Messages in this thread Patch in this message | | | Date | Fri, 11 Jul 2014 21:06:22 +0200 | From | Oleg Nesterov <> | Subject | [PATCH 0/7] tracing: instance_rmdir() leaks ftrace_event_file->filter |
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Hello,
Sorry for delay, I was distracted by other problems.
To remind, we discussed the potential uprobes "mix perf/ftrace" changes and found some off-topic problems. Lets start with ->filter fixes/cleanups.
So far I didn't even try to test this series, although it looks simple except perhaps the last patch. I'll try to somehow test this tomorrow, but I do not really now how.
So please review, these patches need acks anyway.
As for 1/7, I added BUG_ON(file->filter) into remove_event_file_dir() before kmem_cache_free() to verify that yes, the leak does exist. Perhaps this patch should go to stable, or at least to v3.16.
-------------------------------------------------------------------------------- And could someone explain me why apply_subsystem_event_filter("0") clears ->filter_string first, then the whole ->filter? It seems that the only thing filter_free_subsystem_preds() should do is filter_disable(), no? IOW, why the patch below (on top of this series) is wrong?
Oleg.
--- x/kernel/trace/trace_events_filter.c +++ x/kernel/trace/trace_events_filter.c @@ -831,17 +831,6 @@ static int __alloc_preds(struct event_filter *filter, int n_preds) return 0; } -static inline void __remove_filter(struct ftrace_event_file *file) -{ - struct ftrace_event_call *call = file->event_call; - - filter_disable(file); - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - remove_filter_string(call->filter); - else - remove_filter_string(file->filter); -} - static void filter_free_subsystem_preds(struct event_subsystem *system, struct trace_array *tr) { @@ -850,7 +839,7 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, list_for_each_entry(file, &tr->events, list) { if (file->system->subsystem != system) continue; - __remove_filter(file); + filter_disable(file); } }
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