From 84b2bc7fa005b99a06979673225dc2bb7de3fd91 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 25 Jun 2014 10:35:14 -0400 Subject: [PATCH] ftrace/x86: Add call to ftrace_graph_is_dead() in function graph code ftrace_stop() is going away as it disables parts of function tracing that affects users that should not be affected. But ftrace_graph_stop() is built on ftrace_stop(). Here's another example of killing all of function tracing because something went wrong with function graph tracing. Instead of disabling all users of function tracing on function graph error, disable only function graph tracing. To do this, the arch code must call ftrace_graph_is_dead() before it implements function graph. Link: http://lkml.kernel.org/r/53C54D18.3020602@zytor.com Acked-by: H. Peter Anvin Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- arch/x86/kernel/ftrace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index cbc4a91b131e..3386dc9aa333 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -703,6 +703,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, unsigned long return_hooker = (unsigned long) &return_to_handler; + if (unlikely(ftrace_graph_is_dead())) + return; + if (unlikely(atomic_read(¤t->tracing_graph_pause))) return; -- 2.20.1