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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>

---
drivers/infiniband/core/ucm.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 4647484..08f948d 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -706,14 +706,9 @@ static int ib_ucm_alloc_data(const void **dest, u64 src, u32 len)
if (!len)
return 0;

- data = kmalloc(len, GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- if (copy_from_user(data, (void __user *)(unsigned long)src, len)) {
- kfree(data);
- return -EFAULT;
- }
+ data = memdup_user((void __user *)(unsigned long)src, len);
+ if (IS_ERR(data))
+ return PTR_ERR(data);

*dest = data;
return 0;
--
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Prev: [PATCH 6/27] drivers/net/cxgb3: Use memdup_user
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