[PATCH] mmc: block: use memdup_user

[Geliang Tang]

Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangt...@gmail.com>
---
 drivers/mmc/core/block.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 8273b07..47ccb2a 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -342,21 +342,15 @@ static struct mmc_blk_ioc_data 
*mmc_blk_ioctl_copy_from_user(
                return idata;
        }
 
-       idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
-       if (!idata->buf) {
-               err = -ENOMEM;
+       idata->buf = memdup_user((void __user *)(unsigned long)
+                                idata->ic.data_ptr, idata->buf_bytes);
+       if (IS_ERR(idata->buf)) {
+               err = PTR_ERR(idata->buf);
                goto idata_err;
        }
 
-       if (copy_from_user(idata->buf, (void __user *)(unsigned long)
-                                       idata->ic.data_ptr, idata->buf_bytes)) {
-               err = -EFAULT;
-               goto copy_err;
-       }
-
        return idata;
 
-copy_err:
        kfree(idata->buf);
 idata_err:
        kfree(idata);
-- 
2.9.3