Messages in this thread Patch in this message | | | Date | Thu, 5 Aug 2010 08:01:24 GMT | From | tip-bot for Srikar Dronamraju <> | Subject | [tip:perf/core] tracing/kprobes: unregister_trace_probe needs to be called under mutex |
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Commit-ID: 9da79ab83ee33ddc1fdd0858fd3d70925a1bde99 Gitweb: http://git.kernel.org/tip/9da79ab83ee33ddc1fdd0858fd3d70925a1bde99 Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> AuthorDate: Wed, 30 Jun 2010 14:15:48 +0530 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Wed, 4 Aug 2010 12:41:23 -0300
tracing/kprobes: unregister_trace_probe needs to be called under mutex
Comment in unregister_trace_probe() says probe_lock will be held when it gets called. However there is a case where it might called without the probe_lock being held. Also since we are traversing the probe_list and deleting an element from the probe_list, probe_lock should be held.
This was first pointed in uprobes traceevent review by Frederic Weisbecker here. (http://lkml.org/lkml/2010/5/12/106)
Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100630084548.GA10325@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- kernel/trace/trace_kprobe.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 1b79d1c..8b27c98 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -925,14 +925,17 @@ static int create_trace_probe(int argc, char **argv) pr_info("Delete command needs an event name.\n"); return -EINVAL; } + mutex_lock(&probe_lock); tp = find_probe_event(event, group); if (!tp) { + mutex_unlock(&probe_lock); pr_info("Event %s/%s doesn't exist.\n", group, event); return -ENOENT; } /* delete an event */ unregister_trace_probe(tp); free_trace_probe(tp); + mutex_unlock(&probe_lock); return 0; }
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