From: Daniel Vetter Date: Thu, 9 Jul 2015 21:32:42 +0000 (+0200) Subject: drm/rockchip: Don't grab dev->struct_mutex for in mmap offset ioctl X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=648a4ce7ca209db92db5c3cecb05c14d147a2e6a;p=openwrt%2Fstaging%2Fblogic.git drm/rockchip: Don't grab dev->struct_mutex for in mmap offset ioctl Since David Herrmann's mmap vma manager rework we don't need to grab dev->struct_mutex any more to prevent races when looking up the mmap offset. Drop it and instead don't forget to use the unref_unlocked variant (since the drm core still cares). Aside: I stumbled over the mmap handler which directly does a dma_mmap_attrs. But totally fails to grab a reference on the underlying object and hence looks like it happily just leaks the ptes since there's no guarantee the mmap isn't still around when gem_free_object is called. Which the kerneldoc of dma_mmap_attrs explicitly forbids. v2: Fixup compile fail 0-day spotted. Cc: Mark Yao Reviewed-by: Thierry Reding Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c index eba5f8a52fbd..a6d9104f7f15 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c @@ -200,13 +200,10 @@ int rockchip_gem_dumb_map_offset(struct drm_file *file_priv, struct drm_gem_object *obj; int ret; - mutex_lock(&dev->struct_mutex); - obj = drm_gem_object_lookup(dev, file_priv, handle); if (!obj) { DRM_ERROR("failed to lookup gem object.\n"); - ret = -EINVAL; - goto unlock; + return -EINVAL; } ret = drm_gem_create_mmap_offset(obj); @@ -217,10 +214,9 @@ int rockchip_gem_dumb_map_offset(struct drm_file *file_priv, DRM_DEBUG_KMS("offset = 0x%llx\n", *offset); out: - drm_gem_object_unreference(obj); -unlock: - mutex_unlock(&dev->struct_mutex); - return ret; + drm_gem_object_unreference_unlocked(obj); + + return 0; } /*