Patch "drm/amdgpu: reserve root PD while releasing it" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

drm/amdgpu: reserve root PD while releasing it

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-amdgpu-reserve-root-pd-while-releasing-it.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: =?UTF-8?q?Christian=20K=C3=B6nig?= <[email protected]>
Date: Fri, 13 Oct 2017 17:24:31 +0200
Subject: drm/amdgpu: reserve root PD while releasing it
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Christian König <[email protected]>

commit 2642cf110d08a403f585a051e4cbf45a90b3adea upstream.

Otherwise somebody could try to evict it at the same time and try to use half torn down structures.

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

@@ -2586,7 +2586,8 @@ void amdgpu_vm_fini(struct amdgpu_device
 {
 	struct amdgpu_bo_va_mapping *mapping, *tmp;
 	bool prt_fini_needed = !!adev->gart.gart_funcs->set_prt;
-	int i;
+	struct amdgpu_bo *root;
+	int i, r;
 
 	amd_sched_entity_fini(vm->entity.sched, &vm->entity);
 

@@ -2609,7 +2610,15 @@ void amdgpu_vm_fini(struct amdgpu_device
 		amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
 	}
 
-	amdgpu_vm_free_levels(&vm->root);
+	root = amdgpu_bo_ref(vm->root.bo);
+	r = amdgpu_bo_reserve(root, true);
+	if (r) {
+		dev_err(adev->dev, "Leaking page tables because BO reservation failed\n");
+	} else {
+		amdgpu_vm_free_levels(&vm->root);
+		amdgpu_bo_unreserve(root);
+	}
+	amdgpu_bo_unref(&root);
 	dma_fence_put(vm->last_dir_update);
 	for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
 		amdgpu_vm_free_reserved_vmid(adev, vm, i);

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/drm-ttm-fix-ttm_bo_cleanup_refs_or_queue-once-more.patch queue-4.14/drm-ttm-once-more-fix-ttm_buffer_object_transfer.patch queue-4.14/drm-amdgpu-potential-uninitialized-variable-in-amdgpu_vce_ring_parse_cs.patch queue-4.14/drm-amdgpu-reserve-root-pd-while-releasing-it.patch queue-4.14/drm-amdgpu-properly-allocate-vm-invalidate-eng-v2.patch queue-4.14/drm-amdgpu-set-adev-vcn.irq.num_types-for-vcn.patch queue-4.14/drm-amdgpu-potential-uninitialized-variable-in-amdgpu_vm_update_directories.patch queue-4.14/drm-amdgpu-fix-error-handling-in-amdgpu_bo_do_create.patch queue-4.14/drm-ttm-always-and-only-destroy-bo-ttm_resv-in-ttm_bo_release_list.patch queue-4.14/dma-buf-make-reservation_object_copy_fences-rcu-save.patch queue-4.14/drm-amdgpu-move-uvd-vce-and-vcn-structure-out-from-union.patch