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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 45766C63777 for ; Thu, 3 Dec 2020 11:31:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E43B022201 for ; Thu, 3 Dec 2020 11:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730271AbgLCLbJ (ORCPT ); Thu, 3 Dec 2020 06:31:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:58280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728782AbgLCLbI (ORCPT ); Thu, 3 Dec 2020 06:31:08 -0500 Date: Thu, 3 Dec 2020 11:30:21 +0000 From: Catalin Marinas To: Miles Chen Cc: Alexey Dobriyan , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com, Andrey Konovalov , Alexander Potapenko , Vincenzo Frascino , Andrey Ryabinin , Dmitry Vyukov , Marco Elver , Will Deacon , "Eric W . Biederman" , Song Bao Hua , stable@vger.kernel.org Subject: Re: [PATCH v2] proc: use untagged_addr() for pagemap_read addresses Message-ID: <20201203113020.GE2224@gaia> References: <20201127050738.14440-1-miles.chen@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201127050738.14440-1-miles.chen@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 27, 2020 at 01:07:38PM +0800, Miles Chen wrote: > Cc: Will Deacon That should be will@kernel.org. > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 217aa2705d5d..92b277388f05 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1599,11 +1599,15 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, > > src = *ppos; > svpfn = src / PM_ENTRY_BYTES; > - start_vaddr = svpfn << PAGE_SHIFT; > end_vaddr = mm->task_size; > > /* watch out for wraparound */ > - if (svpfn > mm->task_size >> PAGE_SHIFT) > + start_vaddr = end_vaddr; > + if (svpfn < (ULONG_MAX >> PAGE_SHIFT)) Does this need to be strict less-than? I think a less-than or equal would work better. > + start_vaddr = untagged_addr(svpfn << PAGE_SHIFT); > + > + /* Ensure the address is inside the task */ > + if (start_vaddr > mm->task_size) > start_vaddr = end_vaddr; Otherwise the logic looks fine to me. With the above: Reviewed-by: Catalin Marinas 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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 0B5AEC64E8A for ; Thu, 3 Dec 2020 11:30:43 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 81D80208FE for ; Thu, 3 Dec 2020 11:30:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81D80208FE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pReBs9u716BpMbjCjakpGjWLZNh6jLNhcyR3y5IwU4o=; b=eLVay96SJSr6XxXXVRKZaVFsX Z69iUfx7AFunWr4BHbA6PUienTrxmrRUaXZV19cQxUi6CnAwAKBGEfslMD8ebzJPuZeG7lv44NOZD zfREKyckRQ4Iz/GnQHLwiaHedXU6FFMEJIswFp0iMk8zPPMH/SWBwhGjE9aSIZWus5MC+T/BwhJLA t5ZBORY1iD4xOPdmpaRdJwqiKH1Y8y0FZHR/JhgCK/LNdh4DUtpUXng9q21xDk0CFELsufl//k9KI ySv9HjiV9LPIp1hRijyWcUtaGqLm65DZFslBN2691ImhIKI7aTeNO2lxrvnJENpmTNI5FGHovqc/v wDInwbL4g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkmog-0003j8-OJ; Thu, 03 Dec 2020 11:30:30 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkmoe-0003il-Ff for linux-mediatek@lists.infradead.org; Thu, 03 Dec 2020 11:30:29 +0000 Date: Thu, 3 Dec 2020 11:30:21 +0000 From: Catalin Marinas To: Miles Chen Subject: Re: [PATCH v2] proc: use untagged_addr() for pagemap_read addresses Message-ID: <20201203113020.GE2224@gaia> References: <20201127050738.14440-1-miles.chen@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201127050738.14440-1-miles.chen@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201203_063028_659102_B5DD9BB0 X-CRM114-Status: GOOD ( 13.48 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Song Bao Hua , Marco Elver , wsd_upstream@mediatek.com, Andrey Konovalov , linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mediatek@lists.infradead.org, "Eric W . Biederman" , Andrey Ryabinin , linux-fsdevel@vger.kernel.org, Alexander Potapenko , Andrew Morton , Vincenzo Frascino , Will Deacon , Alexey Dobriyan , Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Fri, Nov 27, 2020 at 01:07:38PM +0800, Miles Chen wrote: > Cc: Will Deacon That should be will@kernel.org. > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 217aa2705d5d..92b277388f05 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1599,11 +1599,15 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, > > src = *ppos; > svpfn = src / PM_ENTRY_BYTES; > - start_vaddr = svpfn << PAGE_SHIFT; > end_vaddr = mm->task_size; > > /* watch out for wraparound */ > - if (svpfn > mm->task_size >> PAGE_SHIFT) > + start_vaddr = end_vaddr; > + if (svpfn < (ULONG_MAX >> PAGE_SHIFT)) Does this need to be strict less-than? I think a less-than or equal would work better. > + start_vaddr = untagged_addr(svpfn << PAGE_SHIFT); > + > + /* Ensure the address is inside the task */ > + if (start_vaddr > mm->task_size) > start_vaddr = end_vaddr; Otherwise the logic looks fine to me. With the above: Reviewed-by: Catalin Marinas _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek