diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-12-17 14:03:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-12-17 14:03:11 -0800 |
| commit | 177c2ffe69555dde28fad5ddb62a6d806982e53f (patch) | |
| tree | 62d4e7539eda0a8b6fb7e95096be20fdc7642b9b | |
| parent | 0e389834672c723435a44818ed2cabc4dad24429 (diff) | |
| parent | 7e2c1e4b34f07d9aa8937fab88359d4a0fce468e (diff) | |
Merge tag 'perf_urgent_for_v6.7_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Borislav Petkov:
- Avoid iterating over newly created group leader event's siblings
because there are none, and thus prevent a lockdep splat
* tag 'perf_urgent_for_v6.7_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix perf_event_validate_size() lockdep splat
| -rw-r--r-- | kernel/events/core.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c9d123e13b57..9efd0d7775e7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1947,6 +1947,16 @@ static bool perf_event_validate_size(struct perf_event *event) group_leader->nr_siblings + 1) > 16*1024) return false; + /* + * When creating a new group leader, group_leader->ctx is initialized + * after the size has been validated, but we cannot safely use + * for_each_sibling_event() until group_leader->ctx is set. A new group + * leader cannot have any siblings yet, so we can safely skip checking + * the non-existent siblings. + */ + if (event == group_leader) + return true; + for_each_sibling_event(sibling, group_leader) { if (__perf_event_read_size(sibling->attr.read_format, group_leader->nr_siblings + 1) > 16*1024) |