1 /* 2 * security/tomoyo/memory.c 3 * 4 * Copyright (C) 2005-2011 NTT DATA CORPORATION 5 */ 6 7 #include <linux/hash.h> 8 #include <linux/slab.h> 9 #include "common.h" 10 11 /** 12 * tomoyo_warn_oom - Print out of memory warning message. 13 * 14 * @function: Function's name. 15 */ 16 void tomoyo_warn_oom(const char *function) 17 { 18 /* Reduce error messages. */ 19 static pid_t tomoyo_last_pid; 20 const pid_t pid = current->pid; 21 if (tomoyo_last_pid != pid) { 22 printk(KERN_WARNING "ERROR: Out of memory at %s.\n", 23 function); 24 tomoyo_last_pid = pid; 25 } 26 if (!tomoyo_policy_loaded) 27 panic("MAC Initialization failed.\n"); 28 } 29 30 /* Lock for protecting tomoyo_memory_used. */ 31 static DEFINE_SPINLOCK(tomoyo_policy_memory_lock); 32 /* Memoy currently used by policy/audit log/query. */ 33 unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; 34 /* Memory quota for "policy"/"audit log"/"query". */ 35 unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; 36 37 /** 38 * tomoyo_memory_ok - Check memory quota. 39 * 40 * @ptr: Pointer to allocated memory. 41 * 42 * Returns true on success, false otherwise. 43 * 44 * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. 45 */ 46 bool tomoyo_memory_ok(void *ptr) 47 { 48 if (ptr) { 49 const size_t s = ksize(ptr); 50 bool result; 51 spin_lock(&tomoyo_policy_memory_lock); 52 tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; 53 result = !tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || 54 tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= 55 tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]; 56 if (!result) 57 tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; 58 spin_unlock(&tomoyo_policy_memory_lock); 59 if (result) 60 return true; 61 } 62 tomoyo_warn_oom(__func__); 63 return false; 64 } 65 66 /** 67 * tomoyo_commit_ok - Check memory quota. 68 * 69 * @data: Data to copy from. 70 * @size: Size in byte. 71 * 72 * Returns pointer to allocated memory on success, NULL otherwise. 73 * @data is zero-cleared on success. 74 */ 75 void *tomoyo_commit_ok(void *data, const unsigned int size) 76 { 77 void *ptr = kzalloc(size, GFP_NOFS); 78 if (tomoyo_memory_ok(ptr)) { 79 memmove(ptr, data, size); 80 memset(data, 0, size); 81 return ptr; 82 } 83 kfree(ptr); 84 return NULL; 85 } 86 87 /** 88 * tomoyo_memory_free - Free memory for elements. 89 * 90 * @ptr: Pointer to allocated memory. 91 */ 92 void tomoyo_memory_free(void *ptr) 93 { 94 size_t s = ksize(ptr); 95 spin_lock(&tomoyo_policy_memory_lock); 96 tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; 97 spin_unlock(&tomoyo_policy_memory_lock); 98 kfree(ptr); 99 } 100 101 /** 102 * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". 103 * 104 * @param: Pointer to "struct tomoyo_acl_param". 105 * @idx: Index number. 106 * 107 * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. 108 */ 109 struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, 110 const u8 idx) 111 { 112 struct tomoyo_group e = { }; 113 struct tomoyo_group *group = NULL; 114 struct list_head *list; 115 const char *group_name = tomoyo_read_token(param); 116 bool found = false; 117 if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP) 118 return NULL; 119 e.group_name = tomoyo_get_name(group_name); 120 if (!e.group_name) 121 return NULL; 122 if (mutex_lock_interruptible(&tomoyo_policy_lock)) 123 goto out; 124 list = ¶m->ns->group_list[idx]; 125 list_for_each_entry(group, list, head.list) { 126 if (e.group_name != group->group_name) 127 continue; 128 atomic_inc(&group->head.users); 129 found = true; 130 break; 131 } 132 if (!found) { 133 struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e)); 134 if (entry) { 135 INIT_LIST_HEAD(&entry->member_list); 136 atomic_set(&entry->head.users, 1); 137 list_add_tail_rcu(&entry->head.list, list); 138 group = entry; 139 found = true; 140 } 141 } 142 mutex_unlock(&tomoyo_policy_lock); 143 out: 144 tomoyo_put_name(e.group_name); 145 return found ? group : NULL; 146 } 147 148 /* 149 * tomoyo_name_list is used for holding string data used by TOMOYO. 150 * Since same string data is likely used for multiple times (e.g. 151 * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of 152 * "const struct tomoyo_path_info *". 153 */ 154 struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; 155 156 /** 157 * tomoyo_get_name - Allocate permanent memory for string data. 158 * 159 * @name: The string to store into the permernent memory. 160 * 161 * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. 162 */ 163 const struct tomoyo_path_info *tomoyo_get_name(const char *name) 164 { 165 struct tomoyo_name *ptr; 166 unsigned int hash; 167 int len; 168 struct list_head *head; 169 170 if (!name) 171 return NULL; 172 len = strlen(name) + 1; 173 hash = full_name_hash((const unsigned char *) name, len - 1); 174 head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; 175 if (mutex_lock_interruptible(&tomoyo_policy_lock)) 176 return NULL; 177 list_for_each_entry(ptr, head, head.list) { 178 if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name)) 179 continue; 180 atomic_inc(&ptr->head.users); 181 goto out; 182 } 183 ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS); 184 if (tomoyo_memory_ok(ptr)) { 185 ptr->entry.name = ((char *) ptr) + sizeof(*ptr); 186 memmove((char *) ptr->entry.name, name, len); 187 atomic_set(&ptr->head.users, 1); 188 tomoyo_fill_path_info(&ptr->entry); 189 list_add_tail(&ptr->head.list, head); 190 } else { 191 kfree(ptr); 192 ptr = NULL; 193 } 194 out: 195 mutex_unlock(&tomoyo_policy_lock); 196 return ptr ? &ptr->entry : NULL; 197 } 198 199 /* Initial namespace.*/ 200 struct tomoyo_policy_namespace tomoyo_kernel_namespace; 201 202 /** 203 * tomoyo_mm_init - Initialize mm related code. 204 */ 205 void __init tomoyo_mm_init(void) 206 { 207 int idx; 208 for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) 209 INIT_LIST_HEAD(&tomoyo_name_list[idx]); 210 tomoyo_kernel_namespace.name = "<kernel>"; 211 tomoyo_init_policy_namespace(&tomoyo_kernel_namespace); 212 tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace; 213 INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list); 214 tomoyo_kernel_domain.domainname = tomoyo_get_name("<kernel>"); 215 list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list); 216 } 217