Messages in this thread Patch in this message | | | Date | Thu, 24 Jan 2013 11:39:33 -0800 | From | tip-bot for Hiraku Toyooka <> | Subject | [tip:perf/core] tracing: Add checks if tr-> buffer is NULL in tracing_reset{_online_cpus} |
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Commit-ID: a54164114b96b4693b42cdb553260eec41ea4393 Gitweb: http://git.kernel.org/tip/a54164114b96b4693b42cdb553260eec41ea4393 Author: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> AuthorDate: Wed, 19 Dec 2012 16:02:34 +0900 Committer: Steven Rostedt <rostedt@goodmis.org> CommitDate: Mon, 21 Jan 2013 13:22:32 -0500
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.
Note, the current code does not call tracing_reset*() with max_tr when its buffer is NULL, but future code will. This patch is needed to prevent the future code from crashing.
Link: http://lkml.kernel.org/r/20121219070234.31200.93863.stgit@liselsia
Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/trace/trace.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f8b7c62..72b171b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -922,6 +922,9 @@ void tracing_reset(struct trace_array *tr, int cpu) { struct ring_buffer *buffer = tr->buffer; + if (!buffer) + return; + ring_buffer_record_disable(buffer); /* Make sure all commits have finished */ @@ -936,6 +939,9 @@ void tracing_reset_online_cpus(struct trace_array *tr) struct ring_buffer *buffer = tr->buffer; int cpu; + if (!buffer) + return; + ring_buffer_record_disable(buffer); /* Make sure all commits have finished */
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