Pull perf fixes from Borislav Petkov:
- Prevent the use of exited events as group leaders
- Avoid use-after-free of an event's group leader by promoting detached
sibling events to standalone entities and correct related accounting
and state transitions
* tag 'perf_urgent_for_v7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix group leader use-after-free after sibling detach
perf: Reject exited events as group leaders