Prev: [PATCH 5/27] mm: Use memdup_user
Next: [GIT PULL] SLAB fixes for 2.6.35-rc0
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/char/applicom.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/char/applicom.c b/drivers/char/applicom.c
index 63313a3..f4ae0e0 100644
--- a/drivers/char/applicom.c
+++ b/drivers/char/applicom.c
@@ -703,14 +703,9 @@ static long ac_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
/* In general, the device is only openable by root anyway, so we're not
particularly concerned that bogus ioctls can flood the console. */

- adgl = kmalloc(sizeof(struct st_ram_io), GFP_KERNEL);
- if (!adgl)
- return -ENOMEM;
-
- if (copy_from_user(adgl, argp, sizeof(struct st_ram_io))) {
- kfree(adgl);
- return -EFAULT;
- }
+ adgl = memdup_user(argp, sizeof(struct st_ram_io));
+ if (IS_ERR(adgl))
+ return PTR_ERR(adgl);

lock_kernel();
IndexCard = adgl->num_card-1;
--
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 5/27] mm: Use memdup_user
Next: [GIT PULL] SLAB fixes for 2.6.35-rc0