From patchwork Mon Apr 8 09:49:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 2406051 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id DB0FF3FC71 for ; Mon, 8 Apr 2013 09:51:27 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UP8jJ-0006rt-2x; Mon, 08 Apr 2013 09:51:13 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UP8jG-0006DY-28; Mon, 08 Apr 2013 09:51:10 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UP8jC-0006DE-1A for linux-arm-kernel@lists.infradead.org; Mon, 08 Apr 2013 09:51:06 +0000 Received: from bl15-144-85.dsl.telepac.pt ([188.80.144.85] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UP8j9-0005s1-DW; Mon, 08 Apr 2013 09:51:03 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 001/102] clockevents: Don't allow dummy broadcast timers Date: Mon, 8 Apr 2013 10:49:16 +0100 Message-Id: <1365414657-29191-2-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1365414657-29191-1-git-send-email-luis.henriques@canonical.com> References: <1365414657-29191-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130408_055106_151605_E8B61B63 X-CRM114-Status: GOOD ( 11.47 ) X-Spam-Score: -5.0 (-----) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-5.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [91.189.89.112 listed in list.dnswl.org] -2.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Mark Rutland , "Jon Medhurst \(Tixy\)" , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Luis Henriques X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 3.5.7.10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland commit a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a upstream. Currently tick_check_broadcast_device doesn't reject clock_event_devices with CLOCK_EVT_FEAT_DUMMY, and may select them in preference to real hardware if they have a higher rating value. In this situation, the dummy timer is responsible for broadcasting to itself, and the core clockevents code may attempt to call non-existent callbacks for programming the dummy, eventually leading to a panic. This patch makes tick_check_broadcast_device always reject dummy timers, preventing this problem. Signed-off-by: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: Jon Medhurst (Tixy) Signed-off-by: Thomas Gleixner Signed-off-by: Luis Henriques --- kernel/time/tick-broadcast.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f113755..a13987a 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -66,7 +66,8 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc) */ int tick_check_broadcast_device(struct clock_event_device *dev) { - if ((tick_broadcast_device.evtdev && + if ((dev->features & CLOCK_EVT_FEAT_DUMMY) || + (tick_broadcast_device.evtdev && tick_broadcast_device.evtdev->rating >= dev->rating) || (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0;