Bug#292154: NPTL: pthread_create has a race condition

[Vincent Danjean <Vincent.Danjean@ens-lyon.org>]

Package: libc6
Version: 2.3.2.ds1-20
Severity: normal


NPTL as included in debian has a race condition with pthread_create and
pthread_exit. The program in attachment exposes the race : the main
thread exits with pthread_exit and the whole program exits whereas there
is yet another thread.
 
Please, consider applying the fix already present upstream
Extract of the relevant part of the upstream Changelog :
2004-11-09  Roland McGrath  <roland@redhat.com>

        [BZ #530]
        * sysdeps/pthread/createthread.c (do_clone): Increment __nptl_nthreads
        here, before calling clone.
        * pthread_create.c (start_thread): Don't do it here.

  Best regards,
    Vincent

-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.4-fkt
Locale: LANG=C, LC_CTYPE=fr_FR@euro

Versions of packages libc6 depends on:
ii  libdb1-compat                 2.1.3-7    The Berkeley database routines [gl

-- no debconf information

#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <assert.h>

#define FOREVER for(;;) 

static void* thread(void*); 

int
main()
{
  pthread_t tid;
  int       status;

  status = pthread_create (&tid, NULL, thread, NULL);
  assert (status==0);
  status = pthread_detach (tid); 
  assert (status==0);
  /* sleep (1); */
  pthread_exit (NULL); 
}

void*
thread(void* unused) 
{
  FOREVER {
    fprintf (stderr,"a");
    sleep(3);
  }
}