From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 24 May 2017 14:15:20 -0400
Subject: switch compat_drm_getunique() to drm_ioctl_kernel()
Git-commit: 17e3dade62d6e95131ceba1535eb8d2e84b2e040
Patch-mainline: v4.13-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_internal.h |    1 +
 drivers/gpu/drm/drm_ioc32.c    |   21 ++++++++-------------
 drivers/gpu/drm/drm_ioctl.c    |    2 +-
 3 files changed, 10 insertions(+), 14 deletions(-)

--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -144,3 +144,4 @@ static inline int drm_debugfs_crtc_crc_a
 }
 #endif
 drm_ioctl_t drm_version;
+drm_ioctl_t drm_getunique;
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -125,26 +125,21 @@ static int compat_drm_getunique(struct f
 				unsigned long arg)
 {
 	drm_unique32_t uq32;
-	struct drm_unique __user *u;
+	struct drm_unique uq;
 	int err;
 
 	if (copy_from_user(&uq32, (void __user *)arg, sizeof(uq32)))
 		return -EFAULT;
+	uq = (struct drm_unique){
+		.unique_len = uq32.unique_len,
+		.unique = compat_ptr(uq32.unique),
+	};
 
-	u = compat_alloc_user_space(sizeof(*u));
-	if (!u)
-		return -EFAULT;
-	if (__put_user(uq32.unique_len, &u->unique_len)
-	    || __put_user((void __user *)(unsigned long)uq32.unique,
-			  &u->unique))
-		return -EFAULT;
-
-	err = drm_ioctl(file, DRM_IOCTL_GET_UNIQUE, (unsigned long)u);
+	err = drm_ioctl_kernel(file, drm_getunique, &uq, DRM_UNLOCKED);
 	if (err)
 		return err;
 
-	if (__get_user(uq32.unique_len, &u->unique_len))
-		return -EFAULT;
+	uq32.unique_len = uq.unique_len;
 	if (copy_to_user((void __user *)arg, &uq32, sizeof(uq32)))
 		return -EFAULT;
 	return 0;
@@ -1072,7 +1067,7 @@ static struct {
 } drm_compat_ioctls[] = {
 #define DRM_IOCTL32_DEF(n, f) [DRM_IOCTL_NR(n##32)] = {.fn = f, .name = #n}
 	DRM_IOCTL32_DEF(DRM_IOCTL_VERSION, compat_drm_version),
-	[DRM_IOCTL_NR(DRM_IOCTL_GET_UNIQUE32)].fn = compat_drm_getunique,
+	DRM_IOCTL32_DEF(DRM_IOCTL_GET_UNIQUE, compat_drm_getunique),
 	[DRM_IOCTL_NR(DRM_IOCTL_GET_MAP32)].fn = compat_drm_getmap,
 	[DRM_IOCTL_NR(DRM_IOCTL_GET_CLIENT32)].fn = compat_drm_getclient,
 	[DRM_IOCTL_NR(DRM_IOCTL_GET_STATS32)].fn = compat_drm_getstats,
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -107,7 +107,7 @@
  *
  * Copies the bus id from drm_device::unique into user space.
  */
-static int drm_getunique(struct drm_device *dev, void *data,
+int drm_getunique(struct drm_device *dev, void *data,
 		  struct drm_file *file_priv)
 {
 	struct drm_unique *u = data;