drm/amdgpu: reserve the root PD while freeing PASIDs

Free the pasid only while the root PD is reserved. This prevents use after
free in the page fault handling.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 file changed