From 2ec220e27f5040aec1e88901c1b6ea3d135787ad Mon Sep 17 00:00:00 2001 From: Ken Chen Date: Mon, 10 Nov 2008 11:26:08 +0300 Subject: proc: add /proc/*/stack /proc/*/stack adds the ability to query a task's stack trace. It is more useful than /proc/*/wchan as it provides full stack trace instead of single depth. Example output: $ cat /proc/self/stack [] save_stack_trace_tsk+0x17/0x35 [] proc_pid_stack+0x4a/0x76 [] proc_single_show+0x4a/0x5e [] seq_read+0xf3/0x29f [] vfs_read+0x6d/0x91 [] sys_read+0x3b/0x60 [] syscall_call+0x7/0xb [] 0xffffffff [add save_stack_trace_tsk() on mips, ACK Ralf --adobriyan] Signed-off-by: Ken Chen Signed-off-by: Ingo Molnar Signed-off-by: Alexey Dobriyan --- arch/mips/kernel/stacktrace.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/mips/kernel/stacktrace.c b/arch/mips/kernel/stacktrace.c index 0632e2a849c..58f5cd76c8c 100644 --- a/arch/mips/kernel/stacktrace.c +++ b/arch/mips/kernel/stacktrace.c @@ -32,7 +32,8 @@ static void save_raw_context_stack(struct stack_trace *trace, } } -static void save_context_stack(struct stack_trace *trace, struct pt_regs *regs) +static void save_context_stack(struct stack_trace *trace, + struct task_struct *tsk, struct pt_regs *regs) { unsigned long sp = regs->regs[29]; #ifdef CONFIG_KALLSYMS @@ -41,7 +42,7 @@ static void save_context_stack(struct stack_trace *trace, struct pt_regs *regs) if (raw_show_trace || !__kernel_text_address(pc)) { unsigned long stack_page = - (unsigned long)task_stack_page(current); + (unsigned long)task_stack_page(tsk); if (stack_page && sp >= stack_page && sp <= stack_page + THREAD_SIZE - 32) save_raw_context_stack(trace, sp); @@ -54,7 +55,7 @@ static void save_context_stack(struct stack_trace *trace, struct pt_regs *regs) trace->entries[trace->nr_entries++] = pc; if (trace->nr_entries >= trace->max_entries) break; - pc = unwind_stack(current, &sp, pc, &ra); + pc = unwind_stack(tsk, &sp, pc, &ra); } while (pc); #else save_raw_context_stack(trace, sp); @@ -65,13 +66,24 @@ static void save_context_stack(struct stack_trace *trace, struct pt_regs *regs) * Save stack-backtrace addresses into a stack_trace buffer. */ void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { struct pt_regs dummyregs; struct pt_regs *regs = &dummyregs; WARN_ON(trace->nr_entries || !trace->max_entries); - prepare_frametrace(regs); - save_context_stack(trace, regs); + if (tsk != current) { + regs->regs[29] = tsk->thread.reg29; + regs->regs[31] = 0; + regs->cp0_epc = tsk->thread.reg31; + } else + prepare_frametrace(regs); + save_context_stack(trace, tsk, regs); } -EXPORT_SYMBOL_GPL(save_stack_trace); +EXPORT_SYMBOL_GPL(save_stack_trace_tsk); -- cgit v1.2.3-70-g09d2