Bug#253303: libc6 nptl cond wait and cacelation bug

[Lukas Hejtmanek <xhejtman@mail.muni.cz>]

Package: libc6
Version: 2.3.2.ds1-13

See attached program. It hangs with kernel 2.6.7-rc2. According to this link it
depends on bug in glibc:
http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=108631
Debian glibc is poisioned too still.

-- 
Lukáš Hejtmánek


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

static pthread_mutex_t gbl_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t  gbl_condv = PTHREAD_COND_INITIALIZER;

void waitThread_cleanup(void *arg)
{
  int rc;

  rc = pthread_mutex_unlock(&gbl_mutex);
  assert(rc == 0);

  return;
}

void * waitThread(void *arg)
{
  int rc;

  pthread_cleanup_push(waitThread_cleanup, NULL);

  rc = pthread_mutex_lock(&gbl_mutex);
 assert(rc == 0);

  /* wait until this thread is canceled */

  while (1 == 1) {
    rc = pthread_cond_wait(&gbl_condv, &gbl_mutex);
    assert(rc == 0);
  }

  /* this routine never reaches this point */

  rc = pthread_mutex_unlock(&gbl_mutex);
  assert(rc == 0);

  pthread_cleanup_pop(0);

  return NULL;
}

main (int argc, char *argv[])
{
  int i, rc;
  pthread_t wait_tid;

  for (i = 0; i < 1000000; i++)
    {
      fprintf(stderr, "loop %d
", i);

      rc = pthread_create(&wait_tid, NULL, waitThread, NULL);
      assert(rc == 0);

      rc = pthread_cancel(wait_tid);
      assert(rc == 0);

      rc = pthread_join(wait_tid, NULL);
      assert(rc == 0);
    }

  return;
}