From owner-freebsd-hackers@freebsd.org Tue Jan 16 09:59:20 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DAD7BEB8FFF for ; Tue, 16 Jan 2018 09:59:20 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 71415712D2; Tue, 16 Jan 2018 09:59:20 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id w0G9x9T9095277 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 16 Jan 2018 11:59:12 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua w0G9x9T9095277 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id w0G9x8Id095276; Tue, 16 Jan 2018 11:59:09 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 16 Jan 2018 11:59:08 +0200 From: Konstantin Belousov To: Pedro Giffuni Cc: FreeBSD Hackers Subject: Re: examining Linux core file? Message-ID: <20180116095908.GQ1684@kib.kiev.ua> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Jan 2018 09:59:20 -0000 On Mon, Jan 15, 2018 at 10:02:58PM -0500, Pedro Giffuni wrote: > > On Sun, Jan 14, 2018 at 7:31 PM, Benjamin Kaduk wrote: > > > On Sun, Jan 14, 2018 at 07:57:01AM -0800, Chuck Tuffli wrote: > > >> If a Linux application running under the Linux emulation (a.k.a. > > >> Linuxulator) core dumps, is it possible to examine the resulting core > > >> file? lldb didn't seem to like it: > > > > > > I wonder how a Linux gdb running under the Linuxulator would fare > > > with it? > > > > Sorry, that's what I was trying to show with the last example. The > > Linux gdb from CentOS running under the Linuxulator gives: > > > > # gdb -q ./testcases/bin/mremap05 mremap05.core > > Reading symbols from /opt/ltp/testcases/bin/mremap05...done. > > > > warning: A handler for the OS ABI "FreeBSD ELF" is not built into this > > configuration > > of GDB. Attempting to continue with the default i386:x86-64 settings. > > > > "/opt/ltp/mremap05.core": no core file handler recognizes format > > Weird, I think you would need to build a cross-gdb. > > My memory is sketchy but you may need to build a complete > cross-toolchain for that. Long-long ago we actually did that but the > resulting linux binaries were weird and needed branding always. No cross-toolchain will help there. Problem is that the binary is Linux, while core is FreeBSD. There are enough details significant to the debugger that make such combination a new platform.