kgdboe. The breakpoint tasklet is used as an asynchronous entry point into the debugger which will have a different function scope than the current execution path where it might not be safe to have an inline breakpoint. This is true of some of the kgdb I/O drivers which share code with kgdb and rest of the kernel users. Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 1 + kernel/debug/debug_core.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) (limited to 'kernel') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 19d1b29a269..ee007ea341b 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -271,6 +271,7 @@ extern int kgdb_mem2hex(char *mem, char *buf, int count); extern int kgdb_hex2mem(char *buf, char *mem, int count); extern int kgdb_isremovedbreak(unsigned long addr); +extern void kgdb_schedule_breakpoint(void); extern int kgdb_handle_exception(int ex_vector, int signo, int err_code, diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 375e42f0baf..fff59019cca 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -114,6 +114,7 @@ EXPORT_SYMBOL_GPL(kgdb_active); */ static atomic_t passive_cpu_wait[NR_CPUS]; static atomic_t cpu_in_kgdb[NR_CPUS]; +static atomic_t kgdb_break_tasklet_var; atomic_t kgdb_setting_breakpoint; struct task_struct *kgdb_usethread; @@ -789,6 +790,31 @@ static void kgdb_unregister_callbacks(void) } } +/* + * There are times a tasklet needs to be used vs a compiled in + * break point so as to cause an exception outside a kgdb I/O module, + * such as is the case with kgdboe, where calling a breakpoint in the + * I/O driver itself would be fatal. + */ +static void kgdb_tasklet_bpt(unsigned long ing) +{ + kgdb_breakpoint(); + atomic_set(&kgdb_break_tasklet_var, 0); +} + +static DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0); + +void kgdb_schedule_breakpoint(void) +{ + if (atomic_read(&kgdb_break_tasklet_var) || + atomic_read(&kgdb_active) != -1 || + atomic_read(&kgdb_setting_breakpoint)) + return; + atomic_inc(&kgdb_break_tasklet_var); + tasklet_schedule(&kgdb_tasklet_breakpoint); +} +EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint); + static void kgdb_initial_breakpoint(void) { kgdb_break_asap = 0; -- cgit v1.2.3-70-g09d2 From efe2f29e324fd20e0449bcd6dc6dbe4734c2ba94 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:26 -0500 Subject: kgdboc,kdb: Allow kdb to work on a non open console port If kdb is open on a serial port that is not actually a console make sure to call the poll routines to emit and receive characters. Signed-off-by: Jason Wessel Acked-by: Martin Hicks --- drivers/serial/kgdboc.c | 14 ++++++++++++++ include/linux/kgdb.h | 3 +++ kernel/debug/kdb/kdb_io.c | 16 ++++++++++++++++ 3 files changed, 33 insertions(+) (limited to 'kernel') diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c index ecef6e1a599..b765ab48dfe 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -16,6 +16,7 @@ #include #include #include +#include #define MAX_CONFIG_LEN 40 @@ -93,12 +94,14 @@ static int configure_kgdboc(void) int tty_line = 0; int err; char *cptr = config; + struct console *cons; err = kgdboc_option_setup(config); if (err || !strlen(config) || isspace(config[0])) goto noconfig; err = -ENODEV; + kgdboc_io_ops.is_console = 0; kgdb_tty_driver = NULL; if (kgdboc_register_kbd(&cptr)) @@ -108,6 +111,17 @@ static int configure_kgdboc(void) if (!p) goto noconfig; + cons = console_drivers; + while (cons) { + int idx; + if (cons->device && cons->device(cons, &idx) == p && + idx == tty_line) { + kgdboc_io_ops.is_console = 1; + break; + } + cons = cons->next; + } + kgdb_tty_driver = p; kgdb_tty_line = tty_line; diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index ee007ea341b..6c784ab6856 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -247,6 +247,8 @@ struct kgdb_arch { * the I/O driver. * @post_exception: Pointer to a function that will do any cleanup work * for the I/O driver. + * @is_console: 1 if the end device is a console 0 if the I/O device is + * not a console */ struct kgdb_io { const char *name; @@ -256,6 +258,7 @@ struct kgdb_io { int (*init) (void); void (*pre_exception) (void); void (*post_exception) (void); + int is_console; }; extern struct kgdb_arch arch_kgdb_ops; diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 8339b291e8b..58be7e9c9e9 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -673,6 +673,14 @@ kdb_printit: if (!dbg_kdb_mode && kgdb_connected) { gdbstub_msg_write(kdb_buffer, retlen); } else { + if (!dbg_io_ops->is_console) { + len = strlen(kdb_buffer); + cp = kdb_buffer; + while (len--) { + dbg_io_ops->write_char(*cp); + cp++; + } + } while (c) { c->write(c, kdb_buffer, retlen); touch_nmi_watchdog(); @@ -719,6 +727,14 @@ kdb_printit: kdb_input_flush(); c = console_drivers; + if (!dbg_io_ops->is_console) { + len = strlen(moreprompt); + cp = moreprompt; + while (len--) { + dbg_io_ops->write_char(*cp); + cp++; + } + } while (c) { c->write(c, moreprompt, strlen(moreprompt)); touch_nmi_watchdog(); -- cgit v1.2.3-70-g09d2 From d37d39ae3b4a8f9a21114921fb344fe7cadb1abd Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:27 -0500 Subject: printk,kdb: capture printk() when in kdb shell Certain calls from the kdb shell will call out to printk(), and any of these calls should get vectored back to the kdb_printf() so that the kdb pager and processing can be used, as well as to properly channel I/O to the polled I/O devices. CC: Randy Dunlap Signed-off-by: Jason Wessel Acked-by: Andrew Morton --- include/linux/kdb.h | 3 +++ kernel/debug/kdb/kdb_bt.c | 2 ++ kernel/debug/kdb/kdb_io.c | 24 ++++++++++++++++++++---- kernel/debug/kdb/kdb_main.c | 4 ++++ kernel/printk.c | 9 +++++++++ 5 files changed, 38 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/include/linux/kdb.h b/include/linux/kdb.h index d72fa390812..ccb2b3ec0fe 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -78,6 +78,9 @@ typedef enum { KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ } kdb_reason_t; +extern int kdb_trap_printk; +extern int vkdb_printf(const char *fmt, va_list args) + __attribute__ ((format (printf, 1, 0))); extern int kdb_printf(const char *, ...) __attribute__ ((format (printf, 1, 2))); typedef int (*kdb_printf_t)(const char *, ...) diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c index 483fa4e7aaa..2f62fe85f16 100644 --- a/kernel/debug/kdb/kdb_bt.c +++ b/kernel/debug/kdb/kdb_bt.c @@ -23,6 +23,7 @@ static void kdb_show_stack(struct task_struct *p, void *addr) { int old_lvl = console_loglevel; console_loglevel = 15; + kdb_trap_printk++; kdb_set_current_task(p); if (addr) { show_stack((struct task_struct *)p, addr); @@ -36,6 +37,7 @@ static void kdb_show_stack(struct task_struct *p, void *addr) show_stack(p, NULL); } console_loglevel = old_lvl; + kdb_trap_printk--; } /* diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 58be7e9c9e9..c9b7f4f90bb 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -29,6 +29,7 @@ #define CMD_BUFLEN 256 char kdb_prompt_str[CMD_BUFLEN]; +int kdb_trap_printk; static void kgdb_transition_check(char *buffer) { @@ -533,12 +534,12 @@ static int kdb_search_string(char *searched, char *searchfor) return 0; } -int kdb_printf(const char *fmt, ...) +int vkdb_printf(const char *fmt, va_list ap) { - va_list ap; int diag; int linecount; int logging, saved_loglevel = 0; + int saved_trap_printk; int got_printf_lock = 0; int retlen = 0; int fnd, len; @@ -549,6 +550,9 @@ int kdb_printf(const char *fmt, ...) unsigned long uninitialized_var(flags); preempt_disable(); + saved_trap_printk = kdb_trap_printk; + kdb_trap_printk = 0; + /* Serialize kdb_printf if multiple cpus try to write at once. * But if any cpu goes recursive in kdb, just print the output, * even if it is interleaved with any other text. @@ -575,9 +579,7 @@ int kdb_printf(const char *fmt, ...) next_avail = kdb_buffer; size_avail = sizeof(kdb_buffer); } - va_start(ap, fmt); vsnprintf(next_avail, size_avail, fmt, ap); - va_end(ap); /* * If kdb_parse() found that the command was cmd xxx | grep yyy @@ -805,6 +807,20 @@ kdb_print_out: } else { __release(kdb_printf_lock); } + kdb_trap_printk = saved_trap_printk; preempt_enable(); return retlen; } + +int kdb_printf(const char *fmt, ...) +{ + va_list ap; + int r; + + va_start(ap, fmt); + r = vkdb_printf(fmt, ap); + va_end(ap); + + return r; +} + diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 64ef9ac14ba..b724c791b6d 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1056,7 +1056,9 @@ static void kdb_dumpregs(struct pt_regs *regs) { int old_lvl = console_loglevel; console_loglevel = 15; + kdb_trap_printk++; show_regs(regs); + kdb_trap_printk--; kdb_printf("\n"); console_loglevel = old_lvl; } @@ -1819,7 +1821,9 @@ static int kdb_sr(int argc, const char **argv) if (argc != 1) return KDB_ARGCOUNT; sysrq_toggle_support(1); + kdb_trap_printk++; handle_sysrq(*argv[1], NULL); + kdb_trap_printk--; return 0; } diff --git a/kernel/printk.c b/kernel/printk.c index 9213b8b5bb4..444b770c959 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -602,6 +603,14 @@ asmlinkage int printk(const char *fmt, ...) va_list args; int r; +#ifdef CONFIG_KGDB_KDB + if (unlikely(kdb_trap_printk)) { + va_start(args, fmt); + r = vkdb_printf(fmt, args); + va_end(args); + return r; + } +#endif va_start(args, fmt); r = vprintk(fmt, args); va_end(args); -- cgit v1.2.3-70-g09d2 From 6d90634076200af035f1d9dcc8fc11acefd603e9 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:27 -0500 Subject: debug_core,kdb: Allow the debug core to process a recursive debug entry This allows kdb to debug a crash with in the kms code with a single level recursive re-entry. Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index fff59019cca..b38bb25dbbb 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -445,6 +445,10 @@ static int kgdb_reenter_check(struct kgdb_state *ks) } printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); +#ifdef CONFIG_KGDB_KDB + /* Allow kdb to debug itself one level */ + return 0; +#endif dump_stack(); panic("Recursive entry to debugger"); @@ -489,6 +493,9 @@ acquirelock: */ atomic_inc(&cpu_in_kgdb[cpu]); + if (exception_level == 1) + goto cpu_master_loop; + /* * CPU will loop if it is a slave or request to become a kgdb * master cpu and acquire the kgdb_active lock: -- cgit v1.2.3-70-g09d2 From 4402c153cb9c549cd21d6007ef0dfac50c8d148d Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:28 -0500 Subject: kdb,debug_core: Allow the debug core to receive a panic notification It is highly desirable to trap into kdb on panic. The debug core will attempt to register as the first in line for the panic notifier. CC: Ingo Molnar CC: Andrew Morton CC: Eric W. Biederman Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'kernel') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index b38bb25dbbb..64b5588c963 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -762,11 +762,28 @@ static struct sysrq_key_op sysrq_dbg_op = { }; #endif +static int kgdb_panic_event(struct notifier_block *self, + unsigned long val, + void *data) +{ + if (dbg_kdb_mode) + kdb_printf("PANIC: %s\n", (char *)data); + kgdb_breakpoint(); + return NOTIFY_DONE; +} + +static struct notifier_block kgdb_panic_event_nb = { + .notifier_call = kgdb_panic_event, + .priority = INT_MAX, +}; + static void kgdb_register_callbacks(void) { if (!kgdb_io_module_registered) { kgdb_io_module_registered = 1; kgdb_arch_init(); + atomic_notifier_chain_register(&panic_notifier_list, + &kgdb_panic_event_nb); #ifdef CONFIG_MAGIC_SYSRQ register_sysrq_key('g', &sysrq_dbg_op); #endif @@ -786,6 +803,8 @@ static void kgdb_unregister_callbacks(void) */ if (kgdb_io_module_registered) { kgdb_io_module_registered = 0; + atomic_notifier_chain_unregister(&panic_notifier_list, + &kgdb_panic_event_nb); kgdb_arch_exit(); #ifdef CONFIG_MAGIC_SYSRQ unregister_sysrq_key('g', &sysrq_dbg_op); -- cgit v1.2.3-70-g09d2