parisc: 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.

Link: http://lkml.kernel.org/r/53B08317.7010501@gmx.de
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
index 5beb97bafbb1d5818e3ab83c058199353aaf2bb2..5512ab32c5e0e9c355b83b28f4453cef68224f27 100644 (file)
--- a/arch/parisc/kernel/ftrace.c
+++ b/arch/parisc/kernel/ftrace.c
@@ -112,6 +112,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
        unsigned long long calltime;
        struct ftrace_graph_ent trace;
 
+       if (unlikely(ftrace_graph_is_dead()))
+               return;
+
        if (unlikely(atomic_read(&current->tracing_graph_pause)))
                return;