lib/52386: pthread(3) doesn't respect PTHREAD_DESTRUCTOR_ITERATIONS

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>Number:         52386
>Category:       lib
>Synopsis:       pthread(3) doesn't respect PTHREAD_DESTRUCTOR_ITERATIONS
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jul 09 15:30:00 +0000 2017
>Originator:     Kamil Rytarowski
>Release:        NetBSD 8.99.1 amd64
>Organization:
TNF
>Environment:
NetBSD chieftec 8.99.1 NetBSD 8.99.1 (GENERIC) #5: Sat Jul  1 17:48:34 CEST 2017  root@chieftec:/public/netbsd-root/sys/arch/amd64/compile/GENERIC amd64
>Description:
PTHREAD_DESTRUCTOR_ITERATIONS is not respected as the maximum number of destructor iterations.

This has been caught by LLVM sanitizer tests. This breaks two tests.

compiler-rt/lib/sanitizer_common/tests/sanitizer_posix_test.cc

    SanitizerCommon-Unit :: ./Sanitizer-i386-Test/SanitizerCommon.PthreadDestructorIterations
    SanitizerCommon-Unit :: ./Sanitizer-x86_64-Test/SanitizerCommon.PthreadDestructorIterations
>How-To-Repeat:
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <pthread.h>
#include <limits.h>

static pthread_key_t key;
static bool destructor_executed;

void
destructor(void *arg)
{
  uintptr_t iter = (uintptr_t)arg;
  if (iter > 1) {
    assert(0 == pthread_setspecific(key, (void*)(uintptr_t)(iter - 1)));
    return;
  }
  destructor_executed = true;
}

void *
thread_func(void *arg)
{
  return (void*)(uintptr_t)pthread_setspecific(key, arg);
}

static void
SpawnThread(int iteration)
{
  destructor_executed = false;
  pthread_t tid;
  assert(0 == pthread_create(&tid, 0, thread_func, (void *)(uintptr_t)(iteration)));
  void *retval;               
  assert(0 == pthread_join(tid, &retval));
  assert(0 == retval);
}


int
main(int argc, char **argv)
{
	pthread_key_create(&key, destructor);
	SpawnThread(PTHREAD_DESTRUCTOR_ITERATIONS);
	assert(destructor_executed == true);
	SpawnThread(PTHREAD_DESTRUCTOR_ITERATIONS + 1);
	assert(destructor_executed == false);
	assert(0 == pthread_key_delete(key));

	return 0;
}

>Fix:
N/A