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authorSrikar Dronamraju <srikar@linux.vnet.ibm.com>2010-06-30 14:15:48 +0530
committerArnaldo Carvalho de Melo <acme@redhat.com>2010-08-04 12:41:23 -0300
commit9da79ab83ee33ddc1fdd0858fd3d70925a1bde99 (patch)
tree116f9d3c256a91ede964ebbfd3779949cc5953d4
parentb83f920e179101a54721e5ab1d6c3edfb9d4bcbb (diff)
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>
-rw-r--r--kernel/trace/trace_kprobe.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1b79d1c15726..8b27c9849b42 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;
}