305 lines
9.0 KiB
C
305 lines
9.0 KiB
C
/* Close a shared object opened by `_dl_open'.
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Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <assert.h>
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#include <dlfcn.h>
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#include <libintl.h>
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#include <stdlib.h>
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#include <string.h>
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#include <bits/libc-lock.h>
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#include <ldsodefs.h>
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#include <sys/types.h>
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#include <sys/mman.h>
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/* Type of the constructor functions. */
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typedef void (*fini_t) (void);
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/* During the program run we must not modify the global data of
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loaded shared object simultanously in two threads. Therefore we
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protect `dlopen' and `dlclose' in dlclose.c. */
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__libc_lock_define (extern, _dl_load_lock)
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void
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internal_function
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_dl_close (void *_map)
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{
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struct reldep_list
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{
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struct link_map **rellist;
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unsigned int nrellist;
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struct reldep_list *next;
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} *reldeps = NULL;
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struct link_map **list;
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struct link_map *map = _map;
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unsigned int i;
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unsigned int *new_opencount;
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/* First see whether we can remove the object at all. */
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if ((map->l_flags_1 & DF_1_NODELETE) && map->l_init_called)
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/* Nope. Do nothing. */
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return;
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if (__builtin_expect (map->l_opencount, 1) == 0)
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_dl_signal_error (0, map->l_name, N_("shared object not open"));
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/* Acquire the lock. */
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__libc_lock_lock (_dl_load_lock);
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/* Decrement the reference count. */
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if (map->l_opencount > 1 || map->l_type != lt_loaded)
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{
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/* There are still references to this object. Do nothing more. */
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if (//__builtin_expect (_dl_debug_files, 0))
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__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0))
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{
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char buf[20];
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buf[sizeof buf - 1] = '\0';
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_dl_debug_printf ("\nclosing file=%s; opencount == %u\n",
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map->l_name, map->l_opencount);
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}
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/* One decrement the object itself, not the dependencies. */
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--map->l_opencount;
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__libc_lock_unlock (_dl_load_lock);
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return;
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}
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list = map->l_initfini;
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/* Compute the new l_opencount values. */
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new_opencount = (unsigned int *) alloca (map->l_searchlist.r_nlist
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* sizeof (unsigned int));
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for (i = 0; list[i] != NULL; ++i)
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{
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list[i]->l_idx = i;
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new_opencount[i] = list[i]->l_opencount;
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}
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--new_opencount[0];
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for (i = 1; list[i] != NULL; ++i)
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if ((! (list[i]->l_flags_1 & DF_1_NODELETE) || ! list[i]->l_init_called)
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/* Decrement counter. */
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&& --new_opencount[i] == 0
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/* Test whether this object was also loaded directly. */
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&& list[i]->l_searchlist.r_list != NULL)
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{
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/* In this case we have the decrement all the dependencies of
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this object. They are all in MAP's dependency list. */
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unsigned int j;
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struct link_map **dep_list = list[i]->l_searchlist.r_list;
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for (j = 1; j < list[i]->l_searchlist.r_nlist; ++j)
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if (! (dep_list[j]->l_flags_1 & DF_1_NODELETE)
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|| ! dep_list[j]->l_init_called)
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{
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assert (dep_list[j]->l_idx < map->l_searchlist.r_nlist);
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--new_opencount[dep_list[j]->l_idx];
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}
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}
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assert (new_opencount[0] == 0);
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/* Call all termination functions at once. */
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for (i = 0; list[i] != NULL; ++i)
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{
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struct link_map *imap = list[i];
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if (new_opencount[i] == 0 && imap->l_type == lt_loaded
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&& (imap->l_info[DT_FINI] || imap->l_info[DT_FINI_ARRAY])
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&& (! (imap->l_flags_1 & DF_1_NODELETE) || ! imap->l_init_called)
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/* Skip any half-cooked objects that were never initialized. */
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&& imap->l_init_called)
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{
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/* When debugging print a message first. */
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if (__builtin_expect (_dl_debug_mask & DL_DEBUG_IMPCALLS, 0))
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_dl_debug_printf ("\ncalling fini: %s\n\n", imap->l_name);
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/* Call its termination function. */
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if (imap->l_info[DT_FINI_ARRAY] != NULL)
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{
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ElfW(Addr) *array =
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(ElfW(Addr) *) (imap->l_addr
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+ imap->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
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unsigned int sz = (imap->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
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/ sizeof (ElfW(Addr)));
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unsigned int cnt;
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for (cnt = 0; cnt < sz; ++cnt)
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((fini_t) (imap->l_addr + array[cnt])) ();
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}
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/* Next try the old-style destructor. */
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if (imap->l_info[DT_FINI] != NULL)
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(*(void (*) (void)) DL_DT_FINI_ADDRESS
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(imap, (void *) imap->l_addr
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+ imap->l_info[DT_FINI]->d_un.d_ptr)) ();
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}
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/* Store the new l_opencount value. */
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imap->l_opencount = new_opencount[i];
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/* Just a sanity check. */
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assert (imap->l_type == lt_loaded || imap->l_opencount > 0);
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}
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/* Notify the debugger we are about to remove some loaded objects. */
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_r_debug.r_state = RT_DELETE;
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_dl_debug_state ();
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/* Check each element of the search list to see if all references to
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it are gone. */
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for (i = 0; list[i] != NULL; ++i)
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{
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struct link_map *imap = list[i];
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if (imap->l_opencount == 0 && imap->l_type == lt_loaded)
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{
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struct libname_list *lnp;
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/* That was the last reference, and this was a dlopen-loaded
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object. We can unmap it. */
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if (__builtin_expect (imap->l_global, 0))
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{
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/* This object is in the global scope list. Remove it. */
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unsigned int cnt = _dl_main_searchlist->r_nlist;
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do
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--cnt;
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while (_dl_main_searchlist->r_list[cnt] != imap);
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/* The object was already correctly registered. */
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while (++cnt < _dl_main_searchlist->r_nlist)
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_dl_main_searchlist->r_list[cnt - 1]
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= _dl_main_searchlist->r_list[cnt];
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--_dl_main_searchlist->r_nlist;
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}
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/* We can unmap all the maps at once. We determined the
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start address and length when we loaded the object and
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the `munmap' call does the rest. */
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DL_UNMAP (imap);
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/* Finally, unlink the data structure and free it. */
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#ifdef SHARED
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/* We will unlink the first object only if this is a statically
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linked program. */
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assert (imap->l_prev != NULL);
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imap->l_prev->l_next = imap->l_next;
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#else
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if (imap->l_prev != NULL)
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imap->l_prev->l_next = imap->l_next;
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else
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_dl_loaded = imap->l_next;
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#endif
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--_dl_nloaded;
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if (imap->l_next)
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imap->l_next->l_prev = imap->l_prev;
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if (imap->l_versions != NULL)
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free (imap->l_versions);
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if (imap->l_origin != NULL && imap->l_origin != (char *) -1)
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free ((char *) imap->l_origin);
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/* If the object has relocation dependencies save this
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information for latter. */
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if (__builtin_expect (imap->l_reldeps != NULL, 0))
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{
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struct reldep_list *newrel;
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newrel = (struct reldep_list *) alloca (sizeof (*reldeps));
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newrel->rellist = imap->l_reldeps;
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newrel->nrellist = imap->l_reldepsact;
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newrel->next = reldeps;
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reldeps = newrel;
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}
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/* This name always is allocated. */
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free (imap->l_name);
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/* Remove the list with all the names of the shared object. */
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lnp = imap->l_libname;
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do
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{
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struct libname_list *this = lnp;
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lnp = lnp->next;
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free (this);
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}
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while (lnp != NULL);
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/* Remove the searchlists. */
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if (imap != map)
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free (imap->l_initfini);
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if (imap->l_phdr_allocated)
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free ((void *) imap->l_phdr);
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if (imap->l_rpath_dirs.dirs != (void *) -1)
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free (imap->l_rpath_dirs.dirs);
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if (imap->l_runpath_dirs.dirs != (void *) -1)
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free (imap->l_runpath_dirs.dirs);
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free (imap);
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}
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}
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/* Notify the debugger those objects are finalized and gone. */
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_r_debug.r_state = RT_CONSISTENT;
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_dl_debug_state ();
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/* Now we can perhaps also remove the modules for which we had
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dependencies because of symbol lookup. */
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while (__builtin_expect (reldeps != NULL, 0))
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{
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while (reldeps->nrellist-- > 0)
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_dl_close (reldeps->rellist[reldeps->nrellist]);
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free (reldeps->rellist);
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reldeps = reldeps->next;
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}
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free (list);
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/* Release the lock. */
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__libc_lock_unlock (_dl_load_lock);
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}
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static void
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free_mem (void)
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{
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if (__builtin_expect (_dl_global_scope_alloc, 0) != 0
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&& _dl_main_searchlist->r_nlist == _dl_initial_searchlist.r_nlist)
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{
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/* All object dynamically loaded by the program are unloaded. Free
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the memory allocated for the global scope variable. */
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struct link_map **old = _dl_main_searchlist->r_list;
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/* Put the old map in. */
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_dl_main_searchlist->r_list = _dl_initial_searchlist.r_list;
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/* Signal that the original map is used. */
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_dl_global_scope_alloc = 0;
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/* Now free the old map. */
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free (old);
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}
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}
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text_set_element (__libc_subfreeres, free_mem);
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