Date: Sat, 17 May 2008 13:26:53 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Jeremie Le Hen <jeremie@le-hen.org> Cc: freebsd-hackers@freebsd.org Subject: Re: Debugging rtld Message-ID: <20080517102653.GI18958@deviant.kiev.zoral.com.ua> In-Reply-To: <20080517091740.GI70896@obiwan.tataz.chchile.org> References: <20080517091740.GI70896@obiwan.tataz.chchile.org>
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--1Gc66+8b3xhjZJxW Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, May 17, 2008 at 11:17:40AM +0200, Jeremie Le Hen wrote: > Hi there, >=20 > I tried to compile my source tree with -fstack-protector-all, and it > happens that rtld breaks with this: once the new rtld is installed every > single problem coredumps. I tried to compile rtld-elf without SSP, but > it didn't solve the problem. Then I had to compile libc_pic.a without > SSP and it worked, but I don't understand the root of the problem. > So I want to use the generated coredump for post-mortem analysis with > gdb. >=20 > I compiled world with DEBUG_FLAGS=3D-g. But GDB gives me a backtrace so > long that it can't be real. Moreoever it doesn't seem to bring in the > required symbols. I'm a GDB novice, so I'd like some help. >=20 > chroot> =3D=3D=3D> libexec/rtld-elf (install) > chroot> chflags noschg /usr/libexec/ld-elf.so.1 > chroot> install -s -o root -g wheel -m 555 -C -b -fschg -S ld-elf.so.1 /= libexec > chroot> install -o root -g wheel -m 444 rtld.1.gz /usr/share/man/man1 > chroot> *** Signal 11 > chroot> > chroot> jarjarbinks# cd /root; ls > chroot> Segmentation fault >=20 > host> jarjarbinks:145# ls -l /space/chroot/root/ls.core=20 > host> -rw------- 1 root wheel 184320 May 17 10:19 /space/chroot/root/l= s.core > host> jarjarbinks:149# gdb -c /space/chroot/root/ls.core -e /space/chroot= /bin/ls > host> GNU gdb 6.1.1 [FreeBSD] > host> [...] > host> This GDB was configured as "i386-marcel-freebsd". > host> Core was generated by `ls'. > host> Program terminated with signal 11, Segmentation fault. > host> #0 0x280583e4 in ?? () > host> (gdb) bt > host> #0 0x280583e4 in ?? () > host> #1 0x00000000 in ?? () > host> #2 0x00000000 in ?? () > host> #3 0x00000000 in ?? () > host> #4 0x00000000 in ?? () > host> #5 0x00000000 in ?? () > host> #6 0x00000000 in ?? () > host> #7 0x00000000 in ?? () > host> #8 0x00000000 in ?? () > host> #9 0x00000000 in ?? () > host> #10 0x00000000 in ?? () > host> #11 0xffffffff in ?? () > host> #12 0x00001000 in ?? () > host> [...] > host> #359 0x73763a68 in ?? () > host> #360 0x5b455c3d in ?? () > host> [...] > host> #855 0x00000000 in ?? () > host> [...] >=20 > Any hint on how to proceed would be welcome. I usually add the CFLAGS+=3D-g to the rtld-elf/Makefile. Also, you do not need to bring down the whole host by the broken ld.so.1. Do not install it at all, and specify the path to the rtld by the --dynamic-linker switch, see into ld. BTW, Solaris seems to support $ORIGIN in the interpreter path, but I feel that this is an overkill. --1Gc66+8b3xhjZJxW Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkgusu0ACgkQC3+MBN1Mb4jaqACgz6k2u1rOr9x6q16hFZ5DqH0h CDUAn1xbcoskey+CApBlFCS93/T95NiM =7+4r -----END PGP SIGNATURE----- --1Gc66+8b3xhjZJxW--
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