This is a note to let you know that I've just added the patch titled
drm/amdgpu: install stub fence into potential unused fence pointers
to the 5.15-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-install-stub-fence-into-potential-unused-.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f64e6d9190f76a8facfa91e30a3806c044f79850
Author: Lang Yu <Lang.Yu@xxxxxxx>
Date: Fri May 5 20:14:15 2023 +0800
drm/amdgpu: install stub fence into potential unused fence pointers
[ Upstream commit 187916e6ed9d0c3b3abc27429f7a5f8c936bd1f0 ]
When using cpu to update page tables, vm update fences are unused.
Install stub fence into these fence pointers instead of NULL
to avoid NULL dereference when calling dma_fence_wait() on them.
Suggested-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Lang Yu <Lang.Yu@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 0e4554950e072..788611a50a68e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2260,6 +2260,7 @@ struct amdgpu_bo_va *amdgpu_vm_bo_add(struct amdgpu_device *adev,
amdgpu_vm_bo_base_init(&bo_va->base, vm, bo);
bo_va->ref_count = 1;
+ bo_va->last_pt_update = dma_fence_get_stub();
INIT_LIST_HEAD(&bo_va->valids);
INIT_LIST_HEAD(&bo_va->invalids);
@@ -2974,7 +2975,8 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
vm->update_funcs = &amdgpu_vm_cpu_funcs;
else
vm->update_funcs = &amdgpu_vm_sdma_funcs;
- vm->last_update = NULL;
+
+ vm->last_update = dma_fence_get_stub();
vm->last_unlocked = dma_fence_get_stub();
mutex_init(&vm->eviction_lock);
@@ -3117,7 +3119,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
vm->update_funcs = &amdgpu_vm_sdma_funcs;
}
dma_fence_put(vm->last_update);
- vm->last_update = NULL;
+ vm->last_update = dma_fence_get_stub();
vm->is_compute_context = true;
/* Free the shadow bo for compute VM */
