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From: Wang YanQing <udknight@gmail.com>
To: gregkh@linuxfoundation.org
Cc: jslaby@suse.com, linux-kernel@vger.kernel.org, mikey@neuling.org,
	viro@ZenIV.linux.org.uk, johan@kernel.org,
	peter@hurleysoftware.com, alex.popov@linux.com, robh@kernel.org,
	mpatocka@redhat.com, dvyukov@google.com,
	benh@kernel.crashing.org
Subject: [PATCH] tty:tty_ldisc: add tty_ldisc_lock|unlock to prevent concurrent update to ldisc in tty_ldisc_deinit
Date: Mon, 10 Apr 2017 00:59:03 +0800	[thread overview]
Message-ID: <20170409165903.GA9643@udknight> (raw)

This patch could fix the issue that free_tty_struct in tty_io
calling tty_ldisc_deinit without holding tty->ldisc_sem.

Signed-off-by: Wang YanQing <udknight@gmail.com>
---
 drivers/tty/tty_ldisc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index b1f7fa5..674421b 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -771,7 +771,9 @@ void tty_ldisc_init(struct tty_struct *tty)
  */
 void tty_ldisc_deinit(struct tty_struct *tty)
 {
+	tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT);
 	if (tty->ldisc)
 		tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;
+	tty_ldisc_unlock(tty);
 }
-- 
1.8.5.6.2.g3d8a54e.dirty

             reply	other threads:[~2017-04-09 17:05 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-09 16:59 Wang YanQing [this message]
2017-04-10  0:33 ` [PATCH] tty:tty_ldisc: add tty_ldisc_lock|unlock to prevent concurrent update to ldisc in tty_ldisc_deinit Michael Neuling

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