Re: [PATCH] wan-cosa: Use memdup_user() rather than duplicating its implementation

From: Christophe JAILLET
Date: Sat Aug 20 2016 - 04:55:00 EST


Le 20/08/2016 Ã 10:25, SF Markus Elfring a Ãcrit :
From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Sat, 20 Aug 2016 10:10:12 +0200

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

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/net/wan/cosa.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index b87fe0a..02f5809 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -875,16 +875,10 @@ static ssize_t cosa_write(struct file *file,
if (count > COSA_MTU)
count = COSA_MTU;

- /* Allocate the buffer */
- kbuf = kmalloc(count, GFP_KERNEL|GFP_DMA);
In this case, 'memdup_user()' has a different meaning, as GFP_DMA will no more be used for this memory allocation.

- if (kbuf == NULL) {
+ kbuf = memdup_user(buf, count);
+ if (IS_ERR(kbuf)) {
up(&chan->wsem);
- return -ENOMEM;
- }
- if (copy_from_user(kbuf, buf, count)) {
- up(&chan->wsem);
- kfree(kbuf);
- return -EFAULT;
+ return PTR_ERR(kbuf);
}
chan->tx_status=0;
cosa_start_tx(chan, kbuf, count);



---
L'absence de virus dans ce courrier Ãlectronique a Ãtà vÃrifiÃe par le logiciel antivirus Avast.
https://www.avast.com/antivirus