diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-08-01 15:40:57 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-09 20:04:34 +0200 |
| commit | 0943ce7b7e066a88210ca3ea53db5515d21b3312 (patch) | |
| tree | 7396b6344403bba5b6345dd4bec2faf47bec0d3f /kernel/trace/blktrace.c | |
| parent | 3328bbe314e6d46aff6c074441a7a500209ca345 (diff) | |
tracing: Do not call start/stop() functions when tracing_on does not change
commit f143641bfef9a4a60c57af30de26c63057e7e695 upstream.
Currently, when one echo's in 1 into tracing_on, the current tracer's
"start()" function is executed, even if tracing_on was already one. This can
lead to strange side effects. One being that if the hwlat tracer is enabled,
and someone does "echo 1 > tracing_on" into tracing_on, the hwlat tracer's
start() function is called again which will recreate another kernel thread,
and make it unable to remove the old one.
Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de
Cc: stable@vger.kernel.org
Fixes: 2df8f8a6a897e ("tracing: Fix regression with irqsoff tracer and tracing_on file")
Reported-by: Erica Bugden <erica.bugden@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace/blktrace.c')
0 files changed, 0 insertions, 0 deletions