Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8a8ae62f authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

tty: warn on deprecated serial flags 



When somebody calls TIOCSSERIAL ioctl with serial flags to set one of
* ASYNC_SESSION_LOCKOUT
* ASYNC_PGRP_LOCKOUT
* ASYNC_CALLOUT_NOHUP
* ASYNC_AUTOPROBE
nothing happens. We actually ignore the flags for over a decade at
least (I checked 2.6.0).

So start yelling at users who use those flags, that they shouldn't.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d7685ca7

drivers/tty/tty_io.c

+21 −0
Original line number Original line Diff line number Diff line
@@ -2760,6 +2760,24 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) 
	return 0;

	return 0;

}

}





static void tty_warn_deprecated_flags(struct serial_struct __user *ss)

{

	static DEFINE_RATELIMIT_STATE(depr_flags,

			DEFAULT_RATELIMIT_INTERVAL,

			DEFAULT_RATELIMIT_BURST);

	char comm[TASK_COMM_LEN];

	int flags;



	if (get_user(flags, &ss->flags))

		return;



	flags &= ASYNC_DEPRECATED;



	if (flags && __ratelimit(&depr_flags))

		pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",

				__func__, get_task_comm(comm, current), flags);

}



/*

/*

 * if pty, return the slave side (real_tty)

 * if pty, return the slave side (real_tty)

 * otherwise, return self

 * otherwise, return self
@@ -2903,6 +2921,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
			break;

			break;

		}

		}

		break;

		break;

	case TIOCSSERIAL:

		tty_warn_deprecated_flags(p);

		break;

	}

	}

	if (tty->ops->ioctl) {

	if (tty->ops->ioctl) {

		retval = tty->ops->ioctl(tty, cmd, arg);

		retval = tty->ops->ioctl(tty, cmd, arg);

include/uapi/linux/tty_flags.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -64,6 +64,8 @@ 
#define ASYNC_MAGIC_MULTIPLIER	(1U << ASYNCB_MAGIC_MULTIPLIER)

#define ASYNC_MAGIC_MULTIPLIER	(1U << ASYNCB_MAGIC_MULTIPLIER)





#define ASYNC_FLAGS		((1U << (ASYNCB_LAST_USER + 1)) - 1)

#define ASYNC_FLAGS		((1U << (ASYNCB_LAST_USER + 1)) - 1)

#define ASYNC_DEPRECATED	(ASYNC_SESSION_LOCKOUT | ASYNC_PGRP_LOCKOUT | \

		ASYNC_CALLOUT_NOHUP | ASYNC_AUTOPROBE)

#define ASYNC_USR_MASK		(ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \

#define ASYNC_USR_MASK		(ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \

		ASYNC_LOW_LATENCY)

		ASYNC_LOW_LATENCY)

#define ASYNC_SPD_CUST		(ASYNC_SPD_HI|ASYNC_SPD_VHI)

#define ASYNC_SPD_CUST		(ASYNC_SPD_HI|ASYNC_SPD_VHI)