diff options
Diffstat (limited to 'elf/dl-close.c')
| -rw-r--r-- | elf/dl-close.c | 349 |
1 files changed, 139 insertions, 210 deletions
diff --git a/elf/dl-close.c b/elf/dl-close.c index 6681c5d3e7..51b958dfa7 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -102,19 +102,9 @@ remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, void _dl_close (void *_map) { - struct reldep_list - { - struct link_map **rellist; - unsigned int nrellist; - unsigned int nhandled; - struct reldep_list *next; - bool handled[0]; - } *reldeps = NULL; - struct link_map **list; struct link_map *map = _map; Lmid_t ns = map->l_ns; unsigned int i; - unsigned int *new_opencount; #ifdef USE_TLS bool any_tls = false; #endif @@ -125,160 +115,127 @@ _dl_close (void *_map) /* Nope. Do nothing. */ return; - if (__builtin_expect (map->l_opencount, 1) == 0) + if (__builtin_expect (map->l_direct_opencount, 1) == 0) GLRO(dl_signal_error) (0, map->l_name, NULL, N_("shared object not open")); /* Acquire the lock. */ __rtld_lock_lock_recursive (GL(dl_load_lock)); /* One less direct use. */ - assert (map->l_direct_opencount > 0); --map->l_direct_opencount; /* Decrement the reference count. */ - if (map->l_opencount > 1 || map->l_type != lt_loaded) + if (map->l_direct_opencount > 1 || map->l_type != lt_loaded) { - /* Decrement the object's reference counter, not the dependencies'. */ - --map->l_opencount; - /* There are still references to this object. Do nothing more. */ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)) - _dl_debug_printf ("\nclosing file=%s; opencount=%u\n", - map->l_name, map->l_opencount); - - /* If the direct use counter reaches zero we have to decrement - all the dependencies' usage counter. */ - if (map->l_direct_opencount == 0) - for (i = 1; i < map->l_searchlist.r_nlist; ++i) - --map->l_searchlist.r_list[i]->l_opencount; + _dl_debug_printf ("\nclosing file=%s; direct_opencount=%u\n", + map->l_name, map->l_direct_opencount); __rtld_lock_unlock_recursive (GL(dl_load_lock)); return; } - list = map->l_initfini; - - /* Compute the new l_opencount values. */ - i = map->l_searchlist.r_nlist; - if (__builtin_expect (i == 0, 0)) - /* This can happen if we handle relocation dependencies for an - object which wasn't loaded directly. */ - for (i = 1; list[i] != NULL; ++i) - ; +#define NWORDS(n) (((n) + 8 * sizeof (unsigned long int) - 1) \ + / (sizeof (unsigned long int))) +#define SETBIT(a, n) a[(n) / sizeof (unsigned long int)] \ + |= 1 << ((n) % (sizeof (unsigned long int))) +#define ISSET(a, n) (a[(n) / sizeof (unsigned long int)] \ + & 1 << ((n) % (sizeof (unsigned long int)))) + const unsigned int nloaded = GL(dl_ns)[ns]._ns_nloaded; + unsigned long int used[NWORDS (nloaded)]; + unsigned long int done[NWORDS (nloaded)]; + struct link_map *maps[nloaded]; + + /* Run over the list and assign indeces to the link maps and enter + them into the MAPS array. */ + int idx = 0; + for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL; l = l->l_next) + { + l->l_idx = idx; + maps[idx] = l; + ++idx; + } + assert (idx == nloaded); - unsigned int nopencount = i; - new_opencount = (unsigned int *) alloca (i * sizeof (unsigned int)); + /* Prepare the bitmaps. */ + memset (used, '\0', sizeof (used)); + memset (done, '\0', sizeof (done)); - for (i = 0; list[i] != NULL; ++i) + /* Keep track of the lowest index link map we have covered already. */ + int done_index = -1; + while (++done_index < nloaded) { - list[i]->l_idx = i; - new_opencount[i] = list[i]->l_opencount; - } - --new_opencount[0]; - for (i = 1; list[i] != NULL; ++i) - if ((list[i]->l_flags_1 & DF_1_NODELETE) == 0 - /* Decrement counter. */ - && (assert (new_opencount[i] > 0), --new_opencount[i] == 0)) - { - void mark_removed (struct link_map *remmap) - { - /* Test whether this object was also loaded directly. */ - if (remmap->l_searchlist.r_list != NULL - && remmap->l_direct_opencount > 0) - { - /* In this case we have to decrement all the dependencies of - this object. They are all in MAP's dependency list. */ - unsigned int j; - struct link_map **dep_list = remmap->l_searchlist.r_list; - - for (j = 1; j < remmap->l_searchlist.r_nlist; ++j) - if (! (dep_list[j]->l_flags_1 & DF_1_NODELETE) - || ! dep_list[j]->l_init_called) + struct link_map *l = maps[done_index]; + + if (ISSET (done, done_index)) + /* Already handled. */ + continue; + + /* Check whether this object is still used. */ + if (l->l_type == lt_loaded + && l->l_direct_opencount == 0 + && (l->l_flags_1 & DF_1_NODELETE) == 0 + && !ISSET (used, done_index)) + continue; + + /* We need this object and we handle it now. */ + SETBIT (done, done_index); + SETBIT (used, done_index); + + /* Mark all dependencies as used. */ + if (l->l_initfini != NULL) + { + struct link_map **lp = &l->l_initfini[1]; + while (*lp != NULL) + { + assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded); + + if (!ISSET (used, (*lp)->l_idx)) { - assert (dep_list[j]->l_idx < map->l_searchlist.r_nlist); - assert (new_opencount[dep_list[j]->l_idx] > 0); - if (--new_opencount[dep_list[j]->l_idx] == 0) - { - assert (dep_list[j]->l_type == lt_loaded); - mark_removed (dep_list[j]); - } + SETBIT (used, (*lp)->l_idx); + if ((*lp)->l_idx - 1 < done_index) + done_index = (*lp)->l_idx - 1; } - } - if (remmap->l_reldeps != NULL) + ++lp; + } + } + /* And the same for relocation dependencies. */ + if (l->l_reldeps != NULL) + for (unsigned int j = 0; j < l->l_reldepsact; ++j) + { + struct link_map *jmap = l->l_reldeps[j]; + + assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded); + + if (!ISSET (used, jmap->l_idx)) { - unsigned int j; - for (j = 0; j < remmap->l_reldepsact; ++j) - { - struct link_map *depmap = remmap->l_reldeps[j]; - - /* Find out whether this object is in our list. */ - if (depmap->l_idx < nopencount - && list[depmap->l_idx] == depmap) - { - /* Yes, it is. If is has a search list, make a - recursive call to handle this. */ - if (depmap->l_searchlist.r_list != NULL) - { - assert (new_opencount[depmap->l_idx] > 0); - if (--new_opencount[depmap->l_idx] == 0) - { - /* This one is now gone, too. */ - assert (depmap->l_type == lt_loaded); - mark_removed (depmap); - } - } - else - { - /* Otherwise we have to handle the dependency - deallocation here. */ - unsigned int k; - for (k = 0; depmap->l_initfini[k] != NULL; ++k) - { - struct link_map *rl = depmap->l_initfini[k]; - - if (rl->l_idx < nopencount - && list[rl->l_idx] == rl) - { - assert (new_opencount[rl->l_idx] > 0); - if (--new_opencount[rl->l_idx] == 0) - { - /* Another module to remove. */ - assert (rl->l_type == lt_loaded); - mark_removed (rl); - } - } - else - { - assert (rl->l_opencount > 0); - if (--rl->l_opencount == 0) - mark_removed (rl); - } - } - } - } - } + SETBIT (used, jmap->l_idx); + if (jmap->l_idx - 1 < done_index) + done_index = jmap->l_idx - 1; } } - - mark_removed (list[i]); - } - assert (new_opencount[0] == 0); + } /* Call all termination functions at once. */ #ifdef SHARED bool do_audit = GLRO(dl_naudit) > 0 && !GL(dl_ns)[ns]._ns_loaded->l_auditing; #endif - for (i = 0; list[i] != NULL; ++i) + bool unload_any = false; + unsigned int first_loaded = ~0; + for (i = 0; i < nloaded; ++i) { - struct link_map *imap = list[i]; + struct link_map *imap = maps[i]; /* All elements must be in the same namespace. */ assert (imap->l_ns == ns); - if (new_opencount[i] == 0 && imap->l_type == lt_loaded - && (imap->l_flags_1 & DF_1_NODELETE) == 0) + if (!ISSET (used, i)) { + assert (imap->l_type == lt_loaded + && (imap->l_flags_1 & DF_1_NODELETE) == 0); + /* Call its termination function. Do not do it for half-cooked objects. */ if (imap->l_init_called) @@ -324,42 +281,59 @@ _dl_close (void *_map) } #endif - /* This object must not be used anymore. We must remove the - reference from the scope. */ - unsigned int j; - struct link_map **searchlist = map->l_searchlist.r_list; - unsigned int nsearchlist = map->l_searchlist.r_nlist; + /* This object must not be used anymore. */ + imap->l_removed = 1; -#ifndef NDEBUG - bool found = false; -#endif - for (j = 0; j < nsearchlist; ++j) - if (imap == searchlist[j]) - { - /* This is the object to remove. Copy all the - following ones. */ - while (++j < nsearchlist) - searchlist[j - 1] = searchlist[j]; + /* We indeed have an object to remove. */ + unload_any = true; - searchlist[j - 1] = NULL; - - --map->l_searchlist.r_nlist; - -#ifndef NDEBUG - found = true; -#endif - break; - } - assert (found); + /* Remember where the first dynamically loaded object is. */ + if (i < first_loaded) + first_loaded = i; } + /* Else ISSET (used, i). */ + else if (imap->l_type == lt_loaded) + { + if (imap->l_searchlist.r_list == NULL + && imap->l_initfini != NULL) + { + /* The object is still used. But the object we are + unloading right now is responsible for loading it. If + the current object does not have it's own scope yet we + have to create one. This has to be done before running + the finalizers. + + To do this count the number of dependencies. */ + unsigned int cnt; + for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt) + ; + + /* We simply reuse the l_initfini list. */ + imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1]; + imap->l_searchlist.r_nlist = cnt; + + for (cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) + if (imap->l_scope[cnt] == &map->l_searchlist) + { + imap->l_scope[cnt] = &imap->l_searchlist; + break; + } + } - /* Store the new l_opencount value. */ - imap->l_opencount = new_opencount[i]; + /* The loader is gone, so mark the object as not having one. */ + if (imap->l_loader != NULL && !ISSET (used, imap->l_loader->l_idx)) + imap->l_loader = NULL; - /* Just a sanity check. */ - assert (imap->l_type == lt_loaded || imap->l_opencount > 0); + /* Remember where the first dynamically loaded object is. */ + if (i < first_loaded) + first_loaded = i; + } } + /* If there are no objects to unload, do nothing further. */ + if (!unload_any) + goto out; + #ifdef SHARED /* Auditing checkpoint: we will start deleting objects. */ if (__builtin_expect (do_audit, 0)) @@ -393,12 +367,12 @@ _dl_close (void *_map) /* Check each element of the search list to see if all references to it are gone. */ - for (i = 0; list[i] != NULL; ++i) + for (i = first_loaded; i < nloaded; ++i) { - struct link_map *imap = list[i]; - if (imap->l_opencount == 0 && imap->l_type == lt_loaded) + struct link_map *imap = maps[i]; + if (!ISSET (used, i)) { - struct libname_list *lnp; + assert (imap->l_type == lt_loaded); /* That was the last reference, and this was a dlopen-loaded object. We can unmap it. */ @@ -527,34 +501,7 @@ _dl_close (void *_map) if (imap->l_origin != (char *) -1) free ((char *) imap->l_origin); - /* If the object has relocation dependencies save this - information for latter. */ - if (__builtin_expect (imap->l_reldeps != NULL, 0)) - { - struct reldep_list *newrel; - - newrel = (struct reldep_list *) alloca (sizeof (*reldeps) - + (imap->l_reldepsact - * sizeof (bool))); - newrel->rellist = imap->l_reldeps; - newrel->nrellist = imap->l_reldepsact; - newrel->next = reldeps; - - newrel->nhandled = imap->l_reldepsact; - unsigned int j; - for (j = 0; j < imap->l_reldepsact; ++j) - { - /* Find out whether this object is in our list. */ - if (imap->l_reldeps[j]->l_idx < nopencount - && list[imap->l_reldeps[j]->l_idx] == imap->l_reldeps[j]) - /* Yes, it is. */ - newrel->handled[j] = true; - else - newrel->handled[j] = false; - } - - reldeps = newrel; - } + free (imap->l_reldeps); /* Print debugging message. */ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)) @@ -564,7 +511,8 @@ _dl_close (void *_map) /* This name always is allocated. */ free (imap->l_name); /* Remove the list with all the names of the shared object. */ - lnp = imap->l_libname; + + struct libname_list *lnp = imap->l_libname; do { struct libname_list *this = lnp; @@ -575,8 +523,7 @@ _dl_close (void *_map) while (lnp != NULL); /* Remove the searchlists. */ - if (imap != map) - free (imap->l_initfini); + free (imap->l_initfini); /* Remove the scope array if we allocated it. */ if (imap->l_scope != imap->l_scope_mem) @@ -630,26 +577,8 @@ _dl_close (void *_map) r->r_state = RT_CONSISTENT; _dl_debug_state (); - /* Now we can perhaps also remove the modules for which we had - dependencies because of symbol lookup. */ - while (__builtin_expect (reldeps != NULL, 0)) - { - while (reldeps->nrellist-- > 0) - /* Some of the relocation dependencies might be on the - dependency list of the object we are closing right now. - They were already handled. Do not close them again. */ - if (reldeps->nrellist < reldeps->nhandled - && ! reldeps->handled[reldeps->nrellist]) - _dl_close (reldeps->rellist[reldeps->nrellist]); - - free (reldeps->rellist); - - reldeps = reldeps->next; - } - - free (list); - /* Release the lock. */ + out: __rtld_lock_unlock_recursive (GL(dl_load_lock)); } |