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=-6.5 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 2CB02C433DF for ; Thu, 20 Aug 2020 17:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08676208A9 for ; Thu, 20 Aug 2020 17:10:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="G6qFHzRx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730407AbgHTRKL (ORCPT ); Thu, 20 Aug 2020 13:10:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730393AbgHTRGy (ORCPT ); Thu, 20 Aug 2020 13:06:54 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C494AC061346 for ; Thu, 20 Aug 2020 10:05:50 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id f1so1802112qvx.13 for ; Thu, 20 Aug 2020 10:05:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=b7DoUVnpxFkIRzDbY79jsojJy3aTV9fDe4Ip8iAfTxQ=; b=G6qFHzRxH8tE+NQgVHe3aJDnjfVKpBi9JzEY++QUvnb6xoP4UL5YFe5sbFhKZ0gi1U Pan9TBWTEC7BF+2aZc0mqBv/kQwlsn5r0K3h60LPx01FIqpJljvvKUtcQNEKCuUEIYcf xG6AFaCuH19WI0tH9uTxHYIF5N/361YtX5GqJnekKRRACYb8RA6fhIvLnc1P/Yzeqr+H nm9sZjaq1e7Q8Ernq2ssLtCOLiUok7gbm5TyYkyMnEZ27b7ZMzkQBlVSI2rs4r58X6mp SViazal97l6xDrY5/0ApjBCUDFM/Mc0STSbbb38JOtssSGin/N/gfAXspNajLPcArkNT TMrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=b7DoUVnpxFkIRzDbY79jsojJy3aTV9fDe4Ip8iAfTxQ=; b=X86+LgIEVSz2wsmSngY+ehLKB0574viCjBoJ/i8qkpqgyWQMflU+asTbkn8D78jXVM g6tEXsB7sILxqWg/EuNOuTcEoMiXy09qc/5YVSj4chRetXPqMJarMb4O8ZPmwOZG2u8V 7Wdwh7z+5OUJ+lKib8Gcv+jwird+Ac73bfC7J71ByvnBx3JC0SZ30EChaKOTpEB6cPfd XLjGzT5WAcfhI6RLxYCz00ZlCbHTa3dm3clXmWxUhSR6Ws846Eh9va3hhG94UjeMJhqh W3J3wBxdc238SJo588Z2abSr5D2kBnmypINPD3MSfiegARwHtm9Pa/rOQYbt4vq3AeTw IuoQ== X-Gm-Message-State: AOAM530rDJGOsuUY0BKnyAi5gsAS+Ogpj1oTgzNDl8u87AGCeao1pc3u UojGu4Rx9y51Ivg3B5NM7V8tuYni95NR2H4= X-Google-Smtp-Source: ABdhPJzQ303gG3zC6FMNRV8/7nehOE6TV+ALYSqyVmfx5TexEd8BHJGo0+ecTS9riPmHAJYwqf3lo4sw1B8I4o0= X-Received: from ckennelly28.nyc.corp.google.com ([2620:0:1003:1003:3e52:82ff:fe5a:a91a]) (user=ckennelly job=sendgmr) by 2002:ad4:51c8:: with SMTP id p8mr3882955qvq.31.1597943149942; Thu, 20 Aug 2020 10:05:49 -0700 (PDT) Date: Thu, 20 Aug 2020 13:05:39 -0400 Message-Id: <20200820170541.1132271-1-ckennelly@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.297.g1956fa8f8d-goog Subject: [PATCH v3 0/2] Selecting Load Addresses According to p_align From: Chris Kennelly To: Alexander Viro , Alexey Dobriyan , Song Liu Cc: David Rientjes , Ian Rogers , Hugh Dickens , Andrew Morton , Suren Baghdasaryan , Sandeep Patil , Fangrui Song , Nick Desaulniers , clang-built-linux@googlegroups.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Kennelly Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current ELF loading mechancism provides page-aligned mappings. This can lead to the program being loaded in a way unsuitable for file-backed, transparent huge pages when handling PIE executables. While specifying -z,max-page-size=0x200000 to the linker will generate suitably aligned segments for huge pages on x86_64, the executable needs to be loaded at a suitably aligned address as well. This alignment requires the binary's cooperation, as distinct segments need to be appropriately paddded to be eligible for THP. For binaries built with increased alignment, this limits the number of bits usable for ASLR, but provides some randomization over using fixed load addresses/non-PIE binaries. Changes V2 -> V3: * Minor code tweaks based on off-thread feedback Changes V1 -> V2: * Added test Chris Kennelly (2): fs/binfmt_elf: Use PT_LOAD p_align values for suitable start address. Add self-test for verifying load alignment. fs/binfmt_elf.c | 23 +++++++ tools/testing/selftests/exec/.gitignore | 1 + tools/testing/selftests/exec/Makefile | 9 ++- tools/testing/selftests/exec/load_address.c | 68 +++++++++++++++++++++ 4 files changed, 99 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/exec/load_address.c -- 2.28.0.297.g1956fa8f8d-goog