From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
linux-kernel@vger.kernel.org,
Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH v2 13/19] tty: Handle NULL tty->ldisc
Date: Sat, 9 Jan 2016 20:41:04 -0800 [thread overview]
Message-ID: <1452400870-6005-14-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1452400870-6005-1-git-send-email-peter@hurleysoftware.com>
In preparation of destroying line discipline on hangup, fix
ldisc core operations to properly handle when the tty's ldisc is
NULL.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
drivers/tty/tty_ldisc.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 1c9ce25..5115230 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -269,7 +269,8 @@ const struct file_operations tty_ldiscs_proc_fops = {
struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
{
ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);
- WARN_ON(!tty->ldisc);
+ if (!tty->ldisc)
+ ldsem_up_read(&tty->ldisc_sem);
return tty->ldisc;
}
EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
@@ -462,7 +463,7 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
if (ret)
clear_bit(TTY_LDISC_OPEN, &tty->flags);
- tty_ldisc_debug(tty, "%p: opened\n", tty->ldisc);
+ tty_ldisc_debug(tty, "%p: opened\n", ld);
return ret;
}
return 0;
@@ -483,7 +484,7 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
clear_bit(TTY_LDISC_OPEN, &tty->flags);
if (ld->ops->close)
ld->ops->close(tty);
- tty_ldisc_debug(tty, "%p: closed\n", tty->ldisc);
+ tty_ldisc_debug(tty, "%p: closed\n", ld);
}
/**
@@ -546,6 +547,11 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
if (retval)
goto err;
+ if (!tty->ldisc) {
+ retval = -EIO;
+ goto out;
+ }
+
/* Check the no-op case */
if (tty->ldisc->ops->num == ldisc)
goto out;
@@ -661,7 +667,7 @@ void tty_ldisc_hangup(struct tty_struct *tty)
int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
int err = 0;
- tty_ldisc_debug(tty, "%p: closing\n", tty->ldisc);
+ tty_ldisc_debug(tty, "%p: hangup\n", tty->ldisc);
ld = tty_ldisc_ref(tty);
if (ld != NULL) {
@@ -745,6 +751,8 @@ int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
static void tty_ldisc_kill(struct tty_struct *tty)
{
+ if (!tty->ldisc)
+ return;
/*
* Now kill off the ldisc
*/
--
2.7.0
next prev parent reply other threads:[~2016-01-10 4:43 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-27 21:38 [PATCH 00/19] Fix driver crashes on hangup Peter Hurley
2015-11-27 21:38 ` [PATCH 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2015-11-27 21:38 ` [PATCH 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2015-11-27 21:39 ` [PATCH 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2015-12-02 7:47 ` Marcel Holtmann
2015-11-27 21:39 ` [PATCH 04/19] NFC: nci: " Peter Hurley
2015-11-27 21:39 ` [PATCH 05/19] tty: Remove chars_in_buffer() line discipline method Peter Hurley
2015-11-27 21:39 ` [PATCH 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2015-11-27 21:39 ` [PATCH 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2015-11-27 21:39 ` [PATCH 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2015-11-27 21:39 ` [PATCH 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2015-11-27 21:39 ` [PATCH 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2015-11-27 21:39 ` [PATCH 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2015-11-27 21:39 ` [PATCH 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2015-11-27 21:39 ` [PATCH 13/19] tty: Handle NULL tty->ldisc Peter Hurley
2015-11-27 21:39 ` [PATCH 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2015-11-27 21:39 ` [PATCH 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2015-11-27 21:39 ` [PATCH 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2015-11-27 21:39 ` [PATCH 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2015-11-27 21:39 ` [PATCH 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2015-11-27 21:39 ` [PATCH 19/19] tty: Touch up style issues in ldisc core Peter Hurley
2016-01-10 4:40 ` [PATCH v2 00/19] Fix driver crashes on hangup Peter Hurley
2016-01-10 4:40 ` [PATCH v2 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2016-01-10 4:40 ` [PATCH v2 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2016-01-10 4:40 ` [PATCH v2 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2016-01-10 4:40 ` [PATCH v2 04/19] NFC: nci: " Peter Hurley
2016-01-10 4:40 ` [PATCH v2 05/19] tty: Remove chars_in_buffer() line discipline method Peter Hurley
2016-01-10 4:40 ` [PATCH v2 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2016-01-10 5:24 ` Peter Hurley
2016-01-10 4:40 ` [PATCH v2 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2016-01-10 5:26 ` Peter Hurley
2016-01-10 4:40 ` [PATCH v2 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2016-01-10 4:41 ` [PATCH v2 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2016-01-10 23:16 ` Ben Hutchings
2016-01-11 0:25 ` Peter Hurley
2016-01-11 5:40 ` Peter Hurley
2016-01-11 10:37 ` Ben Hutchings
2016-01-10 4:41 ` [PATCH v2 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2016-01-10 4:41 ` Peter Hurley [this message]
2016-01-10 4:41 ` [PATCH v2 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2016-01-10 4:41 ` [PATCH v2 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2016-01-10 4:41 ` [PATCH v2 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2016-01-10 6:24 ` kbuild test robot
2016-01-10 6:24 ` [PATCH] tty: fix badzero.cocci warnings kbuild test robot
2016-01-10 7:02 ` Peter Hurley
2016-01-10 4:41 ` [PATCH v2 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2016-01-10 4:41 ` [PATCH v2 19/19] tty: Avoid unnecessary temporaries for tty->ldisc Peter Hurley
2016-01-11 6:40 ` [PATCH v3 00/19] Fix driver crashes on hangup Peter Hurley
2016-01-11 6:40 ` [PATCH v3 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2016-01-11 6:40 ` [PATCH v3 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2016-01-11 14:12 ` One Thousand Gnomes
2016-01-11 6:40 ` [PATCH v3 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2016-01-11 6:40 ` [PATCH v3 04/19] NFC: nci: " Peter Hurley
2016-01-11 6:40 ` [PATCH v3 05/19] tty: Remove chars_in_buffer() line discipline method Peter Hurley
2016-01-11 6:40 ` [PATCH v3 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2016-01-11 6:40 ` [PATCH v3 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2016-01-11 6:40 ` [PATCH v3 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2016-01-11 6:40 ` [PATCH v3 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2016-01-11 6:40 ` [PATCH v3 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2016-01-11 6:41 ` [PATCH v3 13/19] tty: Handle NULL tty->ldisc Peter Hurley
2016-01-11 6:41 ` [PATCH v3 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2016-01-11 6:41 ` [PATCH v3 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2016-01-11 6:41 ` [PATCH v3 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2016-01-11 6:41 ` [PATCH v3 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2016-01-11 6:41 ` [PATCH v3 19/19] tty: Avoid unnecessary temporaries for tty->ldisc Peter Hurley
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