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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 01595C3A59E for ; Fri, 16 Aug 2019 10:59:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCB20205F4 for ; Fri, 16 Aug 2019 10:59:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vZkVmKoB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727022AbfHPK74 (ORCPT ); Fri, 16 Aug 2019 06:59:56 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:36003 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbfHPK74 (ORCPT ); Fri, 16 Aug 2019 06:59:56 -0400 Received: by mail-wm1-f65.google.com with SMTP id g67so3727685wme.1; Fri, 16 Aug 2019 03:59:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:openpgp:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=wNVxrpOjRdGMbKUHWPQDveZoPp5EAe+1eRAUxJN9hEk=; b=vZkVmKoBKzHuPi4XcJItsJsLFT49svIQH9FcG5rLBKTteoJMkJJtkHXPcOhINNkhDQ Lqu9+DPd+QCnULTzpmlB5xaNsPq7mtEfDfp7dWAUrnbi46HMbi/hCRAXhTi6gKO+j9me 3nAQXLE7TfrzqY6ZMmra2G27kRCUrdj34Mt8vaUlUHrWu0KLRdTbTnBpR2hYUAbsuC+o JaJPKpBfRKxfsj7SfYZcmpk2VBOjd1XIOsBzbDlxSH8yATnMQFNJ4e9h7bffq1DBY5uQ e4RNF7+DDlr8cDzgz2Rib8nrE9skoO3UiLRLlfL9Q6whq+hon4AsCxqs9I0S8bI2PpdF lu6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=wNVxrpOjRdGMbKUHWPQDveZoPp5EAe+1eRAUxJN9hEk=; b=ju7MeWnXtbS4JOwroPutHR7LZ4cZKPFVQ2CLEht/9p9BFdPfF8HNAr+4C3nU4iSgcc vjWhlX7b8sGfY8rqhjzzyTdwGqVLcci2Pr50oHzIjTszZlot+b5grG0MXte1qKXlScvC FhdHXxjGrRlvPcC5kRwrbup4TUODRvyz1PjHpdrX7P5C1BWO//wl2HZCk9a2vgcs7k// 61LFJhtsQ6mHgrPhxxYFCsLVq+TzwfJO06N4p6TNkel/IkwraPxMAvAfL+G2xyvrDAkT qelfNV0GwQUgVkiTVvlpFHGHX3KBrP7CKgPVGn9zD1kgY+TAXIBhU/AUJfV0Gqw7vL3f UwUw== X-Gm-Message-State: APjAAAV1qf3+j6XG1DGqAD6dCarC6mT8Yf5rJA9tBScAn3UARDEMvsLZ BJhAWRAW3bl0+XWPGI5MpdpobYxHKfY= X-Google-Smtp-Source: APXvYqw0hTdsiWoBfuZx0niUdChJgAbSA0XbpGnoIjKzorYO0Fz9sv2KzliAqzZFWdcAx+GFNk9xGg== X-Received: by 2002:a1c:c5c2:: with SMTP id v185mr7218010wmf.161.1565953193785; Fri, 16 Aug 2019 03:59:53 -0700 (PDT) Received: from [192.168.42.64] (p578adb1c.dip0.t-ipconnect.de. [87.138.219.28]) by smtp.gmail.com with ESMTPSA id p7sm3676908wmh.38.2019.08.16.03.59.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 16 Aug 2019 03:59:53 -0700 (PDT) Subject: Re: [PATCH V3 1/3] PCI: rcar: Move the inbound index check To: Lorenzo Pieralisi Cc: linux-pci@vger.kernel.org, Marek Vasut , Geert Uytterhoeven , Wolfram Sang , linux-renesas-soc@vger.kernel.org References: <20190809175741.7066-1-marek.vasut@gmail.com> <20190816105227.GB23677@e121166-lin.cambridge.arm.com> From: Marek Vasut Openpgp: preference=signencrypt Message-ID: Date: Fri, 16 Aug 2019 12:59:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190816105227.GB23677@e121166-lin.cambridge.arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 8/16/19 12:52 PM, Lorenzo Pieralisi wrote: > On Fri, Aug 09, 2019 at 07:57:39PM +0200, marek.vasut@gmail.com wrote: >> From: Marek Vasut >> >> Since the $idx variable value is stored across multiple calls to >> rcar_pcie_inbound_ranges() function, and the $idx value is used to >> index registers which are written, subsequent calls might cause >> the $idx value to be high enough to trigger writes into nonexistent >> registers. > > Can this really happen ? 'index' is initialized to 0 in > rcar_pci_parse_map_dma_ranges() and, through rcar_pcie_inbound_ranges() > return value, it bails out on idx overrun, we can argue this patch > improves robustness but I do not think it is fixing anything. We probably don't want to write into non-existent registers ? I think it can happen when there are too many ranges in DT.