Merge tag 'drm-misc-fixes-2023-02-09' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

A fix for a circular refcounting in drm/client, one for a memory leak in
amdgpu and a virtio fence fix when interrupted
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230209083600.7hi6roht6xxgldgz@houat

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -1220,10 +1220,13 @@ static int amdgpu_cs_sync_rings(struct amdgpu_cs_parser *p)
 		 * next job actually sees the results from the previous one
 		 * before we start executing on the same scheduler ring.
 		 */
-		if (!s_fence || s_fence->sched != sched)
+		if (!s_fence || s_fence->sched != sched) {
+			dma_fence_put(fence);
 			continue;
+		}
 
 		r = amdgpu_sync_fence(&p->gang_leader->explicit_sync, fence);
+		dma_fence_put(fence);
 		if (r)
 			return r;
 	}

drivers/gpu/drm/drm_client.c

@@ -233,21 +233,17 @@ void drm_client_dev_restore(struct drm_device *dev)
 
 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
 {
-	struct drm_device *dev = buffer->client->dev;
-
 	if (buffer->gem) {
 		drm_gem_vunmap_unlocked(buffer->gem, &buffer->map);
 		drm_gem_object_put(buffer->gem);
 	}
 
-	if (buffer->handle)
-		drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file);
-
 	kfree(buffer);
 }
 
 static struct drm_client_buffer *
-drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
+drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
+			 u32 format, u32 *handle)
 {
 	const struct drm_format_info *info = drm_format_info(format);
 	struct drm_mode_create_dumb dumb_args = { };
@@ -269,16 +265,15 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
 	if (ret)
 		goto err_delete;
 
-	buffer->handle = dumb_args.handle;
-	buffer->pitch = dumb_args.pitch;
-
 	obj = drm_gem_object_lookup(client->file, dumb_args.handle);
 	if (!obj)  {
 		ret = -ENOENT;
 		goto err_delete;
 	}
 
+	buffer->pitch = dumb_args.pitch;
 	buffer->gem = obj;
+	*handle = dumb_args.handle;
 
 	return buffer;
 
@@ -365,7 +360,8 @@ static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
 }
 
 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
-				   u32 width, u32 height, u32 format)
+				   u32 width, u32 height, u32 format,
+				   u32 handle)
 {
 	struct drm_client_dev *client = buffer->client;
 	struct drm_mode_fb_cmd fb_req = { };
@@ -377,7 +373,7 @@ static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
 	fb_req.depth = info->depth;
 	fb_req.width = width;
 	fb_req.height = height;
-	fb_req.handle = buffer->handle;
+	fb_req.handle = handle;
 	fb_req.pitch = buffer->pitch;
 
 	ret = drm_mode_addfb(client->dev, &fb_req, client->file);
@@ -414,13 +410,24 @@ struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
 {
 	struct drm_client_buffer *buffer;
+	u32 handle;
 	int ret;
 
-	buffer = drm_client_buffer_create(client, width, height, format);
+	buffer = drm_client_buffer_create(client, width, height, format,
+					  &handle);
 	if (IS_ERR(buffer))
 		return buffer;
 
-	ret = drm_client_buffer_addfb(buffer, width, height, format);
+	ret = drm_client_buffer_addfb(buffer, width, height, format, handle);
+
+	/*
+	 * The handle is only needed for creating the framebuffer, destroy it
+	 * again to solve a circular dependency should anybody export the GEM
+	 * object as DMA-buf. The framebuffer and our buffer structure are still
+	 * holding references to the GEM object to prevent its destruction.
+	 */
+	drm_mode_destroy_dumb(client->dev, handle, client->file);
+
 	if (ret) {
 		drm_client_buffer_delete(buffer);
 		return ERR_PTR(ret);

drivers/gpu/drm/virtio/virtgpu_ioctl.c

@@ -126,7 +126,6 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
 	void __user *user_bo_handles = NULL;
 	struct virtio_gpu_object_array *buflist = NULL;
 	struct sync_file *sync_file;
-	int in_fence_fd = exbuf->fence_fd;
 	int out_fence_fd = -1;
 	void *buf;
 	uint64_t fence_ctx;
@@ -152,13 +151,11 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
 		ring_idx = exbuf->ring_idx;
 	}
 
-	exbuf->fence_fd = -1;
-
 	virtio_gpu_create_context(dev, file);
 	if (exbuf->flags & VIRTGPU_EXECBUF_FENCE_FD_IN) {
 		struct dma_fence *in_fence;
 
-		in_fence = sync_file_get_fence(in_fence_fd);
+		in_fence = sync_file_get_fence(exbuf->fence_fd);
 
 		if (!in_fence)
 			return -EINVAL;

include/drm/drm_client.h

@@ -126,11 +126,6 @@ struct drm_client_buffer {
 	 */
 	struct drm_client_dev *client;
 
-	/**
-	 * @handle: Buffer handle
-	 */
-	u32 handle;
-
 	/**
 	 * @pitch: Buffer pitch
 	 */

include/uapi/drm/virtgpu_drm.h

@@ -64,6 +64,7 @@ struct drm_virtgpu_map {
 	__u32 pad;
 };
 
+/* fence_fd is modified on success if VIRTGPU_EXECBUF_FENCE_FD_OUT flag is set. */
 struct drm_virtgpu_execbuffer {
 	__u32 flags;
 	__u32 size;