drm/radeon: check new address before removing old one

commit c29c0876 upstream.

Otherwise the change isn't atomic.
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/radeon/radeon_vm.c

@@ -473,6 +473,23 @@ int radeon_vm_bo_set_addr(struct radeon_device *rdev,
 	}
 
 	mutex_lock(&vm->mutex);
+	soffset /= RADEON_GPU_PAGE_SIZE;
+	eoffset /= RADEON_GPU_PAGE_SIZE;
+	if (soffset || eoffset) {
+		struct interval_tree_node *it;
+		it = interval_tree_iter_first(&vm->va, soffset, eoffset - 1);
+		if (it && it != &bo_va->it) {
+			struct radeon_bo_va *tmp;
+			tmp = container_of(it, struct radeon_bo_va, it);
+			/* bo and tmp overlap, invalid offset */
+			dev_err(rdev->dev, "bo %p va 0x%010Lx conflict with "
+				"(bo %p 0x%010lx 0x%010lx)\n", bo_va->bo,
+				soffset, tmp->bo, tmp->it.start, tmp->it.last);
+			mutex_unlock(&vm->mutex);
+			return -EINVAL;
+		}
+	}
+
 	if (bo_va->it.start || bo_va->it.last) {
 		if (bo_va->addr) {
 			/* add a clone of the bo_va to clear the old address */
@@ -499,21 +516,7 @@ int radeon_vm_bo_set_addr(struct radeon_device *rdev,
 		bo_va->it.last = 0;
 	}
 
-	soffset /= RADEON_GPU_PAGE_SIZE;
-	eoffset /= RADEON_GPU_PAGE_SIZE;
 	if (soffset || eoffset) {
-		struct interval_tree_node *it;
-		it = interval_tree_iter_first(&vm->va, soffset, eoffset - 1);
-		if (it) {
-			struct radeon_bo_va *tmp;
-			tmp = container_of(it, struct radeon_bo_va, it);
-			/* bo and tmp overlap, invalid offset */
-			dev_err(rdev->dev, "bo %p va 0x%010Lx conflict with "
-				"(bo %p 0x%010lx 0x%010lx)\n", bo_va->bo,
-				soffset, tmp->bo, tmp->it.start, tmp->it.last);
-			mutex_unlock(&vm->mutex);
-			return -EINVAL;
-		}
 		bo_va->it.start = soffset;
 		bo_va->it.last = eoffset - 1;
 		interval_tree_insert(&bo_va->it, &vm->va);