summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2023-12-17 14:03:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-12-17 14:03:11 -0800
commit177c2ffe69555dde28fad5ddb62a6d806982e53f (patch)
tree62d4e7539eda0a8b6fb7e95096be20fdc7642b9b
parent0e389834672c723435a44818ed2cabc4dad24429 (diff)
parent7e2c1e4b34f07d9aa8937fab88359d4a0fce468e (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.c10
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)