Prev: [PATCH 14/27] drivers/scsi: Use memdup_user
Next: [PATCH 26/27] drivers/isdn: 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>

---
drivers/video/via/viafbdev.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 2bc40e6..1082541 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -578,14 +578,9 @@ static int viafb_ioctl(struct fb_info *info, u_int cmd, u_long arg)
break;

case VIAFB_SET_GAMMA_LUT:
- viafb_gamma_table = kmalloc(256 * sizeof(u32), GFP_KERNEL);
- if (!viafb_gamma_table)
- return -ENOMEM;
- if (copy_from_user(viafb_gamma_table, argp,
- 256 * sizeof(u32))) {
- kfree(viafb_gamma_table);
- return -EFAULT;
- }
+ viafb_gamma_table = memdup_user(argp, 256 * sizeof(u32));
+ if (IS_ERR(viafb_gamma_table))
+ return PTR_ERR(viafb_gamma_table);
viafb_set_gamma_table(viafb_bpp, viafb_gamma_table);
kfree(viafb_gamma_table);
break;
--
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 14/27] drivers/scsi: Use memdup_user
Next: [PATCH 26/27] drivers/isdn: Use memdup_user