The patch below does not apply to the 3.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5f8bf2d263a20b986225ae1ed7d6759dc4b93af9 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> Date: Tue, 15 Jul 2014 11:05:12 -0400 Subject: [PATCH] tracing: Fix graph tracer with stack tracer on other archs 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() Cc: stable@xxxxxxxxxxxxxxx # 3.3+ Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 5b372e3ed675..ac9d1dad630b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -265,12 +265,12 @@ 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. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html