Zhen Kong | ee7bdc6 | 2019-03-14 10:55:19 -0700 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * Copyright (c) 2015-2019, The Linux Foundation. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | /* |
| 7 | * PFK Key Cache |
| 8 | * |
| 9 | * Key Cache used internally in PFK. |
| 10 | * The purpose of the cache is to save access time to QSEE when loading keys. |
| 11 | * Currently the cache is the same size as the total number of keys that can |
| 12 | * be loaded to ICE. Since this number is relatively small, the algorithms for |
| 13 | * cache eviction are simple, linear and based on last usage timestamp, i.e |
| 14 | * the node that will be evicted is the one with the oldest timestamp. |
| 15 | * Empty entries always have the oldest timestamp. |
| 16 | */ |
| 17 | |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/mutex.h> |
| 20 | #include <linux/spinlock.h> |
| 21 | #include <crypto/ice.h> |
| 22 | #include <linux/errno.h> |
| 23 | #include <linux/string.h> |
| 24 | #include <linux/jiffies.h> |
| 25 | #include <linux/slab.h> |
| 26 | #include <linux/printk.h> |
| 27 | #include <linux/sched/signal.h> |
| 28 | |
| 29 | #include "pfk_kc.h" |
| 30 | #include "pfk_ice.h" |
| 31 | |
| 32 | |
| 33 | /** the first available index in ice engine */ |
| 34 | #define PFK_KC_STARTING_INDEX 2 |
| 35 | |
| 36 | /** currently the only supported key and salt sizes */ |
| 37 | #define PFK_KC_KEY_SIZE 32 |
| 38 | #define PFK_KC_SALT_SIZE 32 |
| 39 | |
| 40 | /** Table size */ |
| 41 | #define PFK_KC_TABLE_SIZE ((32) - (PFK_KC_STARTING_INDEX)) |
| 42 | |
| 43 | /** The maximum key and salt size */ |
| 44 | #define PFK_MAX_KEY_SIZE PFK_KC_KEY_SIZE |
| 45 | #define PFK_MAX_SALT_SIZE PFK_KC_SALT_SIZE |
| 46 | #define PFK_UFS "ufs" |
| 47 | |
| 48 | static DEFINE_SPINLOCK(kc_lock); |
| 49 | static unsigned long flags; |
| 50 | static bool kc_ready; |
| 51 | static char *s_type = "sdcc"; |
| 52 | |
| 53 | /** |
| 54 | * enum pfk_kc_entry_state - state of the entry inside kc table |
| 55 | * |
| 56 | * @FREE: entry is free |
| 57 | * @ACTIVE_ICE_PRELOAD: entry is actively used by ICE engine |
| 58 | and cannot be used by others. SCM call |
| 59 | to load key to ICE is pending to be performed |
| 60 | * @ACTIVE_ICE_LOADED: entry is actively used by ICE engine and |
| 61 | cannot be used by others. SCM call to load the |
| 62 | key to ICE was successfully executed and key is |
| 63 | now loaded |
| 64 | * @INACTIVE_INVALIDATING: entry is being invalidated during file close |
| 65 | and cannot be used by others until invalidation |
| 66 | is complete |
| 67 | * @INACTIVE: entry's key is already loaded, but is not |
| 68 | currently being used. It can be re-used for |
| 69 | optimization and to avoid SCM call cost or |
| 70 | it can be taken by another key if there are |
| 71 | no FREE entries |
| 72 | * @SCM_ERROR: error occurred while scm call was performed to |
| 73 | load the key to ICE |
| 74 | */ |
| 75 | enum pfk_kc_entry_state { |
| 76 | FREE, |
| 77 | ACTIVE_ICE_PRELOAD, |
| 78 | ACTIVE_ICE_LOADED, |
| 79 | INACTIVE_INVALIDATING, |
| 80 | INACTIVE, |
| 81 | SCM_ERROR |
| 82 | }; |
| 83 | |
| 84 | struct kc_entry { |
| 85 | unsigned char key[PFK_MAX_KEY_SIZE]; |
| 86 | size_t key_size; |
| 87 | |
| 88 | unsigned char salt[PFK_MAX_SALT_SIZE]; |
| 89 | size_t salt_size; |
| 90 | |
| 91 | u64 time_stamp; |
| 92 | u32 key_index; |
| 93 | |
| 94 | struct task_struct *thread_pending; |
| 95 | |
| 96 | enum pfk_kc_entry_state state; |
| 97 | |
| 98 | /* ref count for the number of requests in the HW queue for this key */ |
| 99 | int loaded_ref_cnt; |
| 100 | int scm_error; |
| 101 | }; |
| 102 | |
| 103 | static struct kc_entry kc_table[PFK_KC_TABLE_SIZE]; |
| 104 | |
| 105 | /** |
| 106 | * kc_is_ready() - driver is initialized and ready. |
| 107 | * |
| 108 | * Return: true if the key cache is ready. |
| 109 | */ |
| 110 | static inline bool kc_is_ready(void) |
| 111 | { |
| 112 | return kc_ready; |
| 113 | } |
| 114 | |
| 115 | static inline void kc_spin_lock(void) |
| 116 | { |
| 117 | spin_lock_irqsave(&kc_lock, flags); |
| 118 | } |
| 119 | |
| 120 | static inline void kc_spin_unlock(void) |
| 121 | { |
| 122 | spin_unlock_irqrestore(&kc_lock, flags); |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * pfk_kc_get_storage_type() - return the hardware storage type. |
| 127 | * |
| 128 | * Return: storage type queried during bootup. |
| 129 | */ |
| 130 | const char *pfk_kc_get_storage_type(void) |
| 131 | { |
| 132 | return s_type; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * kc_entry_is_available() - checks whether the entry is available |
| 137 | * |
| 138 | * Return true if it is , false otherwise or if invalid |
| 139 | * Should be invoked under spinlock |
| 140 | */ |
| 141 | static bool kc_entry_is_available(const struct kc_entry *entry) |
| 142 | { |
| 143 | if (!entry) |
| 144 | return false; |
| 145 | |
| 146 | return (entry->state == FREE || entry->state == INACTIVE); |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * kc_entry_wait_till_available() - waits till entry is available |
| 151 | * |
| 152 | * Returns 0 in case of success or -ERESTARTSYS if the wait was interrupted |
| 153 | * by signal |
| 154 | * |
| 155 | * Should be invoked under spinlock |
| 156 | */ |
| 157 | static int kc_entry_wait_till_available(struct kc_entry *entry) |
| 158 | { |
| 159 | int res = 0; |
| 160 | |
| 161 | while (!kc_entry_is_available(entry)) { |
| 162 | set_current_state(TASK_INTERRUPTIBLE); |
| 163 | if (signal_pending(current)) { |
| 164 | res = -ERESTARTSYS; |
| 165 | break; |
| 166 | } |
| 167 | /* assuming only one thread can try to invalidate |
| 168 | * the same entry |
| 169 | */ |
| 170 | entry->thread_pending = current; |
| 171 | kc_spin_unlock(); |
| 172 | schedule(); |
| 173 | kc_spin_lock(); |
| 174 | } |
| 175 | set_current_state(TASK_RUNNING); |
| 176 | |
| 177 | return res; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * kc_entry_start_invalidating() - moves entry to state |
| 182 | * INACTIVE_INVALIDATING |
| 183 | * If entry is in use, waits till |
| 184 | * it gets available |
| 185 | * @entry: pointer to entry |
| 186 | * |
| 187 | * Return 0 in case of success, otherwise error |
| 188 | * Should be invoked under spinlock |
| 189 | */ |
| 190 | static int kc_entry_start_invalidating(struct kc_entry *entry) |
| 191 | { |
| 192 | int res; |
| 193 | |
| 194 | res = kc_entry_wait_till_available(entry); |
| 195 | if (res) |
| 196 | return res; |
| 197 | |
| 198 | entry->state = INACTIVE_INVALIDATING; |
| 199 | |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * kc_entry_finish_invalidating() - moves entry to state FREE |
| 205 | * wakes up all the tasks waiting |
| 206 | * on it |
| 207 | * |
| 208 | * @entry: pointer to entry |
| 209 | * |
| 210 | * Return 0 in case of success, otherwise error |
| 211 | * Should be invoked under spinlock |
| 212 | */ |
| 213 | static void kc_entry_finish_invalidating(struct kc_entry *entry) |
| 214 | { |
| 215 | if (!entry) |
| 216 | return; |
| 217 | |
| 218 | if (entry->state != INACTIVE_INVALIDATING) |
| 219 | return; |
| 220 | |
| 221 | entry->state = FREE; |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * kc_min_entry() - compare two entries to find one with minimal time |
| 226 | * @a: ptr to the first entry. If NULL the other entry will be returned |
| 227 | * @b: pointer to the second entry |
| 228 | * |
| 229 | * Return the entry which timestamp is the minimal, or b if a is NULL |
| 230 | */ |
| 231 | static inline struct kc_entry *kc_min_entry(struct kc_entry *a, |
| 232 | struct kc_entry *b) |
| 233 | { |
| 234 | if (!a) |
| 235 | return b; |
| 236 | |
| 237 | if (time_before64(b->time_stamp, a->time_stamp)) |
| 238 | return b; |
| 239 | |
| 240 | return a; |
| 241 | } |
| 242 | |
| 243 | /** |
| 244 | * kc_entry_at_index() - return entry at specific index |
| 245 | * @index: index of entry to be accessed |
| 246 | * |
| 247 | * Return entry |
| 248 | * Should be invoked under spinlock |
| 249 | */ |
| 250 | static struct kc_entry *kc_entry_at_index(int index) |
| 251 | { |
| 252 | return &(kc_table[index]); |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * kc_find_key_at_index() - find kc entry starting at specific index |
| 257 | * @key: key to look for |
| 258 | * @key_size: the key size |
| 259 | * @salt: salt to look for |
| 260 | * @salt_size: the salt size |
| 261 | * @sarting_index: index to start search with, if entry found, updated with |
| 262 | * index of that entry |
| 263 | * |
| 264 | * Return entry or NULL in case of error |
| 265 | * Should be invoked under spinlock |
| 266 | */ |
| 267 | static struct kc_entry *kc_find_key_at_index(const unsigned char *key, |
| 268 | size_t key_size, const unsigned char *salt, size_t salt_size, |
| 269 | int *starting_index) |
| 270 | { |
| 271 | struct kc_entry *entry = NULL; |
| 272 | int i = 0; |
| 273 | |
| 274 | for (i = *starting_index; i < PFK_KC_TABLE_SIZE; i++) { |
| 275 | entry = kc_entry_at_index(i); |
| 276 | |
| 277 | if (salt != NULL) { |
| 278 | if (entry->salt_size != salt_size) |
| 279 | continue; |
| 280 | |
| 281 | if (memcmp(entry->salt, salt, salt_size) != 0) |
| 282 | continue; |
| 283 | } |
| 284 | |
| 285 | if (entry->key_size != key_size) |
| 286 | continue; |
| 287 | |
| 288 | if (memcmp(entry->key, key, key_size) == 0) { |
| 289 | *starting_index = i; |
| 290 | return entry; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | return NULL; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * kc_find_key() - find kc entry |
| 299 | * @key: key to look for |
| 300 | * @key_size: the key size |
| 301 | * @salt: salt to look for |
| 302 | * @salt_size: the salt size |
| 303 | * |
| 304 | * Return entry or NULL in case of error |
| 305 | * Should be invoked under spinlock |
| 306 | */ |
| 307 | static struct kc_entry *kc_find_key(const unsigned char *key, size_t key_size, |
| 308 | const unsigned char *salt, size_t salt_size) |
| 309 | { |
| 310 | int index = 0; |
| 311 | |
| 312 | return kc_find_key_at_index(key, key_size, salt, salt_size, &index); |
| 313 | } |
| 314 | |
| 315 | /** |
| 316 | * kc_find_oldest_entry_non_locked() - finds the entry with minimal timestamp |
| 317 | * that is not locked |
| 318 | * |
| 319 | * Returns entry with minimal timestamp. Empty entries have timestamp |
| 320 | * of 0, therefore they are returned first. |
| 321 | * If all the entries are locked, will return NULL |
| 322 | * Should be invoked under spin lock |
| 323 | */ |
| 324 | static struct kc_entry *kc_find_oldest_entry_non_locked(void) |
| 325 | { |
| 326 | struct kc_entry *curr_min_entry = NULL; |
| 327 | struct kc_entry *entry = NULL; |
| 328 | int i = 0; |
| 329 | |
| 330 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) { |
| 331 | entry = kc_entry_at_index(i); |
| 332 | |
| 333 | if (entry->state == FREE) |
| 334 | return entry; |
| 335 | |
| 336 | if (entry->state == INACTIVE) |
| 337 | curr_min_entry = kc_min_entry(curr_min_entry, entry); |
| 338 | } |
| 339 | |
| 340 | return curr_min_entry; |
| 341 | } |
| 342 | |
| 343 | /** |
| 344 | * kc_update_timestamp() - updates timestamp of entry to current |
| 345 | * |
| 346 | * @entry: entry to update |
| 347 | * |
| 348 | */ |
| 349 | static void kc_update_timestamp(struct kc_entry *entry) |
| 350 | { |
| 351 | if (!entry) |
| 352 | return; |
| 353 | |
| 354 | entry->time_stamp = get_jiffies_64(); |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * kc_clear_entry() - clear the key from entry and mark entry not in use |
| 359 | * |
| 360 | * @entry: pointer to entry |
| 361 | * |
| 362 | * Should be invoked under spinlock |
| 363 | */ |
| 364 | static void kc_clear_entry(struct kc_entry *entry) |
| 365 | { |
| 366 | if (!entry) |
| 367 | return; |
| 368 | |
| 369 | memset(entry->key, 0, entry->key_size); |
| 370 | memset(entry->salt, 0, entry->salt_size); |
| 371 | |
| 372 | entry->key_size = 0; |
| 373 | entry->salt_size = 0; |
| 374 | |
| 375 | entry->time_stamp = 0; |
| 376 | entry->scm_error = 0; |
| 377 | |
| 378 | entry->state = FREE; |
| 379 | |
| 380 | entry->loaded_ref_cnt = 0; |
| 381 | entry->thread_pending = NULL; |
| 382 | } |
| 383 | |
| 384 | /** |
| 385 | * kc_update_entry() - replaces the key in given entry and |
| 386 | * loads the new key to ICE |
| 387 | * |
| 388 | * @entry: entry to replace key in |
| 389 | * @key: key |
| 390 | * @key_size: key_size |
| 391 | * @salt: salt |
| 392 | * @salt_size: salt_size |
| 393 | * @data_unit: dun size |
| 394 | * |
| 395 | * The previous key is securely released and wiped, the new one is loaded |
| 396 | * to ICE. |
| 397 | * Should be invoked under spinlock |
| 398 | * Caller to validate that key/salt_size matches the size in struct kc_entry |
| 399 | */ |
| 400 | static int kc_update_entry(struct kc_entry *entry, const unsigned char *key, |
| 401 | size_t key_size, const unsigned char *salt, size_t salt_size, |
| 402 | unsigned int data_unit) |
| 403 | { |
| 404 | int ret; |
| 405 | |
| 406 | kc_clear_entry(entry); |
| 407 | |
| 408 | memcpy(entry->key, key, key_size); |
| 409 | entry->key_size = key_size; |
| 410 | |
| 411 | memcpy(entry->salt, salt, salt_size); |
| 412 | entry->salt_size = salt_size; |
| 413 | |
| 414 | /* Mark entry as no longer free before releasing the lock */ |
| 415 | entry->state = ACTIVE_ICE_PRELOAD; |
| 416 | kc_spin_unlock(); |
| 417 | |
| 418 | ret = qti_pfk_ice_set_key(entry->key_index, entry->key, |
| 419 | entry->salt, s_type, data_unit); |
| 420 | |
| 421 | kc_spin_lock(); |
| 422 | return ret; |
| 423 | } |
| 424 | |
| 425 | /** |
| 426 | * pfk_kc_init() - init function |
| 427 | * |
| 428 | * Return 0 in case of success, error otherwise |
| 429 | */ |
| 430 | int pfk_kc_init(void) |
| 431 | { |
| 432 | int i = 0; |
| 433 | struct kc_entry *entry = NULL; |
| 434 | |
| 435 | kc_spin_lock(); |
| 436 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) { |
| 437 | entry = kc_entry_at_index(i); |
| 438 | entry->key_index = PFK_KC_STARTING_INDEX + i; |
| 439 | } |
| 440 | kc_ready = true; |
| 441 | kc_spin_unlock(); |
| 442 | |
| 443 | return 0; |
| 444 | } |
| 445 | |
| 446 | /** |
| 447 | * pfk_kc_denit() - deinit function |
| 448 | * |
| 449 | * Return 0 in case of success, error otherwise |
| 450 | */ |
| 451 | int pfk_kc_deinit(void) |
| 452 | { |
| 453 | int res = pfk_kc_clear(); |
| 454 | |
| 455 | kc_ready = false; |
| 456 | |
| 457 | return res; |
| 458 | } |
| 459 | |
| 460 | /** |
| 461 | * pfk_kc_load_key_start() - retrieve the key from cache or add it if |
| 462 | * it's not there and return the ICE hw key index in @key_index. |
| 463 | * @key: pointer to the key |
| 464 | * @key_size: the size of the key |
| 465 | * @salt: pointer to the salt |
| 466 | * @salt_size: the size of the salt |
| 467 | * @key_index: the pointer to key_index where the output will be stored |
| 468 | * @async: whether scm calls are allowed in the caller context |
| 469 | * |
| 470 | * If key is present in cache, than the key_index will be retrieved from cache. |
| 471 | * If it is not present, the oldest entry from kc table will be evicted, |
| 472 | * the key will be loaded to ICE via QSEE to the index that is the evicted |
| 473 | * entry number and stored in cache. |
| 474 | * Entry that is going to be used is marked as being used, it will mark |
| 475 | * as not being used when ICE finishes using it and pfk_kc_load_key_end |
| 476 | * will be invoked. |
| 477 | * As QSEE calls can only be done from a non-atomic context, when @async flag |
| 478 | * is set to 'false', it specifies that it is ok to make the calls in the |
| 479 | * current context. Otherwise, when @async is set, the caller should retry the |
| 480 | * call again from a different context, and -EAGAIN error will be returned. |
| 481 | * |
| 482 | * Return 0 in case of success, error otherwise |
| 483 | */ |
| 484 | int pfk_kc_load_key_start(const unsigned char *key, size_t key_size, |
| 485 | const unsigned char *salt, size_t salt_size, u32 *key_index, |
| 486 | bool async, unsigned int data_unit) |
| 487 | { |
| 488 | int ret = 0; |
| 489 | struct kc_entry *entry = NULL; |
| 490 | bool entry_exists = false; |
| 491 | |
| 492 | if (!kc_is_ready()) |
| 493 | return -ENODEV; |
| 494 | |
| 495 | if (!key || !salt || !key_index) { |
| 496 | pr_err("%s key/salt/key_index NULL\n", __func__); |
| 497 | return -EINVAL; |
| 498 | } |
| 499 | |
| 500 | if (key_size != PFK_KC_KEY_SIZE) { |
| 501 | pr_err("unsupported key size %zu\n", key_size); |
| 502 | return -EINVAL; |
| 503 | } |
| 504 | |
| 505 | if (salt_size != PFK_KC_SALT_SIZE) { |
| 506 | pr_err("unsupported salt size %zu\n", salt_size); |
| 507 | return -EINVAL; |
| 508 | } |
| 509 | |
| 510 | kc_spin_lock(); |
| 511 | |
| 512 | entry = kc_find_key(key, key_size, salt, salt_size); |
| 513 | if (!entry) { |
| 514 | if (async) { |
| 515 | pr_debug("%s task will populate entry\n", __func__); |
| 516 | kc_spin_unlock(); |
| 517 | return -EAGAIN; |
| 518 | } |
| 519 | |
| 520 | entry = kc_find_oldest_entry_non_locked(); |
| 521 | if (!entry) { |
| 522 | /* could not find a single non locked entry, |
| 523 | * return EBUSY to upper layers so that the |
| 524 | * request will be rescheduled |
| 525 | */ |
| 526 | kc_spin_unlock(); |
| 527 | return -EBUSY; |
| 528 | } |
| 529 | } else { |
| 530 | entry_exists = true; |
| 531 | } |
| 532 | |
| 533 | pr_debug("entry with index %d is in state %d\n", |
| 534 | entry->key_index, entry->state); |
| 535 | |
| 536 | switch (entry->state) { |
| 537 | case (INACTIVE): |
| 538 | if (entry_exists) { |
| 539 | kc_update_timestamp(entry); |
| 540 | entry->state = ACTIVE_ICE_LOADED; |
| 541 | |
| 542 | if (!strcmp(s_type, (char *)PFK_UFS)) { |
| 543 | if (async) |
| 544 | entry->loaded_ref_cnt++; |
| 545 | } else { |
| 546 | entry->loaded_ref_cnt++; |
| 547 | } |
| 548 | break; |
| 549 | } |
| 550 | case (FREE): |
| 551 | ret = kc_update_entry(entry, key, key_size, salt, salt_size, |
| 552 | data_unit); |
| 553 | if (ret) { |
| 554 | entry->state = SCM_ERROR; |
| 555 | entry->scm_error = ret; |
| 556 | pr_err("%s: key load error (%d)\n", __func__, ret); |
| 557 | } else { |
| 558 | kc_update_timestamp(entry); |
| 559 | entry->state = ACTIVE_ICE_LOADED; |
| 560 | |
| 561 | /* |
| 562 | * In case of UFS only increase ref cnt for async calls, |
| 563 | * sync calls from within work thread do not pass |
| 564 | * requests further to HW |
| 565 | */ |
| 566 | if (!strcmp(s_type, (char *)PFK_UFS)) { |
| 567 | if (async) |
| 568 | entry->loaded_ref_cnt++; |
| 569 | } else { |
| 570 | entry->loaded_ref_cnt++; |
| 571 | } |
| 572 | } |
| 573 | break; |
| 574 | case (ACTIVE_ICE_PRELOAD): |
| 575 | case (INACTIVE_INVALIDATING): |
| 576 | ret = -EAGAIN; |
| 577 | break; |
| 578 | case (ACTIVE_ICE_LOADED): |
| 579 | kc_update_timestamp(entry); |
| 580 | |
| 581 | if (!strcmp(s_type, (char *)PFK_UFS)) { |
| 582 | if (async) |
| 583 | entry->loaded_ref_cnt++; |
| 584 | } else { |
| 585 | entry->loaded_ref_cnt++; |
| 586 | } |
| 587 | break; |
| 588 | case(SCM_ERROR): |
| 589 | ret = entry->scm_error; |
| 590 | kc_clear_entry(entry); |
| 591 | entry->state = FREE; |
| 592 | break; |
| 593 | default: |
| 594 | pr_err("invalid state %d for entry with key index %d\n", |
| 595 | entry->state, entry->key_index); |
| 596 | ret = -EINVAL; |
| 597 | } |
| 598 | |
| 599 | *key_index = entry->key_index; |
| 600 | kc_spin_unlock(); |
| 601 | |
| 602 | return ret; |
| 603 | } |
| 604 | |
| 605 | /** |
| 606 | * pfk_kc_load_key_end() - finish the process of key loading that was started |
| 607 | * by pfk_kc_load_key_start |
| 608 | * by marking the entry as not |
| 609 | * being in use |
| 610 | * @key: pointer to the key |
| 611 | * @key_size: the size of the key |
| 612 | * @salt: pointer to the salt |
| 613 | * @salt_size: the size of the salt |
| 614 | * |
| 615 | */ |
| 616 | void pfk_kc_load_key_end(const unsigned char *key, size_t key_size, |
| 617 | const unsigned char *salt, size_t salt_size) |
| 618 | { |
| 619 | struct kc_entry *entry = NULL; |
| 620 | struct task_struct *tmp_pending = NULL; |
| 621 | int ref_cnt = 0; |
| 622 | |
| 623 | if (!kc_is_ready()) |
| 624 | return; |
| 625 | |
| 626 | if (!key || !salt) |
| 627 | return; |
| 628 | |
| 629 | if (key_size != PFK_KC_KEY_SIZE) |
| 630 | return; |
| 631 | |
| 632 | if (salt_size != PFK_KC_SALT_SIZE) |
| 633 | return; |
| 634 | |
| 635 | kc_spin_lock(); |
| 636 | |
| 637 | entry = kc_find_key(key, key_size, salt, salt_size); |
| 638 | if (!entry) { |
| 639 | kc_spin_unlock(); |
| 640 | pr_err("internal error, there should an entry to unlock\n"); |
| 641 | |
| 642 | return; |
| 643 | } |
| 644 | ref_cnt = --entry->loaded_ref_cnt; |
| 645 | |
| 646 | if (ref_cnt < 0) |
| 647 | pr_err("internal error, ref count should never be negative\n"); |
| 648 | |
| 649 | if (!ref_cnt) { |
| 650 | entry->state = INACTIVE; |
| 651 | /* |
| 652 | * wake-up invalidation if it's waiting |
| 653 | * for the entry to be released |
| 654 | */ |
| 655 | if (entry->thread_pending) { |
| 656 | tmp_pending = entry->thread_pending; |
| 657 | entry->thread_pending = NULL; |
| 658 | |
| 659 | kc_spin_unlock(); |
| 660 | wake_up_process(tmp_pending); |
| 661 | return; |
| 662 | } |
| 663 | } |
| 664 | |
| 665 | kc_spin_unlock(); |
| 666 | } |
| 667 | |
| 668 | /** |
| 669 | * pfk_kc_remove_key() - remove the key from cache and from ICE engine |
| 670 | * @key: pointer to the key |
| 671 | * @key_size: the size of the key |
| 672 | * @salt: pointer to the key |
| 673 | * @salt_size: the size of the key |
| 674 | * |
| 675 | * Return 0 in case of success, error otherwise (also in case of non |
| 676 | * (existing key) |
| 677 | */ |
| 678 | int pfk_kc_remove_key_with_salt(const unsigned char *key, size_t key_size, |
| 679 | const unsigned char *salt, size_t salt_size) |
| 680 | { |
| 681 | struct kc_entry *entry = NULL; |
| 682 | int res = 0; |
| 683 | |
| 684 | if (!kc_is_ready()) |
| 685 | return -ENODEV; |
| 686 | |
| 687 | if (!key) |
| 688 | return -EINVAL; |
| 689 | |
| 690 | if (!salt) |
| 691 | return -EINVAL; |
| 692 | |
| 693 | if (key_size != PFK_KC_KEY_SIZE) |
| 694 | return -EINVAL; |
| 695 | |
| 696 | if (salt_size != PFK_KC_SALT_SIZE) |
| 697 | return -EINVAL; |
| 698 | |
| 699 | kc_spin_lock(); |
| 700 | |
| 701 | entry = kc_find_key(key, key_size, salt, salt_size); |
| 702 | if (!entry) { |
| 703 | pr_debug("%s: key does not exist\n", __func__); |
| 704 | kc_spin_unlock(); |
| 705 | return -EINVAL; |
| 706 | } |
| 707 | |
| 708 | res = kc_entry_start_invalidating(entry); |
| 709 | if (res != 0) { |
| 710 | kc_spin_unlock(); |
| 711 | return res; |
| 712 | } |
| 713 | kc_clear_entry(entry); |
| 714 | |
| 715 | kc_spin_unlock(); |
| 716 | |
| 717 | qti_pfk_ice_invalidate_key(entry->key_index, s_type); |
| 718 | |
| 719 | kc_spin_lock(); |
| 720 | kc_entry_finish_invalidating(entry); |
| 721 | kc_spin_unlock(); |
| 722 | |
| 723 | return 0; |
| 724 | } |
| 725 | |
| 726 | /** |
| 727 | * pfk_kc_remove_key() - remove the key from cache and from ICE engine |
| 728 | * when no salt is available. Will only search key part, if there are several, |
| 729 | * all will be removed |
| 730 | * |
| 731 | * @key: pointer to the key |
| 732 | * @key_size: the size of the key |
| 733 | * |
| 734 | * Return 0 in case of success, error otherwise (also for non-existing key) |
| 735 | */ |
| 736 | int pfk_kc_remove_key(const unsigned char *key, size_t key_size) |
| 737 | { |
| 738 | struct kc_entry *entry = NULL; |
| 739 | int index = 0; |
| 740 | int temp_indexes[PFK_KC_TABLE_SIZE] = {0}; |
| 741 | int temp_indexes_size = 0; |
| 742 | int i = 0; |
| 743 | int res = 0; |
| 744 | |
| 745 | if (!kc_is_ready()) |
| 746 | return -ENODEV; |
| 747 | |
| 748 | if (!key) |
| 749 | return -EINVAL; |
| 750 | |
| 751 | if (key_size != PFK_KC_KEY_SIZE) |
| 752 | return -EINVAL; |
| 753 | |
| 754 | memset(temp_indexes, -1, sizeof(temp_indexes)); |
| 755 | |
| 756 | kc_spin_lock(); |
| 757 | |
| 758 | entry = kc_find_key_at_index(key, key_size, NULL, 0, &index); |
| 759 | if (!entry) { |
| 760 | pr_err("%s: key does not exist\n", __func__); |
| 761 | kc_spin_unlock(); |
| 762 | return -EINVAL; |
| 763 | } |
| 764 | |
| 765 | res = kc_entry_start_invalidating(entry); |
| 766 | if (res != 0) { |
| 767 | kc_spin_unlock(); |
| 768 | return res; |
| 769 | } |
| 770 | |
| 771 | temp_indexes[temp_indexes_size++] = index; |
| 772 | kc_clear_entry(entry); |
| 773 | |
| 774 | /* let's clean additional entries with the same key if there are any */ |
| 775 | do { |
| 776 | index++; |
| 777 | entry = kc_find_key_at_index(key, key_size, NULL, 0, &index); |
| 778 | if (!entry) |
| 779 | break; |
| 780 | |
| 781 | res = kc_entry_start_invalidating(entry); |
| 782 | if (res != 0) { |
| 783 | kc_spin_unlock(); |
| 784 | goto out; |
| 785 | } |
| 786 | |
| 787 | temp_indexes[temp_indexes_size++] = index; |
| 788 | |
| 789 | kc_clear_entry(entry); |
| 790 | |
| 791 | |
| 792 | } while (true); |
| 793 | |
| 794 | kc_spin_unlock(); |
| 795 | |
| 796 | temp_indexes_size--; |
| 797 | for (i = temp_indexes_size; i >= 0 ; i--) |
| 798 | qti_pfk_ice_invalidate_key( |
| 799 | kc_entry_at_index(temp_indexes[i])->key_index, |
| 800 | s_type); |
| 801 | |
| 802 | /* fall through */ |
| 803 | res = 0; |
| 804 | |
| 805 | out: |
| 806 | kc_spin_lock(); |
| 807 | for (i = temp_indexes_size; i >= 0 ; i--) |
| 808 | kc_entry_finish_invalidating( |
| 809 | kc_entry_at_index(temp_indexes[i])); |
| 810 | kc_spin_unlock(); |
| 811 | |
| 812 | return res; |
| 813 | } |
| 814 | |
| 815 | /** |
| 816 | * pfk_kc_clear() - clear the table and remove all keys from ICE |
| 817 | * |
| 818 | * Return 0 on success, error otherwise |
| 819 | * |
| 820 | */ |
| 821 | int pfk_kc_clear(void) |
| 822 | { |
| 823 | struct kc_entry *entry = NULL; |
| 824 | int i = 0; |
| 825 | int res = 0; |
| 826 | |
| 827 | if (!kc_is_ready()) |
| 828 | return -ENODEV; |
| 829 | |
| 830 | kc_spin_lock(); |
| 831 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) { |
| 832 | entry = kc_entry_at_index(i); |
| 833 | res = kc_entry_start_invalidating(entry); |
| 834 | if (res != 0) { |
| 835 | kc_spin_unlock(); |
| 836 | goto out; |
| 837 | } |
| 838 | kc_clear_entry(entry); |
| 839 | } |
| 840 | kc_spin_unlock(); |
| 841 | |
| 842 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) |
| 843 | qti_pfk_ice_invalidate_key(kc_entry_at_index(i)->key_index, |
| 844 | s_type); |
| 845 | |
| 846 | /* fall through */ |
| 847 | res = 0; |
| 848 | out: |
| 849 | kc_spin_lock(); |
| 850 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) |
| 851 | kc_entry_finish_invalidating(kc_entry_at_index(i)); |
| 852 | kc_spin_unlock(); |
| 853 | |
| 854 | return res; |
| 855 | } |
| 856 | |
| 857 | /** |
| 858 | * pfk_kc_clear_on_reset() - clear the table and remove all keys from ICE |
| 859 | * The assumption is that at this point we don't have any pending transactions |
| 860 | * Also, there is no need to clear keys from ICE |
| 861 | * |
| 862 | * Return 0 on success, error otherwise |
| 863 | * |
| 864 | */ |
| 865 | void pfk_kc_clear_on_reset(void) |
| 866 | { |
| 867 | struct kc_entry *entry = NULL; |
| 868 | int i = 0; |
| 869 | |
| 870 | if (!kc_is_ready()) |
| 871 | return; |
| 872 | |
| 873 | kc_spin_lock(); |
| 874 | for (i = 0; i < PFK_KC_TABLE_SIZE; i++) { |
| 875 | entry = kc_entry_at_index(i); |
| 876 | kc_clear_entry(entry); |
| 877 | } |
| 878 | kc_spin_unlock(); |
| 879 | } |
| 880 | |
| 881 | static int pfk_kc_find_storage_type(char **device) |
| 882 | { |
| 883 | char boot[20] = {'\0'}; |
| 884 | char *match = (char *)strnstr(saved_command_line, |
| 885 | "androidboot.bootdevice=", |
| 886 | strlen(saved_command_line)); |
| 887 | if (match) { |
| 888 | memcpy(boot, (match + strlen("androidboot.bootdevice=")), |
| 889 | sizeof(boot) - 1); |
| 890 | if (strnstr(boot, PFK_UFS, strlen(boot))) |
| 891 | *device = PFK_UFS; |
| 892 | |
| 893 | return 0; |
| 894 | } |
| 895 | return -EINVAL; |
| 896 | } |
| 897 | |
| 898 | static int __init pfk_kc_pre_init(void) |
| 899 | { |
| 900 | return pfk_kc_find_storage_type(&s_type); |
| 901 | } |
| 902 | |
| 903 | static void __exit pfk_kc_exit(void) |
| 904 | { |
| 905 | s_type = NULL; |
| 906 | } |
| 907 | |
| 908 | module_init(pfk_kc_pre_init); |
| 909 | module_exit(pfk_kc_exit); |
| 910 | |
| 911 | MODULE_LICENSE("GPL v2"); |
| 912 | MODULE_DESCRIPTION("Per-File-Key-KC driver"); |