From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:45010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730276AbeJKXMq (ORCPT ); Thu, 11 Oct 2018 19:12:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Zijlstra , Reinette Chatre , Thomas Gleixner , fenghua.yu@intel.com, tony.luck@intel.com, acme@kernel.org, gavin.hindman@intel.com, jithu.joseph@intel.com, dave.hansen@intel.com, hpa@zytor.com Subject: [PATCH 4.14 01/45] perf/core: Add sanity check to deal with pinned event failure Date: Thu, 11 Oct 2018 17:39:28 +0200 Message-Id: <20181011152508.938155855@linuxfoundation.org> In-Reply-To: <20181011152508.885515042@linuxfoundation.org> References: <20181011152508.885515042@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Reinette Chatre commit befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7 upstream. It is possible that a failure can occur during the scheduling of a pinned event. The initial portion of perf_event_read_local() contains the various error checks an event should pass before it can be considered valid. Ensure that the potential scheduling failure of a pinned event is checked for and have a credible error. Suggested-by: Peter Zijlstra Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: acme@kernel.org Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/6486385d1f30336e9973b24c8c65f5079543d3d3.1537377064.git.reinette.chatre@intel.com Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3757,6 +3757,12 @@ int perf_event_read_local(struct perf_ev goto out; } + /* If this is a pinned event it must be running on this CPU */ + if (event->attr.pinned && event->oncpu != smp_processor_id()) { + ret = -EBUSY; + goto out; + } + /* * If the event is currently on this CPU, its either a per-task event, * or local to this CPU. Furthermore it means its ACTIVE (otherwise