Prev: [PATCH 3/27] fs/btrfs: Use memdup_user
Next: [PATCH 19/27] drivers/telephony/ixj.c: Use memdup_user
From: Julia Lawall on 22 May 2010 04:30
From: Julia Lawall <julia(a)diku.dk>

Use memdup_user when user data is immediately copied into the
allocated region.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@

- to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }
// </smpl>

Signed-off-by: Julia Lawall <julia(a)diku.dk>

---
net/dccp/proto.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index b03ecf6..f79bcef 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -473,14 +473,9 @@ static int dccp_setsockopt_ccid(struct sock *sk, int type,
if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
return -EINVAL;

- val = kmalloc(optlen, GFP_KERNEL);
- if (val == NULL)
- return -ENOMEM;
-
- if (copy_from_user(val, optval, optlen)) {
- kfree(val);
- return -EFAULT;
- }
+ val = memdup_user(optval, optlen);
+ if (IS_ERR(val))
+ return PTR_ERR(val);

lock_sock(sk);
if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: [PATCH 3/27] fs/btrfs: Use memdup_user
Next: [PATCH 19/27] drivers/telephony/ixj.c: Use memdup_user