From owner-freebsd-toolchain@freebsd.org Sun Feb 23 15:31:33 2020 Return-Path: Delivered-To: freebsd-toolchain@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E57A723FD6D for ; Sun, 23 Feb 2020 15:31:33 +0000 (UTC) (envelope-from pjfloyd@wanadoo.fr) Received: from smtp.smtpout.orange.fr (smtp03.smtpout.orange.fr [80.12.242.125]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "Bizanga Labs SMTP Client Certificate", Issuer "Bizanga Labs CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 48QTgl0VPvz4dQ8 for ; Sun, 23 Feb 2020 15:31:30 +0000 (UTC) (envelope-from pjfloyd@wanadoo.fr) Received: from garrigue.home ([2.7.71.138]) by mwinf5d38 with ME id 6FXT2200L2z0Kde03FXUmc; Sun, 23 Feb 2020 16:31:28 +0100 X-ME-Helo: garrigue.home X-ME-Auth: cGpmbG95ZEB3YW5hZG9vLmZy X-ME-Date: Sun, 23 Feb 2020 16:31:28 +0100 X-ME-IP: 2.7.71.138 From: Paul Floyd Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.60.0.2.5\)) Subject: RO Elf program headers Message-Id: <9AAE92C0-4FD7-43DF-A805-EFEE7EA06B56@wanadoo.fr> Date: Sun, 23 Feb 2020 16:31:27 +0100 To: freebsd-toolchain@freebsd.org X-Mailer: Apple Mail (2.3608.60.0.2.5) X-Rspamd-Queue-Id: 48QTgl0VPvz4dQ8 X-Spamd-Bar: +++ Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of pjfloyd@wanadoo.fr has no SPF policy when checking 80.12.242.125) smtp.mailfrom=pjfloyd@wanadoo.fr X-Spamd-Result: default: False [3.40 / 15.00]; FREEMAIL_FROM(0.00)[wanadoo.fr]; MV_CASE(0.50)[]; TO_DN_NONE(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[138.71.7.2.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.11]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[wanadoo.fr]; ASN(0.00)[asn:3215, ipnet:80.12.240.0/20, country:FR]; MID_RHS_MATCH_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE(0.00)[ip: (3.75), ipnet: 80.12.240.0/20(1.58), asn: 3215(1.67), country: FR(0.00)]; AUTH_NA(1.00)[]; NEURAL_SPAM_MEDIUM(1.00)[0.997,0]; RCPT_COUNT_ONE(0.00)[1]; IP_SCORE_FREEMAIL(0.00)[]; RCVD_TLS_LAST(0.00)[]; NEURAL_SPAM_LONG(1.00)[0.998,0]; RCVD_IN_DNSWL_NONE(0.00)[125.242.12.80.list.dnswl.org : 127.0.5.0]; R_SPF_NA(0.00)[]; DMARC_NA(0.00)[wanadoo.fr]; RWL_MAILSPIKE_POSSIBLE(0.00)[125.242.12.80.rep.mailspike.net : 127.0.0.17]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-toolchain@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Maintenance of FreeBSD's integrated toolchain List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Feb 2020 15:31:34 -0000 Hi I=E2=80=99ve been working on getting Valgrind to work again on FreeBSD. Probably the biggest problem at the moment is that Valgrind doesn=E2=80=99= t (yet) handle the read-only program headers. If I run =E2=80=9Creadelf -l libc++.so.1.0=E2=80=9D on Linux I see two = LOAD headers, the first one =E2=80=9CR E=E2=80=9D (read-execute) and the = second one =E2=80=9CRW=E2=80=9D (read-write). If I do the same on = FreeBSD then I see a third program header which is =E2=80=9CR=E2=80=9D = (read-only), before the other two. My questions are - Does anyone know when this extra header was added? (I assume that it = was added sometime in the past 5 years or so) - What is in these segments, and is it safe to assume that multiple = shared libraries can map the same RO content to the same address? A+ Paul=