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 7A4A0C001B0 for ; Sun, 16 Jul 2023 20:22:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231839AbjGPUWO (ORCPT ); Sun, 16 Jul 2023 16:22:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231827AbjGPUWO (ORCPT ); Sun, 16 Jul 2023 16:22:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70D239F for ; Sun, 16 Jul 2023 13:22:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1022C60E88 for ; Sun, 16 Jul 2023 20:22:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22A4CC433C7; Sun, 16 Jul 2023 20:22:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689538932; bh=C5bO7At461MhjZDtFoWWCzGB2FFFdsQt/fBJLeBaEFE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JWbKspcWPwWyniya4qzk8XXEtmdrzpMKllY7iKrQuAcU+2aqSjyHViry1r+dMUp/A 8gXOTrXloDA3jlvsBK1So7B8/V07oemECkPJOitTdFGfok7QPwgG0COBcAAXNAGJDu nwcvfA5fYG6WsUL3ngKUhPyckBZwZgvkOg+RtLp0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, John Ogness , Tony Lindgren , Sasha Levin Subject: [PATCH 6.4 598/800] serial: 8250: lock port for UART_IER access in omap8250_irq() Date: Sun, 16 Jul 2023 21:47:31 +0200 Message-ID: <20230716195002.992745140@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194949.099592437@linuxfoundation.org> References: <20230716194949.099592437@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: John Ogness [ Upstream commit 25614735a647693c1260f253dc3ab32127697806 ] omap8250_irq() accesses UART_IER. This register is modified twice by each console write (serial8250_console_write()) under the port lock. omap8250_irq() must also take the port lock to guanentee synchronized access to UART_IER. Since the port lock is already being taken for the stop_rx() callback and since it is safe to call cancel_delayed_work() while holding the port lock, simply extend the port lock region to include UART_IER access. Fixes: 1fe0e1fa3209 ("serial: 8250_omap: Handle optional overrun-throttle-ms property") Signed-off-by: John Ogness Reviewed-by: Tony Lindgren Link: https://lore.kernel.org/r/20230525093159.223817-8-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_omap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 05704d8c56566..0a90ddc0bdf66 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -649,17 +649,18 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) if ((lsr & UART_LSR_OE) && up->overrun_backoff_time_ms > 0) { unsigned long delay; + /* Synchronize UART_IER access against the console. */ + spin_lock(&port->lock); up->ier = port->serial_in(port, UART_IER); if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) { - spin_lock(&port->lock); port->ops->stop_rx(port); - spin_unlock(&port->lock); } else { /* Keep restarting the timer until * the input overrun subsides. */ cancel_delayed_work(&up->overrun_backoff); } + spin_unlock(&port->lock); delay = msecs_to_jiffies(up->overrun_backoff_time_ms); schedule_delayed_work(&up->overrun_backoff, delay); -- 2.39.2