/* Call the termination functions of loaded shared objects.
- Copyright (C) 1995,96,1998-2002,2004 Free Software Foundation, Inc.
+ Copyright (C) 1995-2018 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
-#include <alloca.h>
#include <assert.h>
#include <string.h>
#include <ldsodefs.h>
void
-internal_function
_dl_fini (void)
{
/* Lots of fun ahead. We have to call the destructors for all still
- loaded objects. 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.
+ 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.
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. */
- unsigned int i;
- struct link_map *l;
- struct link_map **maps;
- /* Protect against concurrent loads and unloads. */
- __rtld_lock_lock_recursive (GL(dl_load_lock));
-
- /* XXX Could it be (in static binaries) that there is no object loaded? */
- assert (GL(dl_nloaded) > 0);
-
- /* Now we can allocate an array to hold all the pointers and copy
- the pointers in. */
- maps = (struct link_map **) alloca (GL(dl_nloaded)
- * sizeof (struct link_map *));
- for (l = GL(dl_loaded), i = 0; l != NULL; l = l->l_next)
- {
- assert (i < GL(dl_nloaded));
-
- maps[i++] = l;
-
- /* Bump l_opencount of all objects so that they are not dlclose()ed
- from underneath us. */
- ++l->l_opencount;
- }
- assert (i == GL(dl_nloaded));
-
- /* Now we have to do the sorting. */
- for (l = GL(dl_loaded)->l_next; l != NULL; l = l->l_next)
+ /* 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)
{
- unsigned int j;
- unsigned int k;
-
- /* Find the place in the 'maps' array. */
- for (j = 1; maps[j] != l; ++j)
- ;
-
- /* Find all object for which the current one is a dependency and
- move the found object (if necessary) in front. */
- for (k = j + 1; k < GL(dl_nloaded); ++k)
+ /* 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
{
- struct link_map **runp = maps[k]->l_initfini;
- if (runp != NULL)
- {
- while (*runp != NULL)
- if (*runp == l)
- {
- struct link_map *here = maps[k];
-
- /* Move it now. */
- memmove (&maps[j] + 1,
- &maps[j],
- (k - j) * sizeof (struct link_map *));
- maps[j++] = here;
-
- break;
- }
- else
- ++runp;
- }
-
- if (__builtin_expect (maps[k]->l_reldeps != NULL, 0))
+ /* 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 + (ns == LM_ID_BASE), nmaps - (ns == LM_ID_BASE),
+ NULL, 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)
{
- unsigned int m = maps[k]->l_reldepsact;
- struct link_map **relmaps = maps[k]->l_reldeps;
+ struct link_map *l = maps[i];
- while (m-- > 0)
+ if (l->l_init_called)
{
- if (relmaps[m] == l)
- {
- struct link_map *here = maps[k];
+ /* Make sure nothing happens if we are called twice. */
+ l->l_init_called = 0;
- /* Move it now. */
- memmove (&maps[j] + 1,
- &maps[j],
- (k - j) * sizeof (struct link_map *));
- maps[j] = here;
+ /* Is there a destructor function? */
+ if (l->l_info[DT_FINI_ARRAY] != NULL
+ || l->l_info[DT_FINI] != NULL)
+ {
+ /* When debugging print a message first. */
+ if (__builtin_expect (GLRO(dl_debug_mask)
+ & DL_DEBUG_IMPCALLS, 0))
+ _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n",
+ DSO_FILENAME (l->l_name),
+ ns);
+
+ /* First see whether an array is given. */
+ if (l->l_info[DT_FINI_ARRAY] != NULL)
+ {
+ ElfW(Addr) *array =
+ (ElfW(Addr) *) (l->l_addr
+ + l->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
+ unsigned int i = (l->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
+ / sizeof (ElfW(Addr)));
+ while (i-- > 0)
+ ((fini_t) array[i]) ();
+ }
+
+ /* Next try the old-style destructor. */
+ if (l->l_info[DT_FINI] != NULL)
+ DL_CALL_DT_FINI
+ (l, l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr);
+ }
- break;
+#ifdef SHARED
+ /* Auditing checkpoint: another object closed. */
+ if (!do_audit && __builtin_expect (GLRO(dl_naudit) > 0, 0))
+ {
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ if (afct->objclose != NULL)
+ /* Return value is ignored. */
+ (void) afct->objclose (&l->l_audit[cnt].cookie);
+
+ afct = afct->next;
+ }
}
+#endif
}
- }
- }
- }
-
- /* '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 < GL(dl_nloaded); ++i)
- {
- l = maps[i];
-
- if (l->l_init_called)
- {
- /* Make sure nothing happens if we are called twice. */
- l->l_init_called = 0;
-
- /* Don't call the destructors for objects we are not supposed to. */
- if (l->l_name[0] == '\0' && l->l_type == lt_executable)
- continue;
- /* Is there a destructor function? */
- if (l->l_info[DT_FINI_ARRAY] == NULL && l->l_info[DT_FINI] == NULL)
- continue;
-
- /* When debugging print a message first. */
- if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
- INTUSE(_dl_debug_printf) ("\ncalling fini: %s\n\n",
- l->l_name[0]
- ? l->l_name : rtld_progname);
-
- /* First see whether an array is given. */
- if (l->l_info[DT_FINI_ARRAY] != NULL)
- {
- ElfW(Addr) *array =
- (ElfW(Addr) *) (l->l_addr
- + l->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
- unsigned int i = (l->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
- / sizeof (ElfW(Addr)));
- while (i-- > 0)
- ((fini_t) array[i]) ();
+ /* Correct the previous increment. */
+ --l->l_direct_opencount;
}
-
- /* Next try the old-style destructor. */
- if (l->l_info[DT_FINI] != NULL)
- ((fini_t) DL_DT_FINI_ADDRESS (l, l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr)) ();
}
-
- /* Correct the previous increment. */
- --l->l_opencount;
}
- __rtld_lock_unlock_recursive (GL(dl_load_lock));
-
- if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
+#ifdef SHARED
+ if (! do_audit && GLRO(dl_naudit) > 0)
{
- INTUSE(_dl_debug_printf) ("\nruntime linker statistics:\n");
- INTUSE(_dl_debug_printf) ("\
- final number of relocations: %lu\n",
- GL(dl_num_relocations));
- INTUSE(_dl_debug_printf) ("\
-final number of relocations from cache: %lu\n",
- GL(dl_num_cache_relocations));
+ 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
}
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