perf: Fix orphan hole

We should set event->owner before we install the event,
otherwise there is a hole where the target task can fork() and
we'll not inherit the event because it thinks the event is
orphaned.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-01-25 14:08:45 +01:00 committed by Ingo Molnar
parent 45c815f06b
commit 78cd2c748f

View File

@ -8489,6 +8489,8 @@ SYSCALL_DEFINE5(perf_event_open,
perf_event__header_size(event);
perf_event__id_header_size(event);
event->owner = current;
perf_install_in_context(ctx, event, event->cpu);
perf_unpin_context(ctx);
@ -8498,8 +8500,6 @@ SYSCALL_DEFINE5(perf_event_open,
put_online_cpus();
event->owner = current;
mutex_lock(&current->perf_event_mutex);
list_add_tail(&event->owner_entry, &current->perf_event_list);
mutex_unlock(&current->perf_event_mutex);