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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 C3B74C433E0 for ; Wed, 30 Dec 2020 15:44:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5CF2520725 for ; Wed, 30 Dec 2020 15:44:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CF2520725 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9CBEF8D007F; Wed, 30 Dec 2020 10:44:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 97AEF8D0089; Wed, 30 Dec 2020 10:44:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 868578D007F; Wed, 30 Dec 2020 10:44:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0091.hostedemail.com [216.40.44.91]) by kanga.kvack.org (Postfix) with ESMTP id 722668D0089 for ; Wed, 30 Dec 2020 10:44:20 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 3210B180AD807 for ; Wed, 30 Dec 2020 15:44:20 +0000 (UTC) X-FDA: 77650370280.14.noise47_27141c2274a6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id 0C52618229837 for ; Wed, 30 Dec 2020 15:44:20 +0000 (UTC) X-HE-Tag: noise47_27141c2274a6 X-Filterd-Recvd-Size: 4560 Received: from mail-ed1-f42.google.com (mail-ed1-f42.google.com [209.85.208.42]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Wed, 30 Dec 2020 15:44:19 +0000 (UTC) Received: by mail-ed1-f42.google.com with SMTP id h16so15747519edt.7 for ; Wed, 30 Dec 2020 07:44:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5hBnQDw081gPYRJZ5sSOQpvtWrIndiY9aAJP6hoGoCI=; b=jF9zBs3u6j4Qo5O+462fi/y8Z3H2Rg/kS494qsVJ1AZwXnP4CZKBWtNfWVC4M+XY2L a4QSfGMk/T0BX8WKgAXjGmwlhjMR7jUfuM2MJMUhMMzVoz9BLvH3vgISA3wl+9ipOCg7 0Qetw+q4d2hE88fpkR4idIMOjFu7r0tivYhG8TVkhRtIgbM86B8C7RpW5EP6KPEYDHtC vItSy1oO9aljOyRk1izLO06eG2w4wHJ+0sSw2J77SK31m7y6YeOFi1L64eSfXn/5DXnp hbTTEwqrK98bNoVh9B93pHxvRkTOtAv++3QeaGy3wk9I8XYNKJVnZC34WbIzngDe6Wgn Is7A== 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=5hBnQDw081gPYRJZ5sSOQpvtWrIndiY9aAJP6hoGoCI=; b=JOCVweW8GlT3qWySPSuepJDwAdcX1O4IgMgzc1BMI/H/mG5TzV8+LAo1uCzsnzUCHW Aw00QIXIwa2k8dSBo4gQrGivhZ2SV7vYCzCSyBm435e7faFz1OyKoqw2IXdtSamm5hZD u1aXk/4gjWbP1xg9IQGY+K2as0vhUTG7ui6ik4YZIHPStMeG46PoiJp09vH99AxT/LR1 YLFX6A5SE9Y8J5yQ160P9rFXf0sTnx1733dfobW+q3t8w3Qpy3CsjCjOX4m+niHir/6K YDDw5mjsqWkP2Tb/FHPxmyEvxCO0/XOyRUeL7jAZoTPHBocIiquBlo8Gej8fU7sSxZJZ NmVA== X-Gm-Message-State: AOAM530DNJsG+iV0NlRJMiDeiIGthD6VfiiXzaeg1HXoOQjTwIgk/ssh QnglX+BpvlSnF/G8d0FrJ3nL+K+hIKkNDh1Nq+UOdw== X-Google-Smtp-Source: ABdhPJzdhrxVcS8QaW5SwjUUsVlQzNcZNKy+323jJeGcsyxbQ7R92UwEPNUX1N2RLnmmTIXQIt78Z+E0q7QwZmHhaZE= X-Received: by 2002:a50:b5c5:: with SMTP id a63mr50773533ede.227.1609343058152; Wed, 30 Dec 2020 07:44:18 -0800 (PST) MIME-Version: 1.0 References: <20201013013416.390574-1-dima@arista.com> <20201013013416.390574-3-dima@arista.com> In-Reply-To: From: Brian Geffon Date: Wed, 30 Dec 2020 07:43:42 -0800 Message-ID: Subject: Re: [PATCH 2/6] mm/mremap: For MREMAP_DONTUNMAP check security_vm_enough_memory_mm() To: Dmitry Safonov Cc: LKML , Dmitry Safonov <0x7f454c46@gmail.com>, Alexander Viro , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dan Williams , Dave Jiang , Hugh Dickins , Ingo Molnar , "Kirill A. Shutemov" , Mike Kravetz , Minchan Kim , Russell King , Thomas Bogendoerfer , Thomas Gleixner , Vishal Verma , Vlastimil Babka , Will Deacon , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-mm Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Ah, you're right. This individual patch looks good to me. Brian On Mon, Dec 28, 2020 at 11:12 AM Dmitry Safonov wrote: > > On 12/28/20 6:21 PM, Brian Geffon wrote: > > This looks good to me with a small comment. > > > >> if (do_munmap(mm, old_addr, old_len, uf_unmap) < 0) { > >> /* OOM: unable to split vma, just get accounts right */ > >> - if (vm_flags & VM_ACCOUNT) > >> + if (vm_flags & VM_ACCOUNT && !(flags & MREMAP_DONTUNMAP)) > >> vm_acct_memory(new_len >> PAGE_SHIFT); > > > > Checking MREMAP_DONTUNMAP in the do_munmap path is unnecessary as > > MREMAP_DONTUNMAP will have already returned by this point. > > In this code it is also used as err-path. In case move_page_tables() > fails to move all page tables or .mremap() callback fails, the new VMA > is unmapped. > > IOW, MREMAP_DONTUNMAP returns under: > : if (unlikely(!err && (flags & MREMAP_DONTUNMAP))) { > > -- > Dima