* [PATCH 1/2] tracing/trace_stack:Skip 4 instead of 3 when using ftrace_ops_list_func
2014-04-20 15:10 [PATCH 0/2] Stack trace fix and ftrace documentation fixes Jiaxing Wang
@ 2014-04-20 15:10 ` Jiaxing Wang
2014-04-20 15:10 ` [PATCH 2/2] Correct documentation of ftrace_set_global_filter and ftrace_set_global_notrace Jiaxing Wang
2014-04-23 12:21 ` [PATCH 0/2] Stack trace fix and ftrace documentation fixes Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Jiaxing Wang @ 2014-04-20 15:10 UTC (permalink / raw)
To: Steven Rostedt, Frederic Weisbecker, Ingo Molnar
Cc: linux-kernel, Jiaxing Wang
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.
Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn>
---
kernel/trace/ftrace.c | 5 +++++
kernel/trace/trace.h | 1 +
kernel/trace/trace_stack.c | 8 ++++++--
3 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1fd4b94..e7e7302 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -373,6 +373,11 @@ 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 ffc314b..920c0a5 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -822,6 +822,7 @@ extern int ftrace_is_dead(void);
int ftrace_create_function_files(struct trace_array *tr,
struct dentry *parent);
void ftrace_destroy_function_files(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);
--
1.8.3.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] Correct documentation of ftrace_set_global_filter and ftrace_set_global_notrace
2014-04-20 15:10 [PATCH 0/2] Stack trace fix and ftrace documentation fixes Jiaxing Wang
2014-04-20 15:10 ` [PATCH 1/2] tracing/trace_stack:Skip 4 instead of 3 when using ftrace_ops_list_func Jiaxing Wang
@ 2014-04-20 15:10 ` Jiaxing Wang
2014-04-23 12:21 ` [PATCH 0/2] Stack trace fix and ftrace documentation fixes Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Jiaxing Wang @ 2014-04-20 15:10 UTC (permalink / raw)
To: Steven Rostedt, Frederic Weisbecker, Ingo Molnar
Cc: linux-kernel, Jiaxing Wang
Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn>
---
kernel/trace/ftrace.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e7e7302..57cdaba 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3644,8 +3644,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
}
EXPORT_SYMBOL_GPL(ftrace_set_notrace);
/**
- * ftrace_set_filter - set a function to filter on in ftrace
- * @ops - the ops to set the filter with
+ * ftrace_set_global_filter - set a function to filter on with global tracers
* @buf - the string that holds the function filter text.
* @len - the length of the string.
* @reset - non zero to reset all filters before applying this filter.
@@ -3660,8 +3659,7 @@ void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
/**
- * ftrace_set_notrace - set a function to not trace in ftrace
- * @ops - the ops to set the notrace filter with
+ * ftrace_set_global_notrace - set a function to not trace with global tracers
* @buf - the string that holds the function notrace text.
* @len - the length of the string.
* @reset - non zero to reset all filters before applying this filter.
--
1.8.3.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 0/2] Stack trace fix and ftrace documentation fixes
2014-04-20 15:10 [PATCH 0/2] Stack trace fix and ftrace documentation fixes Jiaxing Wang
2014-04-20 15:10 ` [PATCH 1/2] tracing/trace_stack:Skip 4 instead of 3 when using ftrace_ops_list_func Jiaxing Wang
2014-04-20 15:10 ` [PATCH 2/2] Correct documentation of ftrace_set_global_filter and ftrace_set_global_notrace Jiaxing Wang
@ 2014-04-23 12:21 ` Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2014-04-23 12:21 UTC (permalink / raw)
To: Jiaxing Wang; +Cc: Frederic Weisbecker, Ingo Molnar, linux-kernel
On Sun, 20 Apr 2014 23:10:42 +0800
Jiaxing Wang <wangjiaxing@insigma.com.cn> wrote:
> The first patch makes trace_stack to skip 4 instead of 3 function
> return addresses on the stack when ftrace_ops_list_func is used in ftrace,
> and added a function to check for this.
>
> The second correct the documentation of two functions in ftrace.c
>
> Jiaxing Wang (2):
> tracing/trace_stack:Skip 4 instead of 3 when using
> ftrace_ops_list_func
> Correct documentation of ftrace_set_global_filter and
> ftrace_set_global_notrace
>
> kernel/trace/ftrace.c | 11 +++++++----
> kernel/trace/trace.h | 1 +
> kernel/trace/trace_stack.c | 8 ++++++--
> 3 files changed, 14 insertions(+), 6 deletions(-)
>
I'm a bit busy right now, but I have this in my todo list to look at.
Thanks,
-- Steve
^ permalink raw reply [flat|nested] 4+ messages in thread