i915: return -EFAULT if copy_to_user fails

copy_to_user returns the number of bytes remaining to be copied, but we
want to return a negative error code here.  These are returned to
userspace.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 7796f452ed1d..051c4db7a1d3 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -620,8 +620,10 @@ static int i915_batchbuffer(struct drm_device *dev, void *data,
                 ret = copy_from_user(cliprects, batch->cliprects,
                                      batch->num_cliprects *
                                      sizeof(struct drm_clip_rect));
-                if (ret != 0)
+                if (ret != 0) {
+                        ret = -EFAULT;
                         goto fail_free;
+                }
         }
 
         mutex_lock(&dev->struct_mutex);
@@ -662,8 +664,10 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
                 return -ENOMEM;
 
         ret = copy_from_user(batch_data, cmdbuf->buf, cmdbuf->sz);
-        if (ret != 0)
+        if (ret != 0) {
+                ret = -EFAULT;
                 goto fail_batch_free;
+        }
 
         if (cmdbuf->num_cliprects) {
                 cliprects = kcalloc(cmdbuf->num_cliprects,
@@ -676,8 +680,10 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
                 ret = copy_from_user(cliprects, cmdbuf->cliprects,
                                      cmdbuf->num_cliprects *
                                      sizeof(struct drm_clip_rect));
-                if (ret != 0)
+                if (ret != 0) {
+                        ret = -EFAULT;
                         goto fail_clip_free;
+                }
         }
 
         mutex_lock(&dev->struct_mutex);