drm/v3d: fix copy_from_user() error codes

The copy_to/from_user() function returns the number of bytes remaining
to be copied, but we want to return -EFAULT on error.

Fixes: e4165ae8304e ("drm/v3d: add multiple syncobjs support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211011123303.GA14314@kili

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index 6a000d77c568bba92545cb53439649a2ab1fef35..e47ae40a865a8072b9cbb805f969f11739ba1e15 100644 (file)
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -487,8 +487,8 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
                        for (i = 0; i < se->in_sync_count; i++) {
                                struct drm_v3d_sem in;
 
-                               ret = copy_from_user(&in, handle++, sizeof(in));
-                               if (ret) {
+                               if (copy_from_user(&in, handle++, sizeof(in))) {
+                                       ret = -EFAULT;
                                        DRM_DEBUG("Failed to copy wait dep handle.\n");
                                        goto fail_deps;
                                }
@@ -609,8 +609,8 @@ v3d_get_multisync_post_deps(struct drm_file *file_priv,
        for (i = 0; i < count; i++) {
                struct drm_v3d_sem out;
 
-               ret = copy_from_user(&out, post_deps++, sizeof(out));
-               if (ret) {
+               if (copy_from_user(&out, post_deps++, sizeof(out))) {
+                       ret = -EFAULT;
                        DRM_DEBUG("Failed to copy post dep handles\n");
                        goto fail;
                }
@@ -646,9 +646,8 @@ v3d_get_multisync_submit_deps(struct drm_file *file_priv,
        struct v3d_submit_ext *se = data;
        int ret;
 
-       ret = copy_from_user(&multisync, ext, sizeof(multisync));
-       if (ret)
-               return ret;
+       if (copy_from_user(&multisync, ext, sizeof(multisync)))
+               return -EFAULT;
 
        if (multisync.pad)
                return -EINVAL;