diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-02-24 18:45:42 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-25 08:42:33 +0100 |
| commit | a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19 (patch) | |
| tree | d6f0fb9d98cf14837637b2c3d26d3605944d487e /kernel | |
| parent | perf: Do not double free (diff) | |
| download | linux-a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19.tar.xz linux-a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19.zip | |
perf: Allow perf_release() with !event->ctx
In the err_file: fput(event_file) case, the event will not yet have
been attached to a context. However perf_release() does assume it has
been. Cure this.
Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.793996260@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 211a5ce64e3f..d5299e2e435d 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3754,9 +3754,19 @@ static void put_event(struct perf_event *event) */ int perf_event_release_kernel(struct perf_event *event) { - struct perf_event_context *ctx; + struct perf_event_context *ctx = event->ctx; struct perf_event *child, *tmp; + /* + * If we got here through err_file: fput(event_file); we will not have + * attached to a context yet. + */ + if (!ctx) { + WARN_ON_ONCE(event->attach_state & + (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); + goto no_ctx; + } + if (!is_kernel_event(event)) perf_remove_from_owner(event); @@ -3832,8 +3842,8 @@ again: } mutex_unlock(&event->child_mutex); - /* Must be the last reference */ - put_event(event); +no_ctx: + put_event(event); /* Must be the 'last' reference */ return 0; } EXPORT_SYMBOL_GPL(perf_event_release_kernel); |