diff options
Diffstat (limited to 'security/tomoyo/gc.c')
| -rw-r--r-- | security/tomoyo/gc.c | 127 |
1 files changed, 114 insertions, 13 deletions
diff --git a/security/tomoyo/gc.c b/security/tomoyo/gc.c index ba799b49ee3a..de14030823cd 100644 --- a/security/tomoyo/gc.c +++ b/security/tomoyo/gc.c @@ -13,13 +13,30 @@ struct tomoyo_gc { struct list_head list; - int type; + enum tomoyo_policy_id type; struct list_head *element; }; static LIST_HEAD(tomoyo_gc_queue); static DEFINE_MUTEX(tomoyo_gc_mutex); -/* Caller holds tomoyo_policy_lock mutex. */ +/** + * tomoyo_add_to_gc - Add an entry to to be deleted list. + * + * @type: One of values in "enum tomoyo_policy_id". + * @element: Pointer to "struct list_head". + * + * Returns true on success, false otherwise. + * + * Caller holds tomoyo_policy_lock mutex. + * + * Adding an entry needs kmalloc(). Thus, if we try to add thousands of + * entries at once, it will take too long time. Thus, do not add more than 128 + * entries per a scan. But to be able to handle worst case where all entries + * are in-use, we accept one more entry per a scan. + * + * If we use singly linked list using "struct list_head"->prev (which is + * LIST_POISON2), we can avoid kmalloc(). + */ static bool tomoyo_add_to_gc(const int type, struct list_head *element) { struct tomoyo_gc *entry = kzalloc(sizeof(*entry), GFP_ATOMIC); @@ -32,6 +49,13 @@ static bool tomoyo_add_to_gc(const int type, struct list_head *element) return true; } +/** + * tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_transition_control(struct list_head *element) { struct tomoyo_transition_control *ptr = @@ -40,6 +64,13 @@ static void tomoyo_del_transition_control(struct list_head *element) tomoyo_put_name(ptr->program); } +/** + * tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_aggregator(struct list_head *element) { struct tomoyo_aggregator *ptr = @@ -48,6 +79,13 @@ static void tomoyo_del_aggregator(struct list_head *element) tomoyo_put_name(ptr->aggregated_name); } +/** + * tomoyo_del_manager - Delete members in "struct tomoyo_manager". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_manager(struct list_head *element) { struct tomoyo_manager *ptr = @@ -55,6 +93,13 @@ static void tomoyo_del_manager(struct list_head *element) tomoyo_put_name(ptr->manager); } +/** + * tomoyo_del_acl - Delete members in "struct tomoyo_acl_info". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_acl(struct list_head *element) { struct tomoyo_acl_info *acl = @@ -145,12 +190,26 @@ static bool tomoyo_del_domain(struct list_head *element) } +/** + * tomoyo_del_name - Delete members in "struct tomoyo_name". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_name(struct list_head *element) { const struct tomoyo_name *ptr = - container_of(element, typeof(*ptr), list); + container_of(element, typeof(*ptr), head.list); } +/** + * tomoyo_del_path_group - Delete members in "struct tomoyo_path_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_path_group(struct list_head *element) { struct tomoyo_path_group *member = @@ -158,20 +217,43 @@ static void tomoyo_del_path_group(struct list_head *element) tomoyo_put_name(member->member_name); } +/** + * tomoyo_del_group - Delete "struct tomoyo_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_group(struct list_head *element) { struct tomoyo_group *group = - container_of(element, typeof(*group), list); + container_of(element, typeof(*group), head.list); tomoyo_put_name(group->group_name); } +/** + * tomoyo_del_number_group - Delete members in "struct tomoyo_number_group". + * + * @element: Pointer to "struct list_head". + * + * Returns nothing. + */ static void tomoyo_del_number_group(struct list_head *element) { struct tomoyo_number_group *member = container_of(element, typeof(*member), head.list); } -static bool tomoyo_collect_member(struct list_head *member_list, int id) +/** + * tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head". + * + * @id: One of values in "enum tomoyo_policy_id". + * @member_list: Pointer to "struct list_head". + * + * Returns true if some elements are deleted, false otherwise. + */ +static bool tomoyo_collect_member(const enum tomoyo_policy_id id, + struct list_head *member_list) { struct tomoyo_acl_head *member; list_for_each_entry(member, member_list, list) { @@ -195,13 +277,18 @@ static bool tomoyo_collect_acl(struct tomoyo_domain_info *domain) return true; } +/** + * tomoyo_collect_entry - Scan lists for deleted elements. + * + * Returns nothing. + */ static void tomoyo_collect_entry(void) { int i; if (mutex_lock_interruptible(&tomoyo_policy_lock)) return; for (i = 0; i < TOMOYO_MAX_POLICY; i++) { - if (!tomoyo_collect_member(&tomoyo_policy_list[i], i)) + if (!tomoyo_collect_member(i, &tomoyo_policy_list[i])) goto unlock; } { @@ -222,10 +309,10 @@ static void tomoyo_collect_entry(void) } for (i = 0; i < TOMOYO_MAX_HASH; i++) { struct tomoyo_name *ptr; - list_for_each_entry_rcu(ptr, &tomoyo_name_list[i], list) { - if (atomic_read(&ptr->users)) + list_for_each_entry_rcu(ptr, &tomoyo_name_list[i], head.list) { + if (atomic_read(&ptr->head.users)) continue; - if (!tomoyo_add_to_gc(TOMOYO_ID_NAME, &ptr->list)) + if (!tomoyo_add_to_gc(TOMOYO_ID_NAME, &ptr->head.list)) goto unlock; } } @@ -241,13 +328,14 @@ static void tomoyo_collect_entry(void) id = TOMOYO_ID_NUMBER_GROUP; break; } - list_for_each_entry(group, list, list) { - if (!tomoyo_collect_member(&group->member_list, id)) + list_for_each_entry(group, list, head.list) { + if (!tomoyo_collect_member(id, &group->member_list)) goto unlock; if (!list_empty(&group->member_list) || - atomic_read(&group->users)) + atomic_read(&group->head.users)) continue; - if (!tomoyo_add_to_gc(TOMOYO_ID_GROUP, &group->list)) + if (!tomoyo_add_to_gc(TOMOYO_ID_GROUP, + &group->head.list)) goto unlock; } } @@ -291,6 +379,8 @@ static void tomoyo_kfree_entry(void) case TOMOYO_ID_NUMBER_GROUP: tomoyo_del_number_group(element); break; + case TOMOYO_MAX_POLICY: + break; } tomoyo_memory_free(element); list_del(&p->list); @@ -298,6 +388,17 @@ static void tomoyo_kfree_entry(void) } } +/** + * tomoyo_gc_thread - Garbage collector thread function. + * + * @unused: Unused. + * + * In case OOM-killer choose this thread for termination, we create this thread + * as a short live thread whenever /sys/kernel/security/tomoyo/ interface was + * close()d. + * + * Returns 0. + */ static int tomoyo_gc_thread(void *unused) { daemonize("GC for TOMOYO"); |