From: Chris Wilson chris@chris-wilson.co.uk
commit 42723673a193d5f8e30dba6ea9826d42262a502b upstream.
As we allow for parallel threads to create the same vma instance concurrently, and we only filter out the duplicates upon reacquiring the spinlock for the rbtree, we have to free the loser of the constructors' race. When freeing, we should also drop any resource references acquired for the redundant vma.
Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: stable@vger.kernel.org # v5.5+ Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20200702083225.20044-1-chris@c... (cherry picked from commit 2377427cdd2b7514eb4c40241cf5c4dec63c1bec) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/i915_vma.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -198,6 +198,7 @@ vma_create(struct drm_i915_gem_object *o cmp = i915_vma_compare(pos, vm, view); if (cmp == 0) { spin_unlock(&obj->vma.lock); + i915_vm_put(vm); i915_vma_free(vma); return pos; }