1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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_CALLOUT] = { 168 .entc_cls = &fxrng_lo_push, 169 }, 170 [RANDOM_PURE_OCTEON] = { 171 .entc_cls = &fxrng_hi_push, /* Could be made pull. */ 172 }, 173 [RANDOM_PURE_SAFE] = { 174 .entc_cls = &fxrng_hi_push, 175 }, 176 [RANDOM_PURE_GLXSB] = { 177 .entc_cls = &fxrng_hi_push, 178 }, 179 [RANDOM_PURE_HIFN] = { 180 .entc_cls = &fxrng_hi_push, 181 }, 182 [RANDOM_PURE_RDRAND] = { 183 .entc_cls = &fxrng_hi_pull, 184 }, 185 [RANDOM_PURE_NEHEMIAH] = { 186 .entc_cls = &fxrng_hi_pull, 187 }, 188 [RANDOM_PURE_RNDTEST] = { 189 .entc_cls = &fxrng_garbage, 190 }, 191 [RANDOM_PURE_VIRTIO] = { 192 .entc_cls = &fxrng_hi_pull, 193 }, 194 [RANDOM_PURE_BROADCOM] = { 195 .entc_cls = &fxrng_hi_push, 196 }, 197 [RANDOM_PURE_CCP] = { 198 .entc_cls = &fxrng_hi_pull, 199 }, 200 [RANDOM_PURE_DARN] = { 201 .entc_cls = &fxrng_hi_pull, 202 }, 203 [RANDOM_PURE_TPM] = { 204 .entc_cls = &fxrng_hi_push, 205 }, 206 [RANDOM_PURE_VMGENID] = { 207 .entc_cls = &fxrng_hi_push, 208 }, 209 }; 210 211 /* Useful for single-bit-per-source state. */ 212 BITSET_DEFINE(fxrng_bits, ENTROPYSOURCE); 213 214 /* XXX Borrowed from not-yet-committed D22702. */ 215 #ifndef BIT_TEST_SET_ATOMIC_ACQ 216 #define BIT_TEST_SET_ATOMIC_ACQ(_s, n, p) \ 217 (atomic_testandset_acq_long( \ 218 &(p)->__bits[__bitset_word((_s), (n))], (n)) != 0) 219 #endif 220 #define FXENT_TEST_SET_ATOMIC_ACQ(n, p) \ 221 BIT_TEST_SET_ATOMIC_ACQ(ENTROPYSOURCE, n, p) 222 223 /* For special behavior on first-time entropy sources. (§ 3.1) */ 224 static struct fxrng_bits __read_mostly fxrng_seen; 225 226 /* For special behavior for high-entropy sources after a reseed. (§ 3.4) */ 227 _Static_assert(FXENT_HI_SRC_POOL0_BYTES <= UINT8_MAX, ""); 228 static uint8_t __read_mostly fxrng_reseed_seen[ENTROPYSOURCE]; 229 230 /* Entropy pools. Lock order is ENT -> RNG(root) -> RNG(leaf). */ 231 static struct mtx fxent_pool_lk; 232 MTX_SYSINIT(fx_pool, &fxent_pool_lk, "fx entropy pool lock", MTX_DEF); 233 #define FXENT_LOCK() mtx_lock(&fxent_pool_lk) 234 #define FXENT_UNLOCK() mtx_unlock(&fxent_pool_lk) 235 #define FXENT_ASSERT(rng) mtx_assert(&fxent_pool_lk, MA_OWNED) 236 #define FXENT_ASSERT_NOT(rng) mtx_assert(&fxent_pool_lk, MA_NOTOWNED) 237 static struct fxrng_hash fxent_pool[FXRNG_NPOOLS]; 238 static unsigned __read_mostly fxent_nactpools = 1; 239 static struct timeout_task fxent_reseed_timer; 240 static int __read_mostly fxent_timer_ready; 241 242 /* 243 * Track number of bytes of entropy harvested from high-quality sources prior 244 * to initial keying. The idea is to collect more jitter entropy when fewer 245 * high-quality bytes were available and less if we had other good sources. We 246 * want to provide always-on availability but don't necessarily have *any* 247 * great sources on some platforms. 248 * 249 * Like fxrng_ent_char: at some point, if the design seems reasonable, it would 250 * make more sense to pull this up into the abstraction layer instead. 251 * 252 * Jitter entropy is unimplemented for now. 253 */ 254 static unsigned long fxrng_preseed_ent; 255 256 void 257 fxrng_pools_init(void) 258 { 259 size_t i; 260 261 for (i = 0; i < nitems(fxent_pool); i++) 262 fxrng_hash_init(&fxent_pool[i]); 263 } 264 265 static inline bool 266 fxrng_hi_source(enum random_entropy_source src) 267 { 268 return (fxrng_ent_char[src].entc_cls->entc_src_cls == FXRNG_HI); 269 } 270 271 /* 272 * A racy check that this high-entropy source's event should contribute to 273 * pool0 on the basis of per-source byte count. The check is racy for two 274 * reasons: 275 * - Performance: The vast majority of the time, we've already taken 32 bytes 276 * from any present high quality source and the racy check lets us avoid 277 * dirtying the cache for the global array. 278 * - Correctness: It's fine that the check is racy. The failure modes are: 279 * • False positive: We will detect when we take the lock. 280 * • False negative: We still collect the entropy; it just won't be 281 * preferentially placed in pool0 in this case. 282 */ 283 static inline bool 284 fxrng_hi_pool0_eligible_racy(enum random_entropy_source src) 285 { 286 return (atomic_load_acq_8(&fxrng_reseed_seen[src]) < 287 FXENT_HI_SRC_POOL0_BYTES); 288 } 289 290 /* 291 * Top level entropy processing API from randomdev. 292 * 293 * Invoked by the core randomdev subsystem both for preload entropy, "push" 294 * sources (like interrupts, keyboard, etc) and pull sources (RDRAND, etc). 295 */ 296 void 297 fxrng_event_processor(struct harvest_event *event) 298 { 299 enum random_entropy_source src; 300 unsigned pool; 301 bool first_time, first_32; 302 303 src = event->he_source; 304 305 ASSERT_DEBUG(event->he_size <= sizeof(event->he_entropy), 306 "%s: he_size: %u > sizeof(he_entropy): %zu", __func__, 307 (unsigned)event->he_size, sizeof(event->he_entropy)); 308 309 /* 310 * Zero bytes of source entropy doesn't count as observing this source 311 * for the first time. We still harvest the counter entropy. 312 */ 313 first_time = event->he_size > 0 && 314 !FXENT_TEST_SET_ATOMIC_ACQ(src, &fxrng_seen); 315 if (__predict_false(first_time)) { 316 /* 317 * "The first time [any source] provides entropy, it is used to 318 * directly reseed the root PRNG. The entropy pools are 319 * bypassed." (§ 3.1) 320 * 321 * Unlike Windows, we cannot rely on loader(8) seed material 322 * being present, so we perform initial keying in the kernel. 323 * We use brng_generation 0 to represent an unkeyed state. 324 * 325 * Prior to initial keying, it doesn't make sense to try to mix 326 * the entropy directly with the root PRNG state, as the root 327 * PRNG is unkeyed. Instead, we collect pre-keying dynamic 328 * entropy in pool0 and do not bump the root PRNG seed version 329 * or set its key. Initial keying will incorporate pool0 and 330 * bump the brng_generation (seed version). 331 * 332 * After initial keying, we do directly mix in first-time 333 * entropy sources. We use the root BRNG to generate 32 bytes 334 * and use fxrng_hash to mix it with the new entropy source and 335 * re-key with the first 256 bits of hash output. 336 */ 337 FXENT_LOCK(); 338 FXRNG_BRNG_LOCK(&fxrng_root); 339 if (__predict_true(fxrng_root.brng_generation > 0)) { 340 /* Bypass the pools: */ 341 FXENT_UNLOCK(); 342 fxrng_brng_src_reseed(event); 343 FXRNG_BRNG_ASSERT_NOT(&fxrng_root); 344 return; 345 } 346 347 /* 348 * Keying the root PRNG requires both FXENT_LOCK and the PRNG's 349 * lock, so we only need to hold on to the pool lock to prevent 350 * initial keying without this entropy. 351 */ 352 FXRNG_BRNG_UNLOCK(&fxrng_root); 353 354 /* Root PRNG hasn't been keyed yet, just accumulate event. */ 355 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 356 sizeof(event->he_somecounter)); 357 fxrng_hash_update(&fxent_pool[0], event->he_entropy, 358 event->he_size); 359 360 if (fxrng_hi_source(src)) { 361 /* Prevent overflow. */ 362 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 363 fxrng_preseed_ent += event->he_size; 364 } 365 FXENT_UNLOCK(); 366 return; 367 } 368 /* !first_time */ 369 370 /* 371 * "The first 32 bytes produced by a high entropy source after a reseed 372 * from the pools is always put in pool 0." (§ 3.4) 373 * 374 * The first-32-byte tracking data in fxrng_reseed_seen is reset in 375 * fxent_timer_reseed_npools() below. 376 */ 377 first_32 = event->he_size > 0 && 378 fxrng_hi_source(src) && 379 atomic_load_acq_int(&fxent_nactpools) > 1 && 380 fxrng_hi_pool0_eligible_racy(src); 381 if (__predict_false(first_32)) { 382 unsigned rem, seen; 383 384 FXENT_LOCK(); 385 seen = fxrng_reseed_seen[src]; 386 if (seen == FXENT_HI_SRC_POOL0_BYTES) 387 goto round_robin; 388 389 rem = FXENT_HI_SRC_POOL0_BYTES - seen; 390 rem = MIN(rem, event->he_size); 391 392 fxrng_reseed_seen[src] = seen + rem; 393 394 /* 395 * We put 'rem' bytes in pool0, and any remaining bytes are 396 * round-robin'd across other pools. 397 */ 398 fxrng_hash_update(&fxent_pool[0], 399 ((uint8_t *)event->he_entropy) + event->he_size - rem, 400 rem); 401 if (rem == event->he_size) { 402 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 403 sizeof(event->he_somecounter)); 404 FXENT_UNLOCK(); 405 return; 406 } 407 408 /* 409 * If fewer bytes were needed than this even provied, We only 410 * take the last rem bytes of the entropy buffer and leave the 411 * timecounter to be round-robin'd with the remaining entropy. 412 */ 413 event->he_size -= rem; 414 goto round_robin; 415 } 416 /* !first_32 */ 417 418 FXENT_LOCK(); 419 420 round_robin: 421 FXENT_ASSERT(); 422 pool = event->he_destination % fxent_nactpools; 423 fxrng_hash_update(&fxent_pool[pool], event->he_entropy, 424 event->he_size); 425 fxrng_hash_update(&fxent_pool[pool], &event->he_somecounter, 426 sizeof(event->he_somecounter)); 427 428 if (__predict_false(fxrng_hi_source(src) && 429 atomic_load_acq_64(&fxrng_root_generation) == 0)) { 430 /* Prevent overflow. */ 431 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 432 fxrng_preseed_ent += event->he_size; 433 } 434 FXENT_UNLOCK(); 435 } 436 437 /* 438 * Top level "seeded" API/signal from randomdev. 439 * 440 * This is our warning that a request is coming: we need to be seeded. In 441 * fenestrasX, a request for random bytes _never_ fails. "We (ed: ditto) have 442 * observed that there are many callers that never check for the error code, 443 * even if they are generating cryptographic key material." (§ 1.6) 444 * 445 * If we returned 'false', both read_random(9) and chacha20_randomstir() 446 * (arc4random(9)) will blindly charge on with something almost certainly worse 447 * than what we've got, or are able to get quickly enough. 448 */ 449 bool 450 fxrng_alg_seeded(void) 451 { 452 uint8_t hash[FXRNG_HASH_SZ]; 453 sbintime_t sbt; 454 455 /* The vast majority of the time, we expect to already be seeded. */ 456 if (__predict_true(atomic_load_acq_64(&fxrng_root_generation) != 0)) 457 return (true); 458 459 /* 460 * Take the lock and recheck; only one thread needs to do the initial 461 * seeding work. 462 */ 463 FXENT_LOCK(); 464 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 465 FXENT_UNLOCK(); 466 return (true); 467 } 468 /* XXX Any one-off initial seeding goes here. */ 469 470 fxrng_hash_finish(&fxent_pool[0], hash, sizeof(hash)); 471 fxrng_hash_init(&fxent_pool[0]); 472 473 fxrng_brng_reseed(hash, sizeof(hash)); 474 FXENT_UNLOCK(); 475 476 randomdev_unblock(); 477 explicit_bzero(hash, sizeof(hash)); 478 479 /* 480 * This may be called too early for taskqueue_thread to be initialized. 481 * fxent_pool_timer_init will detect if we've already unblocked and 482 * queue the first timer reseed at that point. 483 */ 484 if (atomic_load_acq_int(&fxent_timer_ready) != 0) { 485 sbt = SBT_1S; 486 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 487 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 488 } 489 return (true); 490 } 491 492 /* 493 * Timer-based reseeds and pool expansion. 494 */ 495 static void 496 fxent_timer_reseed_npools(unsigned n) 497 { 498 /* 499 * 64 * 8 => moderately large 512 bytes. Could be static, as we are 500 * only used in a static context. On the other hand, this is in 501 * threadqueue TASK context and we're likely nearly at top of stack 502 * already. 503 */ 504 uint8_t hash[FXRNG_HASH_SZ * FXRNG_NPOOLS]; 505 unsigned i; 506 507 ASSERT_DEBUG(n > 0 && n <= FXRNG_NPOOLS, "n:%u", n); 508 509 FXENT_ASSERT(); 510 /* 511 * Collect entropy from pools 0..n-1 by concatenating the output hashes 512 * and then feeding them into fxrng_brng_reseed, which will hash the 513 * aggregate together with the current root PRNG keystate to produce a 514 * new key. It will also bump the global generation counter 515 * appropriately. 516 */ 517 for (i = 0; i < n; i++) { 518 fxrng_hash_finish(&fxent_pool[i], hash + i * FXRNG_HASH_SZ, 519 FXRNG_HASH_SZ); 520 fxrng_hash_init(&fxent_pool[i]); 521 } 522 523 fxrng_brng_reseed(hash, n * FXRNG_HASH_SZ); 524 explicit_bzero(hash, n * FXRNG_HASH_SZ); 525 526 /* 527 * "The first 32 bytes produced by a high entropy source after a reseed 528 * from the pools is always put in pool 0." (§ 3.4) 529 * 530 * So here we reset the tracking (somewhat naively given the majority 531 * of sources on most machines are not what we consider "high", but at 532 * 32 bytes it's smaller than a cache line), so the next 32 bytes are 533 * prioritized into pool0. 534 * 535 * See corresponding use of fxrng_reseed_seen in fxrng_event_processor. 536 */ 537 memset(fxrng_reseed_seen, 0, sizeof(fxrng_reseed_seen)); 538 FXENT_ASSERT(); 539 } 540 541 static void 542 fxent_timer_reseed(void *ctx __unused, int pending __unused) 543 { 544 static unsigned reseed_intvl_sec = 1; 545 /* Only reseeds after FXENT_RESEED_INTVL_MAX is achieved. */ 546 static uint64_t reseed_number = 1; 547 548 unsigned next_ival, i, k; 549 sbintime_t sbt; 550 551 if (reseed_intvl_sec < FXENT_RESEED_INTVL_MAX) { 552 next_ival = FXENT_RESSED_INTVL_GFACT * reseed_intvl_sec; 553 if (next_ival > FXENT_RESEED_INTVL_MAX) 554 next_ival = FXENT_RESEED_INTVL_MAX; 555 FXENT_LOCK(); 556 fxent_timer_reseed_npools(1); 557 FXENT_UNLOCK(); 558 } else { 559 /* 560 * The creation of entropy pools beyond 0 is enabled when the 561 * reseed interval hits the maximum. (§ 3.3) 562 */ 563 next_ival = reseed_intvl_sec; 564 565 /* 566 * Pool 0 is used every reseed; pool 1..0 every 3rd reseed; and in 567 * general, pool n..0 every 3^n reseeds. 568 */ 569 k = reseed_number; 570 reseed_number++; 571 572 /* Count how many pools, from [0, i), to use for reseed. */ 573 for (i = 1; i < MIN(fxent_nactpools + 1, FXRNG_NPOOLS); i++) { 574 if ((k % FXENT_RESEED_BASE) != 0) 575 break; 576 k /= FXENT_RESEED_BASE; 577 } 578 579 /* 580 * If we haven't activated pool i yet, activate it and only 581 * reseed from [0, i-1). (§ 3.3) 582 */ 583 FXENT_LOCK(); 584 if (i == fxent_nactpools + 1) { 585 fxent_timer_reseed_npools(fxent_nactpools); 586 fxent_nactpools++; 587 } else { 588 /* Just reseed from [0, i). */ 589 fxent_timer_reseed_npools(i); 590 } 591 FXENT_UNLOCK(); 592 } 593 594 /* Schedule the next reseed. */ 595 sbt = next_ival * SBT_1S; 596 taskqueue_enqueue_timeout_sbt(taskqueue_thread, &fxent_reseed_timer, 597 -sbt, (sbt / 3), C_PREL(2)); 598 599 reseed_intvl_sec = next_ival; 600 } 601 602 static void 603 fxent_pool_timer_init(void *dummy __unused) 604 { 605 sbintime_t sbt; 606 607 TIMEOUT_TASK_INIT(taskqueue_thread, &fxent_reseed_timer, 0, 608 fxent_timer_reseed, NULL); 609 610 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 611 sbt = SBT_1S; 612 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 613 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 614 } 615 atomic_store_rel_int(&fxent_timer_ready, 1); 616 } 617 /* After taskqueue_thread is initialized in SI_SUB_TASKQ:SI_ORDER_SECOND. */ 618 SYSINIT(fxent_pool_timer_init, SI_SUB_TASKQ, SI_ORDER_ANY, 619 fxent_pool_timer_init, NULL); 620