From 0a3ccc75a95ff682de9315dee7e55efde1d5e30c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 26 Apr 2020 09:01:49 -0400 Subject: comedi: do_cmd_ioctl(): lift copyin/copyout into the caller Signed-off-by: Al Viro --- drivers/staging/comedi/comedi_fops.c | 48 ++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 24 deletions(-) (limited to 'drivers/staging/comedi/comedi_fops.c') diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 74020fee0ae9..c40df64e3ec7 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -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, ©, 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; -- cgit v1.2.3-59-g8ed1b