From: "Steven Rostedt (Red Hat)" 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@vger.kernel.org # 3.3+ Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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. -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/