projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1df0f0ff | 1 | /* |
| 1df0f0ff AN |
2 | * Stack trace management functions |
| 3 | * | |
| 4 | * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp> | |
| 5 | */ | |
| 6 | #include <linux/sched.h> | |
| 7 | #include <linux/stacktrace.h> | |
| 73bc256d | 8 | #include <linux/export.h> |
| 1df0f0ff AN |
9 | #include <asm/stacktrace.h> |
| 10 | ||
| 11 | /* | |
| 12 | * Save stack-backtrace addresses into a stack_trace buffer: | |
| 13 | */ | |
| 14 | static void save_raw_context_stack(struct stack_trace *trace, | |
| 23126692 | 15 | unsigned long reg29) |
| 1df0f0ff AN |
16 | { |
| 17 | unsigned long *sp = (unsigned long *)reg29; | |
| 18 | unsigned long addr; | |
| 19 | ||
| 20 | while (!kstack_end(sp)) { | |
| 21 | addr = *sp++; | |
| 22 | if (__kernel_text_address(addr)) { | |
| 23126692 AN |
23 | if (trace->skip > 0) |
| 24 | trace->skip--; | |
| 1df0f0ff | 25 | else |
| 23126692 | 26 | trace->entries[trace->nr_entries++] = addr; |
| 1df0f0ff AN |
27 | if (trace->nr_entries >= trace->max_entries) |
| 28 | break; | |
| 29 | } | |
| 30 | } | |
| 31 | } | |
| 32 | ||
| 2ec220e2 KC |
33 | static void save_context_stack(struct stack_trace *trace, |
| 34 | struct task_struct *tsk, struct pt_regs *regs) | |
| 1df0f0ff AN |
35 | { |
| 36 | unsigned long sp = regs->regs[29]; | |
| 37 | #ifdef CONFIG_KALLSYMS | |
| 38 | unsigned long ra = regs->regs[31]; | |
| 39 | unsigned long pc = regs->cp0_epc; | |
| 1df0f0ff AN |
40 | |
| 41 | if (raw_show_trace || !__kernel_text_address(pc)) { | |
| 1924600c | 42 | unsigned long stack_page = |
| 2ec220e2 | 43 | (unsigned long)task_stack_page(tsk); |
| 23126692 AN |
44 | if (stack_page && sp >= stack_page && |
| 45 | sp <= stack_page + THREAD_SIZE - 32) | |
| 46 | save_raw_context_stack(trace, sp); | |
| 1924600c | 47 | return; |
| 1df0f0ff AN |
48 | } |
| 49 | do { | |
| 23126692 AN |
50 | if (trace->skip > 0) |
| 51 | trace->skip--; | |
| 1df0f0ff | 52 | else |
| 23126692 | 53 | trace->entries[trace->nr_entries++] = pc; |
| 1df0f0ff AN |
54 | if (trace->nr_entries >= trace->max_entries) |
| 55 | break; | |
| 2ec220e2 | 56 | pc = unwind_stack(tsk, &sp, pc, &ra); |
| 1df0f0ff AN |
57 | } while (pc); |
| 58 | #else | |
| eea32d4c | 59 | save_raw_context_stack(trace, sp); |
| 1df0f0ff | 60 | #endif |
| 1df0f0ff AN |
61 | } |
| 62 | ||
| 63 | /* | |
| 64 | * Save stack-backtrace addresses into a stack_trace buffer. | |
| 1df0f0ff | 65 | */ |
| ab1b6f03 | 66 | void save_stack_trace(struct stack_trace *trace) |
| 2ec220e2 KC |
67 | { |
| 68 | save_stack_trace_tsk(current, trace); | |
| 69 | } | |
| 70 | EXPORT_SYMBOL_GPL(save_stack_trace); | |
| 71 | ||
| 72 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) | |
| 1df0f0ff AN |
73 | { |
| 74 | struct pt_regs dummyregs; | |
| 75 | struct pt_regs *regs = &dummyregs; | |
| 76 | ||
| 77 | WARN_ON(trace->nr_entries || !trace->max_entries); | |
| 78 | ||
| 2ec220e2 KC |
79 | if (tsk != current) { |
| 80 | regs->regs[29] = tsk->thread.reg29; | |
| 81 | regs->regs[31] = 0; | |
| 82 | regs->cp0_epc = tsk->thread.reg31; | |
| 83 | } else | |
| 84 | prepare_frametrace(regs); | |
| 85 | save_context_stack(trace, tsk, regs); | |
| 1df0f0ff | 86 | } |
| 2ec220e2 | 87 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); |