[PATCH V2] gpu: drm: tegra: switch over to vmemdup_user()

[Qing Wang]

This patch fixes the following Coccinelle warning:

drivers/gpu/drm/tegra/submit.c:173: WARNING opportunity for vmemdup_user
	
Use vmemdup_user rather than duplicating its implementation
This is a little bit restricted to reduce false positives

Signed-off-by: Qing Wang <wangqing at vivo.com>
---
 drivers/gpu/drm/tegra/submit.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/tegra/submit.c b/drivers/gpu/drm/tegra/submit.c
index c326984..0b11f1a
--- a/drivers/gpu/drm/tegra/submit.c
+++ b/drivers/gpu/drm/tegra/submit.c
@@ -169,14 +169,9 @@ static void *alloc_copy_user_array(void __user *from, size_t count, size_t size)
 	if (copy_len > 0x4000)
 		return ERR_PTR(-E2BIG);
 
-	data = kvmalloc(copy_len, GFP_KERNEL);
-	if (!data)
-		return ERR_PTR(-ENOMEM);
-
-	if (copy_from_user(data, from, copy_len)) {
-		kvfree(data);
-		return ERR_PTR(-EFAULT);
-	}
+	data = vmemdup_user(from, copy_len);
+	if (IS_ERR(data))
+		return ERR_CAST(data);
 
 	return data;
 }
-- 
2.7.4