From 29a679754b1a2581ee456eada6c2de7ce95068bb Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 May 2009 23:19:09 -0400 Subject: x86/stacktrace: return 0 instead of -1 for stack ops If we return -1 in the ops->stack for the stacktrace saving, we end up breaking out of the loop if the stack we are tracing is in the exception stack. This causes traces like: -0 [002] 34263.745825: raise_softirq_irqoff <-__blk_complete_request -0 [002] 34263.745826: <= 0 <= 0 <= 0 <= 0 <= 0 <= 0 <= 0 By returning "0" instead, the irq stack is saved as well, and we see: -0 [003] 883.280992: raise_softirq_irqoff <-__hrtimer_star t_range_ns -0 [003] 883.280992: <= hrtimer_start_range_ns <= tick_nohz_restart_sched_tick <= cpu_idle <= start_secondary <= <= 0 <= 0 [ Impact: record stacks from interrupts ] Signed-off-by: Steven Rostedt --- arch/x86/kernel/stacktrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/stacktrace.c') diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index f7bddc2e37d1..4aaf7e48394f 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -20,7 +20,7 @@ save_stack_warning_symbol(void *data, char *msg, unsigned long symbol) static int save_stack_stack(void *data, char *name) { - return -1; + return 0; } static void save_stack_address(void *data, unsigned long addr, int reliable) -- cgit v1.2.3 From acc6be5405b90c9f0fb0eb8a74ec4d4b7b5bf48f Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Tue, 20 May 2008 11:15:43 +0200 Subject: x86: add save_stack_trace_bp() for tracing from a specific stack frame This will help kmemcheck (and possibly other debugging tools) since we can now simply pass regs->bp to the stack tracer instead of specifying the number of stack frames to skip, which is unreliable if gcc decides to inline functions, etc. Note that this makes the API incomplete for other architectures, but I expect that those can be updated lazily, e.g. when they need it. Cc: Arjan van de Ven Signed-off-by: Vegard Nossum --- arch/x86/kernel/stacktrace.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/kernel/stacktrace.c') diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 4aaf7e48394f..c3eb207181fe 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -77,6 +77,13 @@ void save_stack_trace(struct stack_trace *trace) } EXPORT_SYMBOL_GPL(save_stack_trace); +void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp) +{ + dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); -- cgit v1.2.3