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From:   John Ogness <john.ogness@linutronix.de>
To:     Petr Mladek <pmladek@suse.com>
Cc:     Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org,
        Jason Wessel <jason.wessel@windriver.com>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Douglas Anderson <dianders@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        kgdb-bugreport@lists.sourceforge.net, linux-serial@vger.kernel.org
Subject: [PATCH printk 09/18] serial: kgdboc: Lock console list in probe function
Date:   Sat, 24 Sep 2022 02:10:45 +0206
Message-Id: <20220924000454.3319186-10-john.ogness@linutronix.de>
In-Reply-To: <20220924000454.3319186-1-john.ogness@linutronix.de>
References: <20220924000454.3319186-1-john.ogness@linutronix.de>
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From: Thomas Gleixner <tglx@linutronix.de>

Unprotected list walks are not necessarily safe.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/tty/serial/kgdboc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 79b7db8580e0..af2aa76bae15 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -193,7 +193,8 @@ static int configure_kgdboc(void)
 	if (!p)
 		goto noconfig;
 
-	for_each_console(cons) {
+	console_list_lock();
+	for_each_registered_console(cons) {
 		int idx;
 		if (cons->device && cons->device(cons, &idx) == p &&
 		    idx == tty_line) {
@@ -201,6 +202,7 @@ static int configure_kgdboc(void)
 			break;
 		}
 	}
+	console_list_unlock();
 
 	kgdb_tty_driver = p;
 	kgdb_tty_line = tty_line;
-- 
2.30.2