If the initial value of `num_entires` (calculated at line 1654) is not an integral multiple of `AMDGPU_GPU_PAGES_IN_CPU_PAGE`, in line 1681 a value greater than the initial value will be assigned to it. That causes `start > last + 1` after line 1708. Then in the next iteration an underflow happens at line 1654. It causes message
*ERROR* Couldn't update BO_VA (-12)
printed in kernel log, and GPU hanging.
Fortify the criteria of the loop to fix this issue.
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1549 Fixes: a39f2a8d7066 ("drm/amdgpu: nuke amdgpu_vm_bo_split_mapping v2") Reported-by: Xi Ruoyao xry111@mengyan1223.wang Reported-by: Dan Horák dan@danny.cz Cc: stable@vger.kernel.org Signed-off-by: Xi Ruoyao xry111@mengyan1223.wang --- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index ad91c0c3c423..cee0cc9c8085 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -1707,7 +1707,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev, } start = tmp;
- } while (unlikely(start != last + 1)); + } while (unlikely(start < last + 1));
r = vm->update_funcs->commit(¶ms, fence);
base-commit: a5e13c6df0e41702d2b2c77c8ad41677ebb065b3