/*
* security/tomoyo/gc.c
*
- * Implementation of the Domain-Based Mandatory Access Control.
- *
- * Copyright (C) 2005-2010 NTT DATA CORPORATION
- *
+ * Copyright (C) 2005-2011 NTT DATA CORPORATION
*/
#include "common.h"
#include <linux/kthread.h>
#include <linux/slab.h>
-enum tomoyo_gc_id {
- TOMOYO_ID_PATH_GROUP,
- TOMOYO_ID_PATH_GROUP_MEMBER,
- TOMOYO_ID_DOMAIN_INITIALIZER,
- TOMOYO_ID_DOMAIN_KEEPER,
- TOMOYO_ID_ALIAS,
- TOMOYO_ID_GLOBALLY_READABLE,
- TOMOYO_ID_PATTERN,
- TOMOYO_ID_NO_REWRITE,
- TOMOYO_ID_MANAGER,
- TOMOYO_ID_NAME,
- TOMOYO_ID_ACL,
- TOMOYO_ID_DOMAIN
+/* The list for "struct tomoyo_io_buffer". */
+static LIST_HEAD(tomoyo_io_buffer_list);
+/* Lock for protecting tomoyo_io_buffer_list. */
+static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock);
+
+/* Size of an element. */
+static const u8 tomoyo_element_size[TOMOYO_MAX_POLICY] = {
+ [TOMOYO_ID_GROUP] = sizeof(struct tomoyo_group),
+ [TOMOYO_ID_PATH_GROUP] = sizeof(struct tomoyo_path_group),
+ [TOMOYO_ID_NUMBER_GROUP] = sizeof(struct tomoyo_number_group),
+ [TOMOYO_ID_AGGREGATOR] = sizeof(struct tomoyo_aggregator),
+ [TOMOYO_ID_TRANSITION_CONTROL] =
+ sizeof(struct tomoyo_transition_control),
+ [TOMOYO_ID_MANAGER] = sizeof(struct tomoyo_manager),
+ /* [TOMOYO_ID_CONDITION] = "struct tomoyo_condition"->size, */
+ /* [TOMOYO_ID_NAME] = "struct tomoyo_name"->size, */
+ /* [TOMOYO_ID_ACL] =
+ tomoyo_acl_size["struct tomoyo_acl_info"->type], */
+ [TOMOYO_ID_DOMAIN] = sizeof(struct tomoyo_domain_info),
};
-struct tomoyo_gc_entry {
- struct list_head list;
- int type;
- void *element;
+/* Size of a domain ACL element. */
+static const u8 tomoyo_acl_size[] = {
+ [TOMOYO_TYPE_PATH_ACL] = sizeof(struct tomoyo_path_acl),
+ [TOMOYO_TYPE_PATH2_ACL] = sizeof(struct tomoyo_path2_acl),
+ [TOMOYO_TYPE_PATH_NUMBER_ACL] = sizeof(struct tomoyo_path_number_acl),
+ [TOMOYO_TYPE_MKDEV_ACL] = sizeof(struct tomoyo_mkdev_acl),
+ [TOMOYO_TYPE_MOUNT_ACL] = sizeof(struct tomoyo_mount_acl),
};
-static LIST_HEAD(tomoyo_gc_queue);
-static DEFINE_MUTEX(tomoyo_gc_mutex);
-/* Caller holds tomoyo_policy_lock mutex. */
-static bool tomoyo_add_to_gc(const int type, void *element)
+/**
+ * tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not.
+ *
+ * @element: Pointer to "struct list_head".
+ *
+ * Returns true if @element is used by /sys/kernel/security/tomoyo/ users,
+ * false otherwise.
+ */
+static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element)
{
- struct tomoyo_gc_entry *entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
- if (!entry)
- return false;
- entry->type = type;
- entry->element = element;
- list_add(&entry->list, &tomoyo_gc_queue);
- return true;
-}
+ struct tomoyo_io_buffer *head;
+ bool in_use = false;
-static void tomoyo_del_allow_read
-(struct tomoyo_globally_readable_file_entry *ptr)
-{
- tomoyo_put_name(ptr->filename);
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
+ head->users++;
+ spin_unlock(&tomoyo_io_buffer_list_lock);
+ if (mutex_lock_interruptible(&head->io_sem)) {
+ in_use = true;
+ goto out;
+ }
+ if (head->r.domain == element || head->r.group == element ||
+ head->r.acl == element || &head->w.domain->list == element)
+ in_use = true;
+ mutex_unlock(&head->io_sem);
+out:
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ head->users--;
+ if (in_use)
+ break;
+ }
+ spin_unlock(&tomoyo_io_buffer_list_lock);
+ return in_use;
}
-static void tomoyo_del_file_pattern(struct tomoyo_pattern_entry *ptr)
+/**
+ * tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not.
+ *
+ * @string: String to check.
+ * @size: Memory allocated for @string .
+ *
+ * Returns true if @string is used by /sys/kernel/security/tomoyo/ users,
+ * false otherwise.
+ */
+static bool tomoyo_name_used_by_io_buffer(const char *string,
+ const size_t size)
{
- tomoyo_put_name(ptr->pattern);
+ struct tomoyo_io_buffer *head;
+ bool in_use = false;
+
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
+ int i;
+ head->users++;
+ spin_unlock(&tomoyo_io_buffer_list_lock);
+ if (mutex_lock_interruptible(&head->io_sem)) {
+ in_use = true;
+ goto out;
+ }
+ for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) {
+ const char *w = head->r.w[i];
+ if (w < string || w > string + size)
+ continue;
+ in_use = true;
+ break;
+ }
+ mutex_unlock(&head->io_sem);
+out:
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ head->users--;
+ if (in_use)
+ break;
+ }
+ spin_unlock(&tomoyo_io_buffer_list_lock);
+ return in_use;
}
-static void tomoyo_del_no_rewrite(struct tomoyo_no_rewrite_entry *ptr)
+/* Structure for garbage collection. */
+struct tomoyo_gc {
+ struct list_head list;
+ enum tomoyo_policy_id type;
+ size_t size;
+ struct list_head *element;
+};
+/* List of entries to be deleted. */
+static LIST_HEAD(tomoyo_gc_list);
+/* Length of tomoyo_gc_list. */
+static int tomoyo_gc_list_len;
+
+/**
+ * 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)
{
- tomoyo_put_name(ptr->pattern);
+ struct tomoyo_gc *entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+ if (!entry)
+ return false;
+ entry->type = type;
+ if (type == TOMOYO_ID_ACL)
+ entry->size = tomoyo_acl_size[
+ container_of(element,
+ typeof(struct tomoyo_acl_info),
+ list)->type];
+ else if (type == TOMOYO_ID_NAME)
+ entry->size = strlen(container_of(element,
+ typeof(struct tomoyo_name),
+ head.list)->entry.name) + 1;
+ else if (type == TOMOYO_ID_CONDITION)
+ entry->size =
+ container_of(element, typeof(struct tomoyo_condition),
+ head.list)->size;
+ else
+ entry->size = tomoyo_element_size[type];
+ entry->element = element;
+ list_add(&entry->list, &tomoyo_gc_list);
+ list_del_rcu(element);
+ return tomoyo_gc_list_len++ < 128;
}
-static void tomoyo_del_domain_initializer
-(struct tomoyo_domain_initializer_entry *ptr)
+/**
+ * tomoyo_element_linked_by_gc - Validate next element of an entry.
+ *
+ * @element: Pointer to an element.
+ * @size: Size of @element in byte.
+ *
+ * Returns true if @element is linked by other elements in the garbage
+ * collector's queue, false otherwise.
+ */
+static bool tomoyo_element_linked_by_gc(const u8 *element, const size_t size)
{
- tomoyo_put_name(ptr->domainname);
- tomoyo_put_name(ptr->program);
+ struct tomoyo_gc *p;
+ list_for_each_entry(p, &tomoyo_gc_list, list) {
+ const u8 *ptr = (const u8 *) p->element->next;
+ if (ptr < element || element + size < ptr)
+ continue;
+ return true;
+ }
+ return false;
}
-static void tomoyo_del_domain_keeper(struct tomoyo_domain_keeper_entry *ptr)
+/**
+ * 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 =
+ container_of(element, typeof(*ptr), head.list);
tomoyo_put_name(ptr->domainname);
tomoyo_put_name(ptr->program);
}
-static void tomoyo_del_alias(struct tomoyo_alias_entry *ptr)
+/**
+ * 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 =
+ container_of(element, typeof(*ptr), head.list);
tomoyo_put_name(ptr->original_name);
- tomoyo_put_name(ptr->aliased_name);
+ tomoyo_put_name(ptr->aggregated_name);
}
-static void tomoyo_del_manager(struct tomoyo_policy_manager_entry *ptr)
+/**
+ * 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 =
+ container_of(element, typeof(*ptr), head.list);
tomoyo_put_name(ptr->manager);
}
-static void tomoyo_del_acl(struct tomoyo_acl_info *acl)
+/**
+ * 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 =
+ container_of(element, typeof(*acl), list);
+ tomoyo_put_condition(acl->cond);
switch (acl->type) {
case TOMOYO_TYPE_PATH_ACL:
{
tomoyo_put_name_union(&entry->name2);
}
break;
- default:
- printk(KERN_WARNING "Unknown type\n");
+ case TOMOYO_TYPE_PATH_NUMBER_ACL:
+ {
+ struct tomoyo_path_number_acl *entry
+ = container_of(acl, typeof(*entry), head);
+ tomoyo_put_name_union(&entry->name);
+ tomoyo_put_number_union(&entry->number);
+ }
+ break;
+ case TOMOYO_TYPE_MKDEV_ACL:
+ {
+ struct tomoyo_mkdev_acl *entry
+ = container_of(acl, typeof(*entry), head);
+ tomoyo_put_name_union(&entry->name);
+ tomoyo_put_number_union(&entry->mode);
+ tomoyo_put_number_union(&entry->major);
+ tomoyo_put_number_union(&entry->minor);
+ }
+ break;
+ case TOMOYO_TYPE_MOUNT_ACL:
+ {
+ struct tomoyo_mount_acl *entry
+ = container_of(acl, typeof(*entry), head);
+ tomoyo_put_name_union(&entry->dev_name);
+ tomoyo_put_name_union(&entry->dir_name);
+ tomoyo_put_name_union(&entry->fs_type);
+ tomoyo_put_number_union(&entry->flags);
+ }
break;
}
}
-static bool tomoyo_del_domain(struct tomoyo_domain_info *domain)
+/**
+ * tomoyo_del_domain - Delete members in "struct tomoyo_domain_info".
+ *
+ * @element: Pointer to "struct list_head".
+ *
+ * Returns true if deleted, false otherwise.
+ */
+static bool tomoyo_del_domain(struct list_head *element)
{
+ struct tomoyo_domain_info *domain =
+ container_of(element, typeof(*domain), list);
struct tomoyo_acl_info *acl;
struct tomoyo_acl_info *tmp;
/*
if (atomic_read(&domain->users))
return false;
list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) {
- tomoyo_del_acl(acl);
+ tomoyo_del_acl(&acl->list);
tomoyo_memory_free(acl);
}
tomoyo_put_name(domain->domainname);
return true;
}
+/**
+ * tomoyo_del_condition - Delete members in "struct tomoyo_condition".
+ *
+ * @element: Pointer to "struct list_head".
+ *
+ * Returns nothing.
+ */
+void tomoyo_del_condition(struct list_head *element)
+{
+ struct tomoyo_condition *cond = container_of(element, typeof(*cond),
+ head.list);
+ const u16 condc = cond->condc;
+ const u16 numbers_count = cond->numbers_count;
+ const u16 names_count = cond->names_count;
+ const u16 argc = cond->argc;
+ const u16 envc = cond->envc;
+ unsigned int i;
+ const struct tomoyo_condition_element *condp
+ = (const struct tomoyo_condition_element *) (cond + 1);
+ struct tomoyo_number_union *numbers_p
+ = (struct tomoyo_number_union *) (condp + condc);
+ struct tomoyo_name_union *names_p
+ = (struct tomoyo_name_union *) (numbers_p + numbers_count);
+ const struct tomoyo_argv *argv
+ = (const struct tomoyo_argv *) (names_p + names_count);
+ const struct tomoyo_envp *envp
+ = (const struct tomoyo_envp *) (argv + argc);
+ for (i = 0; i < numbers_count; i++)
+ tomoyo_put_number_union(numbers_p++);
+ for (i = 0; i < names_count; i++)
+ tomoyo_put_name_union(names_p++);
+ for (i = 0; i < argc; argv++, i++)
+ tomoyo_put_name(argv->value);
+ for (i = 0; i < envc; envp++, i++) {
+ tomoyo_put_name(envp->name);
+ tomoyo_put_name(envp->value);
+ }
+}
-static void tomoyo_del_name(const struct tomoyo_name_entry *ptr)
+/**
+ * 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), head.list);
}
-static void tomoyo_del_path_group_member(struct tomoyo_path_group_member
- *member)
+/**
+ * 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 =
+ container_of(element, typeof(*member), head.list);
tomoyo_put_name(member->member_name);
}
-static void tomoyo_del_path_group(struct tomoyo_path_group *group)
+/**
+ * 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), 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);
+}
+
+/**
+ * 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) {
+ if (!member->is_deleted)
+ continue;
+ if (!tomoyo_add_to_gc(id, &member->list))
+ return false;
+ }
+ return true;
+}
+
+/**
+ * tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info".
+ *
+ * @list: Pointer to "struct list_head".
+ *
+ * Returns true if some elements are deleted, false otherwise.
+ */
+static bool tomoyo_collect_acl(struct list_head *list)
+{
+ struct tomoyo_acl_info *acl;
+ list_for_each_entry(acl, list, list) {
+ if (!acl->is_deleted)
+ continue;
+ if (!tomoyo_add_to_gc(TOMOYO_ID_ACL, &acl->list))
+ return false;
+ }
+ return true;
+}
+
+/**
+ * tomoyo_collect_entry - Scan lists for deleted elements.
+ *
+ * Returns nothing.
+ */
static void tomoyo_collect_entry(void)
{
+ int i;
+ enum tomoyo_policy_id id;
+ struct tomoyo_policy_namespace *ns;
+ int idx;
if (mutex_lock_interruptible(&tomoyo_policy_lock))
return;
- {
- struct tomoyo_globally_readable_file_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list,
- list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_GLOBALLY_READABLE, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_pattern_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_PATTERN, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_no_rewrite_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_NO_REWRITE, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_domain_initializer_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list,
- list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN_INITIALIZER, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_domain_keeper_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN_KEEPER, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_alias_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_ALIAS, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
- {
- struct tomoyo_policy_manager_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list,
- list) {
- if (!ptr->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_MANAGER, ptr))
- list_del_rcu(&ptr->list);
- else
- break;
- }
- }
+ idx = tomoyo_read_lock();
{
struct tomoyo_domain_info *domain;
list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
- struct tomoyo_acl_info *acl;
- list_for_each_entry_rcu(acl, &domain->acl_info_list,
- list) {
- switch (acl->type) {
- case TOMOYO_TYPE_PATH_ACL:
- if (container_of(acl,
- struct tomoyo_path_acl,
- head)->perm ||
- container_of(acl,
- struct tomoyo_path_acl,
- head)->perm_high)
- continue;
- break;
- case TOMOYO_TYPE_PATH2_ACL:
- if (container_of(acl,
- struct tomoyo_path2_acl,
- head)->perm)
- continue;
- break;
- default:
- continue;
- }
- if (tomoyo_add_to_gc(TOMOYO_ID_ACL, acl))
- list_del_rcu(&acl->list);
- else
- break;
- }
+ if (!tomoyo_collect_acl(&domain->acl_info_list))
+ goto unlock;
if (!domain->is_deleted || atomic_read(&domain->users))
continue;
/*
* refer this domain after successful execve().
* We recheck domain->users after SRCU synchronization.
*/
- if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN, domain))
- list_del_rcu(&domain->list);
- else
- break;
+ if (!tomoyo_add_to_gc(TOMOYO_ID_DOMAIN, &domain->list))
+ goto unlock;
}
}
- {
- int i;
- for (i = 0; i < TOMOYO_MAX_HASH; i++) {
- struct tomoyo_name_entry *ptr;
- list_for_each_entry_rcu(ptr, &tomoyo_name_list[i],
- list) {
- if (atomic_read(&ptr->users))
+ list_for_each_entry_rcu(ns, &tomoyo_namespace_list, namespace_list) {
+ for (id = 0; id < TOMOYO_MAX_POLICY; id++)
+ if (!tomoyo_collect_member(id, &ns->policy_list[id]))
+ goto unlock;
+ for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
+ if (!tomoyo_collect_acl(&ns->acl_group[i]))
+ goto unlock;
+ for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
+ struct list_head *list = &ns->group_list[i];
+ struct tomoyo_group *group;
+ switch (i) {
+ case 0:
+ id = TOMOYO_ID_PATH_GROUP;
+ break;
+ default:
+ id = TOMOYO_ID_NUMBER_GROUP;
+ break;
+ }
+ 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->head.users))
continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_NAME, ptr))
- list_del_rcu(&ptr->list);
- else {
- i = TOMOYO_MAX_HASH;
- break;
- }
+ if (!tomoyo_add_to_gc(TOMOYO_ID_GROUP,
+ &group->head.list))
+ goto unlock;
}
}
}
- {
- struct tomoyo_path_group *group;
- list_for_each_entry_rcu(group, &tomoyo_path_group_list, list) {
- struct tomoyo_path_group_member *member;
- list_for_each_entry_rcu(member, &group->member_list,
- list) {
- if (!member->is_deleted)
- continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_PATH_GROUP_MEMBER,
- member))
- list_del_rcu(&member->list);
- else
- break;
- }
- if (!list_empty(&group->member_list) ||
- atomic_read(&group->users))
+ id = TOMOYO_ID_CONDITION;
+ for (i = 0; i < TOMOYO_MAX_HASH + 1; i++) {
+ struct list_head *list = !i ?
+ &tomoyo_condition_list : &tomoyo_name_list[i - 1];
+ struct tomoyo_shared_acl_head *ptr;
+ list_for_each_entry(ptr, list, list) {
+ if (atomic_read(&ptr->users))
continue;
- if (tomoyo_add_to_gc(TOMOYO_ID_PATH_GROUP, group))
- list_del_rcu(&group->list);
- else
- break;
+ if (!tomoyo_add_to_gc(id, &ptr->list))
+ goto unlock;
}
+ id = TOMOYO_ID_NAME;
}
+unlock:
+ tomoyo_read_unlock(idx);
mutex_unlock(&tomoyo_policy_lock);
}
-static void tomoyo_kfree_entry(void)
+/**
+ * tomoyo_kfree_entry - Delete entries in tomoyo_gc_list.
+ *
+ * Returns true if some entries were kfree()d, false otherwise.
+ */
+static bool tomoyo_kfree_entry(void)
{
- struct tomoyo_gc_entry *p;
- struct tomoyo_gc_entry *tmp;
+ struct tomoyo_gc *p;
+ struct tomoyo_gc *tmp;
+ bool result = false;
+
+ list_for_each_entry_safe(p, tmp, &tomoyo_gc_list, list) {
+ struct list_head *element = p->element;
- list_for_each_entry_safe(p, tmp, &tomoyo_gc_queue, list) {
+ /*
+ * list_del_rcu() in tomoyo_add_to_gc() guarantees that the
+ * list element became no longer reachable from the list which
+ * the element was originally on (e.g. tomoyo_domain_list).
+ * Also, synchronize_srcu() in tomoyo_gc_thread() guarantees
+ * that the list element became no longer referenced by syscall
+ * users.
+ *
+ * However, there are three users which may still be using the
+ * list element. We need to defer until all of these users
+ * forget the list element.
+ *
+ * Firstly, defer until "struct tomoyo_io_buffer"->r.{domain,
+ * group,acl} and "struct tomoyo_io_buffer"->w.domain forget
+ * the list element.
+ */
+ if (tomoyo_struct_used_by_io_buffer(element))
+ continue;
+ /*
+ * Secondly, defer until all other elements in the
+ * tomoyo_gc_list list forget the list element.
+ */
+ if (tomoyo_element_linked_by_gc((const u8 *) element, p->size))
+ continue;
switch (p->type) {
- case TOMOYO_ID_DOMAIN_INITIALIZER:
- tomoyo_del_domain_initializer(p->element);
- break;
- case TOMOYO_ID_DOMAIN_KEEPER:
- tomoyo_del_domain_keeper(p->element);
- break;
- case TOMOYO_ID_ALIAS:
- tomoyo_del_alias(p->element);
- break;
- case TOMOYO_ID_GLOBALLY_READABLE:
- tomoyo_del_allow_read(p->element);
- break;
- case TOMOYO_ID_PATTERN:
- tomoyo_del_file_pattern(p->element);
+ case TOMOYO_ID_TRANSITION_CONTROL:
+ tomoyo_del_transition_control(element);
break;
- case TOMOYO_ID_NO_REWRITE:
- tomoyo_del_no_rewrite(p->element);
+ case TOMOYO_ID_AGGREGATOR:
+ tomoyo_del_aggregator(element);
break;
case TOMOYO_ID_MANAGER:
- tomoyo_del_manager(p->element);
+ tomoyo_del_manager(element);
+ break;
+ case TOMOYO_ID_CONDITION:
+ tomoyo_del_condition(element);
break;
case TOMOYO_ID_NAME:
- tomoyo_del_name(p->element);
+ /*
+ * Thirdly, defer until all "struct tomoyo_io_buffer"
+ * ->r.w[] forget the list element.
+ */
+ if (tomoyo_name_used_by_io_buffer(
+ container_of(element, typeof(struct tomoyo_name),
+ head.list)->entry.name, p->size))
+ continue;
+ tomoyo_del_name(element);
break;
case TOMOYO_ID_ACL:
- tomoyo_del_acl(p->element);
+ tomoyo_del_acl(element);
break;
case TOMOYO_ID_DOMAIN:
- if (!tomoyo_del_domain(p->element))
+ if (!tomoyo_del_domain(element))
continue;
break;
- case TOMOYO_ID_PATH_GROUP_MEMBER:
- tomoyo_del_path_group_member(p->element);
- break;
case TOMOYO_ID_PATH_GROUP:
- tomoyo_del_path_group(p->element);
+ tomoyo_del_path_group(element);
+ break;
+ case TOMOYO_ID_GROUP:
+ tomoyo_del_group(element);
break;
- default:
- printk(KERN_WARNING "Unknown type\n");
+ case TOMOYO_ID_NUMBER_GROUP:
+ tomoyo_del_number_group(element);
+ break;
+ case TOMOYO_MAX_POLICY:
break;
}
- tomoyo_memory_free(p->element);
+ tomoyo_memory_free(element);
list_del(&p->list);
kfree(p);
+ tomoyo_gc_list_len--;
+ result = true;
}
+ return result;
}
+/**
+ * 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)
{
+ /* Garbage collector thread is exclusive. */
+ static DEFINE_MUTEX(tomoyo_gc_mutex);
+ if (!mutex_trylock(&tomoyo_gc_mutex))
+ goto out;
daemonize("GC for TOMOYO");
- if (mutex_trylock(&tomoyo_gc_mutex)) {
- int i;
- for (i = 0; i < 10; i++) {
- tomoyo_collect_entry();
- if (list_empty(&tomoyo_gc_queue))
- break;
- synchronize_srcu(&tomoyo_ss);
- tomoyo_kfree_entry();
+ do {
+ tomoyo_collect_entry();
+ if (list_empty(&tomoyo_gc_list))
+ break;
+ synchronize_srcu(&tomoyo_ss);
+ } while (tomoyo_kfree_entry());
+ {
+ struct tomoyo_io_buffer *head;
+ struct tomoyo_io_buffer *tmp;
+
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list,
+ list) {
+ if (head->users)
+ continue;
+ list_del(&head->list);
+ kfree(head->read_buf);
+ kfree(head->write_buf);
+ kfree(head);
}
- mutex_unlock(&tomoyo_gc_mutex);
+ spin_unlock(&tomoyo_io_buffer_list_lock);
}
- do_exit(0);
+ mutex_unlock(&tomoyo_gc_mutex);
+out:
+ /* This acts as do_exit(0). */
+ return 0;
}
-void tomoyo_run_gc(void)
+/**
+ * tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @is_register: True if register, false if unregister.
+ *
+ * Returns nothing.
+ */
+void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register)
{
- struct task_struct *task = kthread_create(tomoyo_gc_thread, NULL,
- "GC for TOMOYO");
- if (!IS_ERR(task))
- wake_up_process(task);
+ bool is_write = false;
+
+ spin_lock(&tomoyo_io_buffer_list_lock);
+ if (is_register) {
+ head->users = 1;
+ list_add(&head->list, &tomoyo_io_buffer_list);
+ } else {
+ is_write = head->write_buf != NULL;
+ if (!--head->users) {
+ list_del(&head->list);
+ kfree(head->read_buf);
+ kfree(head->write_buf);
+ kfree(head);
+ }
+ }
+ spin_unlock(&tomoyo_io_buffer_list_lock);
+ if (is_write) {
+ struct task_struct *task = kthread_create(tomoyo_gc_thread,
+ NULL,
+ "GC for TOMOYO");
+ if (!IS_ERR(task))
+ wake_up_process(task);
+ }
}
git.openpandora.org / pandora-kernel.git / blobdiff