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mm: use memdup_user

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@diku.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Julia Lawall 2010-08-09 17:18:26 -07:00 committed by Linus Torvalds
parent 9e58143dc0
commit 90d7404558
1 changed files with 3 additions and 8 deletions

View File

@ -225,15 +225,10 @@ char *strndup_user(const char __user *s, long n)
if (length > n)
return ERR_PTR(-EINVAL);
p = kmalloc(length, GFP_KERNEL);
p = memdup_user(s, length);
if (!p)
return ERR_PTR(-ENOMEM);
if (copy_from_user(p, s, length)) {
kfree(p);
return ERR_PTR(-EFAULT);
}
if (IS_ERR(p))
return p;
p[length - 1] = '\0';