1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2019 Conrad Meyer <cem@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/domainset.h> 33 #include <sys/fail.h> 34 #include <sys/limits.h> 35 #include <sys/lock.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/mutex.h> 39 #include <sys/queue.h> 40 #include <sys/random.h> 41 #include <sys/sdt.h> 42 #include <sys/sysctl.h> 43 #include <sys/systm.h> 44 #include <sys/taskqueue.h> 45 46 #include <machine/atomic.h> 47 #include <machine/smp.h> 48 49 #include <dev/random/randomdev.h> 50 #include <dev/random/random_harvestq.h> 51 52 #include <dev/random/fenestrasX/fx_brng.h> 53 #include <dev/random/fenestrasX/fx_hash.h> 54 #include <dev/random/fenestrasX/fx_pool.h> 55 #include <dev/random/fenestrasX/fx_priv.h> 56 #include <dev/random/fenestrasX/fx_pub.h> 57 58 /* 59 * Timer-based reseed interval growth factor and limit in seconds. (§ 3.2) 60 */ 61 #define FXENT_RESSED_INTVL_GFACT 3 62 #define FXENT_RESEED_INTVL_MAX 3600 63 64 /* 65 * Pool reseed schedule. Initially, only pool 0 is active. Until the timer 66 * interval reaches INTVL_MAX, only pool 0 is used. 67 * 68 * After reaching INTVL_MAX, pool k is either activated (if inactive) or used 69 * (if active) every 3^k timer reseeds. (§ 3.3) 70 * 71 * (Entropy harvesting only round robins across active pools.) 72 */ 73 #define FXENT_RESEED_BASE 3 74 75 /* 76 * Number of bytes from high quality sources to allocate to pool 0 before 77 * normal round-robin allocation after each timer reseed. (§ 3.4) 78 */ 79 #define FXENT_HI_SRC_POOL0_BYTES 32 80 81 /* 82 * § 3.1 83 * 84 * Low sources provide unconditioned entropy, such as mouse movements; high 85 * sources are assumed to provide high-quality random bytes. Pull sources are 86 * those which can be polled, i.e., anything randomdev calls a "random_source." 87 * 88 * In the whitepaper, low sources are pull. For us, at least in the existing 89 * design, low-quality sources push into some global ring buffer and then get 90 * forwarded into the RNG by a thread that continually polls. Presumably their 91 * design batches low entopy signals in some way (SHA512?) and only requests 92 * them dynamically on reseed. I'm not sure what the benefit is vs feeding 93 * into the pools directly. 94 */ 95 enum fxrng_ent_access_cls { 96 FXRNG_PUSH, 97 FXRNG_PULL, 98 }; 99 enum fxrng_ent_source_cls { 100 FXRNG_HI, 101 FXRNG_LO, 102 FXRNG_GARBAGE, 103 }; 104 struct fxrng_ent_cls { 105 enum fxrng_ent_access_cls entc_axx_cls; 106 enum fxrng_ent_source_cls entc_src_cls; 107 }; 108 109 static const struct fxrng_ent_cls fxrng_hi_pull = { 110 .entc_axx_cls = FXRNG_PULL, 111 .entc_src_cls = FXRNG_HI, 112 }; 113 static const struct fxrng_ent_cls fxrng_hi_push = { 114 .entc_axx_cls = FXRNG_PUSH, 115 .entc_src_cls = FXRNG_HI, 116 }; 117 static const struct fxrng_ent_cls fxrng_lo_push = { 118 .entc_axx_cls = FXRNG_PUSH, 119 .entc_src_cls = FXRNG_LO, 120 }; 121 static const struct fxrng_ent_cls fxrng_garbage = { 122 .entc_axx_cls = FXRNG_PUSH, 123 .entc_src_cls = FXRNG_GARBAGE, 124 }; 125 126 /* 127 * This table is a mapping of randomdev's current source abstractions to the 128 * designations above; at some point, if the design seems reasonable, it would 129 * make more sense to pull this up into the abstraction layer instead. 130 */ 131 static const struct fxrng_ent_char { 132 const struct fxrng_ent_cls *entc_cls; 133 } fxrng_ent_char[ENTROPYSOURCE] = { 134 [RANDOM_CACHED] = { 135 .entc_cls = &fxrng_hi_push, 136 }, 137 [RANDOM_ATTACH] = { 138 .entc_cls = &fxrng_lo_push, 139 }, 140 [RANDOM_KEYBOARD] = { 141 .entc_cls = &fxrng_lo_push, 142 }, 143 [RANDOM_MOUSE] = { 144 .entc_cls = &fxrng_lo_push, 145 }, 146 [RANDOM_NET_TUN] = { 147 .entc_cls = &fxrng_lo_push, 148 }, 149 [RANDOM_NET_ETHER] = { 150 .entc_cls = &fxrng_lo_push, 151 }, 152 [RANDOM_NET_NG] = { 153 .entc_cls = &fxrng_lo_push, 154 }, 155 [RANDOM_INTERRUPT] = { 156 .entc_cls = &fxrng_lo_push, 157 }, 158 [RANDOM_SWI] = { 159 .entc_cls = &fxrng_lo_push, 160 }, 161 [RANDOM_FS_ATIME] = { 162 .entc_cls = &fxrng_lo_push, 163 }, 164 [RANDOM_UMA] = { 165 .entc_cls = &fxrng_lo_push, 166 }, 167 [RANDOM_PURE_OCTEON] = { 168 .entc_cls = &fxrng_hi_push, /* Could be made pull. */ 169 }, 170 [RANDOM_PURE_SAFE] = { 171 .entc_cls = &fxrng_hi_push, 172 }, 173 [RANDOM_PURE_GLXSB] = { 174 .entc_cls = &fxrng_hi_push, 175 }, 176 [RANDOM_PURE_HIFN] = { 177 .entc_cls = &fxrng_hi_push, 178 }, 179 [RANDOM_PURE_RDRAND] = { 180 .entc_cls = &fxrng_hi_pull, 181 }, 182 [RANDOM_PURE_NEHEMIAH] = { 183 .entc_cls = &fxrng_hi_pull, 184 }, 185 [RANDOM_PURE_RNDTEST] = { 186 .entc_cls = &fxrng_garbage, 187 }, 188 [RANDOM_PURE_VIRTIO] = { 189 .entc_cls = &fxrng_hi_pull, 190 }, 191 [RANDOM_PURE_BROADCOM] = { 192 .entc_cls = &fxrng_hi_push, 193 }, 194 [RANDOM_PURE_CCP] = { 195 .entc_cls = &fxrng_hi_pull, 196 }, 197 [RANDOM_PURE_DARN] = { 198 .entc_cls = &fxrng_hi_pull, 199 }, 200 [RANDOM_PURE_TPM] = { 201 .entc_cls = &fxrng_hi_push, 202 }, 203 [RANDOM_PURE_VMGENID] = { 204 .entc_cls = &fxrng_hi_push, 205 }, 206 }; 207 208 /* Useful for single-bit-per-source state. */ 209 BITSET_DEFINE(fxrng_bits, ENTROPYSOURCE); 210 211 /* XXX Borrowed from not-yet-committed D22702. */ 212 #ifndef BIT_TEST_SET_ATOMIC_ACQ 213 #define BIT_TEST_SET_ATOMIC_ACQ(_s, n, p) \ 214 (atomic_testandset_acq_long( \ 215 &(p)->__bits[__bitset_word((_s), (n))], (n)) != 0) 216 #endif 217 #define FXENT_TEST_SET_ATOMIC_ACQ(n, p) \ 218 BIT_TEST_SET_ATOMIC_ACQ(ENTROPYSOURCE, n, p) 219 220 /* For special behavior on first-time entropy sources. (§ 3.1) */ 221 static struct fxrng_bits __read_mostly fxrng_seen; 222 223 /* For special behavior for high-entropy sources after a reseed. (§ 3.4) */ 224 _Static_assert(FXENT_HI_SRC_POOL0_BYTES <= UINT8_MAX, ""); 225 static uint8_t __read_mostly fxrng_reseed_seen[ENTROPYSOURCE]; 226 227 /* Entropy pools. Lock order is ENT -> RNG(root) -> RNG(leaf). */ 228 static struct mtx fxent_pool_lk; 229 MTX_SYSINIT(fx_pool, &fxent_pool_lk, "fx entropy pool lock", MTX_DEF); 230 #define FXENT_LOCK() mtx_lock(&fxent_pool_lk) 231 #define FXENT_UNLOCK() mtx_unlock(&fxent_pool_lk) 232 #define FXENT_ASSERT(rng) mtx_assert(&fxent_pool_lk, MA_OWNED) 233 #define FXENT_ASSERT_NOT(rng) mtx_assert(&fxent_pool_lk, MA_NOTOWNED) 234 static struct fxrng_hash fxent_pool[FXRNG_NPOOLS]; 235 static unsigned __read_mostly fxent_nactpools = 1; 236 static struct timeout_task fxent_reseed_timer; 237 static int __read_mostly fxent_timer_ready; 238 239 /* 240 * Track number of bytes of entropy harvested from high-quality sources prior 241 * to initial keying. The idea is to collect more jitter entropy when fewer 242 * high-quality bytes were available and less if we had other good sources. We 243 * want to provide always-on availability but don't necessarily have *any* 244 * great sources on some platforms. 245 * 246 * Like fxrng_ent_char: at some point, if the design seems reasonable, it would 247 * make more sense to pull this up into the abstraction layer instead. 248 * 249 * Jitter entropy is unimplemented for now. 250 */ 251 static unsigned long fxrng_preseed_ent; 252 253 void 254 fxrng_pools_init(void) 255 { 256 size_t i; 257 258 for (i = 0; i < nitems(fxent_pool); i++) 259 fxrng_hash_init(&fxent_pool[i]); 260 } 261 262 static inline bool 263 fxrng_hi_source(enum random_entropy_source src) 264 { 265 return (fxrng_ent_char[src].entc_cls->entc_src_cls == FXRNG_HI); 266 } 267 268 /* 269 * A racy check that this high-entropy source's event should contribute to 270 * pool0 on the basis of per-source byte count. The check is racy for two 271 * reasons: 272 * - Performance: The vast majority of the time, we've already taken 32 bytes 273 * from any present high quality source and the racy check lets us avoid 274 * dirtying the cache for the global array. 275 * - Correctness: It's fine that the check is racy. The failure modes are: 276 * • False positive: We will detect when we take the lock. 277 * • False negative: We still collect the entropy; it just won't be 278 * preferentially placed in pool0 in this case. 279 */ 280 static inline bool 281 fxrng_hi_pool0_eligible_racy(enum random_entropy_source src) 282 { 283 return (atomic_load_acq_8(&fxrng_reseed_seen[src]) < 284 FXENT_HI_SRC_POOL0_BYTES); 285 } 286 287 /* 288 * Top level entropy processing API from randomdev. 289 * 290 * Invoked by the core randomdev subsystem both for preload entropy, "push" 291 * sources (like interrupts, keyboard, etc) and pull sources (RDRAND, etc). 292 */ 293 void 294 fxrng_event_processor(struct harvest_event *event) 295 { 296 enum random_entropy_source src; 297 unsigned pool; 298 bool first_time, first_32; 299 300 src = event->he_source; 301 302 ASSERT_DEBUG(event->he_size <= sizeof(event->he_entropy), 303 "%s: he_size: %u > sizeof(he_entropy): %zu", __func__, 304 (unsigned)event->he_size, sizeof(event->he_entropy)); 305 306 /* 307 * Zero bytes of source entropy doesn't count as observing this source 308 * for the first time. We still harvest the counter entropy. 309 */ 310 first_time = event->he_size > 0 && 311 !FXENT_TEST_SET_ATOMIC_ACQ(src, &fxrng_seen); 312 if (__predict_false(first_time)) { 313 /* 314 * "The first time [any source] provides entropy, it is used to 315 * directly reseed the root PRNG. The entropy pools are 316 * bypassed." (§ 3.1) 317 * 318 * Unlike Windows, we cannot rely on loader(8) seed material 319 * being present, so we perform initial keying in the kernel. 320 * We use brng_generation 0 to represent an unkeyed state. 321 * 322 * Prior to initial keying, it doesn't make sense to try to mix 323 * the entropy directly with the root PRNG state, as the root 324 * PRNG is unkeyed. Instead, we collect pre-keying dynamic 325 * entropy in pool0 and do not bump the root PRNG seed version 326 * or set its key. Initial keying will incorporate pool0 and 327 * bump the brng_generation (seed version). 328 * 329 * After initial keying, we do directly mix in first-time 330 * entropy sources. We use the root BRNG to generate 32 bytes 331 * and use fxrng_hash to mix it with the new entropy source and 332 * re-key with the first 256 bits of hash output. 333 */ 334 FXENT_LOCK(); 335 FXRNG_BRNG_LOCK(&fxrng_root); 336 if (__predict_true(fxrng_root.brng_generation > 0)) { 337 /* Bypass the pools: */ 338 FXENT_UNLOCK(); 339 fxrng_brng_src_reseed(event); 340 FXRNG_BRNG_ASSERT_NOT(&fxrng_root); 341 return; 342 } 343 344 /* 345 * Keying the root PRNG requires both FXENT_LOCK and the PRNG's 346 * lock, so we only need to hold on to the pool lock to prevent 347 * initial keying without this entropy. 348 */ 349 FXRNG_BRNG_UNLOCK(&fxrng_root); 350 351 /* Root PRNG hasn't been keyed yet, just accumulate event. */ 352 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 353 sizeof(event->he_somecounter)); 354 fxrng_hash_update(&fxent_pool[0], event->he_entropy, 355 event->he_size); 356 357 if (fxrng_hi_source(src)) { 358 /* Prevent overflow. */ 359 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 360 fxrng_preseed_ent += event->he_size; 361 } 362 FXENT_UNLOCK(); 363 return; 364 } 365 /* !first_time */ 366 367 /* 368 * "The first 32 bytes produced by a high entropy source after a reseed 369 * from the pools is always put in pool 0." (§ 3.4) 370 * 371 * The first-32-byte tracking data in fxrng_reseed_seen is reset in 372 * fxent_timer_reseed_npools() below. 373 */ 374 first_32 = event->he_size > 0 && 375 fxrng_hi_source(src) && 376 atomic_load_acq_int(&fxent_nactpools) > 1 && 377 fxrng_hi_pool0_eligible_racy(src); 378 if (__predict_false(first_32)) { 379 unsigned rem, seen; 380 381 FXENT_LOCK(); 382 seen = fxrng_reseed_seen[src]; 383 if (seen == FXENT_HI_SRC_POOL0_BYTES) 384 goto round_robin; 385 386 rem = FXENT_HI_SRC_POOL0_BYTES - seen; 387 rem = MIN(rem, event->he_size); 388 389 fxrng_reseed_seen[src] = seen + rem; 390 391 /* 392 * We put 'rem' bytes in pool0, and any remaining bytes are 393 * round-robin'd across other pools. 394 */ 395 fxrng_hash_update(&fxent_pool[0], 396 ((uint8_t *)event->he_entropy) + event->he_size - rem, 397 rem); 398 if (rem == event->he_size) { 399 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 400 sizeof(event->he_somecounter)); 401 FXENT_UNLOCK(); 402 return; 403 } 404 405 /* 406 * If fewer bytes were needed than this even provied, We only 407 * take the last rem bytes of the entropy buffer and leave the 408 * timecounter to be round-robin'd with the remaining entropy. 409 */ 410 event->he_size -= rem; 411 goto round_robin; 412 } 413 /* !first_32 */ 414 415 FXENT_LOCK(); 416 417 round_robin: 418 FXENT_ASSERT(); 419 pool = event->he_destination % fxent_nactpools; 420 fxrng_hash_update(&fxent_pool[pool], event->he_entropy, 421 event->he_size); 422 fxrng_hash_update(&fxent_pool[pool], &event->he_somecounter, 423 sizeof(event->he_somecounter)); 424 425 if (__predict_false(fxrng_hi_source(src) && 426 atomic_load_acq_64(&fxrng_root_generation) == 0)) { 427 /* Prevent overflow. */ 428 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 429 fxrng_preseed_ent += event->he_size; 430 } 431 FXENT_UNLOCK(); 432 } 433 434 /* 435 * Top level "seeded" API/signal from randomdev. 436 * 437 * This is our warning that a request is coming: we need to be seeded. In 438 * fenestrasX, a request for random bytes _never_ fails. "We (ed: ditto) have 439 * observed that there are many callers that never check for the error code, 440 * even if they are generating cryptographic key material." (§ 1.6) 441 * 442 * If we returned 'false', both read_random(9) and chacha20_randomstir() 443 * (arc4random(9)) will blindly charge on with something almost certainly worse 444 * than what we've got, or are able to get quickly enough. 445 */ 446 bool 447 fxrng_alg_seeded(void) 448 { 449 uint8_t hash[FXRNG_HASH_SZ]; 450 sbintime_t sbt; 451 452 /* The vast majority of the time, we expect to already be seeded. */ 453 if (__predict_true(atomic_load_acq_64(&fxrng_root_generation) != 0)) 454 return (true); 455 456 /* 457 * Take the lock and recheck; only one thread needs to do the initial 458 * seeding work. 459 */ 460 FXENT_LOCK(); 461 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 462 FXENT_UNLOCK(); 463 return (true); 464 } 465 /* XXX Any one-off initial seeding goes here. */ 466 467 fxrng_hash_finish(&fxent_pool[0], hash, sizeof(hash)); 468 fxrng_hash_init(&fxent_pool[0]); 469 470 fxrng_brng_reseed(hash, sizeof(hash)); 471 FXENT_UNLOCK(); 472 473 randomdev_unblock(); 474 explicit_bzero(hash, sizeof(hash)); 475 476 /* 477 * This may be called too early for taskqueue_thread to be initialized. 478 * fxent_pool_timer_init will detect if we've already unblocked and 479 * queue the first timer reseed at that point. 480 */ 481 if (atomic_load_acq_int(&fxent_timer_ready) != 0) { 482 sbt = SBT_1S; 483 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 484 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 485 } 486 return (true); 487 } 488 489 /* 490 * Timer-based reseeds and pool expansion. 491 */ 492 static void 493 fxent_timer_reseed_npools(unsigned n) 494 { 495 /* 496 * 64 * 8 => moderately large 512 bytes. Could be static, as we are 497 * only used in a static context. On the other hand, this is in 498 * threadqueue TASK context and we're likely nearly at top of stack 499 * already. 500 */ 501 uint8_t hash[FXRNG_HASH_SZ * FXRNG_NPOOLS]; 502 unsigned i; 503 504 ASSERT_DEBUG(n > 0 && n <= FXRNG_NPOOLS, "n:%u", n); 505 506 FXENT_ASSERT(); 507 /* 508 * Collect entropy from pools 0..n-1 by concatenating the output hashes 509 * and then feeding them into fxrng_brng_reseed, which will hash the 510 * aggregate together with the current root PRNG keystate to produce a 511 * new key. It will also bump the global generation counter 512 * appropriately. 513 */ 514 for (i = 0; i < n; i++) { 515 fxrng_hash_finish(&fxent_pool[i], hash + i * FXRNG_HASH_SZ, 516 FXRNG_HASH_SZ); 517 fxrng_hash_init(&fxent_pool[i]); 518 } 519 520 fxrng_brng_reseed(hash, n * FXRNG_HASH_SZ); 521 explicit_bzero(hash, n * FXRNG_HASH_SZ); 522 523 /* 524 * "The first 32 bytes produced by a high entropy source after a reseed 525 * from the pools is always put in pool 0." (§ 3.4) 526 * 527 * So here we reset the tracking (somewhat naively given the majority 528 * of sources on most machines are not what we consider "high", but at 529 * 32 bytes it's smaller than a cache line), so the next 32 bytes are 530 * prioritized into pool0. 531 * 532 * See corresponding use of fxrng_reseed_seen in fxrng_event_processor. 533 */ 534 memset(fxrng_reseed_seen, 0, sizeof(fxrng_reseed_seen)); 535 FXENT_ASSERT(); 536 } 537 538 static void 539 fxent_timer_reseed(void *ctx __unused, int pending __unused) 540 { 541 static unsigned reseed_intvl_sec = 1; 542 /* Only reseeds after FXENT_RESEED_INTVL_MAX is achieved. */ 543 static uint64_t reseed_number = 1; 544 545 unsigned next_ival, i, k; 546 sbintime_t sbt; 547 548 if (reseed_intvl_sec < FXENT_RESEED_INTVL_MAX) { 549 next_ival = FXENT_RESSED_INTVL_GFACT * reseed_intvl_sec; 550 if (next_ival > FXENT_RESEED_INTVL_MAX) 551 next_ival = FXENT_RESEED_INTVL_MAX; 552 FXENT_LOCK(); 553 fxent_timer_reseed_npools(1); 554 FXENT_UNLOCK(); 555 } else { 556 /* 557 * The creation of entropy pools beyond 0 is enabled when the 558 * reseed interval hits the maximum. (§ 3.3) 559 */ 560 next_ival = reseed_intvl_sec; 561 562 /* 563 * Pool 0 is used every reseed; pool 1..0 every 3rd reseed; and in 564 * general, pool n..0 every 3^n reseeds. 565 */ 566 k = reseed_number; 567 reseed_number++; 568 569 /* Count how many pools, from [0, i), to use for reseed. */ 570 for (i = 1; i < MIN(fxent_nactpools + 1, FXRNG_NPOOLS); i++) { 571 if ((k % FXENT_RESEED_BASE) != 0) 572 break; 573 k /= FXENT_RESEED_BASE; 574 } 575 576 /* 577 * If we haven't activated pool i yet, activate it and only 578 * reseed from [0, i-1). (§ 3.3) 579 */ 580 FXENT_LOCK(); 581 if (i == fxent_nactpools + 1) { 582 fxent_timer_reseed_npools(fxent_nactpools); 583 fxent_nactpools++; 584 } else { 585 /* Just reseed from [0, i). */ 586 fxent_timer_reseed_npools(i); 587 } 588 FXENT_UNLOCK(); 589 } 590 591 /* Schedule the next reseed. */ 592 sbt = next_ival * SBT_1S; 593 taskqueue_enqueue_timeout_sbt(taskqueue_thread, &fxent_reseed_timer, 594 -sbt, (sbt / 3), C_PREL(2)); 595 596 reseed_intvl_sec = next_ival; 597 } 598 599 static void 600 fxent_pool_timer_init(void *dummy __unused) 601 { 602 sbintime_t sbt; 603 604 TIMEOUT_TASK_INIT(taskqueue_thread, &fxent_reseed_timer, 0, 605 fxent_timer_reseed, NULL); 606 607 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 608 sbt = SBT_1S; 609 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 610 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 611 } 612 atomic_store_rel_int(&fxent_timer_ready, 1); 613 } 614 /* After taskqueue_thread is initialized in SI_SUB_TASKQ:SI_ORDER_SECOND. */ 615 SYSINIT(fxent_pool_timer_init, SI_SUB_TASKQ, SI_ORDER_ANY, 616 fxent_pool_timer_init, NULL); 617