The patch below does not apply to the 5.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 537457a979a02a410b555fab289dcb28b588f33b Mon Sep 17 00:00:00 2001
From: Chris Wilson chris@chris-wilson.co.uk Date: Mon, 2 Nov 2020 16:19:31 +0000 Subject: [PATCH] drm/i915: Hold onto an explicit ref to i915_vma_work.pinned
Since __vma_release is run by a kworker after the fence has been signaled, it is no longer protected by the active reference on the vma, and so the alias of vw->pinned to vma->obj is also not protected by a reference on the object. Add an explicit reference for vw->pinned so it will always be safe.
Found by inspection.
Fixes: 54d7195f8c64 ("drm/i915: Unpin vma->obj on early error") Reported-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: stable@vger.kernel.org # v5.6+ Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20201102161931.30031-1-chris@c... (cherry picked from commit bc73e5d33048b7ab5f12b11b5d923700467a8e1d) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index ffb5287e055a..caa9b041616b 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -314,8 +314,10 @@ static void __vma_release(struct dma_fence_work *work) { struct i915_vma_work *vw = container_of(work, typeof(*vw), base);
- if (vw->pinned) + if (vw->pinned) { __i915_gem_object_unpin_pages(vw->pinned); + i915_gem_object_put(vw->pinned); + }
i915_vm_free_pt_stash(vw->vm, &vw->stash); i915_vm_put(vw->vm); @@ -431,7 +433,7 @@ int i915_vma_bind(struct i915_vma *vma,
if (vma->obj) { __i915_gem_object_pin_pages(vma->obj); - work->pinned = vma->obj; + work->pinned = i915_gem_object_get(vma->obj); } } else { vma->ops->bind_vma(vma->vm, NULL, vma, cache_level, bind_flags);