/* Call the termination functions of loaded shared objects.
-Copyright (C) 1995 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+ Copyright (C) 1995-2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA. */
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
-#include <link.h>
+#include <assert.h>
+#include <string.h>
+#include <ldsodefs.h>
+#include <elf-initfini.h>
void
_dl_fini (void)
{
- struct link_map *l;
+ /* Lots of fun ahead. We have to call the destructors for all still
+ loaded objects, in all namespaces. The problem is that the ELF
+ specification now demands that dependencies between the modules
+ are taken into account. I.e., the destructor for a module is
+ called before the ones for any of its dependencies.
- for (l = _dl_loaded; l; l = l->l_next)
- if (l->l_init_called && l->l_info[DT_FINI])
- (*(void (*) (void)) (l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr)) ();
+ To make things more complicated, we cannot simply use the reverse
+ order of the constructors. Since the user might have loaded objects
+ using `dlopen' there are possibly several other modules with its
+ dependencies to be taken into account. Therefore we have to start
+ determining the order of the modules once again from the beginning. */
+
+ /* We run the destructors of the main namespaces last. As for the
+ other namespaces, we pick run the destructors in them in reverse
+ order of the namespace ID. */
+#ifdef SHARED
+ int do_audit = 0;
+ again:
+#endif
+ for (Lmid_t ns = GL(dl_nns) - 1; ns >= 0; --ns)
+ {
+ /* Protect against concurrent loads and unloads. */
+ __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+ unsigned int nloaded = GL(dl_ns)[ns]._ns_nloaded;
+ /* No need to do anything for empty namespaces or those used for
+ auditing DSOs. */
+ if (nloaded == 0
+#ifdef SHARED
+ || GL(dl_ns)[ns]._ns_loaded->l_auditing != do_audit
+#endif
+ )
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ else
+ {
+#ifdef SHARED
+ _dl_audit_activity_nsid (ns, LA_ACT_DELETE);
+#endif
+
+ /* Now we can allocate an array to hold all the pointers and
+ copy the pointers in. */
+ struct link_map *maps[nloaded];
+
+ unsigned int i;
+ struct link_map *l;
+ assert (nloaded != 0 || GL(dl_ns)[ns]._ns_loaded == NULL);
+ for (l = GL(dl_ns)[ns]._ns_loaded, i = 0; l != NULL; l = l->l_next)
+ /* Do not handle ld.so in secondary namespaces. */
+ if (l == l->l_real)
+ {
+ assert (i < nloaded);
+
+ maps[i] = l;
+ l->l_idx = i;
+ ++i;
+
+ /* Bump l_direct_opencount of all objects so that they
+ are not dlclose()ed from underneath us. */
+ ++l->l_direct_opencount;
+ }
+ assert (ns != LM_ID_BASE || i == nloaded);
+ assert (ns == LM_ID_BASE || i == nloaded || i == nloaded - 1);
+ unsigned int nmaps = i;
+
+ /* Now we have to do the sorting. We can skip looking for the
+ binary itself which is at the front of the search list for
+ the main namespace. */
+ _dl_sort_maps (maps, nmaps, (ns == LM_ID_BASE), true);
+
+ /* We do not rely on the linked list of loaded object anymore
+ from this point on. We have our own list here (maps). The
+ various members of this list cannot vanish since the open
+ count is too high and will be decremented in this loop. So
+ we release the lock so that some code which might be called
+ from a destructor can directly or indirectly access the
+ lock. */
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+ /* 'maps' now contains the objects in the right order. Now
+ call the destructors. We have to process this array from
+ the front. */
+ for (i = 0; i < nmaps; ++i)
+ {
+ struct link_map *l = maps[i];
+
+ if (l->l_init_called)
+ {
+ _dl_call_fini (l);
+#ifdef SHARED
+ /* Auditing checkpoint: another object closed. */
+ _dl_audit_objclose (l);
+#endif
+ }
+
+ /* Correct the previous increment. */
+ --l->l_direct_opencount;
+ }
+
+#ifdef SHARED
+ _dl_audit_activity_nsid (ns, LA_ACT_CONSISTENT);
+#endif
+ }
+ }
+
+#ifdef SHARED
+ if (! do_audit && GLRO(dl_naudit) > 0)
+ {
+ do_audit = 1;
+ goto again;
+ }
+
+ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS))
+ _dl_debug_printf ("\nruntime linker statistics:\n"
+ " final number of relocations: %lu\n"
+ "final number of relocations from cache: %lu\n",
+ GL(dl_num_relocations),
+ GL(dl_num_cache_relocations));
+#endif
}
projects / thirdparty / glibc.git / blobdiff