Commit f1638fc6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 

Pull tty/serial driver fixes from Greg KH:
 "Here are some tty and serial driver fixes for 4.11-rc4.

  One of these fix a long-standing issue in the ldisc code that was
  found by Dmitry Vyukov with his great fuzzing work. The other fixes
  resolve other reported issues, and there is one revert of a patch in
  4.11-rc1 that wasn't correct.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix data race in tty_ldisc_ref_wait()
  tty: don't panic on OOM in tty_set_ldisc()
  Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
  tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
  serial: 8250_dw: Fix breakage when HAVE_CLK=n
  serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
parents 53b4d591 a4a3e061

drivers/acpi/spcr.c

+1 −1
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ static bool qdf2400_erratum_44_present(struct acpi_table_header *h) 
		return true;



	if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) &&

			h->oem_revision == 0)

			h->oem_revision == 1)

		return true;



	return false;

drivers/tty/serial/8250/8250_dw.c

+7 −2
Original line number Diff line number Diff line
@@ -257,7 +257,7 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, 
{

	unsigned int baud = tty_termios_baud_rate(termios);

	struct dw8250_data *d = p->private_data;

	unsigned int rate;

	long rate;

	int ret;



	if (IS_ERR(d->clk) || !old)
@@ -265,6 +265,11 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, 


	clk_disable_unprepare(d->clk);

	rate = clk_round_rate(d->clk, baud * 16);

	if (rate < 0)

		ret = rate;

	else if (rate == 0)

		ret = -ENOENT;

	else

		ret = clk_set_rate(d->clk, rate);

	clk_prepare_enable(d->clk);

drivers/tty/serial/amba-pl011.c

+1 −1
Original line number Diff line number Diff line
@@ -2373,7 +2373,7 @@ static int __init pl011_console_match(struct console *co, char *name, int idx, 
	if (strcmp(name, "qdf2400_e44") == 0) {

		pr_info_once("UART: Working around QDF2400 SoC erratum 44");

		qdf2400_e44_present = true;

	} else if (strcmp(name, "pl011") != 0 || strcmp(name, "ttyAMA") != 0) {

	} else if (strcmp(name, "pl011") != 0) {

		return -ENODEV;

	}

drivers/tty/tty_ldisc.c

+21 −71
Original line number Diff line number Diff line
@@ -271,10 +271,13 @@ const struct file_operations tty_ldiscs_proc_fops = { 


struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)

{

	struct tty_ldisc *ld;



	ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);

	if (!tty->ldisc)

	ld = tty->ldisc;

	if (!ld)

		ldsem_up_read(&tty->ldisc_sem);

	return tty->ldisc;

	return ld;

}

EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
@@ -488,41 +491,6 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld) 
	tty_ldisc_debug(tty, "%p: closed\n", ld);

}



/**

 *	tty_ldisc_restore	-	helper for tty ldisc change

 *	@tty: tty to recover

 *	@old: previous ldisc

 *

 *	Restore the previous line discipline or N_TTY when a line discipline

 *	change fails due to an open error

 */



static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)

{

	struct tty_ldisc *new_ldisc;

	int r;



	/* There is an outstanding reference here so this is safe */

	old = tty_ldisc_get(tty, old->ops->num);

	WARN_ON(IS_ERR(old));

	tty->ldisc = old;

	tty_set_termios_ldisc(tty, old->ops->num);

	if (tty_ldisc_open(tty, old) < 0) {

		tty_ldisc_put(old);

		/* This driver is always present */

		new_ldisc = tty_ldisc_get(tty, N_TTY);

		if (IS_ERR(new_ldisc))

			panic("n_tty: get");

		tty->ldisc = new_ldisc;

		tty_set_termios_ldisc(tty, N_TTY);

		r = tty_ldisc_open(tty, new_ldisc);

		if (r < 0)

			panic("Couldn't open N_TTY ldisc for "

			      "%s --- error %d.",

			      tty_name(tty), r);

	}

}



/**

 *	tty_set_ldisc		-	set line discipline

 *	@tty: the terminal to set
@@ -536,12 +504,7 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old) 


int tty_set_ldisc(struct tty_struct *tty, int disc)

{

	int retval;

	struct tty_ldisc *old_ldisc, *new_ldisc;



	new_ldisc = tty_ldisc_get(tty, disc);

	if (IS_ERR(new_ldisc))

		return PTR_ERR(new_ldisc);

	int retval, old_disc;



	tty_lock(tty);

	retval = tty_ldisc_lock(tty, 5 * HZ);
@@ -554,7 +517,8 @@ int tty_set_ldisc(struct tty_struct *tty, int disc) 
	}



	/* Check the no-op case */

	if (tty->ldisc->ops->num == disc)

	old_disc = tty->ldisc->ops->num;

	if (old_disc == disc)

		goto out;



	if (test_bit(TTY_HUPPED, &tty->flags)) {
@@ -563,34 +527,25 @@ int tty_set_ldisc(struct tty_struct *tty, int disc) 
		goto out;

	}



	old_ldisc = tty->ldisc;



	/* Shutdown the old discipline. */

	tty_ldisc_close(tty, old_ldisc);



	/* Now set up the new line discipline. */

	tty->ldisc = new_ldisc;

	tty_set_termios_ldisc(tty, disc);



	retval = tty_ldisc_open(tty, new_ldisc);

	retval = tty_ldisc_reinit(tty, disc);

	if (retval < 0) {

		/* Back to the old one or N_TTY if we can't */

		tty_ldisc_put(new_ldisc);

		tty_ldisc_restore(tty, old_ldisc);

		if (tty_ldisc_reinit(tty, old_disc) < 0) {

			pr_err("tty: TIOCSETD failed, reinitializing N_TTY\n");

			if (tty_ldisc_reinit(tty, N_TTY) < 0) {

				/* At this point we have tty->ldisc == NULL. */

				pr_err("tty: reinitializing N_TTY failed\n");

			}

		}

	}



	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {

	if (tty->ldisc && tty->ldisc->ops->num != old_disc &&

	    tty->ops->set_ldisc) {

		down_read(&tty->termios_rwsem);

		tty->ops->set_ldisc(tty);

		up_read(&tty->termios_rwsem);

	}



	/* At this point we hold a reference to the new ldisc and a

	   reference to the old ldisc, or we hold two references to

	   the old ldisc (if it was restored as part of error cleanup

	   above). In either case, releasing a single reference from

	   the old ldisc is correct. */

	new_ldisc = old_ldisc;

out:

	tty_ldisc_unlock(tty);
@@ -598,7 +553,6 @@ out: 
	   already running */

	tty_buffer_restart_work(tty->port);

err:

	tty_ldisc_put(new_ldisc);	/* drop the extra reference */

	tty_unlock(tty);

	return retval;

}
@@ -659,10 +613,8 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc) 
	int retval;



	ld = tty_ldisc_get(tty, disc);

	if (IS_ERR(ld)) {

		BUG_ON(disc == N_TTY);

	if (IS_ERR(ld))

		return PTR_ERR(ld);

	}



	if (tty->ldisc) {

		tty_ldisc_close(tty, tty->ldisc);
@@ -674,11 +626,9 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc) 
	tty_set_termios_ldisc(tty, disc);

	retval = tty_ldisc_open(tty, tty->ldisc);

	if (retval) {

		if (!WARN_ON(disc == N_TTY)) {

		tty_ldisc_put(tty->ldisc);

		tty->ldisc = NULL;

	}

	}

	return retval;

}

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