From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27310 invoked by alias); 1 Nov 2008 06:47:37 -0000 Received: (qmail 27130 invoked by uid 22791); 1 Nov 2008 06:47:36 -0000 X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.33.17) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sat, 01 Nov 2008 06:46:39 +0000 Received: from spaceape13.eur.corp.google.com (spaceape13.eur.corp.google.com [172.28.16.147]) by smtp-out.google.com with ESMTP id mA16kX0N009835 for ; Sat, 1 Nov 2008 06:46:33 GMT Received: from wa-out-1112.google.com (wafj32.prod.google.com [10.114.186.32]) by spaceape13.eur.corp.google.com with ESMTP id mA16kUdS018771 for ; Fri, 31 Oct 2008 23:46:31 -0700 Received: by wa-out-1112.google.com with SMTP id j32so866449waf.7 for ; Fri, 31 Oct 2008 23:46:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.114.147.1 with SMTP id u1mr10716992wad.208.1225521990481; Fri, 31 Oct 2008 23:46:30 -0700 (PDT) In-Reply-To: <490BBEF4.1040801@gmail.com> References: <49065BBD.3050800@gmail.com> <8ac60eac0810271741h135f077bj2c3fcd7391e89ed7@mail.gmail.com> <4906615E.50606@gmail.com> <8ac60eac0810271836saf8c28pb1392b77c7926be0@mail.gmail.com> <4907B915.5040101@gmail.com> <8ac60eac0810281920r4bf71400hc8171bdee3c92ca@mail.gmail.com> <490909B3.2080307@gmail.com> <8ac60eac0810291830g46604c3eye8365240c48007d0@mail.gmail.com> <490BBEF4.1040801@gmail.com> Date: Sat, 01 Nov 2008 06:47:00 -0000 Message-ID: <8ac60eac0810312346l638f3011n66d7681444329486@mail.gmail.com> Subject: Re: "Cannot find new threads" on Fedora 9, but not on CentOS 5 (?) From: Paul Pluzhnikov To: ajloft@umich.edu Cc: gdb@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2008-11/txt/msg00001.txt.bz2 On Fri, Oct 31, 2008 at 7:29 PM, Andrew Lofthouse wrote: > Last night I tried to follow your example and try to debug gdb, but to do > so, I would have to replicate my earlier problem, but I was unable to do so > (meaning, gdb did not have any problems following the new threads, or > finding libpthread symbols). I thought this was because I had explicitly > linked with -pthread previously. I rebooted, rebuilt, and was still unable > to replicate the problem. I re-installed Fedora 9 from scratch, and I'm > still unable to replicate it. I have no idea what changed. Don't you just hate that? One thing that may have changed is prelink addresses -- IIRC, Fedora runs prelink at 2 week intervals. You may want to try: /usr/sbin/prelink -a gdb ... several times, and see if one particular randomized layout triggers the bug again. > Ubuntu 8.04, however, still gives a "cannot find new threads: generic error" > when not explicitly linking to libpthread. Are you running a 64-bit kernel perchance? There is a known kernel bug related to ptrace()ing 32-bit processes, and it sounds from your trace that that might be what you are hitting. > So, the following comes from > Ubuntu. Unfortunately, I cannot find any debug symbols for gdb for Ubuntu > (Fedora seems to have them). It's worse: your GDB has been stripped :( > For what it's worth: > > ==> andrew@ubuntu-vm ~/codes/ufs Fri Oct 31 22:17:01 > 532 $ gdb -ex 'set prompt (top) ' --args gdb /usr/local/bin/ufs2oogl2D > GNU gdb 6.8-debian > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "i486-linux-gnu"... > (no debugging symbols found) > (top) rbreak throw_ > Breakpoint 1 at 0x8132024 > throw_exception; > Breakpoint 2 at 0x8132136 > throw_error; > Breakpoint 3 at 0x8132158 > throw_vfatal; > Breakpoint 4 at 0x8132176 > throw_verror; > Breakpoint 5 at 0x8132196 > deprecated_throw_reason; > (top) run > Starting program: /usr/bin/gdb /usr/local/bin/ufs2oogl2D > (no debugging symbols found) > (no debugging symbols found) > (no debugging symbols found) > (no debugging symbols found) > (no debugging symbols found) > [Thread debugging using libthread_db enabled] > [New Thread 0xb7d396b0 (LWP 31952)] > GNU gdb 6.8-debian > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "i486-linux-gnu"... > (gdb) set verbose on > (gdb) run -T "rho" < UAM10_002_UFS-005000.sim > test.plt > Starting program: /usr/local/bin/ufs2oogl2D -T "rho" < > UAM10_002_UFS-005000.sim > test.plt > Reading symbols from /lib/ld-linux.so.2...Reading symbols from > /usr/lib/debug/lib/ld-2.7.so...done. > done. > Reading symbols from system-supplied DSO at 0xb7f0e000...done. > Reading symbols from /usr/local/lib/libufs2D-0.9.so.2...done. > Reading symbols from /usr/local/lib/libgts-0.7.so.5...done. > Reading symbols from /usr/lib/libgmodule-2.0.so.0...Reading symbols from > /usr/lib/debug/usr/lib/libgmodule-2.0.so.0.1600.6...done. > done. > Reading symbols from /usr/lib/debug/libdl.so.2...done. > Reading symbols from /usr/lib/libglib-2.0.so.0...Reading symbols from > /usr/lib/debug/usr/lib/libglib-2.0.so.0.1600.6...done. > done. > Reading symbols from /usr/lib/debug/libm.so.6...done. > Reading symbols from /usr/lib/debug/libc.so.6...done. > Reading symbols from /usr/lib/libpcre.so.3...Reading symbols from > /usr/lib/debug/usr/lib/libpcre.so.3.12.1...done. > done. > > Detaching after fork from child process 31962. > Reading symbols from /tmp/gfs2O2C03...done. > Reading symbols from /usr/lib/libgthread-2.0.so.0...Reading symbols from > /usr/lib/debug/usr/lib/libgthread-2.0.so.0.1600.6...done. > done. > Reading symbols from /usr/lib/debug/librt.so.1...done. > Reading symbols from /usr/lib/debug/libpthread.so.0...done. > [Thread debugging using libthread_db enabled] > [Switching to Thread 0xb7d396b0 (LWP 31952)] > > Breakpoint 4, 0x08132176 in throw_verror () > (top) where > #0 0x08132176 in throw_verror () > #1 0x0808f403 in error () > #2 0x080a2580 in ?? () > #3 0x080a3d4e in check_for_thread_db () > #4 0x0808782f in ?? () > #5 0x08087987 in observer_notify_new_objfile () > #6 0x08119aaa in ?? () > #7 0x0809aad0 in ?? () > #8 0x08132393 in catch_errors () > #9 0x0809a69c in solib_read_symbols () > #10 0x0809b062 in solib_add () > #11 0x081284eb in handle_inferior_event () > #12 0x08129f77 in wait_for_inferior () > #13 0x0812a147 in proceed () > #14 0x08124dc3 in ?? () > #15 0x0808b531 in execute_command () > #16 0x08135dff in ?? () > #17 0x08136b53 in ?? () > #18 0xb7f27962 in rl_callback_read_char () from /lib/libreadline.so.5 > #19 0x08135fcb in ?? () > #20 0x0813594e in ?? () > ---Type to continue, or q to quit--- > #21 0x08134d90 in ?? () > #22 0x08135630 in gdb_do_one_event () > #23 0x08132393 in catch_errors () > #24 0x080d63c4 in ?? () > #25 0x0813299f in current_interp_command_loop () > #26 0x0808330b in ?? () > #27 0x08132393 in catch_errors () > #28 0x08083c0c in ?? () > #29 0x08132393 in catch_errors () > #30 0x080832f1 in gdb_main () > #31 0x080832b5 in main () > (top) > > > If I have some more time, I'll see what else I can do. You may want to build GDB from sources (either 6.8, or better yet CVS head) on Ubuntu. Then we'll at least have a complete stack trace. > But, I do at least have a work-around... Yes, but we still don't know if there is a GDB bug hiding underneath ... Cheers, -- Paul Pluzhnikov