drm/amdgpu: fix amdgpu_vm_pasid_fault_credit

As soon as the lock is dropped the VM pointer can be invalid.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index cd1752b6afa9..9e266307ce63 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2478,17 +2478,21 @@ bool amdgpu_vm_pasid_fault_credit(struct amdgpu_device *adev,
 
         spin_lock(&adev->vm_manager.pasid_lock);
         vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
-        spin_unlock(&adev->vm_manager.pasid_lock);
-        if (!vm)
+        if (!vm) {
                 /* VM not found, can't track fault credit */
+                spin_unlock(&adev->vm_manager.pasid_lock);
                 return true;
+        }
 
         /* No lock needed. only accessed by IRQ handler */
-        if (!vm->fault_credit)
+        if (!vm->fault_credit) {
                 /* Too many faults in this VM */
+                spin_unlock(&adev->vm_manager.pasid_lock);
                 return false;
+        }
 
         vm->fault_credit--;
+        spin_unlock(&adev->vm_manager.pasid_lock);
         return true;
 }