From f0e4de5cd0bb99a82445c5a3a876f162052689f8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 26 Apr 2020 08:56:55 -0400 Subject: comedi: do_cmdtest_ioctl(): lift copyin/copyout into the caller Signed-off-by: Al Viro --- drivers/staging/comedi/comedi_fops.c | 45 ++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 23 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 c136cb2f676a..74020fee0ae9 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1856,49 +1856,39 @@ cleanup: * possibly modified comedi_cmd structure */ static int do_cmdtest_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; unsigned int __user *user_chanlist; int ret; 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]; /* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */ if (user_chanlist) { /* load channel/gain list */ - ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &cmd); + ret = __comedi_get_user_chanlist(dev, s, user_chanlist, cmd); if (ret) return ret; } - ret = s->do_cmdtest(dev, s, &cmd); + ret = s->do_cmdtest(dev, s, cmd); - kfree(cmd.chanlist); /* free kernel copy of user chanlist */ + kfree(cmd->chanlist); /* free kernel copy of user chanlist */ /* restore chanlist pointer before copying back */ - cmd.chanlist = (unsigned int __force *)user_chanlist; - - if (copy_to_user(arg, &cmd, sizeof(cmd))) { - dev_dbg(dev->class_dev, "bad cmd address\n"); - ret = -EFAULT; - } + cmd->chanlist = (unsigned int __force *)user_chanlist; + *copy = true; return ret; } @@ -2220,10 +2210,19 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, case COMEDI_CMD: rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file); break; - case COMEDI_CMDTEST: - rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg, - file); + case COMEDI_CMDTEST: { + struct comedi_cmd cmd; + bool copy = false; + + if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { + rc = -EFAULT; + break; + } + rc = do_cmdtest_ioctl(dev, &cmd, ©, file); + if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) + rc = -EFAULT; break; + } case COMEDI_INSNLIST: { struct comedi_insnlist insnlist; struct comedi_insn *insns = NULL; -- cgit