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Message-ID: <20220910222300.906633712@linutronix.de>
From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     John Ogness <john.ogness@linutronix.de>,
        Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linuxfoundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Helge Deller <deller@gmx.de>,
        Jason Wessel <jason.wessel@windriver.com>,
        Daniel Thompson <daniel.thompson@linaro.org>
Subject: [patch RFC 09/29] serial: kgdboc: Lock consoles in probe function
References: <20220910221947.171557773@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date:   Sun, 11 Sep 2022 00:27:45 +0200 (CEST)
Precedence: bulk

Unprotected list walks are not necessarily safe.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/tty/serial/kgdboc.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -193,6 +193,7 @@ static int configure_kgdboc(void)
 	if (!p)
 		goto noconfig;
 
+	console_lock();
 	for_each_console(cons) {
 		int idx;
 		if (cons->device && cons->device(cons, &idx) == p &&
@@ -201,6 +202,7 @@ static int configure_kgdboc(void)
 			break;
 		}
 	}
+	console_unlock();
 
 	kgdb_tty_driver = p;
 	kgdb_tty_line = tty_line;