trace: stop all recording to ring buffer on ftrace_dump

Impact: limit ftrace dump output

Currently ftrace_dump only calls ftrace_kill that is a fast way
to prevent the function tracer functions from being called (just sets
a flag and clears the function to call, nothing else). It is better
to also turn off any recording to the ring buffers as well.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1a1c5a6..4d89e84 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3770,6 +3770,7 @@ void ftrace_dump(void)
        dump_ran = 1;
 
        /* No turning back! */
        dump_ran = 1;
 
        /* No turning back! */

+       tracing_off();

        ftrace_kill();
 
        for_each_tracing_cpu(cpu) {
        ftrace_kill();
 
        for_each_tracing_cpu(cpu) {