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![Tetsuo Handa](/assets/img/avatar_default.png)
tomoyo_policy_lock mutex already protects it. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
201 lines
5.4 KiB
C
201 lines
5.4 KiB
C
/*
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* security/tomoyo/memory.c
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*
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* Copyright (C) 2005-2011 NTT DATA CORPORATION
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*/
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#include <linux/hash.h>
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#include <linux/slab.h>
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#include "common.h"
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/**
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* tomoyo_warn_oom - Print out of memory warning message.
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*
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* @function: Function's name.
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*/
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void tomoyo_warn_oom(const char *function)
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{
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/* Reduce error messages. */
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static pid_t tomoyo_last_pid;
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const pid_t pid = current->pid;
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if (tomoyo_last_pid != pid) {
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printk(KERN_WARNING "ERROR: Out of memory at %s.\n",
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function);
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tomoyo_last_pid = pid;
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}
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if (!tomoyo_policy_loaded)
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panic("MAC Initialization failed.\n");
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}
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/* Memoy currently used by policy/audit log/query. */
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unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT];
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/* Memory quota for "policy"/"audit log"/"query". */
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unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT];
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/**
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* tomoyo_memory_ok - Check memory quota.
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*
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* @ptr: Pointer to allocated memory.
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*
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* Returns true on success, false otherwise.
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*
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* Returns true if @ptr is not NULL and quota not exceeded, false otherwise.
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*
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* Caller holds tomoyo_policy_lock mutex.
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*/
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bool tomoyo_memory_ok(void *ptr)
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{
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if (ptr) {
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const size_t s = ksize(ptr);
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tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s;
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if (!tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] ||
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tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <=
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tomoyo_memory_quota[TOMOYO_MEMORY_POLICY])
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return true;
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tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s;
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}
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tomoyo_warn_oom(__func__);
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return false;
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}
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/**
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* tomoyo_commit_ok - Check memory quota.
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*
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* @data: Data to copy from.
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* @size: Size in byte.
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*
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* Returns pointer to allocated memory on success, NULL otherwise.
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* @data is zero-cleared on success.
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*
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* Caller holds tomoyo_policy_lock mutex.
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*/
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void *tomoyo_commit_ok(void *data, const unsigned int size)
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{
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void *ptr = kzalloc(size, GFP_NOFS);
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if (tomoyo_memory_ok(ptr)) {
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memmove(ptr, data, size);
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memset(data, 0, size);
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return ptr;
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}
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kfree(ptr);
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return NULL;
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}
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/**
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* tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group".
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*
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* @param: Pointer to "struct tomoyo_acl_param".
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* @idx: Index number.
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*
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* Returns pointer to "struct tomoyo_group" on success, NULL otherwise.
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*/
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struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param,
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const u8 idx)
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{
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struct tomoyo_group e = { };
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struct tomoyo_group *group = NULL;
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struct list_head *list;
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const char *group_name = tomoyo_read_token(param);
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bool found = false;
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if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP)
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return NULL;
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e.group_name = tomoyo_get_name(group_name);
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if (!e.group_name)
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return NULL;
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if (mutex_lock_interruptible(&tomoyo_policy_lock))
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goto out;
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list = ¶m->ns->group_list[idx];
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list_for_each_entry(group, list, head.list) {
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if (e.group_name != group->group_name ||
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atomic_read(&group->head.users) == TOMOYO_GC_IN_PROGRESS)
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continue;
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atomic_inc(&group->head.users);
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found = true;
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break;
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}
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if (!found) {
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struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e));
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if (entry) {
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INIT_LIST_HEAD(&entry->member_list);
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atomic_set(&entry->head.users, 1);
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list_add_tail_rcu(&entry->head.list, list);
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group = entry;
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found = true;
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}
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}
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mutex_unlock(&tomoyo_policy_lock);
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out:
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tomoyo_put_name(e.group_name);
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return found ? group : NULL;
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}
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/*
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* tomoyo_name_list is used for holding string data used by TOMOYO.
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* Since same string data is likely used for multiple times (e.g.
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* "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
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* "const struct tomoyo_path_info *".
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*/
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struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
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/**
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* tomoyo_get_name - Allocate permanent memory for string data.
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*
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* @name: The string to store into the permernent memory.
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*
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* Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
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*/
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const struct tomoyo_path_info *tomoyo_get_name(const char *name)
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{
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struct tomoyo_name *ptr;
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unsigned int hash;
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int len;
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struct list_head *head;
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if (!name)
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return NULL;
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len = strlen(name) + 1;
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hash = full_name_hash((const unsigned char *) name, len - 1);
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head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
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if (mutex_lock_interruptible(&tomoyo_policy_lock))
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return NULL;
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list_for_each_entry(ptr, head, head.list) {
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if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) ||
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atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
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continue;
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atomic_inc(&ptr->head.users);
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goto out;
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}
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ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS);
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if (tomoyo_memory_ok(ptr)) {
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ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
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memmove((char *) ptr->entry.name, name, len);
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atomic_set(&ptr->head.users, 1);
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tomoyo_fill_path_info(&ptr->entry);
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list_add_tail(&ptr->head.list, head);
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} else {
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kfree(ptr);
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ptr = NULL;
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}
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out:
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mutex_unlock(&tomoyo_policy_lock);
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return ptr ? &ptr->entry : NULL;
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}
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/* Initial namespace.*/
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struct tomoyo_policy_namespace tomoyo_kernel_namespace;
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/**
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* tomoyo_mm_init - Initialize mm related code.
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*/
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void __init tomoyo_mm_init(void)
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{
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int idx;
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for (idx = 0; idx < TOMOYO_MAX_HASH; idx++)
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INIT_LIST_HEAD(&tomoyo_name_list[idx]);
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tomoyo_kernel_namespace.name = "<kernel>";
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tomoyo_init_policy_namespace(&tomoyo_kernel_namespace);
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tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace;
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INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
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tomoyo_kernel_domain.domainname = tomoyo_get_name("<kernel>");
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list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
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}
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