[PATCH 1/2] mmc-block: Use memdup_user() rather than duplicating its implementation

SF Markus Elfring
2016-08-19T21:11:03Z

Date: Fri, 19 Aug 2016 22:46:38 +0200

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

This issue was detected by using the Coccinelle software.

* Delete the integer variable "err" then because the pointer
variable "idata" should be sufficient to handle return values alone
in this function.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/mmc/card/block.c | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 48a5dd7..6ce9492 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -337,22 +337,21 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
struct mmc_ioc_cmd __user *user)
{
struct mmc_blk_ioc_data *idata;
- int err;

idata = kmalloc(sizeof(*idata), GFP_KERNEL);
if (!idata) {
- err = -ENOMEM;
+ idata = ERR_PTR(-ENOMEM);
goto out;
}

if (copy_from_user(&idata->ic, user, sizeof(idata->ic))) {
- err = -EFAULT;
+ idata = ERR_PTR(-EFAULT);
goto idata_err;
}

idata->buf_bytes = (u64) idata->ic.blksz * idata->ic.blocks;
if (idata->buf_bytes > MMC_IOC_MAX_BYTES) {
- err = -EOVERFLOW;
+ idata = ERR_PTR(-EOVERFLOW);
goto idata_err;
}

@@ -361,26 +360,19 @@ 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)) {
+ idata = (void *) 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);
out:
- return ERR_PTR(err);
+ return idata;
}

static int mmc_blk_ioctl_copy_to_user(struct mmc_ioc_cmd __user *ic_ptr,
--
2.9.3