Messages in this thread Patch in this message | | | Date | Wed, 30 Jun 2010 14:15:48 +0530 | From | Srikar Dronamraju <> | Subject | [Bugfix] 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)
This patch is needed for both 2.6.35-rc3 and 2.6.35-rc3-tip
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> ---
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 4f11a56..67670cd 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -269,14 +269,17 @@ 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; }
| |