| /* |
| * security/tomoyo/memory.c |
| * |
| * Memory management functions for TOMOYO. |
| * |
| * Copyright (C) 2005-2010 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"); |
| } |
| |
| /* Lock for protecting tomoyo_memory_used. */ |
| static DEFINE_SPINLOCK(tomoyo_policy_memory_lock); |
| /* 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. |
| */ |
| bool tomoyo_memory_ok(void *ptr) |
| { |
| if (ptr) { |
| const size_t s = ksize(ptr); |
| bool result; |
| spin_lock(&tomoyo_policy_memory_lock); |
| tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; |
| result = !tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || |
| tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= |
| tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]; |
| if (!result) |
| tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; |
| spin_unlock(&tomoyo_policy_memory_lock); |
| if (result) |
| return true; |
| } |
| 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. |
| */ |
| 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_memory_free - Free memory for elements. |
| * |
| * @ptr: Pointer to allocated memory. |
| */ |
| void tomoyo_memory_free(void *ptr) |
| { |
| size_t s = ksize(ptr); |
| spin_lock(&tomoyo_policy_memory_lock); |
| tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; |
| spin_unlock(&tomoyo_policy_memory_lock); |
| kfree(ptr); |
| } |
| |
| /** |
| * 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) |
| 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)) |
| 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); |
| } |