From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 25 May 2017 12:50:51 -0400
Subject: switch compat_drm_getsareactx() to drm_ioctl_kernel()
Git-commit: d7631e30434e7fcf025dd2a7cba879f203f7849b
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_ioc32.c |   23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -517,28 +517,21 @@ static int compat_drm_setsareactx(struct
 static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
 				  unsigned long arg)
 {
-	struct drm_ctx_priv_map __user *request;
+	struct drm_ctx_priv_map req;
+	drm_ctx_priv_map32_t req32;
 	drm_ctx_priv_map32_t __user *argp = (void __user *)arg;
 	int err;
-	unsigned int ctx_id;
-	void *handle;
 
-	if (!access_ok(VERIFY_WRITE, argp, sizeof(*argp))
-	    || __get_user(ctx_id, &argp->ctx_id))
-		return -EFAULT;
-
-	request = compat_alloc_user_space(sizeof(*request));
-	if (!request)
-		return -EFAULT;
-	if (__put_user(ctx_id, &request->ctx_id))
+	if (copy_from_user(&req32, argp, sizeof(req32)))
 		return -EFAULT;
 
-	err = drm_ioctl(file, DRM_IOCTL_GET_SAREA_CTX, (unsigned long)request);
+	req.ctx_id = req32.ctx_id;
+	err = drm_ioctl_kernel(file, drm_legacy_getsareactx, &req, DRM_AUTH);
 	if (err)
 		return err;
 
-	if (__get_user(handle, &request->handle)
-	    || __put_user((unsigned long)handle, &argp->handle))
+	req32.handle = ptr_to_compat(req.handle);
+	if (copy_to_user(argp, &req32, sizeof(req32)))
 		return -EFAULT;
 
 	return 0;
@@ -1007,7 +1000,7 @@ static struct {
 	DRM_IOCTL32_DEF(DRM_IOCTL_FREE_BUFS, compat_drm_freebufs),
 	[DRM_IOCTL_NR(DRM_IOCTL_RM_MAP32)].fn = compat_drm_rmmap,
 	DRM_IOCTL32_DEF(DRM_IOCTL_SET_SAREA_CTX, compat_drm_setsareactx),
-	[DRM_IOCTL_NR(DRM_IOCTL_GET_SAREA_CTX32)].fn = compat_drm_getsareactx,
+	DRM_IOCTL32_DEF(DRM_IOCTL_GET_SAREA_CTX, compat_drm_getsareactx),
 	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX32)].fn = compat_drm_resctx,
 	[DRM_IOCTL_NR(DRM_IOCTL_DMA32)].fn = compat_drm_dma,
 #if IS_ENABLED(CONFIG_AGP)