From: Steven Rostedt (Red Hat) Date: Wed, 25 Jun 2014 14:27:30 +0000 (-0400) Subject: powerpc/ftrace: Add call to ftrace_graph_is_dead() in function graph code X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=96d4f43e3d012824f7e61920a340a1c03b6aacb0;p=linux-beck.git powerpc/ftrace: 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. Cc: Anton Blanchard Acked-by: Benjamin Herrenschmidt Signed-off-by: Steven Rostedt --- diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index d178834fe508..390311c0f03d 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -525,6 +525,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) struct ftrace_graph_ent trace; 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;