From nobody Wed Nov 29 20:51:56 2023 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SgWs70XcTz52F8N for ; Wed, 29 Nov 2023 20:59:07 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from omta001.cacentral1.a.cloudfilter.net (omta001.cacentral1.a.cloudfilter.net [3.97.99.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4SgWs63BM2z4dS4 for ; Wed, 29 Nov 2023 20:59:06 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Authentication-Results: mx1.freebsd.org; dkim=none; spf=none (mx1.freebsd.org: domain of cy.schubert@cschubert.com has no SPF policy when checking 3.97.99.32) smtp.mailfrom=cy.schubert@cschubert.com; dmarc=none Received: from shw-obgw-4003a.ext.cloudfilter.net ([10.228.9.183]) by cmsmtp with ESMTPS id 8IGzrujCA8jpT8RXKrKiig; Wed, 29 Nov 2023 20:51:58 +0000 Received: from spqr.komquats.com ([70.66.152.170]) by cmsmtp with ESMTPSA id 8RXIrhDWYMsNf8RXJrdOtP; Wed, 29 Nov 2023 20:51:57 +0000 X-Authority-Analysis: v=2.4 cv=KJNJsXJo c=1 sm=1 tr=0 ts=6567a46d a=y8EK/9tc/U6QY+pUhnbtgQ==:117 a=y8EK/9tc/U6QY+pUhnbtgQ==:17 a=kj9zAlcOel0A:10 a=BNY50KLci1gA:10 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=EkcXrb_YAAAA:8 a=6GK37-q3vbxVpk9-ZJ0A:9 a=CjuIK1q_8ugA:10 a=Ia-lj3WSrqcvXOmTRaiG:22 a=IjZwj45LgO3ly-622nXo:22 a=LK5xJRSDVpKd5WXXoEvA:22 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id 54986374 for ; Wed, 29 Nov 2023 12:51:56 -0800 (PST) Received: by slippy.cwsent.com (Postfix, from userid 1000) id 1D3BCD2; Wed, 29 Nov 2023 12:51:56 -0800 (PST) X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.8+dev Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: freebsd-hackers@freebsd.org Subject: Re: analysing a coredump In-reply-to: References: Comments: In-reply-to void message dated "Wed, 29 Nov 2023 11:33:34 +0000." List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 29 Nov 2023 12:51:56 -0800 Message-Id: <20231129205156.1D3BCD2@slippy.cwsent.com> X-CMAE-Envelope: MS4xfOOclD7AtuF+dp347Ry2bmOuAwxVfKpBq4e7+yW3Zv12Xaiy62JvzS/VGl2kYJiC7EOVW9M0Ml0XUfuzxotn0ocUURkNeIB3YQmPPsV54Ny2n9qcbBpN 0ZOKW6PGaPF/FFGZAqtizPehFV/Q/JmyM6Tg9JKzI3U92lnWs5l7/2S1eFj1kP4MoeZoze+jOYXEMNdakUAXZhv3JahMdFsYTv4= X-Spamd-Result: default: False [2.55 / 15.00]; R_BAD_CTE_7BIT(3.50)[7bit]; AUTH_NA(1.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-1.000]; MV_CASE(0.50)[]; NEURAL_HAM_LONG(-0.15)[-0.148]; RCVD_IN_DNSWL_LOW(-0.10)[3.97.99.32:from]; MIME_GOOD(-0.10)[text/plain]; RWL_MAILSPIKE_GOOD(-0.10)[3.97.99.32:from]; TO_MATCH_ENVRCPT_ALL(0.00)[]; HAS_REPLYTO(0.00)[Cy.Schubert@cschubert.com]; RCPT_COUNT_ONE(0.00)[1]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; MLMMJ_DEST(0.00)[freebsd-hackers@freebsd.org]; DMARC_NA(0.00)[cschubert.com]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; R_SPF_NA(0.00)[no SPF record]; RCVD_COUNT_THREE(0.00)[4]; TO_DN_NONE(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; REPLYTO_EQ_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:16509, ipnet:3.96.0.0/15, country:US]; GREYLIST(0.00)[pass,body] X-Rspamd-Queue-Id: 4SgWs63BM2z4dS4 X-Spamd-Bar: ++ In message , void writes: > Hi, > > httpd had an unexpected coredump. I installed gbd and with > what little i know of it, ran gdb against the dump: > > (gdb) core /httpd.core > [New LWP 101030] > Core was generated by `/usr/local/sbin/httpd -DNOHTTPACCEPT'. > Program terminated with signal SIGSEGV, Segmentation fault. > Address not mapped to object. > #0 0x000000083f237930 in ?? () > (gdb) bt full > #0 0x000000083f237930 in ?? () > No symbol table info available. > > (goes on like this for another 10 lines) > > I *guess* [1] I'll need to recompile apache24 with debug symbols then > wait for another crash. Is there anything else i can do regarding this proble > m? That usually helps. Back in the day, on the mainframe, the compiler would print a list of statement offsets and variable offsets that one could derive as offsets from the function's base address. I don't believe our current compilers can do this and even then, building and linking after the fact just to get offsets may not result in the same map as your executing program. You're better off recompiling with debugging symbols. If you've used another debugger before, like on a different platform, the transition won't be as painful as you think. The concepts are similar. If you haven't before, it will take a bit of learning. -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org e^(i*pi)+1=0 จจ@L