[RFA][PATCH 07/27] MIPS: ftrace: Add call to ftrace_graph_is_dead() in function graph code

From: Steven Rostedt
Date: Thu Jun 26 2014 - 13:05:52 EST


From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>

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: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
arch/mips/kernel/ftrace.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 60e7e5e45af1..8b6538750fe1 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -302,6 +302,9 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
&return_to_handler;
int faulted, insns;

+ if (unlikely(ftrace_graph_is_dead()))
+ return;
+
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;

--
2.0.0


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