From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org
Cc: "Dmitry Safonov" <0x7f454c46@gmail.com>,
"Dmitry Safonov" <dima@arista.com>,
"Daniel Axtens" <dja@axtens.net>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Mark Rutland" <mark.rutland@arm.com>,
"Michael Neuling" <mikey@neuling.org>,
"Mikulas Patocka" <mpatocka@redhat.com>,
"Nathan March" <nathan@gt.net>, "Pasi Kärkkäinen" <pasik@iki.fi>,
"Peter Hurley" <peter@hurleysoftware.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Rong, Chen" <rong.a.chen@intel.com>,
"Sergey Senozhatsky" <sergey.senozhatsky.work@gmail.com>,
"Tan Xiaojun" <tanxiaojun@huawei.com>,
"Tetsuo Handa" <penguin-kernel@I-love.SAKURA.ne.jp>,
"Jiri Slaby" <jslaby@suse.cz>, "Jiri Slaby" <jslaby@suse.com>,
"Tetsuo Handa" <penguin-kernel@i-love.sakura.ne.jp>,
stable@vger.kernel.org,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Subject: [PATCHv4 1/7] tty: Drop tty->count on tty_reopen() failure
Date: Wed, 12 Sep 2018 01:16:55 +0100 [thread overview]
Message-ID: <20180912001702.18522-2-dima@arista.com> (raw)
In-Reply-To: <20180912001702.18522-1-dima@arista.com>
In case of tty_ldisc_reinit() failure, tty->count should be decremented
back, otherwise we will never release_tty().
Tetsuo reported that it fixes noisy warnings on tty release like:
pts pts4033: tty_release: tty->count(10529) != (#fd's(7) + #kopen's(0))
Fixes: commit 892d1fa7eaae ("tty: Destroy ldisc instance on hangup")
Cc: stable@vger.kernel.org # v4.6+
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Jiri Slaby <jslaby@suse.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
drivers/tty/tty_io.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 32bc3e3fe4d3..5e5da9acaf0a 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1255,6 +1255,7 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *
static int tty_reopen(struct tty_struct *tty)
{
struct tty_driver *driver = tty->driver;
+ int retval;
if (driver->type == TTY_DRIVER_TYPE_PTY &&
driver->subtype == PTY_TYPE_MASTER)
@@ -1268,10 +1269,14 @@ static int tty_reopen(struct tty_struct *tty)
tty->count++;
- if (!tty->ldisc)
- return tty_ldisc_reinit(tty, tty->termios.c_line);
+ if (tty->ldisc)
+ return 0;
- return 0;
+ retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+ if (retval)
+ tty->count--;
+
+ return retval;
}
/**
--
2.13.6
next prev parent reply other threads:[~2018-09-12 0:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-12 0:16 [PATCHv4 0/7] tty: Hold write ldisc sem in tty_reopen() Dmitry Safonov
2018-09-12 0:16 ` Dmitry Safonov [this message]
2018-09-12 0:16 ` [PATCHv4 2/7] tty: Hold tty_ldisc_lock() during tty_reopen() Dmitry Safonov
2018-09-14 9:01 ` [LKP] [tty] f26eb68a52: INFO:task_blocked_for_more_than#seconds kernel test robot
2018-09-14 15:56 ` Dmitry Safonov
2018-09-12 0:16 ` [PATCHv4 3/7] tty/ldsem: Wake up readers after timed out down_write() Dmitry Safonov
2018-09-12 0:16 ` [PATCHv4 4/7] tty: Simplify tty->count math in tty_reopen() Dmitry Safonov
2018-09-12 0:16 ` [PATCHv4 5/7] tty/ldsem: Convert to regular lockdep annotations Dmitry Safonov
2018-09-12 0:17 ` [PATCHv4 6/7] tty/ldsem: Add lockdep asserts for ldisc_sem Dmitry Safonov
2018-09-12 0:17 ` [PATCHv4 7/7] tty/ldsem: Decrement wait_readers on timeouted down_read() Dmitry Safonov
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