tracing/events: Fix locking imbalance in the filter code
Américo Wang noticed that we have a locking imbalance in the error paths of ftrace_profile_set_filter(), causing potential leakage of event_mutex. Also clean up other error codepaths related to event_mutex while at it. Plus fix an initialized variable in the subsystem filter code. Reported-by: Américo Wang <xiyou.wangcong@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <2375c9f90910150247u5ccb8e2at58c764e385ffa490@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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parent
c171b552a7
commit
a66abe7fbf
1 changed files with 16 additions and 12 deletions
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@ -1230,10 +1230,10 @@ static int replace_system_preds(struct event_subsystem *system,
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struct filter_parse_state *ps,
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struct filter_parse_state *ps,
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char *filter_string)
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char *filter_string)
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{
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{
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struct event_filter *filter = system->filter;
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struct ftrace_event_call *call;
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struct ftrace_event_call *call;
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struct event_filter *filter;
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int err;
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bool fail = true;
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bool fail = true;
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int err;
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list_for_each_entry(call, &ftrace_events, list) {
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list_for_each_entry(call, &ftrace_events, list) {
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@ -1262,7 +1262,7 @@ static int replace_system_preds(struct event_subsystem *system,
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if (fail) {
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if (fail) {
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parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
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parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
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return err;
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return -EINVAL;
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}
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}
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return 0;
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return 0;
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}
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}
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@ -1281,8 +1281,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
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if (!strcmp(strstrip(filter_string), "0")) {
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if (!strcmp(strstrip(filter_string), "0")) {
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filter_disable_preds(call);
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filter_disable_preds(call);
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remove_filter_string(call->filter);
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remove_filter_string(call->filter);
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mutex_unlock(&event_mutex);
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goto out_unlock;
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return 0;
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}
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}
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err = -ENOMEM;
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err = -ENOMEM;
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@ -1330,8 +1329,7 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
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if (!strcmp(strstrip(filter_string), "0")) {
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if (!strcmp(strstrip(filter_string), "0")) {
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filter_free_subsystem_preds(system);
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filter_free_subsystem_preds(system);
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remove_filter_string(system->filter);
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remove_filter_string(system->filter);
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mutex_unlock(&event_mutex);
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goto out_unlock;
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return 0;
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}
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}
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err = -ENOMEM;
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err = -ENOMEM;
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@ -1386,15 +1384,20 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id,
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if (call->id == event_id)
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if (call->id == event_id)
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break;
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break;
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}
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}
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if (!call)
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return -EINVAL;
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err = -EINVAL;
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if (!call)
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goto out_unlock;
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err = -EEXIST;
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if (event->filter)
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if (event->filter)
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return -EEXIST;
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goto out_unlock;
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filter = __alloc_preds();
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filter = __alloc_preds();
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if (IS_ERR(filter))
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if (IS_ERR(filter)) {
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return PTR_ERR(filter);
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err = PTR_ERR(filter);
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goto out_unlock;
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}
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err = -ENOMEM;
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err = -ENOMEM;
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ps = kzalloc(sizeof(*ps), GFP_KERNEL);
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ps = kzalloc(sizeof(*ps), GFP_KERNEL);
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@ -1419,6 +1422,7 @@ free_preds:
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if (err)
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if (err)
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__free_preds(filter);
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__free_preds(filter);
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out_unlock:
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mutex_unlock(&event_mutex);
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mutex_unlock(&event_mutex);
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return err;
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return err;
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