Package: libc6 Version: 2.9-25 Severity: normal I'm running alsaplayer on an armel platform, using the -text frontend and the -alsa output. I've configured my armel machine to send a SIGBUS to any process which makes an alignment error by doing this:
echo 5 > /proc/cpu/alignment when i launch the player (compiled with debug symbols), even before it gets to main() i get the SIGBUS. Here's the backtrace i see with libc6-dbg installed: (gdb) bt #0 elf_machine_rel (scope=0x4001e1a0, lazy=1, consider_profiling=0) at ../ports/sysdeps/arm/dl-machine.h:429 #1 elf_dynamic_do_rel (scope=0x4001e1a0, lazy=1, consider_profiling=0) at do-rel.h:120 #2 _dl_relocate_object (scope=0x4001e1a0, lazy=1, consider_profiling=0) at dl-reloc.c:266 #3 0x400039bc in dl_main (phdr=0x8034, phnum=8, user_entry=0xbe98257c) at rtld.c:2231 #4 0x40015110 in _dl_sysdep_start (start_argptr=<value optimized out>, dl_main=0x400021d8 <dl_main>) at ../elf/dl-sysdep.c:239 #5 0x40000cd0 in _dl_start_final (arg=0xbe982870, info=0xbe9825f8) at rtld.c:332 #6 0x40000f68 in _dl_start (arg=0xbe982870) at rtld.c:560 #7 0x400007f0 in _start () from /lib/ld-linux.so.3 #8 0x400007f0 in _start () from /lib/ld-linux.so.3 Backtrace stopped: previous frame identical to this frame (corrupt stack?) (gdb) that last line is just: *reloc_addr += value but reloc_addr is optimized out. unfortunately, rebuilding packages (esp. large packages like libc6) takes a long time on machines like this (it's an NSLU2, 266Mhz with 32MB RAM), so i haven't had a chance to debug further. People interested in this bug might also be interested in discussion from http://bugs.debian.org/397616 . for examples of potential dangers of undetected memory alignment failures, see http://bugs.debian.org/548815 -- hopefully alignment failures in libc6 won't cause higher-level trouble the way they do with some media codecs. I also asked for discussion in general about alignment issues on armel: http://lists.debian.org/debian-arm/2009/09/msg00109.html Let me know if i can provide more debugging help on this. --dkg -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (500, 'testing') Architecture: armel (armv5tel) Kernel: Linux 2.6.30-1-ixp4xx Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968) Shell: /bin/sh linked to /bin/dash Versions of packages libc6 depends on: ii libc-bin 2.9-25 GNU C Library: Binaries ii libgcc1 1:4.4.1-1 GCC support library libc6 recommends no packages. Versions of packages libc6 suggests: ii debconf [debconf-2.0] 1.5.27 Debian configuration management sy pn glibc-doc <none> (no description available) ii locales 2.9-25 GNU C Library: National Language ( -- debconf information: * glibc/restart-services: cron glibc/disable-screensaver: glibc/restart-failed: glibc/upgrade: true -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
