glibc/elf/dl-call_fini.c

/* Invoke DT_FINI and DT_FINI_ARRAY callbacks.
   Copyright (C) 1996-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

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

#include <ldsodefs.h>
#include <sysdep.h>

void
_dl_call_fini (void *closure_map)
{
  struct link_map *map = closure_map;

  /* When debugging print a message first.  */
  if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS))
    _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", map->l_name, map->l_ns);

  /* Make sure nothing happens if we are called twice.  */
  map->l_init_called = 0;

  ElfW(Dyn) *fini_array = map->l_info[DT_FINI_ARRAY];
  if (fini_array != NULL)
    {
      ElfW(Addr) *array = (ElfW(Addr) *) (map->l_addr
                                          + fini_array->d_un.d_ptr);
      size_t sz = (map->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
                   / sizeof (ElfW(Addr)));

      while (sz-- > 0)
        ((fini_t) array[sz]) ();
    }

  /* Next try the old-style destructor.  */
  ElfW(Dyn) *fini = map->l_info[DT_FINI];
  if (fini != NULL)
    DL_CALL_DT_FINI (map, ((void *) map->l_addr + fini->d_un.d_ptr));
}