stdlib/cxa_finalize.c

   1 /* Copyright (C) 1999-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  19 #include <stdlib.h>
  20 #include <atomic.h>
  21 #include "exit.h"
  22 #include <fork.h>
  23 #include <sysdep.h>
  24 #include <stdint.h>
  25
  26 /* If D is non-NULL, call all functions registered with `__cxa_atexit'
  27    with the same dso handle.  Otherwise, if D is NULL, call all of the
  28    registered handlers.  */
  29 void
  30 __cxa_finalize (void *d)
  31 {
  32   struct exit_function_list *funcs;
  33
  34  restart:
  35   for (funcs = __exit_funcs; funcs; funcs = funcs->next)
  36     {
  37       struct exit_function *f;
  38
  39       for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f)
  40         {
  41           void (*cxafn) (void *arg, int status);
  42           void *cxaarg;
  43
  44           if ((d == NULL || d == f->func.cxa.dso_handle)
  45               /* We don't want to run this cleanup more than once.  */
  46               && (cxafn = f->func.cxa.fn,
  47                   cxaarg = f->func.cxa.arg,
  48                   ! catomic_compare_and_exchange_bool_acq (&f->flavor, ef_free,
  49                                                            ef_cxa)))
  50             {
  51               uint64_t check = __new_exitfn_called;
  52
  53 #ifdef PTR_DEMANGLE
  54               PTR_DEMANGLE (cxafn);
  55 #endif
  56               cxafn (cxaarg, 0);
  57
  58               /* It is possible that that last exit function registered
  59                  more exit functions.  Start the loop over.  */
  60               if (__glibc_unlikely (check != __new_exitfn_called))
  61                 goto restart;
  62             }
  63         }
  64     }
  65
  66   /* Also remove the quick_exit handlers, but do not call them.  */
  67   for (funcs = __quick_exit_funcs; funcs; funcs = funcs->next)
  68     {
  69       struct exit_function *f;
  70
  71       for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f)
  72         if (d == NULL || d == f->func.cxa.dso_handle)
  73           f->flavor = ef_free;
  74     }
  75
  76   /* Remove the registered fork handlers.  We do not have to
  77      unregister anything if the program is going to terminate anyway.  */
  78 #ifdef UNREGISTER_ATFORK
  79   if (d != NULL)
  80     UNREGISTER_ATFORK (d);
  81 #endif
  82 }