From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-x235.google.com (mail-oi1-x235.google.com [IPv6:2607:f8b0:4864:20::235]) by sourceware.org (Postfix) with ESMTPS id E3D913858D28 for ; Tue, 17 Jan 2023 14:11:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E3D913858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linaro.org Received: by mail-oi1-x235.google.com with SMTP id p185so4859783oif.2 for ; Tue, 17 Jan 2023 06:11:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=qWZS7VBVyF4MIwdUlY8IIfFuFPaY+Krbo6MRqUj5/Ac=; b=sCOaHz98JNKLel6jyo45gJVGU8WwV4QtLQRM2ZkWL/+BYz+cAgv2OvFv44wlbH1jv2 rQV0jzZESC2yqISAnXx9FZlkymz5tipISRD1eLnfVzpUtVkO7B6EdGjLSuNw8CzkiMex B01bVHVfcY4xkjQ/43zWPjnVXOSxt3TMeqvzZcpSP81uaPbn2QB+frHQGdh9c2a9jspT pmf4lm3HgH3TuRND2cVWrFJGPyTdkdOjSr+0jW+6CgPf4AL5SfJ3cAff05mmE6LqwFOJ qht9TiNeHUQfSILwO5meA2NHIQ5gc+NuQJxejRHKakjpXeyFLCB5fqBPUd7YRVN5fX5R tQ4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=qWZS7VBVyF4MIwdUlY8IIfFuFPaY+Krbo6MRqUj5/Ac=; b=ERlADZ1NlFa66TK8BWkMGHMpep9ssdsG0SaJK53lZX1ODfibmbQg+JP1XcSZ0QoAAc 1ytbv9eiF0PTYdD35pWs30LXS1ZGqguwlyo2vkaxZr4a0xNw1Ee5kKo8TXMip5Id+PfF hnJ1zb8YwiM53+MF+9LJKCdDE7JRicaTOuY48F7A4+ZU0a/cLv2egx7ld50IGUB9OtlN A6TN0QUUB7+aEySnXtGITREy3Sq9MYX5nPkdZiJJ/QWGgeJpoSKndQ5qQsWo8z0KeHTO yhR/VAwqtVG9LDUJ822wxV/P9LISjgzFN02Ede/I49BA3lwZVqg84ivkx7STLb8G+zYS 5Mtw== X-Gm-Message-State: AFqh2krSvMeBAbviQTE5in/owkqOAdUFS3iqy0x/30UrcT8MfDh431ZA 5rhXi+1lYAHASXepKNVnktpZpQ== X-Google-Smtp-Source: AMrXdXtMduK534CO/ibRIJmko9ZyuO73Df5sbgOpMTGizhi0eS9Jj7HcjadTnJvY2Bar07u68lVGZA== X-Received: by 2002:a05:6808:de0:b0:367:8ecc:a72e with SMTP id g32-20020a0568080de000b003678ecca72emr1411540oic.18.1673964674177; Tue, 17 Jan 2023 06:11:14 -0800 (PST) Received: from ?IPV6:2804:1b3:a7c1:1652:49fa:2dd7:dbd:38f6? ([2804:1b3:a7c1:1652:49fa:2dd7:dbd:38f6]) by smtp.gmail.com with ESMTPSA id w25-20020a056830061900b006863c59f685sm3118625oti.28.2023.01.17.06.11.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 17 Jan 2023 06:11:13 -0800 (PST) Message-ID: <6b782360-131f-df4c-9dc4-6765d0fb8c24@linaro.org> Date: Tue, 17 Jan 2023 11:11:10 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: Why does _dl_protect_relro align the end address down? Content-Language: en-US To: Florian Weimer , Joel Molin via Libc-help Cc: Joel Molin References: <87zgah7fv1.fsf@oldenburg.str.redhat.com> From: Adhemerval Zanella Netto Organization: Linaro In-Reply-To: <87zgah7fv1.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-6.5 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 17/01/23 04:57, Florian Weimer via Libc-help wrote: > * Joel Molin via Libc-help: > >> Since mprotect will protect entire pages anyway, wouldn't it make a lot >> more sense here to say `end = ALIGN_UP(...)`? Apart from feeling more >> intuitive, it also seems like it would avoid page size inconsistencies >> between runtime and link editing like the one above. > > ALIGN_UP might make memory read-only that should not be. > > There's some discussion about the alignment here: > > PT_GNU_RELRO is somewhat broken > > > I still think this is fairly broken, but there does not seem to be much > desire to fix it. It was not clear to me from that discussion what you think it is still broken with PT_GNU_RELRO.