From f060660b014a5311748e7bdbbd3a729ab6b3822f Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 12 Feb 2020 15:07:59 +0300
Subject: drm/amdgpu: return -EFAULT if copy_to_user() fails
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Git-commit: 434cbcb1bd5dea181e6e2379f9f4d4949b51d445
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return a negative error code to the user.

Fixes: 030d5b97a54b ("drm/amdgpu: use amdgpu_device_vram_access in amdgpu_ttm_vram_read")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 2d96ec144702..b61830339239 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2284,7 +2284,6 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
 {
 	struct amdgpu_device *adev = file_inode(f)->i_private;
 	ssize_t result = 0;
-	int r;
 
 	if (size & 0x3 || *pos & 0x3)
 		return -EINVAL;
@@ -2298,9 +2297,8 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
 		uint32_t value[AMDGPU_TTM_VRAM_MAX_DW_READ];
 
 		amdgpu_device_vram_access(adev, *pos, value, bytes, false);
-		r = copy_to_user(buf, value, bytes);
-		if (r)
-			return r;
+		if (copy_to_user(buf, value, bytes))
+			return -EFAULT;
 
 		result += bytes;
 		buf += bytes;
-- 
2.28.0