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