1 /* Close a shared object opened by `_dl_open'.
2 Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
23 #include <bits/libc-lock.h>
24 #include <elf/ldsodefs.h>
25 #include <sys/types.h>
29 /* During the program run we must not modify the global data of
30 loaded shared object simultanously in two threads. Therefore we
31 protect `dlopen' and `dlclose' in dlclose.c. */
32 __libc_lock_define (extern, _dl_load_lock)
34 #define LOSE(s) _dl_signal_error (0, map->l_name, s)
38 _dl_close (struct link_map *map)
40 struct link_map **list;
43 if (map->l_opencount == 0)
44 LOSE ("shared object not open");
46 /* Acquire the lock. */
47 __libc_lock_lock (_dl_load_lock);
49 /* Decrement the reference count. */
50 if (map->l_opencount > 1 || map->l_type != lt_loaded)
52 /* There are still references to this object. Do nothing more. */
54 __libc_lock_unlock (_dl_load_lock);
58 list = map->l_searchlist;
60 /* Call all termination functions at once. */
61 for (i = 0; i < map->l_nsearchlist; ++i)
63 struct link_map *imap = list[i];
64 if (imap->l_opencount == 1 && imap->l_type == lt_loaded)
66 if (imap->l_info[DT_FINI])
67 /* Call its termination function. */
68 (*(void (*) (void)) ((void *) imap->l_addr
69 + imap->l_info[DT_FINI]->d_un.d_ptr)) ();
73 /* Notify the debugger we are about to remove some loaded objects. */
74 _r_debug.r_state = RT_DELETE;
77 /* The search list contains a counted reference to each object it
78 points to, the 0th elt being MAP itself. Decrement the reference
79 counts on all the objects MAP depends on. */
80 for (i = 0; i < map->l_nsearchlist; ++i)
81 --list[i]->l_opencount;
83 /* Check each element of the search list to see if all references to
85 for (i = 0; i < map->l_nsearchlist; ++i)
87 struct link_map *imap = list[i];
88 if (imap->l_opencount == 0 && imap->l_type == lt_loaded)
90 /* That was the last reference, and this was a dlopen-loaded
91 object. We can unmap it. */
93 const ElfW(Phdr) *first, *last;
94 ElfW(Addr) mapstart, mapend;
98 /* This object is in the global scope list. Remove it. */
99 struct link_map **tail = _dl_global_scope_end;
102 while (*tail != imap);
103 while (tail < _dl_global_scope_end)
108 --_dl_global_scope_end;
111 /* We can unmap all the maps at once. We just have to determine
112 the length and the `munmap' call does the rest. */
114 for (ph = imap->l_phdr; ph < imap->l_phdr + imap->l_phnum; ++ph)
115 if (ph->p_type == PT_LOAD)
122 /* Now we have all the information we need for the unmapping.
123 See the method used in `_dl_map_object_from_fd'. */
124 mapstart = first->p_vaddr & ~(first->p_align - 1);
125 mapend = last->p_vaddr + last->p_memsz;
126 __munmap ((caddr_t) (imap->l_addr + mapstart), mapend - mapstart);
128 /* Finally, unlink the data structure and free it. */
130 imap->l_prev->l_next = imap->l_next;
132 imap->l_next->l_prev = imap->l_prev;
133 if (imap->l_searchlist && imap->l_searchlist != list)
134 free (imap->l_searchlist);
141 /* Notify the debugger those objects are finalized and gone. */
142 _r_debug.r_state = RT_CONSISTENT;
145 /* Release the lock. */
146 __libc_lock_unlock (_dl_load_lock);