[PATCH v3 -tip 1/4] tracing: add checks if tr->buffer is NULL in tracing_reset{_online_cpus}

max_tr->buffer could be NULL in the tracing_reset{_online_cpus}. In this case, a NULL pointer dereference happens, so we should return immediately from these functions. Signed-off-by: Hiraku Toyooka Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: linux-kernel@vger.kernel.org

[PATCH v3 -tip 1/4] tracing: add checks if tr-buffer is NULL in tracing_reset{_online_cpus}

max_tr-buffer could be NULL in the tracing_reset{_online_cpus}. In this case, a NULL pointer dereference happens, so we should return immediately from these functions. Signed-off-by: Hiraku Toyooka hiraku.toyooka...@hitachi.com Cc: Steven Rostedt rost...@goodmis.org Cc: Frederic Weisbecker