[PATCH v2] ftrace: Hide a extra entry in stack trace
From: Tatsuya S
Date: Thu Sep 26 2024 - 02:15:59 EST
A extra entry is shown on stack trace(CONFIG_UNWINDER_ORC=y).
[003] ..... 110.171589: vfs_write <-__x64_sys_write
[003] ..... 110.171600: <stack trace>
=> XXXXXXXXX (Wrong function name)
=> vfs_write
=> __x64_sys_write
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
To resolve this, increment skip in __ftrace_trace_stack().
The reason why skip is incremented in __ftrace_trace_stack()
is because __ftrace_trace_stack() in stack trace is the only function
that wasn't skipped from anywhere.
Signed-off-by: Tatsuya S <tatsuya.s2862@xxxxxxxxx>
---
kernel/trace/trace.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c3b2c7dfadef..0f2e255f563c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2916,10 +2916,8 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
* Add one, for this function and the call to save_stack_trace()
* If regs is set, then these functions will not be in the way.
*/
-#ifndef CONFIG_UNWINDER_ORC
- if (!regs)
+ if (IS_ENABLED(CONFIG_UNWINDER_ORC) || !regs)
skip++;
-#endif
preempt_disable_notrace();
--
2.46.1