From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759959AbcBYIFP (ORCPT ); Thu, 25 Feb 2016 03:05:15 -0500 Received: from torg.zytor.com ([198.137.202.12]:58698 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759631AbcBYIFN (ORCPT ); Thu, 25 Feb 2016 03:05:13 -0500 Date: Thu, 25 Feb 2016 00:04:34 -0800 From: tip-bot for Peter Zijlstra Message-ID: Cc: jolsa@redhat.com, linux-kernel@vger.kernel.org, acme@redhat.com, torvalds@linux-foundation.org, mingo@kernel.org, peterz@infradead.org, hpa@zytor.com, tglx@linutronix.de, alexander.shishkin@linux.intel.com Reply-To: alexander.shishkin@linux.intel.com, tglx@linutronix.de, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, torvalds@linux-foundation.org, acme@redhat.com, linux-kernel@vger.kernel.org, jolsa@redhat.com In-Reply-To: <20160224174947.793996260@infradead.org> References: <20160224174947.793996260@infradead.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Allow perf_release() with !event->ctx Git-Commit-ID: a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19 Gitweb: http://git.kernel.org/tip/a4f4bb6d0c69d0bb573f1d9e6f1b806f9b038b19 Author: Peter Zijlstra AuthorDate: Wed, 24 Feb 2016 18:45:42 +0100 Committer: Ingo Molnar CommitDate: Thu, 25 Feb 2016 08:42:33 +0100 perf: Allow perf_release() with !event->ctx In the err_file: fput(event_file) case, the event will not yet have been attached to a context. However perf_release() does assume it has been. Cure this. Tested-by: Alexander Shishkin Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.793996260@infradead.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 211a5ce..d5299e2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3754,9 +3754,19 @@ static void put_event(struct perf_event *event) */ int perf_event_release_kernel(struct perf_event *event) { - struct perf_event_context *ctx; + struct perf_event_context *ctx = event->ctx; struct perf_event *child, *tmp; + /* + * If we got here through err_file: fput(event_file); we will not have + * attached to a context yet. + */ + if (!ctx) { + WARN_ON_ONCE(event->attach_state & + (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); + goto no_ctx; + } + if (!is_kernel_event(event)) perf_remove_from_owner(event); @@ -3832,8 +3842,8 @@ again: } mutex_unlock(&event->child_mutex); - /* Must be the last reference */ - put_event(event); +no_ctx: + put_event(event); /* Must be the 'last' reference */ return 0; } EXPORT_SYMBOL_GPL(perf_event_release_kernel);