From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51276 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933515AbdEVRF3 (ORCPT ); Mon, 22 May 2017 13:05:29 -0400 Subject: Patch "drm/nouveau/tmr: fix corruption of the pending list when rescheduling an alarm" has been added to the 4.4-stable tree To: bskeggs@redhat.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 22 May 2017 19:03:58 +0200 Message-ID: <1495472638160148@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled drm/nouveau/tmr: fix corruption of the pending list when rescheduling an alarm to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-nouveau-tmr-fix-corruption-of-the-pending-list-when-rescheduling-an-alarm.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9fc64667ee48c9a25e7dca1a6bcb6906fec5bcc5 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Thu, 11 May 2017 17:03:05 +1000 Subject: drm/nouveau/tmr: fix corruption of the pending list when rescheduling an alarm From: Ben Skeggs commit 9fc64667ee48c9a25e7dca1a6bcb6906fec5bcc5 upstream. At least therm/fantog "attempts" to work around this issue, which could lead to corruption of the pending alarm list. Fix it properly by not updating the timestamp without the lock held, or trying to add an already pending alarm to the pending alarm list.... Signed-off-by: Ben Skeggs Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) --- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c @@ -65,14 +65,17 @@ nvkm_timer_alarm(struct nvkm_timer *tmr, struct nvkm_alarm *list; unsigned long flags; - alarm->timestamp = nvkm_timer_read(tmr) + nsec; - - /* append new alarm to list, in soonest-alarm-first order */ + /* Remove alarm from pending list. + * + * This both protects against the corruption of the list, + * and implements alarm rescheduling/cancellation. + */ spin_lock_irqsave(&tmr->lock, flags); - if (!nsec) { - if (!list_empty(&alarm->head)) - list_del(&alarm->head); - } else { + list_del_init(&alarm->head); + + if (nsec) { + /* Insert into pending list, ordered earliest to latest. */ + alarm->timestamp = nvkm_timer_read(tmr) + nsec; list_for_each_entry(list, &tmr->alarms, head) { if (list->timestamp > alarm->timestamp) break; Patches currently in stable-queue which might be from bskeggs@redhat.com are queue-4.4/drm-nouveau-tmr-ack-interrupt-before-processing-alarms.patch queue-4.4/drm-nouveau-tmr-fix-corruption-of-the-pending-list-when-rescheduling-an-alarm.patch queue-4.4/drm-nouveau-tmr-avoid-processing-completed-alarms-when-adding-a-new-one.patch queue-4.4/drm-nouveau-mmu-nv4a-use-nv04-mmu-rather-than-the-nv44-one.patch queue-4.4/drm-nouveau-therm-remove-ineffective-workarounds-for-alarm-bugs.patch queue-4.4/drm-nouveau-tmr-handle-races-with-hw-when-updating-the-next-alarm-time.patch