[PATCH] mlx5/core: Use memdup_user() rather than duplicating its implementation

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Sat, 20 Aug 2016 07:50:09 +0200

* Reuse existing functionality from memdup_user() instead of keeping
  duplicate source code.

  This issue was detected by using the Coccinelle software.

* Return directly if this copy operation failed.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c 
b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 6388bc0..bb89f04 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1132,7 +1132,6 @@ static ssize_t data_write(struct file *filp, const char 
__user *buf,
        struct mlx5_core_dev *dev = filp->private_data;
        struct mlx5_cmd_debug *dbg = &dev->cmd.dbg;
        void *ptr;
-       int err;
 
        if (*pos != 0)
                return -EINVAL;
@@ -1140,25 +1139,15 @@ static ssize_t data_write(struct file *filp, const char 
__user *buf,
        kfree(dbg->in_msg);
        dbg->in_msg = NULL;
        dbg->inlen = 0;
-
-       ptr = kzalloc(count, GFP_KERNEL);
-       if (!ptr)
-               return -ENOMEM;
-
-       if (copy_from_user(ptr, buf, count)) {
-               err = -EFAULT;
-               goto out;
-       }
+       ptr = memdup_user(buf, count);
+       if (IS_ERR(ptr))
+               return PTR_ERR(ptr);
        dbg->in_msg = ptr;
        dbg->inlen = count;
 
        *pos = count;
 
        return count;
-
-out:
-       kfree(ptr);
-       return err;
 }
 
 static ssize_t data_read(struct file *filp, char __user *buf, size_t count,
-- 
2.9.3