lib/libc/stdlib/cxa_thread_atexit_impl.c

   1 /*
   2  * Copyright (c) 2019 The DragonFly Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  14  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  15  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  16  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  17  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  23  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/queue.h>
  28 #include "namespace.h"
  29 #include <link.h>
  30 #include <stddef.h>
  31 #include <stdlib.h>
  32 #include <unistd.h>
  33 #include "un-namespace.h"
  34
  35 #include "libc_private.h"
  36
  37 #define DTORS_ITERATIONS        5
  38
  39 struct thread_dtorfn {
  40         void (*func)(void *);
  41         void *arg;
  42         void *dso;
  43         LIST_ENTRY(thread_dtorfn) entry;
  44 };
  45 static __thread LIST_HEAD(dtor_list, thread_dtorfn) dtors =
  46     LIST_HEAD_INITIALIZER(dtors);
  47
  48 int __cxa_thread_atexit_impl(void (*func)(void *), void *arg, void *dso);
  49
  50 void
  51 _thread_finalize(void)
  52 {
  53         struct dl_phdr_info phdr_info;
  54         struct thread_dtorfn *fnp, *tdtor;
  55         int i;
  56
  57         /*
  58          * It is possible to get more destructors registered while
  59          * unregistering them on thread exit.  Use maximum DTORS_ITERATIONS
  60          * loops.  If dso is no longer available (dlclose()), skip it.
  61          */
  62         for (i = 0; i < DTORS_ITERATIONS && !LIST_EMPTY(&dtors); i++) {
  63                 LIST_FOREACH_MUTABLE(fnp, &dtors, entry, tdtor) {
  64                         LIST_REMOVE(fnp, entry);
  65                         if (_rtld_addr_phdr(fnp->dso, &phdr_info) &&
  66                             __elf_phdr_match_addr(&phdr_info, fnp->func))
  67                                 fnp->func(fnp->arg);
  68                         free(fnp);
  69                 }
  70         }
  71 }
  72
  73 int
  74 __cxa_thread_atexit_impl(void (*func)(void *), void *arg, void *dso)
  75 {
  76         struct thread_dtorfn *fnp;
  77
  78         fnp = calloc(1, sizeof(*fnp));
  79         if (fnp == NULL)
  80                 return -1;
  81
  82         fnp->func = func;
  83         fnp->arg = arg;
  84         fnp->dso = dso;
  85         LIST_INSERT_HEAD(&dtors, fnp, entry);
  86
  87         return 0;
  88 }