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Code Issues Releases Wiki Activity

comedi: do_cmd_ioctl(): lift copyin/copyout into the caller

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-04-26 09:01:49 -04:00
parent f0e4de5cd0
commit 0a3ccc75a9
1 changed files with 24 additions and 24 deletions
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48
drivers/staging/comedi/comedi_fops.c
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@ -1741,9 +1741,8 @@ static int __comedi_get_user_chanlist(struct comedi_device *dev,
* possibly modified comedi_cmd structure (when -EAGAIN returned)
*/
static int do_cmd_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *arg, void *file)
struct comedi_cmd *cmd, bool *copy, void *file)
{
struct comedi_cmd cmd;
struct comedi_subdevice *s;
struct comedi_async *async;
unsigned int __user *user_chanlist;
@ -1751,20 +1750,15 @@ static int do_cmd_ioctl(struct comedi_device *dev,
lockdep_assert_held(&dev->mutex);
if (copy_from_user(&cmd, arg, sizeof(cmd))) {
dev_dbg(dev->class_dev, "bad cmd address\n");
return -EFAULT;
}
/* get the user's cmd and do some simple validation */
ret = __comedi_get_user_cmd(dev, &cmd);
/* do some simple cmd validation */
ret = __comedi_get_user_cmd(dev, cmd);
if (ret)
return ret;
/* save user's chanlist pointer so it can be restored later */
user_chanlist = (unsigned int __user *)cmd.chanlist;
user_chanlist = (unsigned int __user *)cmd->chanlist;
s = &dev->subdevices[cmd.subdev];
s = &dev->subdevices[cmd->subdev];
async = s->async;
/* are we locked? (ioctl lock) */
@ -1780,13 +1774,13 @@ static int do_cmd_ioctl(struct comedi_device *dev,
}
/* make sure channel/gain list isn't too short */
if (cmd.chanlist_len < 1) {
if (cmd->chanlist_len < 1) {
dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n",
cmd.chanlist_len);
cmd->chanlist_len);
return -EINVAL;
}
async->cmd = cmd;
async->cmd = *cmd;
async->cmd.data = NULL;
/* load channel/gain list */
@ -1798,15 +1792,11 @@ static int do_cmd_ioctl(struct comedi_device *dev,
if (async->cmd.flags & CMDF_BOGUS || ret) {
dev_dbg(dev->class_dev, "test returned %d\n", ret);
cmd = async->cmd;
*cmd = async->cmd;
/* restore chanlist pointer before copying back */
cmd.chanlist = (unsigned int __force *)user_chanlist;
cmd.data = NULL;
if (copy_to_user(arg, &cmd, sizeof(cmd))) {
dev_dbg(dev->class_dev, "fault writing cmd\n");
ret = -EFAULT;
goto cleanup;
}
cmd->chanlist = (unsigned int __force *)user_chanlist;
cmd->data = NULL;
*copy = true;
ret = -EAGAIN;
goto cleanup;
}
@ -2207,9 +2197,19 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
case COMEDI_CANCEL:
rc = do_cancel_ioctl(dev, arg, file);
break;
case COMEDI_CMD:
rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
case COMEDI_CMD: {
struct comedi_cmd cmd;
bool copy = false;
if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) {
rc = -EFAULT;
break;
}
rc = do_cmd_ioctl(dev, &cmd, &copy, file);
if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd)))
rc = -EFAULT;
break;
}
case COMEDI_CMDTEST: {
struct comedi_cmd cmd;
bool copy = false;