From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH v2 13/14] tty: Hold termios_rwsem for tcflow(TCIxxx)
Date: Wed, 10 Sep 2014 15:06:35 -0400 [thread overview]
Message-ID: <1410375996-4693-14-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1410375996-4693-1-git-send-email-peter@hurleysoftware.com>
While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
drivers/tty/tty_ioctl.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 14d9002..32cee97 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -1164,17 +1164,21 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
spin_unlock_irq(&tty->flow_lock);
break;
case TCIOFF:
+ down_read(&tty->termios_rwsem);
if (STOP_CHAR(tty) != __DISABLED_CHAR)
- return tty_send_xchar(tty, STOP_CHAR(tty));
+ retval = tty_send_xchar(tty, STOP_CHAR(tty));
+ up_read(&tty->termios_rwsem);
break;
case TCION:
+ down_read(&tty->termios_rwsem);
if (START_CHAR(tty) != __DISABLED_CHAR)
- return tty_send_xchar(tty, START_CHAR(tty));
+ retval = tty_send_xchar(tty, START_CHAR(tty));
+ up_read(&tty->termios_rwsem);
break;
default:
return -EINVAL;
}
- return 0;
+ return retval;
case TCFLSH:
retval = tty_check_change(tty);
if (retval)
--
2.1.0
next prev parent reply other threads:[~2014-09-10 19:06 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-02 21:39 [PATCH 00/26] tty/serial flow control fixes Peter Hurley
2014-09-02 21:39 ` [PATCH 01/26] Revert "serial: uart: add hw flow control support configuration" Peter Hurley
2014-09-02 21:50 ` Murali Karicheri
2014-09-02 21:58 ` Peter Hurley
2014-09-02 22:17 ` Murali Karicheri
2014-09-02 21:39 ` [PATCH 02/26] serial: Style fix Peter Hurley
2014-09-02 21:39 ` [PATCH 03/26] serial: imx: Fix x_char handling and tx flow control Peter Hurley
2014-09-02 21:39 ` [PATCH 04/26] serial: core: Fix x_char race Peter Hurley
2014-09-02 21:39 ` [PATCH 05/26] serial: core: Remove unsafe x_char optimization Peter Hurley
2014-09-02 21:39 ` [PATCH 06/26] serial: Fix send_xchar() handlers Peter Hurley
2014-09-02 21:39 ` [PATCH 07/26] serial: mpc52xx: Use default serial core x_char handler Peter Hurley
2014-09-02 21:39 ` [PATCH 08/26] serial: sunsab: Don't enable tx if tx stopped Peter Hurley
2014-09-02 21:39 ` [PATCH 09/26] serial: blackfin: Fix missing gpio.h Peter Hurley
2014-09-02 21:39 ` [PATCH 10/26] serial: core: Document lock requirement for UPF_* flags updates Peter Hurley
2014-09-02 21:39 ` [PATCH 11/26] serial: 8250: Document serial8250_modem_status() locking Peter Hurley
2014-09-02 21:39 ` [PATCH 12/26] serial: core: Unwrap tertiary assignment in uart_handle_dcd_change() Peter Hurley
2014-09-02 21:39 ` [PATCH 13/26] locking: Add non-fatal spin lock assert Peter Hurley
2014-09-03 9:27 ` Peter Zijlstra
2014-09-03 11:20 ` Peter Hurley
2014-09-03 14:40 ` Peter Zijlstra
2014-09-03 14:50 ` Peter Hurley
2014-09-03 15:07 ` Peter Zijlstra
2014-09-04 5:14 ` Ingo Molnar
2014-09-10 11:02 ` Peter Hurley
2014-09-10 13:08 ` Peter Zijlstra
2014-09-10 14:45 ` Peter Hurley
2014-09-10 18:34 ` Greg Kroah-Hartman
2014-09-02 21:39 ` [PATCH 14/26] serial: core: Document and assert lock requirements for irq helpers Peter Hurley
2014-09-02 21:39 ` [PATCH 15/26] serial: core: Privatize modem status enable flags Peter Hurley
2014-09-02 21:39 ` [PATCH 16/26] isdn: i4l: Remove ASYNC_CTS_FLOW Peter Hurley
2014-09-02 21:39 ` [PATCH 17/26] serial: core: Privatize tty->hw_stopped Peter Hurley
2014-09-09 0:29 ` Peter Hurley
2014-09-02 21:39 ` [PATCH 18/26] usb: serial: Remove unused tty->hw_stopped Peter Hurley
2014-09-02 21:39 ` [PATCH 19/26] serial: bfin-uart: Fix auto CTS Peter Hurley
2014-09-02 21:39 ` [PATCH 20/26] serial: core: Use spin_lock_irq() in uart_set_termios() Peter Hurley
2014-09-02 21:39 ` [PATCH 21/26] tty: Convert tty_struct bitfield to bools Peter Hurley
2014-09-03 10:58 ` One Thousand Gnomes
2014-09-03 12:14 ` Peter Hurley
2014-09-03 12:19 ` One Thousand Gnomes
2014-09-03 15:10 ` Peter Hurley
2014-09-03 17:56 ` Greg Kroah-Hartman
2014-09-04 16:08 ` Peter Hurley
2014-09-02 21:39 ` [PATCH 22/26] tty: Serialize tty flow control changes with flow_lock Peter Hurley
2014-09-02 21:39 ` [PATCH 23/26] tty: Move packet mode flow control notifications to pty driver Peter Hurley
2014-09-02 21:39 ` [PATCH 24/26] tty: Serialize tcflow() with other tty flow control changes Peter Hurley
2014-09-02 21:39 ` [PATCH 25/26] tty: Move and rename send_prio_char() as tty_send_xchar() Peter Hurley
2014-09-02 21:39 ` [PATCH 26/26] tty: Hold termios_rwsem for tcflow(TCIxxx) Peter Hurley
2014-09-08 23:24 ` [PATCH 00/26] tty/serial flow control fixes Greg Kroah-Hartman
2014-09-08 23:33 ` Peter Hurley
2014-09-08 23:43 ` Greg Kroah-Hartman
2014-09-08 23:46 ` Peter Hurley
2014-09-09 0:01 ` Greg Kroah-Hartman
2014-09-10 19:06 ` [PATCH v2 00/14] " Peter Hurley
2014-09-10 19:06 ` [PATCH v2 01/14] serial: core: Document and assert lock requirements for irq helpers Peter Hurley
2014-09-10 19:06 ` [PATCH v2 02/14] serial: core: Privatize modem status enable flags Peter Hurley
2014-09-10 19:06 ` [PATCH v2 03/14] isdn: i4l: Remove ASYNC_CTS_FLOW Peter Hurley
2014-09-10 19:06 ` [PATCH v2 04/14] serial: core: Privatize tty->hw_stopped Peter Hurley
2014-09-10 19:06 ` [PATCH v2 05/14] usb: serial: Remove unused tty->hw_stopped Peter Hurley
2014-09-23 15:33 ` Johan Hovold
2014-09-10 19:06 ` [PATCH v2 06/14] serial: bfin-uart: Fix auto CTS Peter Hurley
2014-09-10 19:06 ` [PATCH v2 07/14] serial: core: Use spin_lock_irq() in uart_set_termios() Peter Hurley
2014-09-10 19:06 ` [PATCH v2 08/14] tty: Convert tty_struct bitfield to ints Peter Hurley
2014-09-10 19:06 ` [PATCH v2 09/14] tty: Serialize tty flow control changes with flow_lock Peter Hurley
2014-09-10 19:06 ` [PATCH v2 10/14] tty: Move packet mode flow control notifications to pty driver Peter Hurley
2014-09-10 19:06 ` [PATCH v2 11/14] tty: Serialize tcflow() with other tty flow control changes Peter Hurley
2014-09-10 19:06 ` [PATCH v2 12/14] tty: Move and rename send_prio_char() as tty_send_xchar() Peter Hurley
2014-09-10 19:06 ` Peter Hurley [this message]
2014-09-10 19:06 ` [PATCH v2 14/14] tty: Workaround Alpha non-atomic byte storage in tty_struct Peter Hurley
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