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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 AFC09C7618F for ; Fri, 19 Jul 2019 22:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7DDEC2089C for ; Fri, 19 Jul 2019 22:36:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="k5cvThBK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732217AbfGSWg4 (ORCPT ); Fri, 19 Jul 2019 18:36:56 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:43000 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727344AbfGSWgz (ORCPT ); Fri, 19 Jul 2019 18:36:55 -0400 Received: by mail-pf1-f196.google.com with SMTP id q10so14751449pff.9; Fri, 19 Jul 2019 15:36:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=wAss8MkDxKIIgy8BTidUKVu2SDLEFNknmikznCRAAGQ=; b=k5cvThBK3wJKtD1Za30SOuiQVN1iVUYJBonh2XIGi63dUT89kDP3i+8bzFlL+MZnKj v3o1YKs4EZZmFxog2QKeLgINbq9xHA05MP9VXbQuqGuteIzW2vPhBoxCWcz3oDemK0fF 7v/CZM70Y7BtfhiiNzldMmk+gnWFsQpgQBq5rleDKvu4Xsz+9KIx1fX//MA6GtFMzHM1 jrvm+5gJ5pe/1fy1ZmHZYgllaz+jvxCZCV9JlPHUd1c5xxNdQ96jqqV63BmkofyIrIu4 MsWFIA8pZXICSTilbdev8prHdM3jBKa7Z2pL7ZcpKvZCA9JQDZWGGtdykRbGKzEsF+rj ynPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wAss8MkDxKIIgy8BTidUKVu2SDLEFNknmikznCRAAGQ=; b=AY5F1tV+AH0seVB3Tv7tTqlI4qwctZVZr3tcVbqaipoVwHtwY8InFzfpFyIUJpkye8 UHO7+QVNvdBOf+I7Hgb5qCA5h8uMTSuF0k3B/i2f7c52Cc1tfBbEiPGxAMKF2gN+5F/g pvtbMmrj+oK2KzSNw3MBefgChqlyzIpqKEmd+JYkdHMEO05XvVzH6I7JlPcrvjxcdiub mB6+bCDW8zp4QlQUGTNEgD6ymofu9unpISSbvTKbDVfKQtEa5eMPyYCQiVACEH7SmCxQ PM31a2LDT6S4zxfXCfa/SOIwa7Xgj9i/QKEjqEjj49yr/VRx4cXoJ/OWHAEHFUrVEuPX HYAw== X-Gm-Message-State: APjAAAUuUM9ejFr+ZtoGHGEowIItpOrVTE6VKpbtS15AyO9t+LxcBtOA uQznZZq5U8YpiZWXPnDeNlshV9EKaBoHBkZhraE= X-Google-Smtp-Source: APXvYqxIAT2MjupmE3GE3TOk6AKXqWFa/nakBIR3qA8YjXoMbBdV3jA2tNJDKXUQYfZIYJzR3KZlUxm+uTiW0C+Nh3M= X-Received: by 2002:a17:90b:d8b:: with SMTP id bg11mr60350469pjb.30.1563575814670; Fri, 19 Jul 2019 15:36:54 -0700 (PDT) MIME-Version: 1.0 References: <20190719151519.GO9224@smile.fi.intel.com> <20190719174848.24216-1-navid.emamdoost@gmail.com> In-Reply-To: <20190719174848.24216-1-navid.emamdoost@gmail.com> From: Andy Shevchenko Date: Sat, 20 Jul 2019 01:36:43 +0300 Message-ID: Subject: Re: [PATCH v2] 8250_lpss: check null return when calling pci_ioremap_bar To: Navid Emamdoost Cc: Andy Shevchenko , emamd001@umn.edu, Kangjie Lu , smccaman@umn.edu, Greg Kroah-Hartman , Jiri Slaby , Vinod Koul , "open list:SERIAL DRIVERS" , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 20, 2019 at 12:45 AM 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. > Reviewed-by: Andy Shevchenko > Signed-off-by: Navid Emamdoost > --- > drivers/tty/serial/8250/8250_lpss.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c > index 53ca9ba6ab4b..d07e431110d9 100644 > --- a/drivers/tty/serial/8250/8250_lpss.c > +++ b/drivers/tty/serial/8250/8250_lpss.c > @@ -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); > @@ -195,11 +197,15 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) > > 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); > } > #else /* CONFIG_SERIAL_8250_DMA */ > static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {} > -- > 2.17.1 > -- With Best Regards, Andy Shevchenko