diff options
Diffstat (limited to 'elf/dl-close.c')
| -rw-r--r-- | elf/dl-close.c | 113 |
1 files changed, 72 insertions, 41 deletions
diff --git a/elf/dl-close.c b/elf/dl-close.c index 1c7a861db1..c9a7d06577 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -138,30 +138,31 @@ _dl_close_worker (struct link_map *map, bool force) bool any_tls = false; const unsigned int nloaded = ns->_ns_nloaded; - struct link_map *maps[nloaded]; - /* Run over the list and assign indexes to the link maps and enter - them into the MAPS array. */ + /* Run over the list and assign indexes to the link maps. */ int idx = 0; for (struct link_map *l = ns->_ns_loaded; l != NULL; l = l->l_next) { l->l_map_used = 0; l->l_map_done = 0; l->l_idx = idx; - maps[idx] = l; ++idx; } assert (idx == nloaded); - /* Keep track of the lowest index link map we have covered already. */ - int done_index = -1; - while (++done_index < nloaded) + /* Keep marking link maps until no new link maps are found. */ + for (struct link_map *l = ns->_ns_loaded; l != NULL; ) { - struct link_map *l = maps[done_index]; + /* next is reset to earlier link maps for remarking. */ + struct link_map *next = l->l_next; + int next_idx = l->l_idx + 1; /* next->l_idx, but covers next == NULL. */ if (l->l_map_done) - /* Already handled. */ - continue; + { + /* Already handled. */ + l = next; + continue; + } /* Check whether this object is still used. */ if (l->l_type == lt_loaded @@ -171,7 +172,10 @@ _dl_close_worker (struct link_map *map, bool force) acquire is sufficient and correct. */ && atomic_load_acquire (&l->l_tls_dtor_count) == 0 && !l->l_map_used) - continue; + { + l = next; + continue; + } /* We need this object and we handle it now. */ l->l_map_used = 1; @@ -198,8 +202,11 @@ _dl_close_worker (struct link_map *map, bool force) already processed it, then we need to go back and process again from that point forward to ensure we keep all of its dependencies also. */ - if ((*lp)->l_idx - 1 < done_index) - done_index = (*lp)->l_idx - 1; + if ((*lp)->l_idx < next_idx) + { + next = *lp; + next_idx = next->l_idx; + } } } @@ -219,44 +226,65 @@ _dl_close_worker (struct link_map *map, bool force) if (!jmap->l_map_used) { jmap->l_map_used = 1; - if (jmap->l_idx - 1 < done_index) - done_index = jmap->l_idx - 1; + if (jmap->l_idx < next_idx) + { + next = jmap; + next_idx = next->l_idx; + } } } } - } - /* Sort the entries. 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, nloaded, (nsid == LM_ID_BASE), true); + l = next; + } - /* Call all termination functions at once. */ - bool unload_any = false; - bool scope_mem_left = false; - unsigned int unload_global = 0; - unsigned int first_loaded = ~0; - for (unsigned int i = 0; i < nloaded; ++i) + /* Call the destructors in reverse constructor order, and remove the + closed link maps from the list. */ + for (struct link_map **init_called_head = &_dl_init_called_list; + *init_called_head != NULL; ) { - struct link_map *imap = maps[i]; + struct link_map *imap = *init_called_head; - /* All elements must be in the same namespace. */ - assert (imap->l_ns == nsid); - - if (!imap->l_map_used) + /* _dl_init_called_list is global, to produce a global odering. + Ignore the other namespaces (and link maps that are still used). */ + if (imap->l_ns != nsid || imap->l_map_used) + init_called_head = &imap->l_init_called_next; + else { assert (imap->l_type == lt_loaded && !imap->l_nodelete_active); - /* Call its termination function. Do not do it for - half-cooked objects. Temporarily disable exception - handling, so that errors are fatal. */ - if (imap->l_init_called) + /* _dl_init_called_list is updated at the same time as + l_init_called. */ + assert (imap->l_init_called); + + if (imap->l_info[DT_FINI_ARRAY] != NULL + || imap->l_info[DT_FINI] != NULL) _dl_catch_exception (NULL, _dl_call_fini, imap); #ifdef SHARED /* Auditing checkpoint: we remove an object. */ _dl_audit_objclose (imap); #endif + /* Unlink this link map. */ + *init_called_head = imap->l_init_called_next; + } + } + + + bool unload_any = false; + bool scope_mem_left = false; + unsigned int unload_global = 0; + + /* For skipping un-unloadable link maps in the second loop. */ + struct link_map *first_loaded = ns->_ns_loaded; + /* Iterate over the namespace to find objects to unload. Some + unloadable objects may not be on _dl_init_called_list due to + dlopen failure. */ + for (struct link_map *imap = first_loaded; imap != NULL; imap = imap->l_next) + { + if (!imap->l_map_used) + { /* This object must not be used anymore. */ imap->l_removed = 1; @@ -267,8 +295,8 @@ _dl_close_worker (struct link_map *map, bool force) ++unload_global; /* Remember where the first dynamically loaded object is. */ - if (i < first_loaded) - first_loaded = i; + if (first_loaded == NULL) + first_loaded = imap; } /* Else imap->l_map_used. */ else if (imap->l_type == lt_loaded) @@ -404,8 +432,8 @@ _dl_close_worker (struct link_map *map, bool force) imap->l_loader = NULL; /* Remember where the first dynamically loaded object is. */ - if (i < first_loaded) - first_loaded = i; + if (first_loaded == NULL) + first_loaded = imap; } } @@ -476,10 +504,11 @@ _dl_close_worker (struct link_map *map, bool force) /* Check each element of the search list to see if all references to it are gone. */ - for (unsigned int i = first_loaded; i < nloaded; ++i) + for (struct link_map *imap = first_loaded; imap != NULL; ) { - struct link_map *imap = maps[i]; - if (!imap->l_map_used) + if (imap->l_map_used) + imap = imap->l_next; + else { assert (imap->l_type == lt_loaded); @@ -690,7 +719,9 @@ _dl_close_worker (struct link_map *map, bool force) if (imap == GL(dl_initfirst)) GL(dl_initfirst) = NULL; + struct link_map *next = imap->l_next; free (imap); + imap = next; } } |