From: Steven Rostedt (Red Hat) Date: Tue, 15 Jul 2014 15:05:12 +0000 (-0400) Subject: tracing: Fix graph tracer with stack tracer on other archs X-Git-Tag: upstream/snapshot3+hdmi~2056 X-Git-Url: http://review.tizen.org/git/?p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git;a=commitdiff_plain;h=45ed61bc4fe2bb437f042420501e3980cf1ff3f6 tracing: Fix graph tracer with stack tracer on other archs commit 5f8bf2d263a20b986225ae1ed7d6759dc4b93af9 upstream. Running my ftrace tests on PowerPC, it failed the test that checks if function_graph tracer is affected by the stack tracer. It was. Looking into this, I found that the update_function_graph_func() must be called even if the trampoline function is not changed. This is because archs like PowerPC do not support ftrace_ops being passed by assembly and instead uses a helper function (what the trampoline function points to). Since this function is not changed even when multiple ftrace_ops are added to the code, the test that falls out before calling update_function_graph_func() will miss that the update must still be done. Call update_function_graph_function() for all calls to update_ftrace_function() Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 868633e..e3be87e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -331,12 +331,12 @@ static void update_ftrace_function(void) func = ftrace_ops_list_func; } + update_function_graph_func(); + /* If there's no change, then do nothing more here */ if (ftrace_trace_function == func) return; - update_function_graph_func(); - /* * If we are using the list function, it doesn't care * about the function_trace_ops.