Files
android_kernel_xiaomi_sm8450/include/linux
Jiri Slaby acfa747baf TTY: open/hangup race fixup
Like in the "TTY: don't allow reopen when ldisc is changing" patch,
this one fixes a TTY WARNING as described in the option 1) there:
1) __tty_hangup from tty_ldisc_hangup to tty_ldisc_enable. During this
section tty_lock is held. However tty_lock is temporarily dropped in
the middle of the function by tty_ldisc_hangup.

The fix is to introduce a new flag which we set during the unlocked
window and check it in tty_reopen too. The flag is TTY_HUPPING and is
cleared after TTY_HUPPED is set.

While at it, remove duplicate TTY_HUPPED set_bit. The one after
calling ops->hangup seems to be more correct. But anyway, we hold
tty_lock, so there should be no difference.

Also document the function it does that kind of crap.

Nicely reproducible with two forked children:
static void do_work(const char *tty)
{
	if (signal(SIGHUP, SIG_IGN) == SIG_ERR) exit(1);
	setsid();
	while (1) {
		int fd = open(tty, O_RDWR|O_NOCTTY);
		if (fd < 0) continue;
		if (ioctl(fd, TIOCSCTTY)) continue;
		if (vhangup()) continue;
		close(fd);
	}
	exit(0);
}

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: <Valdis.Kletnieks@vt.edu>
Reported-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 14:52:48 -08:00
..
2010-10-30 08:31:35 -07:00
2010-08-05 13:26:20 +01:00
2010-08-12 06:38:24 +10:00
2010-03-12 15:53:10 -08:00
2010-10-15 21:18:59 +02:00
2010-10-26 14:51:00 -04:00
2010-06-15 09:56:01 +10:00
2010-05-27 09:12:53 -07:00
2010-09-23 14:33:39 -07:00
2010-10-30 08:45:43 -04:00
2010-11-10 14:54:09 +01:00
2010-11-10 14:54:09 +01:00
2010-11-10 14:54:09 +01:00
2010-06-24 21:30:09 -07:00
2010-10-25 21:18:20 -04:00
2010-10-25 08:02:40 -07:00
2010-08-06 15:36:47 -05:00
2010-08-19 17:18:00 -07:00
2010-05-19 22:41:57 -04:00
2010-05-10 16:08:01 -07:00
2010-08-04 11:00:45 +02:00
2010-08-12 04:14:05 +01:00
2010-10-22 15:55:22 +02:00
2010-10-21 14:47:59 +02:00
2010-09-23 14:33:39 -07:00
2010-10-28 17:22:16 -04:00
2010-08-19 17:18:03 -07:00
2010-08-18 08:35:46 -04:00
2010-09-09 20:46:30 +02:00
2010-07-12 14:41:40 +02:00
2010-10-25 14:11:37 -07:00
2010-05-21 09:34:29 -07:00
2010-10-23 22:49:32 +02:00
2010-03-07 22:17:09 +01:00
2010-10-12 16:53:37 +02:00
2010-08-11 09:23:22 +02:00
2010-11-15 22:40:38 +01:00
2010-03-02 12:23:42 +01:00
2010-11-15 22:40:38 +01:00
2010-06-16 18:08:13 +02:00
2010-06-03 03:21:52 -07:00
2010-09-21 18:04:47 -07:00
2010-08-29 21:57:55 -07:00
2010-08-19 17:16:23 -07:00
2010-09-30 21:16:05 -07:00
2010-10-26 16:52:08 -07:00
2010-08-09 20:45:05 -07:00
2010-03-12 15:52:40 -08:00
2010-10-07 14:08:55 +01:00
2010-06-03 03:21:52 -07:00
2010-08-10 11:49:21 -07:00
2010-08-18 10:19:52 +02:00
2010-08-12 11:27:58 +02:00
2010-10-28 17:22:13 -04:00
2010-10-22 15:34:12 -05:00
2010-08-19 17:18:00 -07:00
2010-05-21 09:37:29 -07:00
2010-09-09 18:57:24 -07:00
2010-06-29 10:07:09 +02:00
2010-05-14 15:09:32 -04:00
2010-08-02 06:39:44 +03:00
2010-04-03 14:56:05 -07:00
2010-11-12 07:55:32 -08:00
2010-10-21 21:18:54 -04:00
2010-10-25 21:24:15 -04:00
2010-06-16 18:03:15 +02:00
2010-10-28 09:08:47 -05:00
2010-08-09 16:48:45 -04:00
2010-06-03 03:21:52 -07:00
2010-10-26 16:52:05 -07:00
2010-08-11 00:29:47 -04:00
2010-05-11 14:40:55 +02:00
2010-10-12 16:53:34 +02:00
2010-10-04 21:10:52 +02:00
2010-10-04 21:10:52 +02:00
2010-10-01 17:18:59 -04:00
2010-10-07 18:48:49 -04:00
2010-08-19 17:18:02 -07:00
2010-07-05 16:14:52 -06:00
2010-10-15 12:45:44 +02:00
2010-10-17 20:03:03 -07:00
2010-10-17 20:03:06 -07:00
2010-10-24 15:07:11 -07:00
2010-08-21 23:40:14 -07:00
2010-07-19 01:58:48 +02:00
2010-07-19 01:58:48 +02:00
2010-08-04 21:53:17 -07:00
2010-11-12 07:55:32 -08:00
2010-10-29 04:16:31 -04:00
2010-09-08 18:16:55 -07:00
2010-03-12 15:52:44 -08:00
2010-08-09 16:47:27 -04:00
2010-10-25 21:18:20 -04:00
2010-10-27 18:03:16 -07:00
2010-05-11 10:09:47 +02:00
2010-03-12 15:53:10 -08:00
2010-10-05 00:29:48 -07:00
2010-07-23 17:08:41 +04:00
2010-06-03 03:21:52 -07:00
2010-10-30 12:12:50 +02:00
2010-03-12 15:52:44 -08:00
2010-10-20 03:02:23 -07:00
2010-10-21 15:44:13 +02:00
2010-10-27 17:28:36 +01:00
2010-10-07 14:08:55 +01:00
2010-08-09 16:48:44 -04:00
2010-09-24 21:27:41 -07:00
2010-05-15 23:28:39 -07:00
2010-08-30 13:23:33 -07:00
2010-03-25 17:18:43 -07:00
2010-03-23 17:19:38 +01:00
2010-10-21 04:11:07 -07:00
2010-09-09 20:41:20 +02:00
2010-10-22 10:20:04 -07:00
2010-11-29 14:52:48 -08:00
2010-10-26 16:52:03 -07:00
2010-10-22 10:16:43 -07:00
2010-11-08 12:28:32 -08:00
2010-05-19 22:40:47 -04:00
2010-05-19 22:15:46 +09:30
2010-10-26 16:52:14 -07:00
2010-04-06 20:35:58 +04:00