Bug#272219: Valgrind bug probably due to libc6

[Claus Fischer <claus.fischer@clausfischer.com>]

Package: libc6
Version: 2.3.2.ds1-16


Valgrind problem on most recent Sarge (18 Sep 2004).
====================================================

I'm not completely sure whether the bug is due to libc6,
but that's my best guess.

A rather large program of mine, when compiled and run with
valgrind on the latest sarge, gets a SIGSEGV signal:

$ valgrind ./eisclient 
==2714== Memcheck, a memory error detector for x86-linux.
==2714== Copyright (C) 2002-2004, and GNU GPL'd, by Julian Seward et al.
==2714== Using valgrind-2.2.0, a program supervision framework for x86-linux.
==2714== Copyright (C) 2000-2004, and GNU GPL'd, by Julian Seward et al.
==2714== For more details, rerun with: -v
==2714== 
==2714== 
==2714== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==2714==    at 0x1B8EA23C: _dl_map_object (in /lib/ld-2.3.2.so)
==2714==    by 0x1B8EEA18: (within /lib/ld-2.3.2.so)
==2714==    by 0x1B8EFF25: _dl_catch_error (in /lib/ld-2.3.2.so)
==2714==    by 0x1B8EF490: _dl_map_object_deps (in /lib/ld-2.3.2.so)
==2714== 
==2714== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
==2714== malloc/free: in use at exit: 0 bytes in 0 blocks.
==2714== malloc/free: 0 allocs, 0 frees, 0 bytes allocated.
==2714== For a detailed leak analysis,  rerun with: --leak-check=yes
==2714== For counts of detected errors, rerun with: -v
Segmentation fault
$ ldd eisclient
        libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x40026000)
        libm.so.6 => /lib/libm.so.6 (0x400e0000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x40102000)
        libc.so.6 => /lib/libc.so.6 (0x4010c000)
        /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)


The same binary runs fine with valgrind on a slightly older Sarge,
without the SIGSEGV. With the same /usr/bin/valgrind.bin, the only
apparent difference is in the libc packages:
2.3.2.ds1-16 triggers the bug, 2.3.2.ds1-13 doesn't.



I found a small program to trigger the same bug on the Internet:
    #include <dlfcn.h>
    
    int main( int argc, char* argv[] )
    {
        void *handle;
        handle = dlopen( argv[1], RTLD_LAZY );
        dlclose( handle );
    }
Compile with g++ -o main main.c -ldl, then run with valgrind.
The error messages are identical to above, even the addresses
reported by valgrind are the same.


I have put my binary of this small program on a website
http://www.clausfischer.com/valgrind-bug in order to exclude
influence of different compilers.

The problem exists both with valgrind versions 2.1.2-2 and
2.2.0-2.

-- 
Claus Fischer <claus.fischer@clausfischer.com>
http://www.clausfischer.com/