Peter Zijlstra dd0ea88b0a perf: Fix sys_perf_event_open() race against self ... commit 3ac6487e58 upstream. Norbert reported that it's possible to race sys_perf_event_open() such that the looser ends up in another context from the group leader, triggering many WARNs. The move_group case checks for races against itself, but the !move_group case doesn't, seemingly relying on the previous group_leader->ctx == ctx check. However, that check is racy due to not holding any locks at that time. Therefore, re-check the result after acquiring locks and bailing if they no longer match. Additionally, clarify the not_move_group case from the move_group-vs-move_group race. Fixes: f63a8daa58 ("perf: Fix event->ctx locking") Reported-by: Norbert Slusarek <nslusarek@gmx.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-05-25 09:14:34 +02:00
..
callchain.c
core.c	perf: Fix sys_perf_event_open() race against self	2022-05-25 09:14:34 +02:00
hw_breakpoint.c	perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initialization	2019-09-06 08:24:01 +02:00
internal.h	perf: Fix get_recursion_context()	2020-11-18 19:20:28 +01:00
Makefile
ring_buffer.c
uprobes.c	uprobes: __replace_page() avoid BUG in munlock_vma_page()	2020-08-26 10:40:51 +02:00