1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * pkey base: debug feature, pkey handler registry 4 * 5 * Copyright IBM Corp. 2024 6 */ 7 8 #define KMSG_COMPONENT "pkey" 9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 10 11 #include <linux/cpufeature.h> 12 #include <linux/init.h> 13 #include <linux/list.h> 14 #include <linux/module.h> 15 #include <linux/rculist.h> 16 17 #include "pkey_base.h" 18 19 MODULE_LICENSE("GPL"); 20 MODULE_AUTHOR("IBM Corporation"); 21 MODULE_DESCRIPTION("s390 protected key base and api"); 22 23 /* 24 * pkey debug feature 25 */ 26 debug_info_t *pkey_dbf_info; 27 EXPORT_SYMBOL(pkey_dbf_info); 28 29 /* 30 * pkey handler registry 31 */ 32 33 static DEFINE_SPINLOCK(handler_list_write_lock); 34 static LIST_HEAD(handler_list); 35 36 int pkey_handler_register(struct pkey_handler *handler) 37 { 38 const struct pkey_handler *h; 39 40 if (!handler || 41 !handler->is_supported_key || 42 !handler->is_supported_keytype) 43 return -EINVAL; 44 45 if (!try_module_get(handler->module)) 46 return -ENXIO; 47 48 spin_lock(&handler_list_write_lock); 49 50 rcu_read_lock(); 51 list_for_each_entry_rcu(h, &handler_list, list) { 52 if (h == handler) { 53 rcu_read_unlock(); 54 spin_unlock(&handler_list_write_lock); 55 module_put(handler->module); 56 return -EEXIST; 57 } 58 } 59 rcu_read_unlock(); 60 61 list_add_rcu(&handler->list, &handler_list); 62 spin_unlock(&handler_list_write_lock); 63 synchronize_rcu(); 64 65 module_put(handler->module); 66 67 PKEY_DBF_INFO("%s pkey handler '%s' registered\n", __func__, 68 handler->name ?: "<no name>"); 69 70 return 0; 71 } 72 EXPORT_SYMBOL(pkey_handler_register); 73 74 int pkey_handler_unregister(struct pkey_handler *handler) 75 { 76 spin_lock(&handler_list_write_lock); 77 list_del_rcu(&handler->list); 78 INIT_LIST_HEAD_RCU(&handler->list); 79 spin_unlock(&handler_list_write_lock); 80 synchronize_rcu(); 81 82 PKEY_DBF_INFO("%s pkey handler '%s' unregistered\n", __func__, 83 handler->name ?: "<no name>"); 84 85 return 0; 86 } 87 EXPORT_SYMBOL(pkey_handler_unregister); 88 89 /* 90 * Handler invocation functions. 91 */ 92 93 const struct pkey_handler *pkey_handler_get_keybased(const u8 *key, u32 keylen) 94 { 95 const struct pkey_handler *h; 96 97 rcu_read_lock(); 98 list_for_each_entry_rcu(h, &handler_list, list) { 99 if (!try_module_get(h->module)) 100 continue; 101 if (h->is_supported_key(key, keylen)) { 102 rcu_read_unlock(); 103 return h; 104 } 105 module_put(h->module); 106 } 107 rcu_read_unlock(); 108 109 return NULL; 110 } 111 EXPORT_SYMBOL(pkey_handler_get_keybased); 112 113 const struct pkey_handler *pkey_handler_get_keytypebased(enum pkey_key_type kt) 114 { 115 const struct pkey_handler *h; 116 117 rcu_read_lock(); 118 list_for_each_entry_rcu(h, &handler_list, list) { 119 if (!try_module_get(h->module)) 120 continue; 121 if (h->is_supported_keytype(kt)) { 122 rcu_read_unlock(); 123 return h; 124 } 125 module_put(h->module); 126 } 127 rcu_read_unlock(); 128 129 return NULL; 130 } 131 EXPORT_SYMBOL(pkey_handler_get_keytypebased); 132 133 void pkey_handler_put(const struct pkey_handler *handler) 134 { 135 const struct pkey_handler *h; 136 137 if (!handler) 138 return; 139 140 rcu_read_lock(); 141 list_for_each_entry_rcu(h, &handler_list, list) { 142 if (h == handler) { 143 module_put(h->module); 144 break; 145 } 146 } 147 rcu_read_unlock(); 148 } 149 EXPORT_SYMBOL(pkey_handler_put); 150 151 int pkey_handler_key_to_protkey(const struct pkey_apqn *apqns, size_t nr_apqns, 152 const u8 *key, u32 keylen, 153 u8 *protkey, u32 *protkeylen, u32 *protkeytype) 154 { 155 const struct pkey_handler *h; 156 int rc = -ENODEV; 157 158 h = pkey_handler_get_keybased(key, keylen); 159 if (h && h->key_to_protkey) { 160 rc = h->key_to_protkey(apqns, nr_apqns, key, keylen, 161 protkey, protkeylen, 162 protkeytype); 163 } 164 pkey_handler_put(h); 165 166 return rc; 167 } 168 EXPORT_SYMBOL(pkey_handler_key_to_protkey); 169 170 /* 171 * This handler invocation is special as there may be more than 172 * one handler providing support for the very same key (type). 173 * And the handler may not respond true on is_supported_key(), 174 * so simple try and check return value here. 175 */ 176 int pkey_handler_slowpath_key_to_protkey(const struct pkey_apqn *apqns, 177 size_t nr_apqns, 178 const u8 *key, u32 keylen, 179 u8 *protkey, u32 *protkeylen, 180 u32 *protkeytype) 181 { 182 const struct pkey_handler *h, *htmp[10]; 183 int i, n = 0, rc = -ENODEV; 184 185 rcu_read_lock(); 186 list_for_each_entry_rcu(h, &handler_list, list) { 187 if (!try_module_get(h->module)) 188 continue; 189 if (h->slowpath_key_to_protkey && n < ARRAY_SIZE(htmp)) 190 htmp[n++] = h; 191 else 192 module_put(h->module); 193 } 194 rcu_read_unlock(); 195 196 for (i = 0; i < n; i++) { 197 h = htmp[i]; 198 if (rc) 199 rc = h->slowpath_key_to_protkey(apqns, nr_apqns, 200 key, keylen, 201 protkey, protkeylen, 202 protkeytype); 203 module_put(h->module); 204 } 205 206 return rc; 207 } 208 EXPORT_SYMBOL(pkey_handler_slowpath_key_to_protkey); 209 210 int pkey_handler_gen_key(const struct pkey_apqn *apqns, size_t nr_apqns, 211 u32 keytype, u32 keysubtype, 212 u32 keybitsize, u32 flags, 213 u8 *keybuf, u32 *keybuflen, u32 *keyinfo) 214 { 215 const struct pkey_handler *h; 216 int rc = -ENODEV; 217 218 h = pkey_handler_get_keytypebased(keysubtype); 219 if (h && h->gen_key) { 220 rc = h->gen_key(apqns, nr_apqns, keytype, keysubtype, 221 keybitsize, flags, 222 keybuf, keybuflen, keyinfo); 223 } 224 pkey_handler_put(h); 225 226 return rc; 227 } 228 EXPORT_SYMBOL(pkey_handler_gen_key); 229 230 int pkey_handler_clr_to_key(const struct pkey_apqn *apqns, size_t nr_apqns, 231 u32 keytype, u32 keysubtype, 232 u32 keybitsize, u32 flags, 233 const u8 *clrkey, u32 clrkeylen, 234 u8 *keybuf, u32 *keybuflen, u32 *keyinfo) 235 { 236 const struct pkey_handler *h; 237 int rc = -ENODEV; 238 239 h = pkey_handler_get_keytypebased(keysubtype); 240 if (h && h->clr_to_key) { 241 rc = h->clr_to_key(apqns, nr_apqns, keytype, keysubtype, 242 keybitsize, flags, clrkey, clrkeylen, 243 keybuf, keybuflen, keyinfo); 244 } 245 pkey_handler_put(h); 246 247 return rc; 248 } 249 EXPORT_SYMBOL(pkey_handler_clr_to_key); 250 251 int pkey_handler_verify_key(const u8 *key, u32 keylen, 252 u16 *card, u16 *dom, 253 u32 *keytype, u32 *keybitsize, u32 *flags) 254 { 255 const struct pkey_handler *h; 256 int rc = -ENODEV; 257 258 h = pkey_handler_get_keybased(key, keylen); 259 if (h && h->verify_key) { 260 rc = h->verify_key(key, keylen, card, dom, 261 keytype, keybitsize, flags); 262 } 263 pkey_handler_put(h); 264 265 return rc; 266 } 267 EXPORT_SYMBOL(pkey_handler_verify_key); 268 269 int pkey_handler_apqns_for_key(const u8 *key, u32 keylen, u32 flags, 270 struct pkey_apqn *apqns, size_t *nr_apqns) 271 { 272 const struct pkey_handler *h; 273 int rc = -ENODEV; 274 275 h = pkey_handler_get_keybased(key, keylen); 276 if (h && h->apqns_for_key) 277 rc = h->apqns_for_key(key, keylen, flags, apqns, nr_apqns); 278 pkey_handler_put(h); 279 280 return rc; 281 } 282 EXPORT_SYMBOL(pkey_handler_apqns_for_key); 283 284 int pkey_handler_apqns_for_keytype(enum pkey_key_type keysubtype, 285 u8 cur_mkvp[32], u8 alt_mkvp[32], u32 flags, 286 struct pkey_apqn *apqns, size_t *nr_apqns) 287 { 288 const struct pkey_handler *h; 289 int rc = -ENODEV; 290 291 h = pkey_handler_get_keytypebased(keysubtype); 292 if (h && h->apqns_for_keytype) { 293 rc = h->apqns_for_keytype(keysubtype, 294 cur_mkvp, alt_mkvp, flags, 295 apqns, nr_apqns); 296 } 297 pkey_handler_put(h); 298 299 return rc; 300 } 301 EXPORT_SYMBOL(pkey_handler_apqns_for_keytype); 302 303 void pkey_handler_request_modules(void) 304 { 305 #ifdef CONFIG_MODULES 306 static const char * const pkey_handler_modules[] = { 307 #if IS_MODULE(CONFIG_PKEY_CCA) 308 "pkey_cca", 309 #endif 310 #if IS_MODULE(CONFIG_PKEY_EP11) 311 "pkey_ep11", 312 #endif 313 #if IS_MODULE(CONFIG_PKEY_PCKMO) 314 "pkey_pckmo", 315 #endif 316 #if IS_MODULE(CONFIG_PKEY_UV) 317 "pkey_uv", 318 #endif 319 }; 320 int i; 321 322 for (i = 0; i < ARRAY_SIZE(pkey_handler_modules); i++) { 323 const struct pkey_handler *h; 324 bool found = false; 325 326 rcu_read_lock(); 327 list_for_each_entry_rcu(h, &handler_list, list) { 328 if (h->module && 329 !strcmp(h->module->name, pkey_handler_modules[i])) { 330 found = true; 331 break; 332 } 333 } 334 rcu_read_unlock(); 335 if (!found) { 336 pr_debug("request_module(%s)\n", pkey_handler_modules[i]); 337 request_module(pkey_handler_modules[i]); 338 } 339 } 340 #endif 341 } 342 EXPORT_SYMBOL(pkey_handler_request_modules); 343 344 /* 345 * Module init 346 */ 347 static int __init pkey_init(void) 348 { 349 int rc; 350 351 /* init debug feature */ 352 pkey_dbf_info = debug_register("pkey", 1, 1, 5 * sizeof(long)); 353 debug_register_view(pkey_dbf_info, &debug_sprintf_view); 354 debug_set_level(pkey_dbf_info, 4); 355 356 /* the handler registry does not need any init */ 357 358 rc = pkey_api_init(); 359 if (rc) 360 debug_unregister(pkey_dbf_info); 361 362 return rc; 363 } 364 365 /* 366 * Module exit 367 */ 368 static void __exit pkey_exit(void) 369 { 370 pkey_api_exit(); 371 } 372 373 module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_init); 374 module_exit(pkey_exit); 375