diff options
Diffstat (limited to 'elf/dl-lookup.c')
| -rw-r--r-- | elf/dl-lookup.c | 142 |
1 files changed, 70 insertions, 72 deletions
diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 2faa9fb99c..26c839caa7 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -79,92 +79,94 @@ internal_function add_dependency (struct link_map *undef_map, struct link_map *map) { struct link_map **list; + struct link_map *runp; unsigned int act; unsigned int i; int result = 0; + /* Avoid self-references. */ + if (undef_map == map) + return 0; + /* Make sure nobody can unload the object while we are at it. */ __libc_lock_lock_recursive (_dl_load_lock); /* Determine whether UNDEF_MAP already has a reference to MAP. First look in the normal dependencies. */ - list = undef_map->l_initfini; - - for (i = 0; list[i] != NULL; ++i) - if (list[i] == map) - break; - - if (__builtin_expect (list[i] == NULL, 1)) + if (undef_map->l_searchlist.r_list != NULL) { - /* No normal dependency. See whether we already had to add it - to the special list of dynamic dependencies. */ - list = undef_map->l_reldeps; - act = undef_map->l_reldepsact; + list = undef_map->l_initfini; - for (i = 0; i < act; ++i) + for (i = 0; list[i] != NULL; ++i) if (list[i] == map) - break; + goto out; + } + + /* No normal dependency. See whether we already had to add it + to the special list of dynamic dependencies. */ + list = undef_map->l_reldeps; + act = undef_map->l_reldepsact; - if (i == act) + for (i = 0; i < act; ++i) + if (list[i] == map) + goto out; + + /* The object is not yet in the dependency list. Before we add + it make sure just one more time the object we are about to + reference is still available. There is a brief period in + which the object could have been removed since we found the + definition. */ + runp = _dl_loaded; + while (runp != NULL && runp != map) + runp = runp->l_next; + + if (runp != NULL) + { + /* The object is still available. Add the reference now. */ + if (__builtin_expect (act >= undef_map->l_reldepsmax, 0)) { - /* The object is not yet in the dependency list. Before we add - it make sure just one more time the object we are about to - reference is still available. There is a brief period in - which the object could have been removed since we found the - definition. */ - struct link_map *runp = _dl_loaded; - - while (runp != NULL && runp != map) - runp = runp->l_next; - - if (runp != NULL) - { - /* The object is still available. Add the reference now. */ - if (__builtin_expect (act >= undef_map->l_reldepsmax, 0)) - { - /* Allocate more memory for the dependency list. Since - this can never happen during the startup phase we can - use `realloc'. */ - void *newp; - - undef_map->l_reldepsmax += 5; - newp = realloc (undef_map->l_reldeps, - undef_map->l_reldepsmax - * sizeof(struct link_map *)); - - if (__builtin_expect (newp != NULL, 1)) - undef_map->l_reldeps = (struct link_map **) newp; - else - /* Correct the addition. */ - undef_map->l_reldepsmax -= 5; - } - - /* If we didn't manage to allocate memory for the list this - is no fatal mistake. We simply increment the use counter - of the referenced object and don't record the dependencies. - This means this increment can never be reverted and the - object will never be unloaded. This is semantically the - correct behaviour. */ - if (__builtin_expect (act < undef_map->l_reldepsmax, 1)) - undef_map->l_reldeps[undef_map->l_reldepsact++] = map; - - /* And increment the counter in the referenced object. */ - ++map->l_opencount; - - /* Display information if we are debugging. */ - if (__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0)) - _dl_debug_printf ("\ -\nfile=%s; needed by %s (relocation dependency)\n\n", - map->l_name[0] ? map->l_name : _dl_argv[0], - undef_map->l_name[0] - ? undef_map->l_name : _dl_argv[0]); - } + /* Allocate more memory for the dependency list. Since this + can never happen during the startup phase we can use + `realloc'. */ + void *newp; + + undef_map->l_reldepsmax += 5; + newp = realloc (undef_map->l_reldeps, + undef_map->l_reldepsmax + * sizeof (struct link_map *)); + + if (__builtin_expect (newp != NULL, 1)) + undef_map->l_reldeps = (struct link_map **) newp; else - /* Whoa, that was bad luck. We have to search again. */ - result = -1; + /* Correct the addition. */ + undef_map->l_reldepsmax -= 5; } + + /* If we didn't manage to allocate memory for the list this is + no fatal mistake. We simply increment the use counter of the + referenced object and don't record the dependencies. This + means this increment can never be reverted and the object + will never be unloaded. This is semantically the correct + behaviour. */ + if (__builtin_expect (act < undef_map->l_reldepsmax, 1)) + undef_map->l_reldeps[undef_map->l_reldepsact++] = map; + + /* And increment the counter in the referenced object. */ + ++map->l_opencount; + + /* Display information if we are debugging. */ + if (__builtin_expect (_dl_debug_mask & DL_DEBUG_FILES, 0)) + _dl_debug_printf ("\ +\nfile=%s; needed by %s (relocation dependency)\n\n", + map->l_name[0] ? map->l_name : _dl_argv[0], + undef_map->l_name[0] + ? undef_map->l_name : _dl_argv[0]); } + else + /* Whoa, that was bad luck. We have to search again. */ + result = -1; + out: /* Release the lock. */ __libc_lock_unlock_recursive (_dl_load_lock); @@ -212,8 +214,6 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, we have to prevent the latter from being unloaded unless the UNDEF_MAP object is also unloaded. */ if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) - && current_value.m->l_global - && undef_map != current_value.m /* Don't do this for explicit lookups as opposed to implicit runtime lookups. */ && ! explicit @@ -395,8 +395,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, we have to prevent the latter from being unloaded unless the UNDEF_MAP object is also unloaded. */ if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) - && current_value.m->l_global - && undef_map != current_value.m /* Don't do this for explicit lookups as opposed to implicit runtime lookups. */ && ! explicit |