MIPS: 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: Ralf Baechle <ralf@linux-mips.org>
Tested-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 60e7e5e45af15135375a0183cca9759ff06442c0..8b6538750fe1949c7dd67fe7eb9962da4c0e58c5 100644 (file)
--- 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;