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[81.101.252.173]) by smtp.gmail.com with ESMTPSA id m10-20020a5d56ca000000b002207cec45cesm14144004wrw.81.2022.08.22.09.29.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Aug 2022 09:29:45 -0700 (PDT) Message-ID: <91dff341-3665-17af-6bda-d48058ace8bd@jguk.org> Date: Mon, 22 Aug 2022 17:29:44 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: ld-linux-x86-64 core file SIGSEGV Content-Language: en-GB To: Florian Weimer Cc: libc-help@sourceware.org References: <87a67w6aqn.fsf@oldenburg.str.redhat.com> <87o7wczhgi.fsf@oldenburg.str.redhat.com> <34136fcb-da3c-f8f7-d091-ec1c8b3c187e@jguk.org> <87fshozh27.fsf@oldenburg.str.redhat.com> From: Jonny Grant In-Reply-To: <87fshozh27.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-help@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-help mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Aug 2022 16:29:55 -0000 On 22/08/2022 11:52, Florian Weimer wrote: > * Jonny Grant: > >> On 22/08/2022 11:43, Florian Weimer wrote: >>> * Jonny Grant: >>> >>>> I got it to load the debug symbol using "file" command you >>>> mentioned. Unfortunately backtrace still empty. The debug symbols >>>> /usr/lib/debug/.build-id/61/ef896a699bb1c2e4e231642b2e1688b2f1a61e.debug >>>> are only 592,952 bytes >>>> >>>> I would probably just prefer if binaries weren't separated from their >>>> debug symbols. Do you know any distributions that don't strip symbols >>>> from glibc? >>> >>> I'm not sure if this is caused by debuginfo separation. I run into GDB >>> when I use my own custom-built glibc with unstripped debuginfo. >>> >>> Anyway, you can probably use eu-unstrip from elfutils to undo the >>> debuginfo separation. >>> >>> Thanks, >>> Florian >> >> That's a good tip than you. >> >> I did use objdump -d on the ld.so, but couldn't spot anything similar >> to what I saw in "layout asm" from gdb. > > In my experience, the missing symbols are usually from the main program, > and then the stack backtrace runs off the rails pretty quickly > (resulting in garbage addresses). > >> Is it ever possible to match up disassembly with the gdb core >> disassembly this way? > > You cloud get the object addresses from /proc/PID/mem, compute the > relative offset, and then use addr2line or objdump to find out more. > > Thanks, > Florian > Thank you for the extra information. I will try to find a way to reproduce it, maybe that's clearer. Thanks, Jonny