From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Tue, 9 Jan 2018 19:18:59 +0100
Subject: drm/amdgpu: fix amdgpu_vm_pasid_fault_credit
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Git-commit: d958939afc39391c0d007a0ca43153856d63ec2a
Patch-mainline: v4.16-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
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>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2477,17 +2477,21 @@ bool amdgpu_vm_pasid_fault_credit(struct
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;
}