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-rw-r--r--kernel/kgdb.c1764
1 files changed, 0 insertions, 1764 deletions
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 <jason.wessel@windriver.com>
- *
- * Copyright (C) 2000-2001 VERITAS Software Corporation.
- * Copyright (C) 2002-2004 Timesys Corporation
- * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
- * Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
- * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
- * 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 <mingo@redhat.com>
- *
- * Contributors at various stages not listed above:
- * Jason Wessel ( jason.wessel@windriver.com )
- * George Anzinger <george@mvista.com>
- * Anurekh Saxena (anurekh.saxena@timesys.com)
- * Lake Stevens Instrument Division (Glenn Engel)
- * Jim Kingdon, Cygnus Support.
- *
- * Original KGDB stub: David Grothe <dave@gcom.com>,
- * Tigran Aivazian <tigran@sco.com>
- *
- * 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 <linux/pid_namespace.h>
-#include <linux/clocksource.h>
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/console.h>
-#include <linux/threads.h>
-#include <linux/uaccess.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/ptrace.h>
-#include <linux/reboot.h>
-#include <linux/string.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/sysrq.h>
-#include <linux/init.h>
-#include <linux/kgdb.h>
-#include <linux/pid.h>
-#include <linux/smp.h>
-#include <linux/mm.h>
-
-#include <asm/cacheflush.h>
-#include <asm/byteorder.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-#include <asm/unaligned.h>
-
-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 $<data>#<checksum> */
-static void get_packet(char *buffer)
-{
- unsigned char checksum;
- unsigned char xmitcsum;
- int count;
- char ch;
-
- do {
- /*
- * Spin and wait around for the start character, ignore all
- * other characters:
- */
- while ((ch = (kgdb_io_ops->read_char())) != '$')
- /* 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;
-
- /*
- * $<packet info>#<checksum>.
- */
- while (1) {
- kgdb_io_ops->write_char('$');
- 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);