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 77990C433E0 for ; Mon, 28 Dec 2020 18:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 364902242A for ; Mon, 28 Dec 2020 18:23:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728667AbgL1SXP (ORCPT ); Mon, 28 Dec 2020 13:23:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727941AbgL1SXO (ORCPT ); Mon, 28 Dec 2020 13:23:14 -0500 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 151A2C0613D6 for ; Mon, 28 Dec 2020 10:22:33 -0800 (PST) Received: by mail-ej1-x632.google.com with SMTP id b9so15308879ejy.0 for ; Mon, 28 Dec 2020 10:22:33 -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=z2QbH8RGPNV6UCpysofOcmKw2kvcdsWtyhs8XyCCINw=; b=oK1bIMFlk9+9P3yM6IxgC3sGgIIGBKSSzhxKjcmUmJw7zLxWGUG5Z4FT5RjgRhaBPN i7pYF9MtjhuJl7YWB8Sew1jRxwXZSpYdf7aochu1zb+ZWaH/fiz/eL4vSeZrajQE63Mv z8yRPyof9nFuCxMdTOpQKJbsFriOk4ifql5kOVecC6wXCqfH3/TJiCf5HKOIcx3H/IHz eIH4ub0+o/wzo0oEQ22VsKGEYwpVGASXaadXI+DYrBGeTAtjrCS7Bn2U/ZMS4ZMjCFOD I+9SQ2avnuepdBFUxQ4VZoQZyuyE/I1RxB1mpVZUmeo/uUA5VcVuLaaClMMSXkvR+40v RCrA== 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=z2QbH8RGPNV6UCpysofOcmKw2kvcdsWtyhs8XyCCINw=; b=eoqhwjhugPN+XIrgxML4oyUTUpI2S848BeDVSflDlV+lwtJ+6U75HaumVTxGZzVlm+ OhrTWFFr1H4M0v5LtBcItUY96Zn2TbeIRjZ6kYQI1hLUKCNNiQaJXx344uxQq2U/DQoA riH5AwZQp5zdeR9PXS4hCDOU2eLYbCEwdA56qSL2FmHb8AIvnadnsIH1eGsNnjB/B6O+ cGiSzhEXh0TNsjVPF8nZdiP/3Vqi5YJqONNijMD+q574QFFXh02t6gfvuyV0nXzoujip dc6KbGbPRt6B/S6OuL3qz8TJ15+7MueLE/26Vz42otyvtYmAXOTIJqynQl9q78Ue83Zz c3Kw== X-Gm-Message-State: AOAM533OQz7jM4CkSevh03AK5cAVhYyPCkWAYvaSoNSiW1nkKv20Y4yo YW5MYrKaY2wWyqhqhQE4RUwY0hA8lEHOl3tZ3LZPrQ== X-Google-Smtp-Source: ABdhPJwvPxy4pkRK8okJN0/k8NDFvWE5wVUKTWXkCWpjS8Ii2ZVkfms8OJy9V0jmRbDe+48+k7MFRRK2mCrz0IR2NF4= X-Received: by 2002:a17:906:447:: with SMTP id e7mr42157038eja.172.1609179752023; Mon, 28 Dec 2020 10:22:32 -0800 (PST) MIME-Version: 1.0 References: <20201013013416.390574-1-dima@arista.com> <20201013013416.390574-3-dima@arista.com> In-Reply-To: <20201013013416.390574-3-dima@arista.com> From: Brian Geffon Date: Mon, 28 Dec 2020 10:21:56 -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" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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.