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i2c-dev: Use memdup_user

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Use memdup_user when user data is immediately copied into the allocated
region.  Note that in the second case, the ++i is no longer necessary, as
the last value is already freed if needed by the call to memdup_user.

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>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Julia Lawall 2010-08-11 18:20:55 +02:00 committed by Jean Delvare
parent 35a56c5b82
commit f1c2e33c29
1 changed files with 6 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
drivers/i2c/i2c-dev.c
View file

@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf,
if (count > 8192) if (count > 8192)
count = 8192; count = 8192;
tmp = kmalloc(count, GFP_KERNEL); tmp = memdup_user(buf, count);
if (tmp == NULL) if (IS_ERR(tmp))
return -ENOMEM; return PTR_ERR(tmp);
if (copy_from_user(tmp, buf, count)) {
kfree(tmp);
return -EFAULT;
}
pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
iminor(file->f_path.dentry->d_inode), count); iminor(file->f_path.dentry->d_inode), count);
@ -245,15 +241,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
break; break;
} }
data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
if (rdwr_pa[i].buf == NULL) { if (IS_ERR(rdwr_pa[i].buf)) {
res = -ENOMEM; res = PTR_ERR(rdwr_pa[i].buf);
break;
}
if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
rdwr_pa[i].len)) {
++i; /* Needs to be kfreed too */
res = -EFAULT;
break; break;
} }
} }