Commit 78cd2c74 authored Jan 25, 2016 by Peter Zijlstra Committed by Ingo Molnar Jan 28, 2016

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>

parent 45c815f0

kernel/events/core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);