2 * Stack trace management functions
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
6 #include <linux/sched.h>
7 #include <linux/sched/debug.h>
8 #include <linux/sched/task_stack.h>
9 #include <linux/stacktrace.h>
10 #include <linux/export.h>
11 #include <asm/stacktrace.h>
14 * Save stack-backtrace addresses into a stack_trace buffer:
16 static void save_raw_context_stack(struct stack_trace *trace,
17 unsigned long reg29, int savesched)
19 unsigned long *sp = (unsigned long *)reg29;
22 while (!kstack_end(sp)) {
24 if (__kernel_text_address(addr) &&
25 (savesched || !in_sched_functions(addr))) {
29 trace->entries[trace->nr_entries++] = addr;
30 if (trace->nr_entries >= trace->max_entries)
36 static void save_context_stack(struct stack_trace *trace,
37 struct task_struct *tsk, struct pt_regs *regs, int savesched)
39 unsigned long sp = regs->regs[29];
40 #ifdef CONFIG_KALLSYMS
41 unsigned long ra = regs->regs[31];
42 unsigned long pc = regs->cp0_epc;
44 if (raw_show_trace || !__kernel_text_address(pc)) {
45 unsigned long stack_page =
46 (unsigned long)task_stack_page(tsk);
47 if (stack_page && sp >= stack_page &&
48 sp <= stack_page + THREAD_SIZE - 32)
49 save_raw_context_stack(trace, sp, savesched);
53 if (savesched || !in_sched_functions(pc)) {
57 trace->entries[trace->nr_entries++] = pc;
58 if (trace->nr_entries >= trace->max_entries)
61 pc = unwind_stack(tsk, &sp, pc, &ra);
64 save_raw_context_stack(trace, sp, savesched);
69 * Save stack-backtrace addresses into a stack_trace buffer.
71 void save_stack_trace(struct stack_trace *trace)
73 save_stack_trace_tsk(current, trace);
75 EXPORT_SYMBOL_GPL(save_stack_trace);
77 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
79 struct pt_regs dummyregs;
80 struct pt_regs *regs = &dummyregs;
82 WARN_ON(trace->nr_entries || !trace->max_entries);
85 regs->regs[29] = tsk->thread.reg29;
87 regs->cp0_epc = tsk->thread.reg31;
89 prepare_frametrace(regs);
90 save_context_stack(trace, tsk, regs, tsk == current);
92 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);