From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932254Ab3IBJJ7 (ORCPT ); Mon, 2 Sep 2013 05:09:59 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37705 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758295Ab3IBIzH (ORCPT ); Mon, 2 Sep 2013 04:55:07 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Will Deacon , Russell King , Luis Henriques Subject: [PATCH 18/58] ARM: 7809/1: perf: fix event validation for software group leaders Date: Mon, 2 Sep 2013 09:54:03 +0100 Message-Id: <1378112083-9475-19-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1378112083-9475-1-git-send-email-luis.henriques@canonical.com> References: <1378112083-9475-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit c95eb3184ea1a3a2551df57190c81da695e2144b upstream. It is possible to construct an event group with a software event as a group leader and then subsequently add a hardware event to the group. This results in the event group being validated by adding all members of the group to a fake PMU and attempting to allocate each event on their respective PMU. Unfortunately, for software events wthout a corresponding arm_pmu, this results in a kernel crash attempting to dereference the ->get_event_idx function pointer. This patch fixes the problem by checking explicitly for software events and ignoring those in event validation (since they can always be scheduled). We will probably want to revisit this for 3.12, since the validation checks don't appear to work correctly when dealing with multiple hardware PMUs anyway. Reported-by: Vince Weaver Tested-by: Vince Weaver Tested-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Russell King [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques --- arch/arm/kernel/perf_event.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 55790a5..522c11d 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -319,6 +319,9 @@ validate_event(struct pmu_hw_events *hw_events, struct hw_perf_event fake_event = event->hw; struct pmu *leader_pmu = event->group_leader->pmu; + if (is_software_event(event)) + return 1; + if (event->pmu != leader_pmu || event->state < PERF_EVENT_STATE_OFF) return 1; -- 1.8.3.2