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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 BADFDC7618B for ; Fri, 26 Jul 2019 11:57:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B79C218DA for ; Fri, 26 Jul 2019 11:57:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726853AbfGZL5w (ORCPT ); Fri, 26 Jul 2019 07:57:52 -0400 Received: from mga07.intel.com ([134.134.136.100]:18066 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726816AbfGZL5v (ORCPT ); Fri, 26 Jul 2019 07:57:51 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jul 2019 04:57:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,310,1559545200"; d="scan'208";a="181843620" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.145]) by orsmga002.jf.intel.com with ESMTP; 26 Jul 2019 04:57:48 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1hqyr4-0001Sf-QX; Fri, 26 Jul 2019 14:57:46 +0300 Date: Fri, 26 Jul 2019 14:57:46 +0300 From: Andy Shevchenko To: Bartlomiej Zolnierkiewicz Cc: Navid Emamdoost , emamd001@umn.edu, kjlu@umn.edu, smccaman@umn.edu, Greg Kroah-Hartman , Jiri Slaby , Vinod Koul , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] 8250_lpss: check null return when calling pci_ioremap_bar Message-ID: <20190726115746.GT9224@smile.fi.intel.com> References: <20190719151519.GO9224@smile.fi.intel.com> <20190719174848.24216-1-navid.emamdoost@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 26, 2019 at 01:32:21PM +0200, Bartlomiej Zolnierkiewicz wrote: > On 7/19/19 7:48 PM, Navid Emamdoost wrote: > > pci_ioremap_bar may return null. This is eventually de-referenced at > > drivers/dma/dw/core.c:1154 and drivers/dma/dw/core.c:1168. A null check > > is needed to prevent null de-reference. I am adding the check and in case > > of failure. Thanks to Andy Shevchenko for the hint on the necessity of > > pci_iounmap when exiting. > > @@ -169,10 +169,12 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) > > struct pci_dev *pdev = to_pci_dev(port->dev); > > int ret; > > > > + chip->pdata = &qrk_serial_dma_pdata; > > chip->dev = &pdev->dev; > > chip->irq = pci_irq_vector(pdev, 0); > > chip->regs = pci_ioremap_bar(pdev, 1); > > - chip->pdata = &qrk_serial_dma_pdata; > > + if (!chip->regs) > > + return; > > > > /* Falling back to PIO mode if DMA probing fails */ > > ret = dw_dma_probe(chip); > > pci_iounmap() should also be called on dw_dma_probe() failure (in such > case param->dma_dev is NULL so pci_iounmap() in qrk_serial_exit_dma() > won't be called during exit). Oh, yes, good catch! Navid, can you send a follow up fix? > > @@ -195,11 +197,15 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) > > pci_iounmap > > static void qrk_serial_exit_dma(struct lpss8250 *lpss) > > { > > + struct dw_dma_chip *chip = &lpss->dma_chip; > > struct dw_dma_slave *param = &lpss->dma_param; > > > > if (!param->dma_dev) > > return; > > - dw_dma_remove(&lpss->dma_chip); > > + > > + dw_dma_remove(chip); > > + > > + pci_iounmap(to_pci_dev(chip->dev), chip->regs); > > } -- With Best Regards, Andy Shevchenko