From owner-freebsd-hackers@freebsd.org Mon Nov 16 13:07:37 2020 Return-Path: Delivered-To: freebsd-hackers@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 ECD322EF201 for ; Mon, 16 Nov 2020 13:07:37 +0000 (UTC) (envelope-from pjfloyd@wanadoo.fr) Received: from smtp.smtpout.orange.fr (smtp13.smtpout.orange.fr [80.12.242.135]) (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 4CZTrS5drKz3MfB for ; Mon, 16 Nov 2020 13:07:35 +0000 (UTC) (envelope-from pjfloyd@wanadoo.fr) Received: from [192.168.1.17] ([2.7.192.66]) by mwinf5d75 with ME id t17Y2300N1SQe2i0317ZjZ; Mon, 16 Nov 2020 14:07:33 +0100 X-ME-Helo: [192.168.1.17] X-ME-Auth: cGpmbG95ZEB3YW5hZG9vLmZy X-ME-Date: Mon, 16 Nov 2020 14:07:33 +0100 X-ME-IP: 2.7.192.66 To: FreeBSD Hackers From: Paul Floyd Subject: FreeBSD 12.2 extra RW program header Message-ID: <8ff8067a-3354-3587-4eda-1aa802f6c86b@wanadoo.fr> Date: Mon, 16 Nov 2020 14:07:32 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Rspamd-Queue-Id: 4CZTrS5drKz3MfB 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 80.12.242.135) smtp.mailfrom=pjfloyd@wanadoo.fr X-Spamd-Result: default: False [-0.33 / 15.00]; FREEMAIL_FROM(0.00)[wanadoo.fr]; TO_DN_ALL(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[2.7.192.66:received]; RCVD_TLS_LAST(0.00)[]; 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)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[80.12.242.135:from]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[wanadoo.fr]; AUTH_NA(1.00)[]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[80.12.242.135:from:127.0.2.255]; NEURAL_SPAM_SHORT(0.77)[0.770]; RCVD_IN_DNSWL_NONE(0.00)[80.12.242.135:from]; R_SPF_NA(0.00)[no SPF record]; RWL_MAILSPIKE_POSSIBLE(0.00)[80.12.242.135:from]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-hackers] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Nov 2020 13:07:38 -0000 Hi I see that FreeBSD 12.2 has added an extra RW program header. Can anyone explain what this does? (My initial guess is things like thread mutexes and barriers). Full details: 12.1 Program Headers:   Type           Offset             VirtAddr           PhysAddr                  FileSiz            MemSiz              Flg Align   PHDR           0x0000000000000040 0x0000000000200040 0x0000000000200040                  0x0000000000000230 0x0000000000000230  R      0x8   INTERP         0x0000000000000270 0x0000000000200270 0x0000000000200270                  0x0000000000000015 0x0000000000000015  R      0x1       [Requesting program interpreter: /libexec/ld-elf.so.1]   LOAD           0x0000000000000000 0x0000000000200000 0x0000000000200000                  0x000000000000086c 0x000000000000086c  R 0x1000   LOAD           0x0000000000001000 0x0000000000201000 0x0000000000201000                  0x00000000000006b0 0x00000000000006b0  R E 0x1000   LOAD           0x0000000000002000 0x0000000000202000 0x0000000000202000                  0x0000000000001158 0x0000000000002014  RW 0x1000   DYNAMIC        0x0000000000003028 0x0000000000203028 0x0000000000203028                  0x0000000000000130 0x0000000000000130  RW     0x8 12.2: Program Headers:   Type           Offset             VirtAddr           PhysAddr                  FileSiz            MemSiz              Flg Align   PHDR           0x0000000000000040 0x0000000000200040 0x0000000000200040                  0x0000000000000268 0x0000000000000268  R      0x8   INTERP         0x00000000000002a8 0x00000000002002a8 0x00000000002002a8                  0x0000000000000015 0x0000000000000015  R      0x1       [Requesting program interpreter: /libexec/ld-elf.so.1]   LOAD           0x0000000000000000 0x0000000000200000 0x0000000000200000                  0x00000000000008bc 0x00000000000008bc  R 0x1000   LOAD           0x00000000000008c0 0x00000000002018c0 0x00000000002018c0                  0x00000000000006c0 0x00000000000006c0  R E 0x1000   LOAD           0x0000000000000f80 0x0000000000202f80 0x0000000000202f80                  0x0000000000000158 0x0000000000000158  RW 0x1000 extra header here ->   LOAD           0x00000000000010d8 0x00000000002040d8 0x00000000002040d8                  0x0000000000000090 0x00000000000000a8  RW 0x1000   DYNAMIC        0x0000000000000fa8 0x0000000000202fa8 0x0000000000202fa8                  0x0000000000000130 0x0000000000000130  RW     0x8 A+ Paul