From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FFFCCCA47C for ; Mon, 13 Jun 2022 10:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245599AbiFMKaw (ORCPT ); Mon, 13 Jun 2022 06:30:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344320AbiFMK24 (ORCPT ); Mon, 13 Jun 2022 06:28:56 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DD26255B6; Mon, 13 Jun 2022 03:20:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 8B8FBCE1102; Mon, 13 Jun 2022 10:20:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CB6EC36B07; Mon, 13 Jun 2022 10:20:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655115621; bh=vdHmBAw1oESu3mBgdYJHfUNiSBmK3oQCUHtDEM6Fx5M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XPaGdE4Adzz07hkawUovR1OUDmsKMDb8afHWJF1pB6N6mHkFQa4Wu8RvbBzwpxVke z1X4wELJRX0IGyQ35TrpZFRH+NgN+kx8UqAdtQXZA3XZnRsQ5NirtaU9+md2jH2hku F8GjkU8xsxQ9+EjOxmx4zZfi8I06Z9BShgfzlOFc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marek Szyprowski , Petr Mladek , John Ogness , Sasha Levin Subject: [PATCH 4.9 151/167] serial: msm_serial: disable interrupts in __msm_console_write() Date: Mon, 13 Jun 2022 12:10:25 +0200 Message-Id: <20220613094916.316552520@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094840.720778945@linuxfoundation.org> References: <20220613094840.720778945@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: John Ogness [ Upstream commit aabdbb1b7a5819e18c403334a31fb0cc2c06ad41 ] __msm_console_write() assumes that interrupts are disabled, but with threaded console printers it is possible that the write() callback of the console is called with interrupts enabled. Explicitly disable interrupts using local_irq_save() to preserve the assumed context. Reported-by: Marek Szyprowski Reviewed-by: Petr Mladek Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20220506213324.470461-1-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/msm_serial.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index c284e61ed4fc..33d035f9fded 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -1578,6 +1578,7 @@ static inline struct uart_port *msm_get_port_from_line(unsigned int line) static void __msm_console_write(struct uart_port *port, const char *s, unsigned int count, bool is_uartdm) { + unsigned long flags; int i; int num_newlines = 0; bool replaced = false; @@ -1595,6 +1596,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, num_newlines++; count += num_newlines; + local_irq_save(flags); + if (port->sysrq) locked = 0; else if (oops_in_progress) @@ -1640,6 +1643,8 @@ static void __msm_console_write(struct uart_port *port, const char *s, if (locked) spin_unlock(&port->lock); + + local_irq_restore(flags); } static void msm_console_write(struct console *co, const char *s, -- 2.35.1