From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936145Ab3DKUvd (ORCPT ); Thu, 11 Apr 2013 16:51:33 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:26790 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935925Ab3DKUtg (ORCPT ); Thu, 11 Apr 2013 16:49:36 -0400 X-Authority-Analysis: v=2.0 cv=F+XVh9dN c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=hbz-8L9Mu38A:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=EmLvEcgK89wA:10 a=7CQSdrXTAAAA:8 a=JfrnYn6hAAAA:8 a=KKAkSRfTAAAA:8 a=VwQbUJbxAAAA:8 a=azCPoUKV1MNu8TPkOAQA:9 a=ESTKKtUg-DoA:10 a=WwgC8nHKvroA:10 a=Zh68SRI7RUMA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130411202556.227197057@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 11 Apr 2013 16:26:04 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mark Rutland , , "Jon Medhurst (Tixy)" , Thomas Gleixner Subject: [ 061/171 ] clockevents: Dont allow dummy broadcast timers References: <20130411202503.783159048@goodmis.org> Content-Disposition: inline; filename=0061-clockevents-Don-t-allow-dummy-broadcast-timers.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland [ Upstream commit a7dc19b8652c862d5b7c4d2339bd3c428bd29c4a ] 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) Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- 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; -- 1.7.10.4