From 7eea4fce0246fe3a15ad7f3bb8d0a56d1f9440e6 Mon Sep 17 00:00:00 2001 From: Jiaxing Wang Date: Sun, 20 Apr 2014 23:10:43 +0800 Subject: tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_func When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn Signed-off-by: Jiaxing Wang Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 5 +++++ kernel/trace/trace.h | 1 + kernel/trace/trace_stack.c | 8 ++++++-- 3 files changed, 12 insertions(+), 2 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 846888e..3cfeb66 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -313,6 +313,11 @@ static void update_ftrace_function(void) ftrace_trace_function = func; } +int using_ftrace_ops_list_func(void) +{ + return ftrace_trace_function == ftrace_ops_list_func; +} + static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) { ops->next = *list; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5d2f07d..8624b50 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -830,6 +830,7 @@ void ftrace_destroy_function_files(struct trace_array *tr); void ftrace_init_global_array_ops(struct trace_array *tr); void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func); void ftrace_reset_array_ops(struct trace_array *tr); +int using_ftrace_ops_list_func(void); #else static inline int ftrace_trace_task(struct task_struct *task) { diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 21b320e..5aa9a5b 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -85,8 +85,12 @@ check_stack(unsigned long ip, unsigned long *stack) max_stack_size = this_size; - max_stack_trace.nr_entries = 0; - max_stack_trace.skip = 3; + max_stack_trace.nr_entries = 0; + + if (using_ftrace_ops_list_func()) + max_stack_trace.skip = 4; + else + max_stack_trace.skip = 3; save_stack_trace(&max_stack_trace); -- cgit v1.1