tracing: Add skip argument to trace_dump_stack()
Altough the trace_dump_stack() already skips three functions in
the call to stack trace, which gets the stack trace to start
at the caller of the function, the caller may want to skip some
more too (as it may have helper functions).
Add a skip argument to the trace_dump_stack() that lets the caller
skip back tracing functions that it doesn't care about.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d0a16fe..239dbb9 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -597,7 +597,7 @@
__trace_puts(_THIS_IP_, str, strlen(str)); \
})
-extern void trace_dump_stack(void);
+extern void trace_dump_stack(int skip);
/*
* The double __builtin_constant_p is because gcc will give us an error
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c5b8446..8aa5321 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1657,8 +1657,9 @@
/**
* trace_dump_stack - record a stack back trace in the trace buffer
+ * @skip: Number of functions to skip (helper handlers)
*/
-void trace_dump_stack(void)
+void trace_dump_stack(int skip)
{
unsigned long flags;
@@ -1667,9 +1668,13 @@
local_save_flags(flags);
- /* skipping 3 traces, seems to get us at the caller of this function */
- __ftrace_trace_stack(global_trace.trace_buffer.buffer, flags, 3,
- preempt_count(), NULL);
+ /*
+ * Skip 3 more, seems to get us at the caller of
+ * this function.
+ */
+ skip += 3;
+ __ftrace_trace_stack(global_trace.trace_buffer.buffer,
+ flags, skip, preempt_count(), NULL);
}
static DEFINE_PER_CPU(int, user_stack_count);