I traced down the same problem trying to build debian-installer initrd and found that this command generates different libc.so.6-so depending on binutils version. The one using 2.21.0.20110327-1 works, while using 2.21.51.20110419-2 the chroot ends with seg fault. I work on powerpcspe architecture.
gcc -nostdlib -nostartfiles -shared -Wl,-soname=libc.so.6 -ugetpid -uwmemset -unl_langinfo -usched_get_priority_min -usetitimer -ucfgetospeed -usigaction -umempcpy -uexecv -u__gettimeofday -u__dso_handle -u__sched_getscheduler -u_dl_sym -ufchdir -u__res_maybe_init -ustderr -uvasprintf -urecv -ugethostname -uatoi -u__res_init -u__fcntl -ufseek -ufputc -uisatty -umadvise -uwmemchr -u_exit -usysconf -ugetsockname -ustrcasestr -ufclose -u__xmknod -ulocaltime -ustrcmp -u_dl_vsym -udup -usyslog -umbrtowc -ustrncat -uinet_nsap_ntoa -u__ctype_toupper_loc -utcsetattr -ugnu_dev_minor -ustrncasecmp -urecvmsg -u__libc_start_main -ufseeko64 -u__libc_fork -ugetgid -urename -uaccess -urealpath -umkdtemp -utfind -u__environ -u__poll -ulseek64 -usymlink -utime -ustrcpy -utdelete -uusleep -upclose -ustrerror -umount -u__lxstat -upread -urindex -uchmod -u__libc_current_sigrtmin_private -ustrncmp -u__novmx__libc_siglongjmp -ulisten -ustrsep -upopen -ufread -uvfprintf -uconnect -u__fxstat64 -ugetrlimit -uglob -u__libc_siglongjmp -u__novmx__libc_longjmp -uvprintf -u__getdelim -u__libc_dlopen_mode -usetsid -umkstemp64 -udifftime -ulink -utsearch -uwcstombs -u_IO_getc -uiswupper -ummap -ureadlink -usnprintf -u__statfs -u__sysv_signal -ustrcat -uiswspace -u_setjmp -u__sysconf -uqsort -ubind -urand -u__getpagesize -uwcschr -ucalloc -umblen -uwmemcmp -umemcpy -uinet_ntop -uttyname -ufreopen -usetuid -u__res_iclose -ustrdup -ummap64 -ustrncpy -u__setmntent -usetlocale -uperror -u_libc_intl_domainname -uin6addr_any -utextdomain -ufgets -uputenv -uwcslen -urecvfrom -uiswpunct -uwmemmove -u__getmntent_r -u__libc_thread_freeres -u__libc_system -uputs -u__isoc99_sscanf -ucfsetospeed -u__libc_dl_error_tsd -umbstowcs -umemchr -ugetcwd -uclosedir -utwalk -ugetpwent -u__strdup -ufgetc -u__sched_getparam -ufeof -ugetopt_long -uunsetenv -usetgroups -ustdin -usetgid -uread -usignal -ustrtod -ugetmntent -ugettimeofday -uiswalpha -ubasename -uwcwidth -uinit_module -uwaitpid -uh_errno -uexit -ualarm -ufopen64 -uwctomb -ugetpeername -uscandir -uclearerr -ucfmakeraw -u__ctype_tolower_loc -usigemptyset -ufputs -usched_setparam -upoll -usigaddset -ubsearch -umkfifo -uprintf -uregerror -usetpriority -uutime -u__xstat -uwcsnlen -utcflush -ufprintf -uiswblank -ureaddir64 -urmdir -umbtowc -ustrtok -ustrrchr -uabort -ustrspn -uopendir -u__fxstat -uexecl -ustrchr -uregcomp -umunmap -ugetuid -uvsyslog -u_environ -ustrndup -umkdir -u__libc_pthread_init -u__ctype_b_loc -umalloc -u__errno_location -udup2 -umemset -usend -ugetpwnam -u__endmntent -uopen64 -u__libc_current_sigrtmax_private -u__clone -utowlower -uopenlog -ustrcasecmp -uexecvp -u_IO_putc -u__asprintf -utolower -usched_get_priority_max -utempnam -u__sched_setscheduler -usetsockopt -u__dcgettext -umktemp -ugetegid -ucfsetispeed -utowupper -uiswalnum -ustdout -uendmntent -uftell -ugeteuid -ufileno -ureaddir -uopen -unice -usyscall -u_dl_addr -ugetopt -ugrantpt -uungetc -u__libc_longjmp -usched_yield -u__libc_fatal -uioctl -uwritev -uwmemcpy -uaddmntent -ugmtime -ufopen -uputchar -upwrite -ukill -uferror -uchdir -usetenv -uchown -ugetenv -usetmntent -uftruncate -u__resp -usleep -uselect -ufcntl -uumask -umemmove -ugetpwuid -uasprintf -usprintf -utdestroy -urealloc -ustrlen -usetbuf -ustrstr -ustrnlen -ufnmatch -uptsname -u__libc_dlsym -ufwrite -usigfillset -ufseeko -uerrno -ugnu_dev_makedev -u__lxstat64 -ugetgrnam -uclose -udelete_module -usystem -ufflush -u__libc_dlclose -umlock -uregfree -ucloselog -usendto -ufdopen -usigprocmask -uwrite -usscanf -uunlink -ustatfs -u__res_state -ualphasort -umunlock -uchroot -uendpwent -ustrtoul -uftello -ustrftime -u__register_atfork -ufork -uunlockpt -upipe -u__cxa_atexit -ufree -uexecve -ustrtoull -u__ctype_get_mb_cur_max -ustrcspn -u__assert_fail -umemcmp -uvsnprintf -ugnu_dev_major -uuname -u__cxa_finalize -u__xstat64 -umprotect -uinet_ntoa -uregexec -uindex -uglobfree -udcgettext -ustrpbrk -usocket -utcgetattr -u__libc_allocate_rtsig_private -ustrtol -ugetc_unlocked -uenviron -uiswcntrl -uclearenv -u__h_errno_location -o libc.so.6-so /usr/lib/libc_pic/soinit.o /usr/lib//libc_pic.a /usr/lib/libc_pic/sofini.o -Wl,--version-script=/usr/lib//libc_pic.map /lib//ld.so.1
