Re: %gs:0x14

[Neill Miller]

On Tue, 14 Nov 2006 17:57:50 +0100
Thomas Schwinge <tschwinge@gnu.org> wrote:

Hello,

Hope this helps!

> ... because this is a Debian testing system and they're still using a
> 2.3-based glibc.  That's probably it.  If someone has easy access to a
> system with a really recent GCC 4.1 or GCC 4.2 and a glibc like 2.4 or
> newer, could they please post the output of the following:
> 
> #v+
> $ echo 'void f (void) { volatile char a[8]; a[3]; }' | gcc -S -x c -O2 
> -fstack-protector - -o -; uname -a; /lib/libc-*.so
> #v-

neillm@macglob ~ $ /lib/libc.so.6 
GNU C Library development release version 2.4, by Roland McGrath et al.
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.1.1 (Gentoo 4.1.1).
Compiled on a Linux 2.6.11 system on 2006-07-10.
Available extensions:
        The C stubs add-on version 2.1.2.
        crypt add-on version 2.1 by Michael Glad and others
        GNU Libidn by Simon Josefsson
        GNU libio by Per Bothner
        NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
        Native POSIX Threads Library by Ulrich Drepper et al
        Support for some architectures added on, not maintained in glibc core.
        BIND-8.2.3-T5B
Thread-local storage support included.
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
neillm@macglob ~ $ gcc -v
Using built-in specs.
Target: powerpc-unknown-linux-gnu
Configured with: /var/tmp/portage/gcc-4.1.1/work/gcc-4.1.1/configure 
--prefix=/usr --bindir=/usr/powerpc-unknown-linux-gnu/gcc-bin/4.1.1 
--includedir=/usr/lib/gcc/powerpc-unknown-linux-gnu/4.1.1/include 
--datadir=/usr/share/gcc-data/powerpc-unknown-linux-gnu/4.1.1 
--mandir=/usr/share/gcc-data/powerpc-unknown-linux-gnu/4.1.1/man 
--infodir=/usr/share/gcc-data/powerpc-unknown-linux-gnu/4.1.1/info 
--with-gxx-include-dir=/usr/lib/gcc/powerpc-unknown-linux-gnu/4.1.1/include/g++-v4
 --host=powerpc-unknown-linux-gnu --build=powerpc-unknown-linux-gnu 
--enable-altivec --enable-nls --without-included-gettext --with-system-zlib 
--disable-checking --disable-werror --disable-libunwind-exceptions 
--disable-multilib --disable-libmudflap --disable-libssp --disable-libgcj 
--enable-languages=c,c++,fortran --enable-shared --enable-threads=posix 
--enable-__cxa_atexit --enable-clocale=gnu
Thread model: posix
gcc version 4.1.1 (Gentoo 4.1.1)
neillm@macglob ~ $ echo 'void f (void) { volatile char a[8]; a[3]; }' | gcc -S 
-x c -O2 -fstack-protector - -o -; uname -a; /lib/libc-*.so
        .file   ""
        .section        ".text"
        .align 2
        .globl f
        .type   f, @function
f:
        mflr 0
        stwu 1,-32(1)
        stw 0,36(1)
        lwz 0,-28680(2)
        stw 0,28(1)
        li 0,0
        lbz 0,23(1)
        lwz 9,28(1)
        lwz 0,-28680(2)
        xor. 9,9,0
        li 0,0
        bne- 0,.L5
        lwz 0,36(1)
        addi 1,1,32
        mtlr 0
        blr
.L5:
        bl __stack_chk_fail
        .size   f, .-f
        .ident  "GCC: (GNU) 4.1.1 (Gentoo 4.1.1)"
        .section        .note.GNU-stack,"",@progbits
Linux macglob 2.6.19-rc3 #1 PREEMPT Wed Oct 25 10:00:35 CDT 2006 ppc 7447A, 
altivec supported GNU/Linux
GNU C Library development release version 2.4, by Roland McGrath et al.
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.1.1 (Gentoo 4.1.1).
Compiled on a Linux 2.6.11 system on 2006-07-10.
Available extensions:
        The C stubs add-on version 2.1.2.
        crypt add-on version 2.1 by Michael Glad and others
        GNU Libidn by Simon Josefsson
        GNU libio by Per Bothner
        NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
        Native POSIX Threads Library by Ulrich Drepper et al
        Support for some architectures added on, not maintained in glibc core.
        BIND-8.2.3-T5B
Thread-local storage support included.
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
neillm@macglob ~ $ 

-Neill.

(IRC: __sempai)