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| author |   Peter Zijlstra <peterz@infradead.org> | 2025-04-15 12:12:52 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2025-04-17 14:21:15 +0200 |
| commit | 162c9e3faf58eef653c74d0c774e6583d9225467 (patch) | |
| tree | 874bf0bd8699f7bc8c6e5394a3053379dfe14f71 | |
| parent | perf/core: Fix put_ctx() ordering (diff) | |
| download | wireguard-linux-162c9e3faf58eef653c74d0c774e6583d9225467.tar.xz wireguard-linux-162c9e3faf58eef653c74d0c774e6583d9225467.zip | |
perf/core: Fix event->parent life-time issue
Due to an oversight in merging:
da916e96e2de ("perf: Make perf_pmu_unregister() useable")
on top of:
56799bc03565 ("perf: Fix hang while freeing sigtrap event")
.. it is now possible to hit put_event(EVENT_TOMBSTONE), which makes
the computer sad.
This also means that for the event->parent == EVENT_TOMBSTONE, the
put_event() matching inherit_event() has gone missing.
Previously this was done in perf_event_release_kernel() after calling
perf_remove_from_context(), but with it delegated to put_event(), this
case is now entirely missed, leading to leaks.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: kernel test robot <oliver.sang@intel.com>
Tested-by: James Clark <james.clark@linaro.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/oe-lkp/202504131701.941039cd-lkp@intel.com
Link: https://lkml.kernel.org/r/20250415131446.GN5600@noisy.programming.kicks-ass.net
| -rw-r--r-- | kernel/events/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 1a19df9d54fd..43d87de3d4f2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2343,6 +2343,7 @@ static void perf_child_detach(struct perf_event *event) * not being a child event. See for example unaccount_event(). */ event->parent = EVENT_TOMBSTONE; + put_event(parent_event); } static bool is_orphaned_event(struct perf_event *event) @@ -5688,7 +5689,7 @@ static void put_event(struct perf_event *event) _free_event(event); /* Matches the refcount bump in inherit_event() */ - if (parent) + if (parent && parent != EVENT_TOMBSTONE) put_event(parent); } |