From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA9B8C28CF6 for ; Wed, 1 Aug 2018 18:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 879B02083D for ; Wed, 1 Aug 2018 18:20:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 879B02083D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732908AbeHAUHu (ORCPT ); Wed, 1 Aug 2018 16:07:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46150 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404451AbeHATDj (ORCPT ); Wed, 1 Aug 2018 15:03:39 -0400 Received: from localhost (D57E6652.static.ziggozakelijk.nl [213.126.102.82]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 41C551064; Wed, 1 Aug 2018 17:01:14 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Skeggs , Sasha Levin Subject: [PATCH 4.17 155/336] drm/nouveau: remove fence wait code from deferred client work handler Date: Wed, 1 Aug 2018 18:48:10 +0200 Message-Id: <20180801165035.053908707@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180801165028.930831994@linuxfoundation.org> References: <20180801165028.930831994@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Skeggs [ Upstream commit 11e451e74050d9e9030581ce40337838acfcea5b ] Fences attached to deferred client work items now originate from channels belonging to the client, meaning we can be certain they've been signalled before we destroy a client. This closes a race that could happen if the dma_fence_wait_timeout() call didn't succeed. When the fence was later signalled, a use-after-free was possible. Signed-off-by: Ben Skeggs Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/nouveau_drm.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -116,24 +116,22 @@ nouveau_name(struct drm_device *dev) } static inline bool -nouveau_cli_work_ready(struct dma_fence *fence, bool wait) +nouveau_cli_work_ready(struct dma_fence *fence) { - if (!dma_fence_is_signaled(fence)) { - if (!wait) - return false; - WARN_ON(dma_fence_wait_timeout(fence, false, 2 * HZ) <= 0); - } + if (!dma_fence_is_signaled(fence)) + return false; dma_fence_put(fence); return true; } static void -nouveau_cli_work_flush(struct nouveau_cli *cli, bool wait) +nouveau_cli_work(struct work_struct *w) { + struct nouveau_cli *cli = container_of(w, typeof(*cli), work); struct nouveau_cli_work *work, *wtmp; mutex_lock(&cli->lock); list_for_each_entry_safe(work, wtmp, &cli->worker, head) { - if (!work->fence || nouveau_cli_work_ready(work->fence, wait)) { + if (!work->fence || nouveau_cli_work_ready(work->fence)) { list_del(&work->head); work->func(work); } @@ -162,16 +160,16 @@ nouveau_cli_work_queue(struct nouveau_cl } static void -nouveau_cli_work(struct work_struct *w) -{ - struct nouveau_cli *cli = container_of(w, typeof(*cli), work); - nouveau_cli_work_flush(cli, false); -} - -static void nouveau_cli_fini(struct nouveau_cli *cli) { - nouveau_cli_work_flush(cli, true); + /* All our channels are dead now, which means all the fences they + * own are signalled, and all callback functions have been called. + * + * So, after flushing the workqueue, there should be nothing left. + */ + flush_work(&cli->work); + WARN_ON(!list_empty(&cli->worker)); + usif_client_fini(cli); nouveau_vmm_fini(&cli->vmm); nvif_mmu_fini(&cli->mmu);