From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19243 invoked by alias); 9 Jan 2007 22:43:30 -0000 Received: (qmail 19233 invoked by uid 22791); 9 Jan 2007 22:43:29 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Tue, 09 Jan 2007 22:43:25 +0000 Received: from drow by nevyn.them.org with local (Exim 4.63) (envelope-from ) id 1H4Pgh-0001uD-4V; Tue, 09 Jan 2007 17:43:23 -0500 Date: Tue, 09 Jan 2007 22:43:00 -0000 From: Daniel Jacobowitz To: Jan Kratochvil Cc: gdb-patches@sourceware.org Subject: Re: [review] Fix backtrace of prelinked libc with separate debuginfo Message-ID: <20070109224323.GJ30631@nevyn.them.org> Mail-Followup-To: Jan Kratochvil , gdb-patches@sourceware.org References: <20061029223912.GA24248@host0.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061029223912.GA24248@host0.dyn.jankratochvil.net> User-Agent: Mutt/1.5.13 (2006-08-11) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2007-01/txt/msg00278.txt.bz2 On Sun, Oct 29, 2006 at 11:39:12PM +0100, Jan Kratochvil wrote: > It is (I believe) due to the fact the system libc gets prelinked to some > address but the separate debuginfo file is not updated for the prelinked > address. `matching_bfd_sections' will fail to match afterwards. > > Not sure if the testcase properly fails on all systems, it works for me with > the prelinking in effect. Right. It won't fail on Debian even with prelinking - I think this is because Debian uses binutils' objcopy program, which puts the stripped symbols in the debug file, but eu-strip leaves them only in the original file. Which seems pretty strange but that's what it does. > 2006-10-29 Jan Kratochvil > > * gdb/symtab.c (matching_bfd_sections): Fix VMA matching for objects > loaded at a different address than stored on the disk. > > 2006-10-29 Jan Kratochvil > > * gdb.base/relativedebug.c, gdb.base/relativedebug.exp: New file, > resolving of PC in libc pause(3) (with possibly different on-disk VMA). I updated the test case to work with remote targets and then checked this in. -- Daniel Jacobowitz CodeSourcery 2007-01-09 Jan Kratochvil * symtab.c (matching_bfd_sections): Fix VMA matching for prelinked objects. 2007-01-09 Jan Kratochvil * gdb.base/relativedebug.c, gdb.base/relativedebug.exp: New files. Index: symtab.c =================================================================== RCS file: /cvs/src/src/gdb/symtab.c,v retrieving revision 1.151 diff -u -p -r1.151 symtab.c --- symtab.c 9 Jan 2007 17:58:59 -0000 1.151 +++ symtab.c 9 Jan 2007 22:39:14 -0000 @@ -739,8 +739,11 @@ matching_bfd_sections (asection *first, if (bfd_get_section_size (first) != bfd_get_section_size (second)) return 0; + /* In-memory addresses may start at a different offset, relativize them. */ if (bfd_get_section_vma (first->owner, first) - != bfd_get_section_vma (second->owner, second)) + - bfd_get_start_address (first->owner) + != bfd_get_section_vma (second->owner, second) + - bfd_get_start_address (second->owner)) return 0; if (bfd_get_section_name (first->owner, first) == NULL Index: testsuite/gdb.base/relativedebug.c =================================================================== RCS file: testsuite/gdb.base/relativedebug.c diff -N testsuite/gdb.base/relativedebug.c --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ testsuite/gdb.base/relativedebug.c 9 Jan 2007 22:39:14 -0000 @@ -0,0 +1,37 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2007 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + 02111-1307, USA. */ + +#include +#include +#include + + +static void handler (int signo) +{ + abort (); +} + +int main (void) +{ + signal (SIGALRM, handler); + alarm (1); + pause (); + pause (); + return 0; +} Index: testsuite/gdb.base/relativedebug.exp =================================================================== RCS file: testsuite/gdb.base/relativedebug.exp diff -N testsuite/gdb.base/relativedebug.exp --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ testsuite/gdb.base/relativedebug.exp 9 Jan 2007 22:39:14 -0000 @@ -0,0 +1,71 @@ +# Copyright 2007 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +if $tracelevel then { + strace $tracelevel +} + +set testfile relativedebug +set srcfile ${testfile}.c +set binfile ${objdir}/${subdir}/${testfile} +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { + untested "Couldn't compile test program" + return -1 +} + +# Get things started. + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +runto_main + +# pause () -> SIGALRM -> handler () -> abort () +gdb_test "continue" "Program received signal SIGABRT.*" + +# Backtracing through pause broke if glibc has been prelinked, +# because the separate debug files in /usr/lib/debug had different +# base addresses. + +# incorrect (#6): +# (gdb) bt +# #0 0x00325402 in __kernel_vsyscall () +# #1 0x00718f20 in *__GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64 +# #2 0x0071a801 in *__GI_abort () at abort.c:88 +# #3 0x0804841f in handler (signo=14) at ./gdb.base/relativedebug.c:27 +# #4 +# #5 0x00325402 in __kernel_vsyscall () +# #6 0x0077ebc6 in ?? () from /lib/i686/nosegneg/libc.so.6 +# #7 0x08048455 in main () at ./gdb.base/relativedebug.c:34 +# (gdb) + +# correct (#6): +# (gdb) bt +# #0 0x00b33402 in __kernel_vsyscall () +# #1 0x00718f20 in *__GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64 +# #2 0x0071a801 in *__GI_abort () at abort.c:88 +# #3 0x0804841f in handler (signo=14) at ./gdb.base/relativedebug.c:27 +# #4 +# #5 0x00b33402 in __kernel_vsyscall () +# #6 0x0077ebc6 in __pause_nocancel () from /lib/i686/nosegneg/libc.so.6 +# #7 0x08048455 in main () at ./gdb.base/relativedebug.c:34 +# (gdb) + +gdb_test "bt" \ + ".*\[^a-zA-Z\]pause\[^a-zA-Z\].*" \ + "pause found in backtrace"