Re: [PATCH 05/50] tty_ioctl(): start taking TIOC[SG]SERIAL into separate methods

From: Johan Hovold
Date: Fri Sep 14 2018 - 09:22:21 EST


On Thu, Sep 13, 2018 at 03:40:04AM +0100, Al Viro wrote:
> From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>
> ->set_serial() and ->get_serial() resp., both taking tty and
> a kernel pointer to serial_struct.
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/tty/tty_io.c | 36 ++++++++++++++++++++++++++++++------
> include/linux/tty_driver.h | 3 +++
> 2 files changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index 2b34ccf269e0..91d73732e11c 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -97,6 +97,7 @@
> #include <linux/seq_file.h>
> #include <linux/serial.h>
> #include <linux/ratelimit.h>
> +#include <linux/compat.h>

Looks like you don't need this (just yet anyway).

> #include <linux/uaccess.h>
>
> @@ -2455,22 +2456,40 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
> return 0;
> }

[...]

> +static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss)
> +{
> + struct serial_struct v;
> + int err;

Missing newline.

> + memset(&v, 0, sizeof(struct serial_struct));
> +
> + if (!tty->ops->set_serial)

You want get_serial here.

> + return -ENOIOCTLCMD;
> + err = tty->ops->get_serial(tty, &v);
> + if (!err && copy_to_user(ss, &v, sizeof(struct serial_struct)))
> + err = -EFAULT;
> + return err;
> }
>
> /*
> @@ -2602,8 +2621,13 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> }
> break;
> case TIOCSSERIAL:
> - tty_warn_deprecated_flags(p);
> - break;
> + retval = tty_tiocsserial(tty, p);
> + if (retval != -ENOIOCTLCMD)
> + return retval;

Missing break.

> + case TIOCGSERIAL:
> + retval = tty_tiocgserial(tty, p);
> + if (retval != -ENOIOCTLCMD)
> + return retval;

Missing break.

> case TIOCGPTPEER:
> /* Special because the struct file is needed */
> return ptm_open_peer(file, tty, (int)arg);

Johan