pthread_create hangs when both app & shlib linked against -lpthread

[Erland Lewin]

I have a bug related to linking and pthreads under glibc-2.2.2 and Linux 
(2.4.19-pre56). gcc version 3.0.2, gcc thread model: posix.

I create a shared library, which I link against -lpthread. I then create 
an application which I link against both the shared library and 
-lpthread. When the application calls pthread_create, it will hang 
because the thread manager thread segfaults. I havn't managed to debug 
why the thread manager thread segfaults, gdb doesn't seem to want to 
step into the thread manager init function.

If I remember correctly, one should link with the shared libraries at 
all times to make sure the symbol-versioning works correctly, right?

Find attached a minimal case. When you run testapp.c it will freeze. If 
testapp.c isn't linked agains libpthread, it will not hang.

Please cc: replies to me directly with any comments or advice, since I 
don't subscribe to bug-glibc.

I'm sending this mail to those who seem to be maintaining linuxthreads, 
forgive me if I sent it too indiscriminately.

 Thanks for any help!

   Erland Lewin

LOADLIBES = -lpthread
CFLAGS = -g
LDFLAGS = -L.

all: libtestlib.so testapp

libtestlib.so: testlib.o
        $(LD) -shared testlib.o -lpthread -o libtestlib.so

testapp: testapp.o libtestlib.so
        $(CC) -L. testapp.o -lpthread -ltestlib -o testapp

/*
 * testapp
 *
 * To test behaviour with linking of pthread
 */

#include <assert.h>
#include <stdio.h>
#include <pthread.h>
#include "testlib.h"

static void *threadFunc( void *args );

int main( int argc, char **argv )
{
  int err;
  pthread_t thread;
  
  fprintf( stderr, "initializing testlib.\n" );
  testlib_init();
  
  fprintf( stderr, "testlib initialized, creating thread.\n" );
  
  err = pthread_create( &thread, NULL, threadFunc, NULL );
  assert( err == 0 );
  
  fprintf( stderr, "thread created, joining...\n" );
  
  pthread_join( thread, NULL );
  
  fprintf( stderr, "thread joined, finished.\n" );
  
  return 0;
}

static void *threadFunc( void *args )
{
  return args;
}

/*
  testlib.h
*/

void testlib_init();

/*
 * Test library
 */

void testlib_init()
{
}