linux/drivers/tty/tty_io.c, branch v4.5Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
https://git.shady.money/linux/atom?h=v4.52016-02-07T00:56:46Ztty: Drop krefs for interrupted tty lock2016-02-07T00:56:46ZPeter Hurleypeter@hurleysoftware.com2016-02-05T18:49:36Zurn:sha1:e9036d0662360cd4c79578565ce422ed5872f301
When the tty lock is interrupted on attempted re-open, 2 tty krefs
are still held. Drop extra kref before returning failure from
tty_lock_interruptible(), and drop lookup kref before returning
failure from tty_open().
Fixes: 0bfd464d3fdd ("tty: Wait interruptibly for tty lock on reopen")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)2016-01-27T07:17:54ZPeter Hurleypeter@hurleysoftware.com2016-01-11T06:40:55Zurn:sha1:5c17c861a357e9458001f021a7afa7aab9937439
ioctl(TIOCGETD) retrieves the line discipline id directly from the
ldisc because the line discipline id (c_line) in termios is untrustworthy;
userspace may have set termios via ioctl(TCSETS*) without actually
changing the line discipline via ioctl(TIOCSETD).
However, directly accessing the current ldisc via tty->ldisc is
unsafe; the ldisc ptr dereferenced may be stale if the line discipline
is changing via ioctl(TIOCSETD) or hangup.
Wait for the line discipline reference (just like read() or write())
to retrieve the "current" line discipline id.
Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Retry failed reopen if tty teardown in-progress2016-01-27T07:17:54ZPeter Hurleypeter@hurleysoftware.com2016-01-10T05:13:45Zurn:sha1:7f22f6c935cda600660e623a411fe380015d28d9
A small window exists where a tty reopen will observe the tty
just prior to imminent teardown (tty->count == 0); in this case, open()
returns EIO to userspace.
Instead, retry the open after checking for signals and yielding;
this interruptible retry loop allows teardown to commence and initialize
a new tty on retry. Never retry the BSD master pty reopen; there is no
guarantee the pty pair teardown is imminent since the slave file
descriptors may remain open indefinitely.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 4.4
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Wait interruptibly for tty lock on reopen2016-01-27T07:17:54ZPeter Hurleypeter@hurleysoftware.com2016-01-10T05:13:44Zurn:sha1:0bfd464d3fdd5bb322f9cace4cc47f1796545cf7
Allow a signal to interrupt the wait for a tty reopen; eg., if
the tty has starting final close and is waiting for the device to
drain.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 4.4
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Only allow slave pty as controlling tty2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T14:06:05Zurn:sha1:d1d3a0f7448fe038ce7e94e2c281dcd2f91b23c6
A master pty should never be a controlling tty in Linux; if the
master pty is specified to ioctl(TIOCSCTTY), silently substitute the slave
pty as the controlling tty.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: core: Prefer dev_dbg() over pr_debug()2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T18:01:21Zurn:sha1:83db1df4461c8731a413cd6cb1cbf351f01a57b1
Where possible, use dev_dbg() instead of pr_debug()
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Remove __func__ from tty_debug() macro2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T18:01:19Zurn:sha1:d435cefe9cbc9308cac8d4b19069a572e2bd1558
Now that tty_debug() macro uses pr_debug(), the function name can
be printed when using dynamic debug; printing the function name within
the format string is redundant.
Remove the __func__ parameter and print specifier from the format string.
Add context to messages for when the function name is not printed by
dynamic debug, or when dynamic debug is not enabled.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: core: Prefer pr_* to printk(*)2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T18:01:18Zurn:sha1:89222e62662237faee90cd8486d23350f26b181d
Convert remaining printk() use to pr_*() when tty is unknown or
unsafe to use.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: core: Add driver name to invalid device registration message2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T18:01:15Zurn:sha1:656fb86770cffe25d002e1228931960219ccda6b
Include the driver name in the tty_register_device_attr() error
message for invalid index.
Note that tty_err() cannot be used here because there is no tty;
use pr_err().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Convert SAK messages to tty_notice()2015-12-14T03:59:48ZPeter Hurleypeter@hurleysoftware.com2015-11-08T18:01:14Zurn:sha1:9b42bb750f24f5925d2fffed3f071726af72763a
Use tty_notice() for unified message format from the tty core.
Fix each message to accurately reflect the cause of each termination.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>