From patchwork Tue Sep 29 10:58:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 263347 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 7FA24C4727F for ; Tue, 29 Sep 2020 11:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48F4B221EC for ; Tue, 29 Sep 2020 11:13:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601378023; bh=iKkHY2dspMh7JLTw8WbSLOadNhNVO8XjzTETA9tU5jc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1DbVSKAD6HppbNNldPuyhQwC0rylOHcyRIrYv2TR6g171KUMSFMOjsNQiiyLgf8JP E1XZh30X5mCjubLYRpIUJ5A/aLC1YRFdggeEzSQ6j2rWnWspPvzw9ue6d+MZzKredZ 4xz07IX01Bvb6uPVUSrINmgE5D9034+ubakSEwTw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729126AbgI2LN2 (ORCPT ); Tue, 29 Sep 2020 07:13:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:54856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729359AbgI2LMw (ORCPT ); Tue, 29 Sep 2020 07:12:52 -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 030822158C; Tue, 29 Sep 2020 11:12:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377971; bh=iKkHY2dspMh7JLTw8WbSLOadNhNVO8XjzTETA9tU5jc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PUkFeBH0naVH0vLJZBmXVoT3/1p4goPlQXDnQdqMLWVsxCXaqPIV5nEvqbkcFheTD FMnMt8eR78CfyShIsZRYO0qcp9/PnbGKaDh1os/7T0LvUF2OkN3772Nvz5pQB15P9k 190Za+TVi21FUxIi44OY7i2e+ITb+JLu/MiwB1BM= 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 4.14 017/166] serial: 8250: Avoid error message on reprobe Date: Tue, 29 Sep 2020 12:58:49 +0200 Message-Id: <20200929105936.046617281@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105935.184737111@linuxfoundation.org> References: <20200929105935.184737111@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 4.14, 4.19: 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 @@ -1065,8 +1065,10 @@ int serial8250_register_8250_port(struct serial8250_apply_quirks(uart); 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", @@ -1091,6 +1093,11 @@ 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);