From: Christian König <christian.koenig@amd.com>
Date: Tue, 9 Jan 2018 18:18:59 +0000 (+0100)
Subject: drm/amdgpu: fix amdgpu_vm_pasid_fault_credit
X-Git-Tag: v4.16-rc1~31^2~7^2~16
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=d958939afc39391c0d007a0ca43153856d63ec2a;p=uclinux-h8%2Flinux.git

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>
---

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;
 }