From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27783 invoked by alias); 11 Jun 2016 06:44:30 -0000 Mailing-List: contact gnu-gabi-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: gnu-gabi-owner@sourceware.org Received: (qmail 27768 invoked by uid 89); 11 Jun 2016 06:44:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.99.1 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=H*R:D*gmail.com X-Spam-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-HELO: mail-oi0-f45.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=reply-to:subject:references:to:cc:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=hAstqZMi6kK/B0Iw2f/7Gp0/pP3ud02jTUrWo9k159o=; b=NnhlHiBzukmXI1oYWlDKfSmz2LRoelvphaPA3prJlzNDuwM+fXL0VZq7DiBvuD/qJ7 1zgT0lvnwNtQ5U7Kzufu5MDY/Hy5wsBIH2fUt4egHVRcddCcgBlA7OSST4ItF4ZOeeFl rIlEPGrA91OIpJU2cFeGrO/Lr34tzYHReki9Vbn5sCy5gTGRG1uKRUt8f9ckNp4bP6Ho kwHPcL7pqEORC+vc4f0kb98UigHvSCDI+CksS4HtwyxaexhFZUG81ILUViAllotcNQii M7u4PXnTKQ5cud7Ga6EbugJDsSWQLrKOzEuR+uGVnJxLYvD5KS53srqL6i5YbDtbOewU xByQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:reply-to:subject:references:to:cc:from :organization:message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding; bh=hAstqZMi6kK/B0Iw2f/7Gp0/pP3ud02jTUrWo9k159o=; b=A1o1F5aotO9U+5+PJqeNCQPSAdfnR+tMren+NhYapfROmlHRX9237ZHZcpygHJkEWo lQWpY8CebTy8rtoL1znDuUMW77xPKOZ1LlYDsgA+Y29DJRsjHZyzDC+4napWHyy4jRGk 9QEoQwYtKX5e+bKht4GY5GhKykABkXlO9vUZ5FyCWVSqbfBpJBEjXNil8M9E33p/lIZQ sS5EGHPTNRO0fO+tYKQuV7I/vTzaId+1R4p618EI06Fg/2DJlqUEkVuhEDMZG05PsyYW dlPUtrdGZbLeR77Yk19T5rtt7kuEKBdcxXimnT0aHoZw1aiMhUO5wMx92TYMBhifdmDX 0n6w== X-Gm-Message-State: ALyK8tK9SkWwWp//ISr1Oxrao9fFmLXJvr1uRnKVcdBOYcml/40iBQXOKQFSxNO4yTq61A== X-Received: by 10.202.82.129 with SMTP id g123mr3091330oib.36.1465627466423; Fri, 10 Jun 2016 23:44:26 -0700 (PDT) Reply-To: hegdesmailbox@gmail.com Subject: Re: OSABI on Linux Distros References: <7160c0e3-b49c-1ab8-c0d3-cee12355f895@gmail.com> <20160610212256.D5A772C39F7@topped-with-meat.com> To: Roland McGrath Cc: gnu-gabi@sourceware.org From: Suprateeka R Hegde Organization: HEGDESASPECT Message-ID: Date: Fri, 01 Jan 2016 00:00:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <20160610212256.D5A772C39F7@topped-with-meat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Antivirus: avast! (VPS 160610-1, 10-06-2016), Outbound message X-Antivirus-Status: Clean X-SW-Source: 2016-q2/txt/msg00014.txt.bz2 On 11-Jun-2016 02:52 AM, Roland McGrath wrote: >> What is the reason why we emit OSABI value as "UNIX - System V" >> (ELFOSABI_SYSV) even on GNU/Linux systems? Shouldn't it be just "GNU" >> (ELFOSABI_GNU)? > > In GNU systems the use of this field is specifically to indicate that > certain GNU extensions to ELF are used in the particular object. In > particular, if any .dynsym entries use STT_GNU_IFUNC o STB_GNU_UNIQUE, > then e_ident[EI_OSABI] must be ELFOSABI_GNU. OK. I understood this part. But then I did not know this set is partial. I thought use of *any* GNU specific extension should mark it as GNU OSABI. For instance, GNU_RELRO, GNU_EH_FRAME, GNU_STACK, etc. Even with all these, it is still marked SYSV ABI. So, 1. Do we have a documented list of GNU extensions that are necessary to mark an ELF as GNU ABI? 2. Why the list is partial? Why not all GNU extensions? -- Supra Otherwise, it can be > ELFOSABI_NONE (aka ELFOSABI_SYSV). In fact, it should be, and the > tools (linkers) implement that distinction. This makes it possible > for current tools (without special switches or whatnot) to produce > binaries that are compatible with older dynamic linker implementations > that did not support these GNU extensions to ELF. > > This is arguably a bad overloading of the original instead of > EI_OSABI, but it's what's been done for GNU systems and so now it's an > unchangeable part of the GNU ELF gABI. >