malloc/set-freeres.c

   1 /* Copyright (C) 1997-2021 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <atomic.h>
  19 #include <stdlib.h>
  20 #include <set-hooks.h>
  21 #include <libc-internal.h>
  22 #include <unwind-link.h>
  23 #include <dlfcn/dlerror.h>
  24
  25 #include "../nss/nsswitch.h"
  26 #include "../libio/libioP.h"
  27
  28 DEFINE_HOOK (__libc_subfreeres, (void));
  29
  30 symbol_set_define (__libc_freeres_ptrs);
  31
  32 extern void __libpthread_freeres (void)
  33 #if PTHREAD_IN_LIBC && defined SHARED
  34 /* It is possible to call __libpthread_freeres directly in shared
  35    builds with an integrated libpthread.  */
  36   attribute_hidden
  37 #else
  38   __attribute__ ((weak))
  39 #endif
  40   ;
  41
  42 void __libc_freeres_fn_section
  43 __libc_freeres (void)
  44 {
  45   /* This function might be called from different places.  So better
  46      protect for multiple executions since these are fatal.  */
  47   static long int already_called;
  48
  49   if (!atomic_compare_and_exchange_bool_acq (&already_called, 1, 0))
  50     {
  51       void *const *p;
  52
  53       call_function_static_weak (__nss_module_freeres);
  54       call_function_static_weak (__nss_action_freeres);
  55       call_function_static_weak (__nss_database_freeres);
  56
  57       _IO_cleanup ();
  58
  59       /* We run the resource freeing after IO cleanup.  */
  60       RUN_HOOK (__libc_subfreeres, ());
  61
  62       call_function_static_weak (__libpthread_freeres);
  63
  64 #ifdef SHARED
  65       __libc_unwind_link_freeres ();
  66 #endif
  67
  68       call_function_static_weak (__libc_dlerror_result_free);
  69
  70       for (p = symbol_set_first_element (__libc_freeres_ptrs);
  71            !symbol_set_end_p (__libc_freeres_ptrs, p); ++p)
  72         free (*p);
  73     }
  74 }
  75 libc_hidden_def (__libc_freeres)