From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48006 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752052AbdFLMu4 (ORCPT ); Mon, 12 Jun 2017 08:50:56 -0400 Subject: Patch "drm/nouveau/tmr: fully separate alarm execution/pending lists" has been added to the 4.9-stable tree To: bskeggs@redhat.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 12 Jun 2017 14:50:44 +0200 Message-ID: <1497271844100130@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: fully separate alarm execution/pending lists to the 4.9-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-fully-separate-alarm-execution-pending-lists.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From b4e382ca7586a63b6c1e5221ce0863ff867c2df6 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Mon, 5 Jun 2017 17:23:32 +1000 Subject: drm/nouveau/tmr: fully separate alarm execution/pending lists From: Ben Skeggs commit b4e382ca7586a63b6c1e5221ce0863ff867c2df6 upstream. Reusing the list_head for both is a bad idea. Callback execution is done with the lock dropped so that alarms can be rescheduled from the callback, which means that with some unfortunate timing, lists can get corrupted. The execution list should not require its own locking, the single function that uses it can only be called from a single context. Signed-off-by: Ben Skeggs Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/include/nvkm/subdev/timer.h | 1 + drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c | 7 ++++--- 2 files changed, 5 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/timer.h +++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/timer.h @@ -4,6 +4,7 @@ struct nvkm_alarm { struct list_head head; + struct list_head exec; u64 timestamp; void (*func)(struct nvkm_alarm *); }; --- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c @@ -50,7 +50,8 @@ nvkm_timer_alarm_trigger(struct nvkm_tim /* Move to completed list. We'll drop the lock before * executing the callback so it can reschedule itself. */ - list_move_tail(&alarm->head, &exec); + list_del_init(&alarm->head); + list_add(&alarm->exec, &exec); } /* Shut down interrupt if no more pending alarms. */ @@ -59,8 +60,8 @@ nvkm_timer_alarm_trigger(struct nvkm_tim spin_unlock_irqrestore(&tmr->lock, flags); /* Execute completed callbacks. */ - list_for_each_entry_safe(alarm, atemp, &exec, head) { - list_del_init(&alarm->head); + list_for_each_entry_safe(alarm, atemp, &exec, exec) { + list_del(&alarm->exec); alarm->func(alarm); } } Patches currently in stable-queue which might be from bskeggs@redhat.com are queue-4.9/drm-nouveau-tmr-fully-separate-alarm-execution-pending-lists.patch