[patch] drm/vc4: Return -EFAULT on copy_from_user() failure

[Dan Carpenter]

The copy_from_user() function returns the number of bytes not copied but
we want to return a negative error code.

Fixes: 463873d57014 ('drm/vc4: Add an API for creating GPU shaders in GEM BOs.')
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
index 034ef2d..9807bc9 100644
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -498,11 +498,12 @@ vc4_create_shader_bo_ioctl(struct drm_device *dev, void 
*data,
        if (IS_ERR(bo))
                return PTR_ERR(bo);

-       ret = copy_from_user(bo->base.vaddr,
+       if (copy_from_user(bo->base.vaddr,
                             (void __user *)(uintptr_t)args->data,
-                            args->size);
-       if (ret != 0)
+                            args->size)) {
+               ret = -EFAULT;
                goto fail;
+       }
        /* Clear the rest of the memory from allocating from the BO
         * cache.
         */