From b43decd2c513ae44a5462a1a4c2622f0fa77c9e0 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Sun, 24 Mar 2013 15:36:38 +0100 Subject: [PATCH] drm/nouveau: fix handling empty channel list in ioctl's 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+] Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nouveau_abi16.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_abi16.c b/drivers/gpu/drm/nouveau/nouveau_abi16.c index 3b6dc883e150..5eb3e0da7c6e 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) -- 2.20.1