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/param.h> 29 #include <sys/domainset.h> 30 #include <sys/fail.h> 31 #include <sys/limits.h> 32 #include <sys/lock.h> 33 #include <sys/kernel.h> 34 #include <sys/malloc.h> 35 #include <sys/mutex.h> 36 #include <sys/queue.h> 37 #include <sys/random.h> 38 #include <sys/sdt.h> 39 #include <sys/sysctl.h> 40 #include <sys/systm.h> 41 #include <sys/taskqueue.h> 42 43 #include <machine/atomic.h> 44 #include <machine/smp.h> 45 46 #include <dev/random/randomdev.h> 47 #include <dev/random/random_harvestq.h> 48 49 #include <dev/random/fenestrasX/fx_brng.h> 50 #include <dev/random/fenestrasX/fx_hash.h> 51 #include <dev/random/fenestrasX/fx_pool.h> 52 #include <dev/random/fenestrasX/fx_priv.h> 53 #include <dev/random/fenestrasX/fx_pub.h> 54 55 /* 56 * Timer-based reseed interval growth factor and limit in seconds. (§ 3.2) 57 */ 58 #define FXENT_RESSED_INTVL_GFACT 3 59 #define FXENT_RESEED_INTVL_MAX 3600 60 61 /* 62 * Pool reseed schedule. Initially, only pool 0 is active. Until the timer 63 * interval reaches INTVL_MAX, only pool 0 is used. 64 * 65 * After reaching INTVL_MAX, pool k is either activated (if inactive) or used 66 * (if active) every 3^k timer reseeds. (§ 3.3) 67 * 68 * (Entropy harvesting only round robins across active pools.) 69 */ 70 #define FXENT_RESEED_BASE 3 71 72 /* 73 * Number of bytes from high quality sources to allocate to pool 0 before 74 * normal round-robin allocation after each timer reseed. (§ 3.4) 75 */ 76 #define FXENT_HI_SRC_POOL0_BYTES 32 77 78 /* 79 * § 3.1 80 * 81 * Low sources provide unconditioned entropy, such as mouse movements; high 82 * sources are assumed to provide high-quality random bytes. Pull sources are 83 * those which can be polled, i.e., anything randomdev calls a "random_source." 84 * 85 * In the whitepaper, low sources are pull. For us, at least in the existing 86 * design, low-quality sources push into some global ring buffer and then get 87 * forwarded into the RNG by a thread that continually polls. Presumably their 88 * design batches low entopy signals in some way (SHA512?) and only requests 89 * them dynamically on reseed. I'm not sure what the benefit is vs feeding 90 * into the pools directly. 91 */ 92 enum fxrng_ent_access_cls { 93 FXRNG_PUSH, 94 FXRNG_PULL, 95 }; 96 enum fxrng_ent_source_cls { 97 FXRNG_HI, 98 FXRNG_LO, 99 FXRNG_GARBAGE, 100 }; 101 struct fxrng_ent_cls { 102 enum fxrng_ent_access_cls entc_axx_cls; 103 enum fxrng_ent_source_cls entc_src_cls; 104 }; 105 106 static const struct fxrng_ent_cls fxrng_hi_pull = { 107 .entc_axx_cls = FXRNG_PULL, 108 .entc_src_cls = FXRNG_HI, 109 }; 110 static const struct fxrng_ent_cls fxrng_hi_push = { 111 .entc_axx_cls = FXRNG_PUSH, 112 .entc_src_cls = FXRNG_HI, 113 }; 114 static const struct fxrng_ent_cls fxrng_lo_push = { 115 .entc_axx_cls = FXRNG_PUSH, 116 .entc_src_cls = FXRNG_LO, 117 }; 118 static const struct fxrng_ent_cls fxrng_garbage = { 119 .entc_axx_cls = FXRNG_PUSH, 120 .entc_src_cls = FXRNG_GARBAGE, 121 }; 122 123 /* 124 * This table is a mapping of randomdev's current source abstractions to the 125 * designations above; at some point, if the design seems reasonable, it would 126 * make more sense to pull this up into the abstraction layer instead. 127 */ 128 static const struct fxrng_ent_char { 129 const struct fxrng_ent_cls *entc_cls; 130 } fxrng_ent_char[ENTROPYSOURCE] = { 131 [RANDOM_CACHED] = { 132 .entc_cls = &fxrng_hi_push, 133 }, 134 [RANDOM_ATTACH] = { 135 .entc_cls = &fxrng_lo_push, 136 }, 137 [RANDOM_KEYBOARD] = { 138 .entc_cls = &fxrng_lo_push, 139 }, 140 [RANDOM_MOUSE] = { 141 .entc_cls = &fxrng_lo_push, 142 }, 143 [RANDOM_NET_TUN] = { 144 .entc_cls = &fxrng_lo_push, 145 }, 146 [RANDOM_NET_ETHER] = { 147 .entc_cls = &fxrng_lo_push, 148 }, 149 [RANDOM_NET_NG] = { 150 .entc_cls = &fxrng_lo_push, 151 }, 152 [RANDOM_INTERRUPT] = { 153 .entc_cls = &fxrng_lo_push, 154 }, 155 [RANDOM_SWI] = { 156 .entc_cls = &fxrng_lo_push, 157 }, 158 [RANDOM_FS_ATIME] = { 159 .entc_cls = &fxrng_lo_push, 160 }, 161 [RANDOM_UMA] = { 162 .entc_cls = &fxrng_lo_push, 163 }, 164 [RANDOM_CALLOUT] = { 165 .entc_cls = &fxrng_lo_push, 166 }, 167 [RANDOM_RANDOMDEV] = { 168 .entc_cls = &fxrng_lo_push, 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_RDRAND] = { 177 .entc_cls = &fxrng_hi_pull, 178 }, 179 [RANDOM_PURE_RDSEED] = { 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 [RANDOM_PURE_QUALCOMM] = { 207 .entc_cls = &fxrng_hi_pull, 208 }, 209 [RANDOM_PURE_ARMV8] = { 210 .entc_cls = &fxrng_hi_pull, 211 }, 212 [RANDOM_PURE_ARM_TRNG] = { 213 .entc_cls = &fxrng_hi_pull, 214 }, 215 }; 216 217 /* Useful for single-bit-per-source state. */ 218 BITSET_DEFINE(fxrng_bits, ENTROPYSOURCE); 219 220 /* XXX Borrowed from not-yet-committed D22702. */ 221 #ifndef BIT_TEST_SET_ATOMIC_ACQ 222 #define BIT_TEST_SET_ATOMIC_ACQ(_s, n, p) \ 223 (atomic_testandset_acq_long( \ 224 &(p)->__bits[__bitset_word((_s), (n))], (n)) != 0) 225 #endif 226 #define FXENT_TEST_SET_ATOMIC_ACQ(n, p) \ 227 BIT_TEST_SET_ATOMIC_ACQ(ENTROPYSOURCE, n, p) 228 229 /* For special behavior on first-time entropy sources. (§ 3.1) */ 230 static struct fxrng_bits __read_mostly fxrng_seen; 231 232 /* For special behavior for high-entropy sources after a reseed. (§ 3.4) */ 233 _Static_assert(FXENT_HI_SRC_POOL0_BYTES <= UINT8_MAX, ""); 234 static uint8_t __read_mostly fxrng_reseed_seen[ENTROPYSOURCE]; 235 236 /* Entropy pools. Lock order is ENT -> RNG(root) -> RNG(leaf). */ 237 static struct mtx fxent_pool_lk; 238 MTX_SYSINIT(fx_pool, &fxent_pool_lk, "fx entropy pool lock", MTX_DEF); 239 #define FXENT_LOCK() mtx_lock(&fxent_pool_lk) 240 #define FXENT_UNLOCK() mtx_unlock(&fxent_pool_lk) 241 #define FXENT_ASSERT(rng) mtx_assert(&fxent_pool_lk, MA_OWNED) 242 #define FXENT_ASSERT_NOT(rng) mtx_assert(&fxent_pool_lk, MA_NOTOWNED) 243 static struct fxrng_hash fxent_pool[FXRNG_NPOOLS]; 244 static unsigned __read_mostly fxent_nactpools = 1; 245 static struct timeout_task fxent_reseed_timer; 246 static int __read_mostly fxent_timer_ready; 247 248 /* 249 * Track number of bytes of entropy harvested from high-quality sources prior 250 * to initial keying. The idea is to collect more jitter entropy when fewer 251 * high-quality bytes were available and less if we had other good sources. We 252 * want to provide always-on availability but don't necessarily have *any* 253 * great sources on some platforms. 254 * 255 * Like fxrng_ent_char: at some point, if the design seems reasonable, it would 256 * make more sense to pull this up into the abstraction layer instead. 257 * 258 * Jitter entropy is unimplemented for now. 259 */ 260 static unsigned long fxrng_preseed_ent; 261 262 void 263 fxrng_pools_init(void) 264 { 265 size_t i; 266 267 for (i = 0; i < nitems(fxent_pool); i++) 268 fxrng_hash_init(&fxent_pool[i]); 269 } 270 271 static inline bool 272 fxrng_hi_source(enum random_entropy_source src) 273 { 274 return (fxrng_ent_char[src].entc_cls->entc_src_cls == FXRNG_HI); 275 } 276 277 /* 278 * A racy check that this high-entropy source's event should contribute to 279 * pool0 on the basis of per-source byte count. The check is racy for two 280 * reasons: 281 * - Performance: The vast majority of the time, we've already taken 32 bytes 282 * from any present high quality source and the racy check lets us avoid 283 * dirtying the cache for the global array. 284 * - Correctness: It's fine that the check is racy. The failure modes are: 285 * • False positive: We will detect when we take the lock. 286 * • False negative: We still collect the entropy; it just won't be 287 * preferentially placed in pool0 in this case. 288 */ 289 static inline bool 290 fxrng_hi_pool0_eligible_racy(enum random_entropy_source src) 291 { 292 return (atomic_load_acq_8(&fxrng_reseed_seen[src]) < 293 FXENT_HI_SRC_POOL0_BYTES); 294 } 295 296 /* 297 * Top level entropy processing API from randomdev. 298 * 299 * Invoked by the core randomdev subsystem both for preload entropy, "push" 300 * sources (like interrupts, keyboard, etc) and pull sources (RDRAND, etc). 301 */ 302 void 303 fxrng_event_processor(struct harvest_event *event) 304 { 305 enum random_entropy_source src; 306 unsigned pool; 307 bool first_time, first_32; 308 309 src = event->he_source; 310 311 ASSERT_DEBUG(event->he_size <= sizeof(event->he_entropy), 312 "%s: he_size: %u > sizeof(he_entropy): %zu", __func__, 313 (unsigned)event->he_size, sizeof(event->he_entropy)); 314 315 /* 316 * Zero bytes of source entropy doesn't count as observing this source 317 * for the first time. We still harvest the counter entropy. 318 */ 319 first_time = event->he_size > 0 && 320 !FXENT_TEST_SET_ATOMIC_ACQ(src, &fxrng_seen); 321 if (__predict_false(first_time)) { 322 /* 323 * "The first time [any source] provides entropy, it is used to 324 * directly reseed the root PRNG. The entropy pools are 325 * bypassed." (§ 3.1) 326 * 327 * Unlike Windows, we cannot rely on loader(8) seed material 328 * being present, so we perform initial keying in the kernel. 329 * We use brng_generation 0 to represent an unkeyed state. 330 * 331 * Prior to initial keying, it doesn't make sense to try to mix 332 * the entropy directly with the root PRNG state, as the root 333 * PRNG is unkeyed. Instead, we collect pre-keying dynamic 334 * entropy in pool0 and do not bump the root PRNG seed version 335 * or set its key. Initial keying will incorporate pool0 and 336 * bump the brng_generation (seed version). 337 * 338 * After initial keying, we do directly mix in first-time 339 * entropy sources. We use the root BRNG to generate 32 bytes 340 * and use fxrng_hash to mix it with the new entropy source and 341 * re-key with the first 256 bits of hash output. 342 */ 343 FXENT_LOCK(); 344 FXRNG_BRNG_LOCK(&fxrng_root); 345 if (__predict_true(fxrng_root.brng_generation > 0)) { 346 /* Bypass the pools: */ 347 FXENT_UNLOCK(); 348 fxrng_brng_src_reseed(event); 349 FXRNG_BRNG_ASSERT_NOT(&fxrng_root); 350 return; 351 } 352 353 /* 354 * Keying the root PRNG requires both FXENT_LOCK and the PRNG's 355 * lock, so we only need to hold on to the pool lock to prevent 356 * initial keying without this entropy. 357 */ 358 FXRNG_BRNG_UNLOCK(&fxrng_root); 359 360 /* Root PRNG hasn't been keyed yet, just accumulate event. */ 361 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 362 sizeof(event->he_somecounter)); 363 fxrng_hash_update(&fxent_pool[0], event->he_entropy, 364 event->he_size); 365 366 if (fxrng_hi_source(src)) { 367 /* Prevent overflow. */ 368 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 369 fxrng_preseed_ent += event->he_size; 370 } 371 FXENT_UNLOCK(); 372 return; 373 } 374 /* !first_time */ 375 376 /* 377 * "The first 32 bytes produced by a high entropy source after a reseed 378 * from the pools is always put in pool 0." (§ 3.4) 379 * 380 * The first-32-byte tracking data in fxrng_reseed_seen is reset in 381 * fxent_timer_reseed_npools() below. 382 */ 383 first_32 = event->he_size > 0 && 384 fxrng_hi_source(src) && 385 atomic_load_acq_int(&fxent_nactpools) > 1 && 386 fxrng_hi_pool0_eligible_racy(src); 387 if (__predict_false(first_32)) { 388 unsigned rem, seen; 389 390 FXENT_LOCK(); 391 seen = fxrng_reseed_seen[src]; 392 if (seen == FXENT_HI_SRC_POOL0_BYTES) 393 goto round_robin; 394 395 rem = FXENT_HI_SRC_POOL0_BYTES - seen; 396 rem = MIN(rem, event->he_size); 397 398 fxrng_reseed_seen[src] = seen + rem; 399 400 /* 401 * We put 'rem' bytes in pool0, and any remaining bytes are 402 * round-robin'd across other pools. 403 */ 404 fxrng_hash_update(&fxent_pool[0], 405 ((uint8_t *)event->he_entropy) + event->he_size - rem, 406 rem); 407 if (rem == event->he_size) { 408 fxrng_hash_update(&fxent_pool[0], &event->he_somecounter, 409 sizeof(event->he_somecounter)); 410 FXENT_UNLOCK(); 411 return; 412 } 413 414 /* 415 * If fewer bytes were needed than this even provied, We only 416 * take the last rem bytes of the entropy buffer and leave the 417 * timecounter to be round-robin'd with the remaining entropy. 418 */ 419 event->he_size -= rem; 420 goto round_robin; 421 } 422 /* !first_32 */ 423 424 FXENT_LOCK(); 425 426 round_robin: 427 FXENT_ASSERT(); 428 pool = event->he_destination % fxent_nactpools; 429 fxrng_hash_update(&fxent_pool[pool], event->he_entropy, 430 event->he_size); 431 fxrng_hash_update(&fxent_pool[pool], &event->he_somecounter, 432 sizeof(event->he_somecounter)); 433 434 if (__predict_false(fxrng_hi_source(src) && 435 atomic_load_acq_64(&fxrng_root_generation) == 0)) { 436 /* Prevent overflow. */ 437 if (fxrng_preseed_ent <= ULONG_MAX - event->he_size) 438 fxrng_preseed_ent += event->he_size; 439 } 440 FXENT_UNLOCK(); 441 } 442 443 /* 444 * Top level "seeded" API/signal from randomdev. 445 * 446 * This is our warning that a request is coming: we need to be seeded. In 447 * fenestrasX, a request for random bytes _never_ fails. "We (ed: ditto) have 448 * observed that there are many callers that never check for the error code, 449 * even if they are generating cryptographic key material." (§ 1.6) 450 * 451 * If we returned 'false', both read_random(9) and chacha20_randomstir() 452 * (arc4random(9)) will blindly charge on with something almost certainly worse 453 * than what we've got, or are able to get quickly enough. 454 */ 455 bool 456 fxrng_alg_seeded(void) 457 { 458 uint8_t hash[FXRNG_HASH_SZ]; 459 sbintime_t sbt; 460 461 /* The vast majority of the time, we expect to already be seeded. */ 462 if (__predict_true(atomic_load_acq_64(&fxrng_root_generation) != 0)) 463 return (true); 464 465 /* 466 * Take the lock and recheck; only one thread needs to do the initial 467 * seeding work. 468 */ 469 FXENT_LOCK(); 470 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 471 FXENT_UNLOCK(); 472 return (true); 473 } 474 /* XXX Any one-off initial seeding goes here. */ 475 476 fxrng_hash_finish(&fxent_pool[0], hash, sizeof(hash)); 477 fxrng_hash_init(&fxent_pool[0]); 478 479 fxrng_brng_reseed(hash, sizeof(hash)); 480 FXENT_UNLOCK(); 481 482 randomdev_unblock(); 483 explicit_bzero(hash, sizeof(hash)); 484 485 /* 486 * This may be called too early for taskqueue_thread to be initialized. 487 * fxent_pool_timer_init will detect if we've already unblocked and 488 * queue the first timer reseed at that point. 489 */ 490 if (atomic_load_acq_int(&fxent_timer_ready) != 0) { 491 sbt = SBT_1S; 492 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 493 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 494 } 495 return (true); 496 } 497 498 /* 499 * Timer-based reseeds and pool expansion. 500 */ 501 static void 502 fxent_timer_reseed_npools(unsigned n) 503 { 504 /* 505 * 64 * 8 => moderately large 512 bytes. Could be static, as we are 506 * only used in a static context. On the other hand, this is in 507 * threadqueue TASK context and we're likely nearly at top of stack 508 * already. 509 */ 510 uint8_t hash[FXRNG_HASH_SZ * FXRNG_NPOOLS]; 511 unsigned i; 512 513 ASSERT_DEBUG(n > 0 && n <= FXRNG_NPOOLS, "n:%u", n); 514 515 FXENT_ASSERT(); 516 /* 517 * Collect entropy from pools 0..n-1 by concatenating the output hashes 518 * and then feeding them into fxrng_brng_reseed, which will hash the 519 * aggregate together with the current root PRNG keystate to produce a 520 * new key. It will also bump the global generation counter 521 * appropriately. 522 */ 523 for (i = 0; i < n; i++) { 524 fxrng_hash_finish(&fxent_pool[i], hash + i * FXRNG_HASH_SZ, 525 FXRNG_HASH_SZ); 526 fxrng_hash_init(&fxent_pool[i]); 527 } 528 529 fxrng_brng_reseed(hash, n * FXRNG_HASH_SZ); 530 explicit_bzero(hash, n * FXRNG_HASH_SZ); 531 532 /* 533 * "The first 32 bytes produced by a high entropy source after a reseed 534 * from the pools is always put in pool 0." (§ 3.4) 535 * 536 * So here we reset the tracking (somewhat naively given the majority 537 * of sources on most machines are not what we consider "high", but at 538 * 32 bytes it's smaller than a cache line), so the next 32 bytes are 539 * prioritized into pool0. 540 * 541 * See corresponding use of fxrng_reseed_seen in fxrng_event_processor. 542 */ 543 memset(fxrng_reseed_seen, 0, sizeof(fxrng_reseed_seen)); 544 FXENT_ASSERT(); 545 } 546 547 static void 548 fxent_timer_reseed(void *ctx __unused, int pending __unused) 549 { 550 static unsigned reseed_intvl_sec = 1; 551 /* Only reseeds after FXENT_RESEED_INTVL_MAX is achieved. */ 552 static uint64_t reseed_number = 1; 553 554 unsigned next_ival, i, k; 555 sbintime_t sbt; 556 557 if (reseed_intvl_sec < FXENT_RESEED_INTVL_MAX) { 558 next_ival = FXENT_RESSED_INTVL_GFACT * reseed_intvl_sec; 559 if (next_ival > FXENT_RESEED_INTVL_MAX) 560 next_ival = FXENT_RESEED_INTVL_MAX; 561 FXENT_LOCK(); 562 fxent_timer_reseed_npools(1); 563 FXENT_UNLOCK(); 564 } else { 565 /* 566 * The creation of entropy pools beyond 0 is enabled when the 567 * reseed interval hits the maximum. (§ 3.3) 568 */ 569 next_ival = reseed_intvl_sec; 570 571 /* 572 * Pool 0 is used every reseed; pool 1..0 every 3rd reseed; and in 573 * general, pool n..0 every 3^n reseeds. 574 */ 575 k = reseed_number; 576 reseed_number++; 577 578 /* Count how many pools, from [0, i), to use for reseed. */ 579 for (i = 1; i < MIN(fxent_nactpools + 1, FXRNG_NPOOLS); i++) { 580 if ((k % FXENT_RESEED_BASE) != 0) 581 break; 582 k /= FXENT_RESEED_BASE; 583 } 584 585 /* 586 * If we haven't activated pool i yet, activate it and only 587 * reseed from [0, i-1). (§ 3.3) 588 */ 589 FXENT_LOCK(); 590 if (i == fxent_nactpools + 1) { 591 fxent_timer_reseed_npools(fxent_nactpools); 592 fxent_nactpools++; 593 } else { 594 /* Just reseed from [0, i). */ 595 fxent_timer_reseed_npools(i); 596 } 597 FXENT_UNLOCK(); 598 } 599 600 /* Schedule the next reseed. */ 601 sbt = next_ival * SBT_1S; 602 taskqueue_enqueue_timeout_sbt(taskqueue_thread, &fxent_reseed_timer, 603 -sbt, (sbt / 3), C_PREL(2)); 604 605 reseed_intvl_sec = next_ival; 606 } 607 608 static void 609 fxent_pool_timer_init(void *dummy __unused) 610 { 611 sbintime_t sbt; 612 613 TIMEOUT_TASK_INIT(taskqueue_thread, &fxent_reseed_timer, 0, 614 fxent_timer_reseed, NULL); 615 616 if (atomic_load_acq_64(&fxrng_root_generation) != 0) { 617 sbt = SBT_1S; 618 taskqueue_enqueue_timeout_sbt(taskqueue_thread, 619 &fxent_reseed_timer, -sbt, (sbt / 3), C_PREL(2)); 620 } 621 atomic_store_rel_int(&fxent_timer_ready, 1); 622 } 623 /* After taskqueue_thread is initialized in SI_SUB_TASKQ:SI_ORDER_SECOND. */ 624 SYSINIT(fxent_pool_timer_init, SI_SUB_TASKQ, SI_ORDER_ANY, 625 fxent_pool_timer_init, NULL); 626