From the shrinker paths, we want to relinquish the GPU and GGTT access to

the object, releasing the backing storage back to the system for swapout. As a part of that process we would unpin the pages, marking them for access by the CPU (for the swapout/swapin). However, if that process was interrupted after unbind the vma, we missed a flush of the inflight GGTT writes before we made that GTT space available again for reuse, with the prospect that we would redirect them to another page.

The bug dates back to the introduction of multiple GGTT vma, but the code itself dates to commit 02bef8f98d26 ("drm/i915: Unbind closed vma for i915_gem_object_unbind()").

Fixes: 02bef8f98d26 ("drm/i915: Unbind closed vma for i915_gem_object_unbind()") Fixes: c5ad54cf7dd8 ("drm/i915: Use partial view in mmap fault handler") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org Reviewed-by: Joonas Lahtinen joonas.lahtinen@linux.intel.com --- drivers/gpu/drm/i915/i915_gem.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index e083f242b8dc..80b78fb5daac 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -330,17 +330,10 @@ int i915_gem_object_unbind(struct drm_i915_gem_object *obj) * must wait for all rendering to complete to the object (as unbinding * must anyway), and retire the requests. */ - ret = i915_gem_object_wait(obj, - I915_WAIT_INTERRUPTIBLE | - I915_WAIT_LOCKED | - I915_WAIT_ALL, - MAX_SCHEDULE_TIMEOUT, - NULL); + ret = i915_gem_object_set_to_cpu_domain(obj, false); if (ret) return ret;

- i915_gem_retire_requests(to_i915(obj->base.dev)); - while ((vma = list_first_entry_or_null(&obj->vma_list, struct i915_vma, obj_link))) {