Bug#442858: libc6-prof: programs linked agains libc_p.a crash with a SEGV

[Stephane Chazelas <stephane@artesyncp.com>]

Package: libc6-prof
Version: 2.6.1-4
Severity: grave
Justification: renders package unusable


Hi,

I don't seem to able build any program linked against the
profiled version of the glibc.

I can reproduce the problem with any version of gcc (3.3, 3.4,
4.0, 4.1, 4.2), with 2.6.1-1 and 2.6.1-4. Manually linking
against libc6-prof_2.3.6.ds1-13etch4_i386.deb using the crt's in
libc6-dev_2.3.6.ds1-13etch4_i386.deb (on the same unstable
debian host) is OK.

Consider this simple C program:

#include <stdio.h>
int main()
{
  printf("a\n");
  return 0;
}

Compiled with:

~$ gcc -o b -pg -g b.c -lc_p
~$ ./b
zsh: floating point exception (core dumped)  ./b

But, the thing is that both the profiled and non-profiled are
linked in:

~$ ldd b
        linux-gate.so.1 =>  (0xffffe000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7f87000)
        libc.so.6 => /lib/libc.so.6 (0xb7e3f000)
        /lib/ld-linux.so.2 (0xb7fac000)

Then trying to build it statically:

~$ gcc -o b -static -nodefaultlibs -pg -g b.c -lc_p -lgcc_eh
/usr/lib/gcc/i486-linux-gnu/4.2.1/libgcc_eh.a(unwind-dw2-fde-glibc.o): In function `_Unwind_Find_FDE':
(.text+0x1a87): undefined reference to `dl_iterate_phdr'
collect2: ld returned 1 exit status

I do get the same with -lc, and it seems it's because of some
circular dependencies for which I need:

gcc -o b -static -nodefaultlibs -pg -g b.c -Wl,-start-group -lc_p -lgcc_eh -Wl,-end-group

Same can be achieved by calling ld directly and replacing -lc
with -lc_p.

But now:

~$ ./b
zsh: segmentation fault (core dumped)  ./b

(gdb) bt
#0  0x08072d5b in __mcount_internal ()
#1  0x00000000 in ?? ()
(gdb) disassemble
Dump of assembler code for function __mcount_internal:
0x08072d40 <__mcount_internal+0>:       push   %ebp
0x08072d41 <__mcount_internal+1>:       mov    %eax,%ecx
0x08072d43 <__mcount_internal+3>:       mov    %esp,%ebp
0x08072d45 <__mcount_internal+5>:       xor    %eax,%eax
0x08072d47 <__mcount_internal+7>:       sub    $0x10,%esp
0x08072d4a <__mcount_internal+10>:      mov    %edx,0xfffffff0(%ebp)
0x08072d4d <__mcount_internal+13>:      mov    $0x1,%edx
0x08072d52 <__mcount_internal+18>:      mov    %ebx,0xfffffff4(%ebp)
0x08072d55 <__mcount_internal+21>:      mov    %esi,0xfffffff8(%ebp)
0x08072d58 <__mcount_internal+24>:      mov    %edi,0xfffffffc(%ebp)
0x08072d5b <__mcount_internal+27>:      cmpl   $0x0,%gs:0xc
0x08072d63 <__mcount_internal+35>:      je     0x8072d66 <__mcount_internal+38>
0x08072d65 <__mcount_internal+37>:      lock cmpxchg %edx,0x80c4e40
0x08072d6d <__mcount_internal+45>:      test   %eax,%eax
0x08072d6f <__mcount_internal+47>:      jne    0x8072d8b <__mcount_internal+75>
0x08072d71 <__mcount_internal+49>:      mov    %ecx,%eax
0x08072d73 <__mcount_internal+51>:      sub    0x80c4e60,%eax
0x08072d79 <__mcount_internal+57>:      cmp    0x80c4e68,%eax
[...]

Again, the same works fine with etch's libc (2.3.6).

Here are the details for the related packages:

||/ Name                                    Version    
+++-=======================================-===========
ii  binutils                                2.18-1     
ii  gcc                                     4:4.2.1-6  
ii  gcc-3.3                                 1:3.3.6-15 
ii  gcc-3.4                                 3.4.6-6    
ii  gcc-4.0                                 4.0.3-7    
ii  gcc-4.1                                 4.1.2-16   
ii  gcc-4.2                                 4.2.1-5    
ii  libc6-dev                               2.6.1-4    
ii  libc6-prof                              2.6.1-4    


-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.23-rc6
Locale: LANG=en_GB.ISO-8859-15, LC_CTYPE=en_GB.ISO-8859-15 (charmap=ISO-8859-15)
Shell: /bin/sh linked to /bin/bash

Versions of packages libc6-prof depends on:
ii  libc6                         2.6.1-4    GNU C Library: Shared libraries

libc6-prof recommends no packages.

-- no debconf information