Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 3/3] tracing/kprobes: unregister_trace_probe needs to be called under mutex | Date | Wed, 4 Aug 2010 18:26:04 -0300 |
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From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
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; } -- 1.6.2.5
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