From patchwork Tue Sep 29 10:59:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 263417 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53476C47425 for ; Tue, 29 Sep 2020 11:02:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0785321734 for ; Tue, 29 Sep 2020 11:02:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377377; bh=ETEyGheTsSDLc+qsGa6lhWJ+2kesIX87e5bInOXxsV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QS0OgcHFw6oPrA++EjCMjPW9WV4BxEELv+aZTyO2W5tbuKz++9OZs9ou0HdgxcR+5 2ZhHTnOpwsR21Q1Ti1oNPBhRArAYx/1nn3beC7SRcU5m5DWd4AlrouZZftU8MZ9Mb0 TpYYe5DHQmGMQXh8KlzTx/2zwekjyctDOEbeLp98= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728251AbgI2LCp (ORCPT ); Tue, 29 Sep 2020 07:02:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:38246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728228AbgI2LCp (ORCPT ); Tue, 29 Sep 2020 07:02:45 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A4B3B20C09; Tue, 29 Sep 2020 11:02:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377364; bh=ETEyGheTsSDLc+qsGa6lhWJ+2kesIX87e5bInOXxsV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f1rA8SHjeAZlYOXvJQh9tsCq1W0UluJvzZIK51d4nTCb5D+QbyXe6Lz7STNTKK1m2 bQiqgig/0guliZB9fiJyltlVYUSqpWY3p52e2vnKy2MxQjThq/wkW9L0nhrc7r3zWD lQQZz60ue1d0mjXbuYiInrGZvPSVw81tsrr3wXps= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Wunner , Andy Shevchenko , "Nobuhiro Iwamatsu (CIP)" Subject: [PATCH 4.4 11/85] serial: 8250: Avoid error message on reprobe Date: Tue, 29 Sep 2020 12:59:38 +0200 Message-Id: <20200929105928.782728807@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105928.198942536@linuxfoundation.org> References: <20200929105928.198942536@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lukas Wunner commit e0a851fe6b9b619527bd928aa93caaddd003f70c upstream. If the call to uart_add_one_port() in serial8250_register_8250_port() fails, a half-initialized entry in the serial_8250ports[] array is left behind. A subsequent reprobe of the same serial port causes that entry to be reused. Because uart->port.dev is set, uart_remove_one_port() is called for the half-initialized entry and bails out with an error message: bcm2835-aux-uart 3f215040.serial: Removing wrong port: (null) != (ptrval) The same happens on failure of mctrl_gpio_init() since commit 4a96895f74c9 ("tty/serial/8250: use mctrl_gpio helpers"). Fix by zeroing the uart->port.dev pointer in the probe error path. The bug was introduced in v2.6.10 by historical commit befff6f5bf5f ("[SERIAL] Add new port registration/unregistration functions."): https://git.kernel.org/tglx/history/c/befff6f5bf5f The commit added an unconditional call to uart_remove_one_port() in serial8250_register_port(). In v3.7, commit 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") made that call conditional on uart->port.dev which allows me to fix the issue by zeroing that pointer in the error path. Thus, the present commit will fix the problem as far back as v3.7 whereas still older versions need to also cherry-pick 835d844d1a28. Fixes: 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v2.6.10 Cc: stable@vger.kernel.org # v2.6.10: 835d844d1a28: 8250_pnp: do pnp probe before legacy Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/b4a072013ee1a1d13ee06b4325afb19bda57ca1b.1589285873.git.lukas@wunner.de [iwamatsu: Backported to 4.4, 4.9: adjust context] Signed-off-by: Nobuhiro Iwamatsu (CIP) Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1037,8 +1037,10 @@ int serial8250_register_8250_port(struct ret = uart_add_one_port(&serial8250_reg, &uart->port); - if (ret == 0) - ret = uart->port.line; + if (ret) + goto err; + + ret = uart->port.line; } else { dev_info(uart->port.dev, "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n", @@ -1052,6 +1054,11 @@ int serial8250_register_8250_port(struct mutex_unlock(&serial_mutex); return ret; + +err: + uart->port.dev = NULL; + mutex_unlock(&serial_mutex); + return ret; } EXPORT_SYMBOL(serial8250_register_8250_port);