/* Copyright (C) 2002-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <unistd.h>

#include <list.h>

#include <fork.h>

#include <dl-sysdep.h>

#include <tls.h>

#include <string.h>

#include <pthreadP.h>

#include <libc-lock.h>

#include <sysdep.h>

#include <ldsodefs.h>

unsigned long int *__fork_generation_pointer;

#ifdef TLS_MULTIPLE_THREADS_IN_TCB

void

#else

extern int __libc_multiple_threads attribute_hidden;

int *

#endif

__libc_pthread_init (unsigned long int *ptr, void (*reclaim) (void),

		     const struct pthread_functions *functions)

{

  /* Remember the pointer to the generation counter in libpthread.  */

  __fork_generation_pointer = ptr;

  /* Called by a child after fork.  */

  __register_atfork (NULL, NULL, reclaim, NULL);

#ifdef SHARED

  /* Copy the function pointers into an array in libc.  This enables

     access with just one memory reference but moreso, it prevents

     hijacking the function pointers with just one pointer change.  We

     "encrypt" the function pointers since we cannot write-protect the

     array easily enough.  */

  union ptrhack

  {

    struct pthread_functions pf;

# define NPTRS (sizeof (struct pthread_functions) / sizeof (void *))

    void *parr[NPTRS];

  } __attribute__ ((may_alias)) const *src;

  union ptrhack *dest;

  src = (const void *) functions;

  dest = (void *) &__libc_pthread_functions;

  for (size_t cnt = 0; cnt < NPTRS; ++cnt)

    {

      void *p = src->parr[cnt];

      PTR_MANGLE (p);

      dest->parr[cnt] = p;

    }

  __libc_pthread_functions_init = 1;

#endif

#ifndef TLS_MULTIPLE_THREADS_IN_TCB

  return &__libc_multiple_threads;

#endif

}