drm/client: Fix error code in drm_client_buffer_vmap_local()

[ Upstream commit b5fbf924f125ba3638cfdc21c0515eb7e76264ca ]

This function accidentally returns zero/success on the failure path.
It leads to locking issues and an uninitialized *map_copy in the
caller.

Fixes: b4b0193e83cb ("drm/fbdev-generic: Fix locking with drm_client_buffer_vmap_local()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/89d13df3-747c-4c5d-b122-d081aef5110a@stanley.mountain
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 2803ac111bbd8ad5a069b7700832365175de76da..bfedcbf516dbe2b1efd037ed22efe4cfe139da48 100644 (file)
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -355,7 +355,7 @@ int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
 
 err_drm_gem_vmap_unlocked:
        drm_gem_unlock(gem);
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL(drm_client_buffer_vmap_local);