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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 A9F20C5517A for ; Thu, 5 Nov 2020 19:38:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0128020704 for ; Thu, 5 Nov 2020 19:38:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0128020704 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 05BC76B0182; Thu, 5 Nov 2020 14:38:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 00ED06B0184; Thu, 5 Nov 2020 14:38:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3E096B0187; Thu, 5 Nov 2020 14:38:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0028.hostedemail.com [216.40.44.28]) by kanga.kvack.org (Postfix) with ESMTP id B294C6B0182 for ; Thu, 5 Nov 2020 14:38:05 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 42618362B for ; Thu, 5 Nov 2020 19:38:05 +0000 (UTC) X-FDA: 77451375330.23.pet36_1b0db17272cc Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 1EF7737606 for ; Thu, 5 Nov 2020 19:38:05 +0000 (UTC) X-HE-Tag: pet36_1b0db17272cc X-Filterd-Recvd-Size: 5177 Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Nov 2020 19:38:04 +0000 (UTC) Received: from mail-qv1-f69.google.com ([209.85.219.69]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kal58-0000yo-C0 for linux-mm@kvack.org; Thu, 05 Nov 2020 19:38:02 +0000 Received: by mail-qv1-f69.google.com with SMTP id d41so1537792qvc.23 for ; Thu, 05 Nov 2020 11:38:02 -0800 (PST) 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=U+a+gNIbJITYFSm1fPB5NcpyqxVoTmbEhGD5seomukY=; b=IQNYyTcO/KkkH24iYdwd817sZiPun3ZYpQJTlINTK8y86+xYdAWOif5elRuzqXurVS HnuyPtobwk0cVpnp7HA4UZ7RQb4atX0ZhIfN8O6FXjcbtkVkmbZO5eWpR3KJeuahKon1 f01PdRXtlmw6oDNJIW2S942elrcMrsbxtZbZyWiEyLHBR//qGGF1zbBRwYxzUeBOBUBq YlMuZfNonKbmGd52OnQciW8M/ULbT6okn91TOmwq9CPtW0lw8k0+49izEVF3hUBnVgIL xtI3i08Lq58g8ycTusLEdoiM729LbgCJJ4BOEYCnfmrpDPyKc+UOksORmXwDSWRFzp6y CqXQ== X-Gm-Message-State: AOAM53285ozIYHLSr340nOKPgiw+Od/p8r+GYTHalGPY55A+Qy/qapIS typ/JpABu7XjHJHQo+E1iM5WVoy0pGJBVQHFRUtTkChToLGK0YMqIiwNttKfIkvI+6Z33hJD3uY F/L2EBKikODH+5eAhaTqXIeQBqlIz X-Received: by 2002:ac8:540e:: with SMTP id b14mr3630714qtq.136.1604605081491; Thu, 05 Nov 2020 11:38:01 -0800 (PST) X-Google-Smtp-Source: ABdhPJwogUYq8CCKM+u/T4cSYijlorWkNQQUKBHl8kr1d+TVLfKeqZioURlPJbfLkAGZuLSMkNW7mg== X-Received: by 2002:ac8:540e:: with SMTP id b14mr3630680qtq.136.1604605081219; Thu, 05 Nov 2020 11:38:01 -0800 (PST) Received: from [192.168.1.75] ([177.215.78.178]) by smtp.gmail.com with ESMTPSA id z2sm1693271qkl.22.2020.11.05.11.37.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Nov 2020 11:38:00 -0800 (PST) Subject: Re: [PATCH] mm, hugetlb: Avoid double clearing for hugetlb pages To: linux-mm@kvack.org Cc: kernel-hardening@lists.openwall.com, linux-hardening@vger.kernel.org, linux-security-module@vger.kernel.org, kernel@gpiccoli.net, cascardo@canonical.com, Alexander Potapenko , James Morris , Kees Cook , Michal Hocko , Mike Kravetz , david@redhat.com References: <20201019182853.7467-1-gpiccoli@canonical.com> From: "Guilherme G. Piccoli" Autocrypt: addr=gpiccoli@canonical.com; prefer-encrypt=mutual; keydata= xsBNBFpVBxcBCADPNKmu2iNKLepiv8+Ssx7+fVR8lrL7cvakMNFPXsXk+f0Bgq9NazNKWJIn Qxpa1iEWTZcLS8ikjatHMECJJqWlt2YcjU5MGbH1mZh+bT3RxrJRhxONz5e5YILyNp7jX+Vh 30rhj3J0vdrlIhPS8/bAt5tvTb3ceWEic9mWZMsosPavsKVcLIO6iZFlzXVu2WJ9cov8eQM/ irIgzvmFEcRyiQ4K+XUhuA0ccGwgvoJv4/GWVPJFHfMX9+dat0Ev8HQEbN/mko/bUS4Wprdv 7HR5tP9efSLucnsVzay0O6niZ61e5c97oUa9bdqHyApkCnGgKCpg7OZqLMM9Y3EcdMIJABEB AAHNLUd1aWxoZXJtZSBHLiBQaWNjb2xpIDxncGljY29saUBjYW5vbmljYWwuY29tPsLAdwQT AQgAIQUCWmClvQIbAwULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRDOR5EF9K/7Gza3B/9d 5yczvEwvlh6ksYq+juyuElLvNwMFuyMPsvMfP38UslU8S3lf+ETukN1S8XVdeq9yscwtsRW/ 4YoUwHinJGRovqy8gFlm3SAtjfdqysgJqUJwBmOtcsHkmvFXJmPPGVoH9rMCUr9s6VDPox8f q2W5M7XE9YpsfchS/0fMn+DenhQpV3W6pbLtuDvH/81GKrhxO8whSEkByZbbc+mqRhUSTdN3 iMpRL0sULKPVYbVMbQEAnfJJ1LDkPqlTikAgt3peP7AaSpGs1e3pFzSEEW1VD2jIUmmDku0D LmTHRl4t9KpbU/H2/OPZkrm7809QovJGRAxjLLPcYOAP7DUeltvezsBNBFpVBxcBCADbxD6J aNw/KgiSsbx5Sv8nNqO1ObTjhDR1wJw+02Bar9DGuFvx5/qs3ArSZkl8qX0X9Vhptk8rYnkn pfcrtPBYLoux8zmrGPA5vRgK2ItvSc0WN31YR/6nqnMfeC4CumFa/yLl26uzHJa5RYYQ47jg kZPehpc7IqEQ5IKy6cCKjgAkuvM1rDP1kWQ9noVhTUFr2SYVTT/WBHqUWorjhu57/OREo+Tl nxI1KrnmW0DbF52tYoHLt85dK10HQrV35OEFXuz0QPSNrYJT0CZHpUprkUxrupDgkM+2F5LI bIcaIQ4uDMWRyHpDbczQtmTke0x41AeIND3GUc+PQ4hWGp9XABEBAAHCwF8EGAEIAAkFAlpV BxcCGwwACgkQzkeRBfSv+xv1wwgAj39/45O3eHN5pK0XMyiRF4ihH9p1+8JVfBoSQw7AJ6oU 1Hoa+sZnlag/l2GTjC8dfEGNoZd3aRxqfkTrpu2TcfT6jIAsxGjnu+fUCoRNZzmjvRziw3T8 egSPz+GbNXrTXB8g/nc9mqHPPprOiVHDSK8aGoBqkQAPZDjUtRwVx112wtaQwArT2+bDbb/Y Yh6gTrYoRYHo6FuQl5YsHop/fmTahpTx11IMjuh6IJQ+lvdpdfYJ6hmAZ9kiVszDF6pGFVkY kHWtnE2Aa5qkxnA2HoFpqFifNWn5TyvJFpyqwVhVI8XYtXyVHub/WbXLWQwSJA4OHmqU8gDl X18zwLgdiQ== Message-ID: <6c17f146-3d1e-8b9f-835c-1dc33d95aa0c@canonical.com> Date: Thu, 5 Nov 2020 16:37:55 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201019182853.7467-1-gpiccoli@canonical.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000035, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Thanks all for the valuable opinions and feedback! Closing the loop here: so, the proposal wasn't accepted, but an interesting idea to optimize later hugeTLB allocations was discussed in the thread - it doesn't help much our case, but it is a performance optimization. Cheers, Guilherme