From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gnu.wildebeest.org (wildebeest.demon.nl [212.238.236.112]) by sourceware.org (Postfix) with ESMTPS id 015373851C09 for ; Tue, 27 Oct 2020 22:24:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 015373851C09 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=klomp.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mark@klomp.org Received: from librem (deer0x15.wildebeest.org [172.31.17.151]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id DF72130278CD; Tue, 27 Oct 2020 23:24:19 +0100 (CET) Received: by librem (Postfix, from userid 1000) id 446AFC04CA; Tue, 27 Oct 2020 23:23:29 +0100 (CET) Date: Tue, 27 Oct 2020 23:23:29 +0100 From: Mark Wielaard To: Paul Smith Cc: elfutils-devel@sourceware.org Subject: Re: Writing core files to contain buildids Message-ID: <20201027222329.GC2691@wildebeest.org> References: <20536cfebaa78dd034154b1d024775a52d12b6d1.camel@mad-scientist.net> <5f52aa0c1f901761a5ad2ce60a2c420a1275f37f.camel@klomp.org> <574f7a8554cd07ef641482bfb0145c20967783b8.camel@mad-scientist.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <574f7a8554cd07ef641482bfb0145c20967783b8.camel@mad-scientist.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: elfutils-devel@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Elfutils-devel mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Oct 2020 22:24:22 -0000 Hi Paul, On Tue, Oct 27, 2020 at 04:20:51PM -0400, Paul Smith wrote: > On Tue, 2020-10-27 at 15:39 +0100, Mark Wielaard wrote: > > The basic idea behind getting buildids into core files is that they > > (the GNU ELF notes) are at the start of the file in the first page > > that is dumped (together with the phdrs) in the core file so when > > core file consumers can walk the program headers and find the buildid > > note (almost immediately following those headers). > > Something is missing; if I check the binary I see a build ID in it. I > can control whether the userspace coredumper or the kernel coredumper > is used via an environment variable: the kernel-generated core contains > a full set of build ID values including vdso.so, the binary, and all > normal .so's. > > But when using the userspace coredumper I get a completely valid > coredump that GDB is happy with, for example, but there is only the > vdso.so build ID present: I don't see any build IDs from the binary or > shared libraries. > > I guess another possibility is that they are there but eu-unstrip > --core can't find them? Do you have the generated core files somehwere so others can look at them? How exactly are you testing the build-id notes are there? Cheers, Mark