diff options
Diffstat (limited to 'elf/dl-fini.c')
| -rw-r--r-- | elf/dl-fini.c | 281 |
1 files changed, 0 insertions, 281 deletions
diff --git a/elf/dl-fini.c b/elf/dl-fini.c deleted file mode 100644 index 93b337bea1..0000000000 --- a/elf/dl-fini.c +++ /dev/null @@ -1,281 +0,0 @@ -/* Call the termination functions of loaded shared objects. - Copyright (C) 1995-2017 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 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 - 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, see - <http://www.gnu.org/licenses/>. */ - -#include <assert.h> -#include <string.h> -#include <ldsodefs.h> - - -/* Type of the constructor functions. */ -typedef void (*fini_t) (void); - - -void -internal_function -_dl_sort_fini (struct link_map **maps, size_t nmaps, char *used, Lmid_t ns) -{ - /* A list of one element need not be sorted. */ - if (nmaps == 1) - return; - - /* We can skip looking for the binary itself which is at the front - of the search list for the main namespace. */ - unsigned int i = ns == LM_ID_BASE; - uint16_t seen[nmaps]; - memset (seen, 0, nmaps * sizeof (seen[0])); - while (1) - { - /* Keep track of which object we looked at this round. */ - ++seen[i]; - struct link_map *thisp = maps[i]; - - /* Do not handle ld.so in secondary namespaces and object which - are not removed. */ - if (thisp != thisp->l_real || thisp->l_idx == -1) - goto skip; - - /* Find the last object in the list for which the current one is - a dependency and move the current object behind the object - with the dependency. */ - unsigned int k = nmaps - 1; - while (k > i) - { - struct link_map **runp = maps[k]->l_initfini; - if (runp != NULL) - /* Look through the dependencies of the object. */ - while (*runp != NULL) - if (__glibc_unlikely (*runp++ == thisp)) - { - move: - /* Move the current object to the back past the last - object with it as the dependency. */ - memmove (&maps[i], &maps[i + 1], - (k - i) * sizeof (maps[0])); - maps[k] = thisp; - - if (used != NULL) - { - char here_used = used[i]; - memmove (&used[i], &used[i + 1], - (k - i) * sizeof (used[0])); - used[k] = here_used; - } - - if (seen[i + 1] > nmaps - i) - { - ++i; - goto next_clear; - } - - uint16_t this_seen = seen[i]; - memmove (&seen[i], &seen[i + 1], (k - i) * sizeof (seen[0])); - seen[k] = this_seen; - - goto next; - } - - if (__glibc_unlikely (maps[k]->l_reldeps != NULL)) - { - unsigned int m = maps[k]->l_reldeps->act; - struct link_map **relmaps = &maps[k]->l_reldeps->list[0]; - - /* Look through the relocation dependencies of the object. */ - while (m-- > 0) - if (__glibc_unlikely (relmaps[m] == thisp)) - { - /* If a cycle exists with a link time dependency, - preserve the latter. */ - struct link_map **runp = thisp->l_initfini; - if (runp != NULL) - while (*runp != NULL) - if (__glibc_unlikely (*runp++ == maps[k])) - goto ignore; - goto move; - } - ignore:; - } - - --k; - } - - skip: - if (++i == nmaps) - break; - next_clear: - memset (&seen[i], 0, (nmaps - i) * sizeof (seen[0])); - - next:; - } -} - - -void -internal_function -_dl_fini (void) -{ - /* 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. - - 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 - { - /* 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. */ - _dl_sort_fini (maps, nmaps, NULL, ns); - - /* 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) - { - /* Make sure nothing happens if we are called twice. */ - l->l_init_called = 0; - - /* 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); - } - -#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 - } - - /* Correct the previous increment. */ - --l->l_direct_opencount; - } - } - } - -#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 -} |