diff options
| -rw-r--r-- | arch/arc/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arc/include/asm/kgdb.h | 61 | ||||
| -rw-r--r-- | arch/arc/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arc/kernel/kgdb.c | 205 | ||||
| -rw-r--r-- | arch/arc/kernel/traps.c | 6 |
5 files changed, 275 insertions, 1 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index f8042835e74..69a939af72c 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -22,6 +22,7 @@ config ARC select GENERIC_PENDING_IRQ if SMP select GENERIC_SIGALTSTACK select GENERIC_SMP_IDLE_THREAD + select HAVE_ARCH_KGDB select HAVE_ARCH_TRACEHOOK select HAVE_GENERIC_HARDIRQS select HAVE_KPROBES @@ -378,7 +379,7 @@ config ARC_DW2_UNWIND config ARC_DBG_TLB_PARANOIA bool "Paranoia Checks in Low Level TLB Handlers" - depends on ARC_DBG && !SMP + depends on ARC_DBG default n config ARC_DBG_TLB_MISS_COUNT diff --git a/arch/arc/include/asm/kgdb.h b/arch/arc/include/asm/kgdb.h new file mode 100644 index 00000000000..f3c4934f0ca --- /dev/null +++ b/arch/arc/include/asm/kgdb.h @@ -0,0 +1,61 @@ +/* + * kgdb support for ARC + * + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __ARC_KGDB_H__ +#define __ARC_KGDB_H__ + +#ifdef CONFIG_KGDB + +#include <asm/user.h> + +/* to ensure compatibility with Linux 2.6.35, we don't implement the get/set + * register API yet */ +#undef DBG_MAX_REG_NUM + +#define GDB_MAX_REGS 39 + +#define BREAK_INSTR_SIZE 2 +#define CACHE_FLUSH_IS_SAFE 1 +#define NUMREGBYTES (GDB_MAX_REGS * 4) +#define BUFMAX 2048 + +static inline void arch_kgdb_breakpoint(void) +{ + __asm__ __volatile__ ("trap_s 0x4\n"); +} + +extern void kgdb_trap(struct pt_regs *regs, int param); + +enum arc700_linux_regnums { + _R0 = 0, + _R1, _R2, _R3, _R4, _R5, _R6, _R7, _R8, _R9, _R10, _R11, _R12, _R13, + _R14, _R15, _R16, _R17, _R18, _R19, _R20, _R21, _R22, _R23, _R24, + _R25, _R26, + _BTA = 27, + _LP_START = 28, + _LP_END = 29, + _LP_COUNT = 30, + _STATUS32 = 31, + _BLINK = 32, + _FP = 33, + __SP = 34, + _EFA = 35, + _RET = 36, + _ORIG_R8 = 37, + _STOP_PC = 38 +}; + +#else +static inline void kgdb_trap(struct pt_regs *regs, int param) +{ +} +#endif + +#endif /* __ARC_KGDB_H__ */ diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile index 507a33d4a25..6da2b12cf7e 100644 --- a/arch/arc/kernel/Makefile +++ b/arch/arc/kernel/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_ARC_DW2_UNWIND) += unwind.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_ARC_MISALIGN_ACCESS) += unaligned.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_ARC_FPU_SAVE_RESTORE) += fpu.o CFLAGS_fpu.o += -mdpfp diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c new file mode 100644 index 00000000000..2888ba5be47 --- /dev/null +++ b/arch/arc/kernel/kgdb.c @@ -0,0 +1,205 @@ +/* + * kgdb support for ARC + * + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kgdb.h> +#include <asm/disasm.h> +#include <asm/cacheflush.h> + +static void to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs, + struct callee_regs *cregs) +{ + int regno; + + for (regno = 0; regno <= 26; regno++) + gdb_regs[_R0 + regno] = get_reg(regno, kernel_regs, cregs); + + for (regno = 27; regno < GDB_MAX_REGS; regno++) + gdb_regs[regno] = 0; + + gdb_regs[_FP] = kernel_regs->fp; + gdb_regs[__SP] = kernel_regs->sp; + gdb_regs[_BLINK] = kernel_regs->blink; + gdb_regs[_RET] = kernel_regs->ret; + gdb_regs[_STATUS32] = kernel_regs->status32; + gdb_regs[_LP_COUNT] = kernel_regs->lp_count; + gdb_regs[_LP_END] = kernel_regs->lp_end; + gdb_regs[_LP_START] = kernel_regs->lp_start; + gdb_regs[_BTA] = kernel_regs->bta; + gdb_regs[_STOP_PC] = kernel_regs->ret; +} + +static void from_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs, + struct callee_regs *cregs) +{ + int regno; + + for (regno = 0; regno <= 26; regno++) + set_reg(regno, gdb_regs[regno + _R0], kernel_regs, cregs); + + kernel_regs->fp = gdb_regs[_FP]; + kernel_regs->sp = gdb_regs[__SP]; + kernel_regs->blink = gdb_regs[_BLINK]; + kernel_regs->ret = gdb_regs[_RET]; + kernel_regs->status32 = gdb_regs[_STATUS32]; + kernel_regs->lp_count = gdb_regs[_LP_COUNT]; + kernel_regs->lp_end = gdb_regs[_LP_END]; + kernel_regs->lp_start = gdb_regs[_LP_START]; + kernel_regs->bta = gdb_regs[_BTA]; +} + + +void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs) +{ + to_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *) + current->thread.callee_reg); +} + +void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs) +{ + from_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *) + current->thread.callee_reg); +} + +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, + struct task_struct *task) +{ + if (task) + to_gdb_regs(gdb_regs, task_pt_regs(task), + (struct callee_regs *) task->thread.callee_reg); +} + +struct single_step_data_t { + uint16_t opcode[2]; + unsigned long address[2]; + int is_branch; + int armed; +} single_step_data; + +static void undo_single_step(struct pt_regs *regs) +{ + if (single_step_data.armed) { + int i; + + for (i = 0; i < (single_step_data.is_branch ? 2 : 1); i++) { + memcpy((void *) single_step_data.address[i], + &single_step_data.opcode[i], + BREAK_INSTR_SIZE); + + flush_icache_range(single_step_data.address[i], + single_step_data.address[i] + + BREAK_INSTR_SIZE); + } + single_step_data.armed = 0; + } +} + +static void place_trap(unsigned long address, void *save) +{ + memcpy(save, (void *) address, BREAK_INSTR_SIZE); + memcpy((void *) address, &arch_kgdb_ops.gdb_bpt_instr, + BREAK_INSTR_SIZE); + flush_icache_range(address, address + BREAK_INSTR_SIZE); +} + +static void do_single_step(struct pt_regs *regs) +{ + single_step_data.is_branch = disasm_next_pc((unsigned long) + regs->ret, regs, (struct callee_regs *) + current->thread.callee_reg, + &single_step_data.address[0], + &single_step_data.address[1]); + + place_trap(single_step_data.address[0], &single_step_data.opcode[0]); + + if (single_step_data.is_branch) { + place_trap(single_step_data.address[1], + &single_step_data.opcode[1]); + } + + single_step_data.armed++; +} + +int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, + char *remcomInBuffer, char *remcomOutBuffer, + struct pt_regs *regs) +{ + unsigned long addr; + char *ptr; + + undo_single_step(regs); + + switch (remcomInBuffer[0]) { + case 's': + case 'c': + ptr = &remcomInBuffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + regs->ret = addr; + + case 'D': + case 'k': + atomic_set(&kgdb_cpu_doing_single_step, -1); + + if (remcomInBuffer[0] == 's') { + do_single_step(regs); + atomic_set(&kgdb_cpu_doing_single_step, + smp_processor_id()); + } + + return 0; + } + return -1; +} + +unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int kgdb_arch_init(void) +{ + single_step_data.armed = 0; + return 0; +} + +void kgdb_trap(struct pt_regs *regs, int param) +{ + /* trap_s 3 is used for breakpoints that overwrite existing + * instructions, while trap_s 4 is used for compiled breakpoints. + * + * with trap_s 3 breakpoints the original instruction needs to be + * restored and continuation needs to start at the location of the + * breakpoint. + * + * with trap_s 4 (compiled) breakpoints, continuation needs to + * start after the breakpoint. + */ + if (param == 3) + instruction_pointer(regs) -= BREAK_INSTR_SIZE; + + kgdb_handle_exception(1, SIGTRAP, 0, regs); +} + +void kgdb_arch_exit(void) +{ +} + +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) +{ + instruction_pointer(regs) = ip; +} + +struct kgdb_arch arch_kgdb_ops = { + /* breakpoint instruction: TRAP_S 0x3 */ +#ifdef CONFIG_CPU_BIG_ENDIAN + .gdb_bpt_instr = {0x78, 0x7e}, +#else + .gdb_bpt_instr = {0x7e, 0x78}, +#endif +}; diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c index ec802c52a1c..7496995371e 100644 --- a/arch/arc/kernel/traps.c +++ b/arch/arc/kernel/traps.c @@ -20,6 +20,7 @@ #include <asm/setup.h> #include <asm/kprobes.h> #include <asm/unaligned.h> +#include <asm/kgdb.h> void __init trap_init(void) { @@ -141,6 +142,11 @@ void do_non_swi_trap(unsigned long cause, unsigned long address, trap_is_kprobe(param, address, regs); break; + case 3: + case 4: + kgdb_trap(regs, param); + break; + default: break; } |