DRM client's vmap/vunmap functions don't allow for multiple vmap operations. Calling drm_client_buffer_vmap() twice returns the same mapping, then calling drm_client_buffer_vunmap() twice already unmaps on the first call. This leads to unbalanced vmap refcounts. Fix this by calling drm_gem_vmap() unconditionally in drm_client_buffer_vmap().
All drivers that support DRM clients have to implement correct ref- counting for their vmap operations, or not vunmap at all. This is the case for drivers that use CMA, SHMEM and VRAM helpers, and QXL. Other drivers are not affected.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de --- drivers/gpu/drm/drm_client.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c index fe573acf1067..ce45e380f4a2 100644 --- a/drivers/gpu/drm/drm_client.c +++ b/drivers/gpu/drm/drm_client.c @@ -314,9 +314,6 @@ drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map *map struct dma_buf_map *map = &buffer->map; int ret;
- if (dma_buf_map_is_set(map)) - goto out; - /* * FIXME: The dependency on GEM here isn't required, we could * convert the driver handle to a dma-buf instead and use the @@ -329,7 +326,6 @@ drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map *map if (ret) return ret;
-out: *map_copy = *map;
return 0;