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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH, URIBL_BLOCKED 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 9FB30C64EB1 for ; Fri, 7 Dec 2018 21:10:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6C0862082D for ; Fri, 7 Dec 2018 21:10:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="soAEdhH8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C0862082D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=qKF23M341nJLLE1rzpDOsflURv/6nqpoRQCFGlTo+RY=; b=soAEdhH8AhoxGIuw6+aAssnQl Yf/s+fnHP6V5fHWUkb1Zwdps5fO5Fd+YkVAJ8lwnVE6lR9yFyRrZFNF0nbkrIUXFJ/v7pEu+EhhAI NpxkDGbghTRB0jsSWAPd9QpzOloXZ5QuD68Iqcd+32/SPS0cDaaBTi6ejHRieK7cgHUmo+anUwqVj 6sB5cIZ9JgLnDOn8IYJhCvIwGaAI28zkRlJlLUEOhjsAWkTanDKnQzmDcQSm2dA8mchwUxb5tFsxa Kjl5cLrz34sqrJ57nBHomGRo1hBdO7TRFpbsG2+o1e0rvVWeUupme2t+MtO6yZGvPrSSm208JqOJO 9wscQw9Fg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gVNOH-0007uN-T6; Fri, 07 Dec 2018 21:10:29 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gVNOE-0007sv-Rv; Fri, 07 Dec 2018 21:10:28 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8ADFD15AB; Fri, 7 Dec 2018 13:10:15 -0800 (PST) Received: from [192.168.1.123] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 152E83F614; Fri, 7 Dec 2018 13:10:06 -0800 (PST) Subject: Re: [PATCH v3 1/9] mm: Introduce new vm_insert_range API To: Souptick Joarder , Matthew Wilcox References: <20181206183945.GA20932@jordon-HP-15-Notebook-PC> <53bbc095-c9f5-5d6a-6e50-6e060d17eb68@arm.com> <20181207171116.GA29923@bombadil.infradead.org> From: Robin Murphy Message-ID: <67495f8f-2092-e42d-321e-5216c346513f@arm.com> Date: Fri, 7 Dec 2018 21:10:00 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:60.0) Gecko/20100101 Thunderbird/60.3.2 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181207_131026_910463_C76A40E2 X-CRM114-Status: GOOD ( 18.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , Heiko Stuebner , Peter Zijlstra , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Linux-MM , linux1394-devel@lists.sourceforge.net, Marek Szyprowski , Stephen Rothwell , oleksandr_andrushchenko@epam.com, joro@8bytes.org, Russell King - ARM Linux , iommu@lists.linux-foundation.org, airlied@linux.ie, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, treding@nvidia.com, linux-media@vger.kernel.org, Kees Cook , pawel@osciak.com, Rik van Riel , rppt@linux.vnet.ibm.com, Boris Ostrovsky , mchehab@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz, Juergen Gross , hjc@rock-chips.com, xen-devel@lists.xen.org, Kyungmin Park , stefanr@s5r6.in-berlin.de, Andrew Morton , "Kirill A. Shutemov" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2018-12-07 7:28 pm, Souptick Joarder wrote: > On Fri, Dec 7, 2018 at 10:41 PM Matthew Wilcox wrote: >> >> On Fri, Dec 07, 2018 at 03:34:56PM +0000, Robin Murphy wrote: >>>> +int vm_insert_range(struct vm_area_struct *vma, unsigned long addr, >>>> + struct page **pages, unsigned long page_count) >>>> +{ >>>> + unsigned long uaddr = addr; >>>> + int ret = 0, i; >>> >>> Some of the sites being replaced were effectively ensuring that vma and >>> pages were mutually compatible as an initial condition - would it be worth >>> adding something here for robustness, e.g.: >>> >>> + if (page_count != vma_pages(vma)) >>> + return -ENXIO; >> >> I think we want to allow this to be used to populate part of a VMA. >> So perhaps: >> >> if (page_count > vma_pages(vma)) >> return -ENXIO; > > Ok, This can be added. > > I think Patch [2/9] is the only leftover place where this > check could be removed. Right, 9/9 could also have relied on my stricter check here, but since it's really testing whether it actually managed to allocate vma_pages() worth of pages earlier, Matthew's more lenient version won't help for that one. (Why privcmd_buf_mmap() doesn't clean up and return an error as soon as that allocation loop fails, without taking the mutex under which it still does a bunch more pointless work to only undo it again, is a mind-boggling mystery, but that's not our problem here...) Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel