From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 85229 invoked by alias); 7 Jan 2020 17:07:54 -0000 Mailing-List: contact libabigail-help@sourceware.org; run by ezmlm Precedence: bulk List-Post: List-Help: List-Id: List-Subscribe: Sender: libabigail-owner@sourceware.org Received: (qmail 85219 invoked by uid 89); 7 Jan 2020 17:07:54 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.100.3 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-6.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 spammy=upset X-Spam-Status: No, score=-6.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on sourceware.org X-Spam-Level: X-HELO: relay12.mail.gandi.net Received: from relay12.mail.gandi.net (HELO relay12.mail.gandi.net) (217.70.178.232) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 07 Jan 2020 17:07:52 +0000 Received: from localhost (91-166-131-130.subs.proxad.net [91.166.131.130]) (Authenticated sender: dodj@seketeli.org) by relay12.mail.gandi.net (Postfix) with ESMTPSA id F39F2200007; Tue, 7 Jan 2020 17:07:49 +0000 (UTC) Received: by localhost (Postfix, from userid 1001) id 10E651A11F8; Tue, 7 Jan 2020 18:07:49 +0100 (CET) From: Dodji Seketeli To: Matthias Maennich Cc: libabigail@sourceware.org, kernel-team@android.com Subject: Re: [RFC PATCH] dwarf-reader: support ksymtab symbol lookup by name Organization: Me, myself and I References: <20191202171933.261787-1-maennich@google.com> X-Operating-System: Red Hat Enterprise Linux Server 7.7 X-URL: http://www.seketeli.net/~dodji Date: Wed, 01 Jan 2020 00:00:00 -0000 In-Reply-To: <20191202171933.261787-1-maennich@google.com> (Matthias Maennich's message of "Mon, 2 Dec 2019 17:19:33 +0000") Message-ID: <86pnfvjiu2.fsf@seketeli.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2020-q1/txt/msg00008.txt Hello, Thank you for working on this. Before going deep in the patch itself, I'd have some questions about basic understanding of what is going on, if you don't mind. Matthias Maennich a =C3=A9crit: > The ksymtab address entry might not be actually pointing to a GLOBAL > visible symbol in .symtab of the same binary. E.g. that happens when > compiling the kernel with clang's -fsanitize-cfi* and friends. Just so that I understand better; in cases where the address part of a ksymtab entry cointains a number that is not the address of a GLOBAL visible symbol in .symtab, what does that number represent? I am thinking maybe that number is the address of an artificial "stub" symbol that would have been generated by the sanitizer, but I am not sure at this point. > In contrast, the ksymtab.name entry has to match an entry in > .symtab. It would otherwise upset linkers very much. It does seem odd to me that the address part of a ksymtab entry does not point to a symbol in .symtab that we can use, and yet the name part of that same entry points to the name of a symbol in .symtab that we can use. Doesn't it? I guess the information I am missing is related to my earlier question. Thanks, --=20 Dodji