lib/49006: thread specific storage not always initialized to NULL

[tony%develop-help.com@localhost]

>Number:         49006
>Category:       lib
>Synopsis:       thread specific storage not always initialized to NULL
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 17 06:00:00 +0000 2014
>Originator:     Tony Cook
>Release:        6.1.3
>Organization:
>Environment:
NetBSD neso.tony.develop-help.com 6.1.3 NetBSD 6.1.3 (GENERIC) amd64
>Description:
pthread_getspecific() will return non-NULL in some cases in a new thread.

If you:

a) create a key with pthread_key_create() with no desructor, 

b) create a thread which initializes the key to non-NULL,

c) join that thread, and

d) create a new thread,

that new thread will have non-NULL for the key.

>How-To-Repeat:
The output of the test program below should always be "result: 0x0".

neso$ cat pthread-specific.c
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

pthread_key_t key;

int x; /* something to point to */

static void *
thread1(void *p) {
  pthread_setspecific(key, &x);

  return NULL;
}

static void *
thread2(void *p) {
  return pthread_getspecific(key);
}

static void
dest(void *p) { /* do nothing */ }

static void
fail(const char *msg) {
  fprintf(stderr, "%s\n", msg);
  exit(1);
}

int main() {
#ifdef HAVE_DESTRUCTOR
  int rs = pthread_key_create(&key, dest);
#else
  int rs = pthread_key_create(&key, NULL);
#endif
  if (rs)
    fail("pthread_key_create");

  void *result;
#ifndef ONE_THREAD
  pthread_t t1;
  if (pthread_create(&t1, NULL, thread1, NULL))
    fail("pthread_create(t1)");

  if (pthread_join(t1, &result))
    fail("pthread_join(t1)");
#endif

  pthread_t t2;
  if (pthread_create(&t2, NULL, thread2, NULL))
    fail("pthread_create(t2)");

  result = NULL;
  if (pthread_join(t2, &result))
    fail("pthread_join(t2)");

  printf("result: %p\n", result);

  return 0;
}
neso$ gcc -lpthread -opthread-specific pthread-specific.c 
neso$ ./pthread-specific 
result: 0x601508
neso$ gcc -lpthread -opthread-specific pthread-specific.c -DHAVE_DESTRUCTOR
neso$ ./pthread-specific 
result: 0x0
neso$ gcc -lpthread -opthread-specific pthread-specific.c -DONE_THREAD
neso$ ./pthread-specific 
result: 0x0
neso$ uname -a
NetBSD neso.tony.develop-help.com 6.1.3 NetBSD 6.1.3 (GENERIC) amd64

>Fix: