From patchwork Sun Mar 24 14:36:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maarten Lankhorst X-Patchwork-Id: 2326691 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by patchwork2.kernel.org (Postfix) with ESMTP id 501CADFB79 for ; Sun, 24 Mar 2013 14:36:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 19B70E650C for ; Sun, 24 Mar 2013 07:36:56 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by gabe.freedesktop.org (Postfix) with ESMTP id 456D8E5CD9; Sun, 24 Mar 2013 07:36:43 -0700 (PDT) Received: from 5ed48cef.cm-7-5c.dynamic.ziggo.nl ([94.212.140.239] helo=[192.168.1.128]) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1UJm2M-0002y8-Er; Sun, 24 Mar 2013 14:36:42 +0000 Message-ID: <514F0F76.5090709@canonical.com> Date: Sun, 24 Mar 2013 15:36:38 +0100 From: Maarten Lankhorst User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: nouveau@lists.freedesktop.org Subject: [PATCH] drm/nouveau: fix handling empty channel list in ioctl's Cc: "dri-devel@lists.freedesktop.org" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org Errors-To: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org If there are no channels, chan would never end up being NULL, and so the null pointer check would fail. Solve this by initializing chan to NULL, and iterating over temp instead. Fixes oops when running intel-gpu-tools/tests/kms_flip, which attempts to do some intel ioctl's on a nouveau device. Signed-off-by: Maarten Lankhorst Cc: stable@vger.kernel.org [3.7+] diff --git a/drivers/gpu/drm/nouveau/nouveau_abi16.c b/drivers/gpu/drm/nouveau/nouveau_abi16.c index 3b6dc88..5eb3e0d 100644 --- a/drivers/gpu/drm/nouveau/nouveau_abi16.c +++ b/drivers/gpu/drm/nouveau/nouveau_abi16.c @@ -391,7 +391,7 @@ nouveau_abi16_ioctl_notifierobj_alloc(ABI16_IOCTL_ARGS) struct nouveau_drm *drm = nouveau_drm(dev); struct nouveau_device *device = nv_device(drm->device); struct nouveau_abi16 *abi16 = nouveau_abi16_get(file_priv, dev); - struct nouveau_abi16_chan *chan, *temp; + struct nouveau_abi16_chan *chan = NULL, *temp; struct nouveau_abi16_ntfy *ntfy; struct nouveau_object *object; struct nv_dma_class args = {}; @@ -404,10 +404,11 @@ nouveau_abi16_ioctl_notifierobj_alloc(ABI16_IOCTL_ARGS) if (unlikely(nv_device(abi16->device)->card_type >= NV_C0)) return nouveau_abi16_put(abi16, -EINVAL); - list_for_each_entry_safe(chan, temp, &abi16->channels, head) { - if (chan->chan->handle == (NVDRM_CHAN | info->channel)) + list_for_each_entry(temp, &abi16->channels, head) { + if (temp->chan->handle == (NVDRM_CHAN | info->channel)) { + chan = temp; break; - chan = NULL; + } } if (!chan) @@ -459,17 +460,18 @@ nouveau_abi16_ioctl_gpuobj_free(ABI16_IOCTL_ARGS) { struct drm_nouveau_gpuobj_free *fini = data; struct nouveau_abi16 *abi16 = nouveau_abi16_get(file_priv, dev); - struct nouveau_abi16_chan *chan, *temp; + struct nouveau_abi16_chan *chan = NULL, *temp; struct nouveau_abi16_ntfy *ntfy; int ret; if (unlikely(!abi16)) return -ENOMEM; - list_for_each_entry_safe(chan, temp, &abi16->channels, head) { - if (chan->chan->handle == (NVDRM_CHAN | fini->channel)) + list_for_each_entry(temp, &abi16->channels, head) { + if (temp->chan->handle == (NVDRM_CHAN | fini->channel)) { + chan = temp; break; - chan = NULL; + } } if (!chan)