--- zzzz-none-000/linux-3.10.107/lib/random32.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/lib/random32.c 2021-02-04 17:41:59.000000000 +0000 @@ -1,43 +1,51 @@ /* - This is a maximally equidistributed combined Tausworthe generator - based on code from GNU Scientific Library 1.5 (30 Jun 2004) - - x_n = (s1_n ^ s2_n ^ s3_n) - - s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19)) - s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25)) - s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11)) - - The period of this generator is about 2^88. - - From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe - Generators", Mathematics of Computation, 65, 213 (1996), 203--213. - - This is available on the net from L'Ecuyer's home page, - - http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps - ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps - - There is an erratum in the paper "Tables of Maximally - Equidistributed Combined LFSR Generators", Mathematics of - Computation, 68, 225 (1999), 261--269: - http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps - - ... the k_j most significant bits of z_j must be non- - zero, for each j. (Note: this restriction also applies to the - computer code given in [4], but was mistakenly not mentioned in - that paper.) - - This affects the seeding procedure by imposing the requirement - s1 > 1, s2 > 7, s3 > 15. - -*/ + * This is a maximally equidistributed combined Tausworthe generator + * based on code from GNU Scientific Library 1.5 (30 Jun 2004) + * + * lfsr113 version: + * + * x_n = (s1_n ^ s2_n ^ s3_n ^ s4_n) + * + * s1_{n+1} = (((s1_n & 4294967294) << 18) ^ (((s1_n << 6) ^ s1_n) >> 13)) + * s2_{n+1} = (((s2_n & 4294967288) << 2) ^ (((s2_n << 2) ^ s2_n) >> 27)) + * s3_{n+1} = (((s3_n & 4294967280) << 7) ^ (((s3_n << 13) ^ s3_n) >> 21)) + * s4_{n+1} = (((s4_n & 4294967168) << 13) ^ (((s4_n << 3) ^ s4_n) >> 12)) + * + * The period of this generator is about 2^113 (see erratum paper). + * + * From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe + * Generators", Mathematics of Computation, 65, 213 (1996), 203--213: + * http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps + * ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps + * + * There is an erratum in the paper "Tables of Maximally Equidistributed + * Combined LFSR Generators", Mathematics of Computation, 68, 225 (1999), + * 261--269: http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps + * + * ... the k_j most significant bits of z_j must be non-zero, + * for each j. (Note: this restriction also applies to the + * computer code given in [4], but was mistakenly not mentioned + * in that paper.) + * + * This affects the seeding procedure by imposing the requirement + * s1 > 1, s2 > 7, s3 > 15, s4 > 127. + */ #include #include #include #include #include +#include +#include + +#ifdef CONFIG_RANDOM32_SELFTEST +static void __init prandom_state_selftest(void); +#else +static inline void prandom_state_selftest(void) +{ +} +#endif static DEFINE_PER_CPU(struct rnd_state, net_rand_state); @@ -50,13 +58,13 @@ */ u32 prandom_u32_state(struct rnd_state *state) { -#define TAUSWORTHE(s,a,b,c,d) ((s&c)<>b) - - state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12); - state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4); - state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17); +#define TAUSWORTHE(s, a, b, c, d) ((s & c) << d) ^ (((s << a) ^ s) >> b) + state->s1 = TAUSWORTHE(state->s1, 6U, 13U, 4294967294U, 18U); + state->s2 = TAUSWORTHE(state->s2, 2U, 27U, 4294967288U, 2U); + state->s3 = TAUSWORTHE(state->s3, 13U, 21U, 4294967280U, 7U); + state->s4 = TAUSWORTHE(state->s4, 3U, 12U, 4294967168U, 13U); - return (state->s1 ^ state->s2 ^ state->s3); + return (state->s1 ^ state->s2 ^ state->s3 ^ state->s4); } EXPORT_SYMBOL(prandom_u32_state); @@ -69,15 +77,17 @@ */ u32 prandom_u32(void) { - unsigned long r; struct rnd_state *state = &get_cpu_var(net_rand_state); - r = prandom_u32_state(state); + u32 res; + + res = prandom_u32_state(state); put_cpu_var(state); - return r; + + return res; } EXPORT_SYMBOL(prandom_u32); -/* +/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -87,27 +97,23 @@ * This is used for pseudo-randomness with no outside seeding. * For more random results, use prandom_bytes(). */ -void prandom_bytes_state(struct rnd_state *state, void *buf, int bytes) +void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) { - unsigned char *p = buf; - int i; + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(prandom_u32_state(state), (u32 *) ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } - for (i = 0; i < round_down(bytes, sizeof(u32)); i += sizeof(u32)) { - u32 random = prandom_u32_state(state); - int j; - - for (j = 0; j < sizeof(u32); j++) { - p[i + j] = random; - random >>= BITS_PER_BYTE; - } - } - if (i < bytes) { - u32 random = prandom_u32_state(state); - - for (; i < bytes; i++) { - p[i] = random; - random >>= BITS_PER_BYTE; - } + if (bytes > 0) { + u32 rem = prandom_u32_state(state); + do { + *ptr++ = (u8) rem; + bytes--; + rem >>= BITS_PER_BYTE; + } while (bytes > 0); } } EXPORT_SYMBOL(prandom_bytes_state); @@ -117,7 +123,7 @@ * @buf: where to copy the pseudo-random bytes to * @bytes: the requested number of bytes */ -void prandom_bytes(void *buf, int bytes) +void prandom_bytes(void *buf, size_t bytes) { struct rnd_state *state = &get_cpu_var(net_rand_state); @@ -126,6 +132,42 @@ } EXPORT_SYMBOL(prandom_bytes); +static void prandom_warmup(struct rnd_state *state) +{ + /* Calling RNG ten times to satisfy recurrence condition */ + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); + prandom_u32_state(state); +} + +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + /** * prandom_seed - add entropy to pseudo random number generator * @seed: seed value @@ -139,9 +181,11 @@ * No locking on the CPUs, but then somewhat random results are, well, * expected. */ - for_each_possible_cpu (i) { + for_each_possible_cpu(i) { struct rnd_state *state = &per_cpu(net_rand_state, i); - state->s1 = __seed(state->s1 ^ entropy, 2); + + state->s1 = __seed(state->s1 ^ entropy, 2U); + prandom_warmup(state); } } EXPORT_SYMBOL(prandom_seed); @@ -154,46 +198,267 @@ { int i; + prandom_state_selftest(); + for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state,i); + struct rnd_state *state = &per_cpu(net_rand_state, i); + u32 weak_seed = (i + jiffies) ^ random_get_entropy(); -#define LCG(x) ((x) * 69069) /* super-duper LCG */ - state->s1 = __seed(LCG(i + jiffies), 2); - state->s2 = __seed(LCG(state->s1), 8); - state->s3 = __seed(LCG(state->s2), 16); - - /* "warm it up" */ - prandom_u32_state(state); - prandom_u32_state(state); - prandom_u32_state(state); - prandom_u32_state(state); - prandom_u32_state(state); - prandom_u32_state(state); + prandom_seed_early(state, weak_seed, true); + prandom_warmup(state); } + return 0; } core_initcall(prandom_init); -/* - * Generate better values after random number generator - * is fully initialized. - */ -static int __init prandom_reseed(void) +static void __prandom_timer(unsigned long dontcare); + +static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0); + +static void __prandom_timer(unsigned long dontcare) +{ + u32 entropy; + unsigned long expires; + + get_random_bytes(&entropy, sizeof(entropy)); + prandom_seed(entropy); + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = 40 + prandom_u32_max(40); + seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); + + add_timer(&seed_timer); +} + +static void __init __prandom_start_seed_timer(void) +{ + set_timer_slack(&seed_timer, HZ); + seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); + add_timer(&seed_timer); +} + +void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state,i); - u32 seeds[3]; + struct rnd_state *state = per_cpu_ptr(pcpu_state, i); + u32 seeds[4]; get_random_bytes(&seeds, sizeof(seeds)); - state->s1 = __seed(seeds[0], 2); - state->s2 = __seed(seeds[1], 8); - state->s3 = __seed(seeds[2], 16); + state->s1 = __seed(seeds[0], 2U); + state->s2 = __seed(seeds[1], 8U); + state->s3 = __seed(seeds[2], 16U); + state->s4 = __seed(seeds[3], 128U); - /* mix it in */ - prandom_u32_state(state); + prandom_warmup(state); } +} + +/* + * Generate better values after random number generator + * is fully initialized. + */ +static void __prandom_reseed(bool late) +{ + unsigned long flags; + static bool latch = false; + static DEFINE_SPINLOCK(lock); + + /* Asking for random bytes might result in bytes getting + * moved into the nonblocking pool and thus marking it + * as initialized. In this case we would double back into + * this function and attempt to do a late reseed. + * Ignore the pointless attempt to reseed again if we're + * already waiting for bytes when the nonblocking pool + * got initialized. + */ + + /* only allow initial seeding (late == false) once */ + if (!spin_trylock_irqsave(&lock, flags)) + return; + + if (latch && !late) + goto out; + + latch = true; + prandom_seed_full_state(&net_rand_state); +out: + spin_unlock_irqrestore(&lock, flags); +} + +void prandom_reseed_late(void) +{ + __prandom_reseed(true); +} + +static int __init prandom_reseed(void) +{ + __prandom_reseed(false); + __prandom_start_seed_timer(); return 0; } late_initcall(prandom_reseed); + +#ifdef CONFIG_RANDOM32_SELFTEST +static struct prandom_test1 { + u32 seed; + u32 result; +} test1[] = { + { 1U, 3484351685U }, + { 2U, 2623130059U }, + { 3U, 3125133893U }, + { 4U, 984847254U }, +}; + +static struct prandom_test2 { + u32 seed; + u32 iteration; + u32 result; +} test2[] = { + /* Test cases against taus113 from GSL library. */ + { 931557656U, 959U, 2975593782U }, + { 1339693295U, 876U, 3887776532U }, + { 1545556285U, 961U, 1615538833U }, + { 601730776U, 723U, 1776162651U }, + { 1027516047U, 687U, 511983079U }, + { 416526298U, 700U, 916156552U }, + { 1395522032U, 652U, 2222063676U }, + { 366221443U, 617U, 2992857763U }, + { 1539836965U, 714U, 3783265725U }, + { 556206671U, 994U, 799626459U }, + { 684907218U, 799U, 367789491U }, + { 2121230701U, 931U, 2115467001U }, + { 1668516451U, 644U, 3620590685U }, + { 768046066U, 883U, 2034077390U }, + { 1989159136U, 833U, 1195767305U }, + { 536585145U, 996U, 3577259204U }, + { 1008129373U, 642U, 1478080776U }, + { 1740775604U, 939U, 1264980372U }, + { 1967883163U, 508U, 10734624U }, + { 1923019697U, 730U, 3821419629U }, + { 442079932U, 560U, 3440032343U }, + { 1961302714U, 845U, 841962572U }, + { 2030205964U, 962U, 1325144227U }, + { 1160407529U, 507U, 240940858U }, + { 635482502U, 779U, 4200489746U }, + { 1252788931U, 699U, 867195434U }, + { 1961817131U, 719U, 668237657U }, + { 1071468216U, 983U, 917876630U }, + { 1281848367U, 932U, 1003100039U }, + { 582537119U, 780U, 1127273778U }, + { 1973672777U, 853U, 1071368872U }, + { 1896756996U, 762U, 1127851055U }, + { 847917054U, 500U, 1717499075U }, + { 1240520510U, 951U, 2849576657U }, + { 1685071682U, 567U, 1961810396U }, + { 1516232129U, 557U, 3173877U }, + { 1208118903U, 612U, 1613145022U }, + { 1817269927U, 693U, 4279122573U }, + { 1510091701U, 717U, 638191229U }, + { 365916850U, 807U, 600424314U }, + { 399324359U, 702U, 1803598116U }, + { 1318480274U, 779U, 2074237022U }, + { 697758115U, 840U, 1483639402U }, + { 1696507773U, 840U, 577415447U }, + { 2081979121U, 981U, 3041486449U }, + { 955646687U, 742U, 3846494357U }, + { 1250683506U, 749U, 836419859U }, + { 595003102U, 534U, 366794109U }, + { 47485338U, 558U, 3521120834U }, + { 619433479U, 610U, 3991783875U }, + { 704096520U, 518U, 4139493852U }, + { 1712224984U, 606U, 2393312003U }, + { 1318233152U, 922U, 3880361134U }, + { 855572992U, 761U, 1472974787U }, + { 64721421U, 703U, 683860550U }, + { 678931758U, 840U, 380616043U }, + { 692711973U, 778U, 1382361947U }, + { 677703619U, 530U, 2826914161U }, + { 92393223U, 586U, 1522128471U }, + { 1222592920U, 743U, 3466726667U }, + { 358288986U, 695U, 1091956998U }, + { 1935056945U, 958U, 514864477U }, + { 735675993U, 990U, 1294239989U }, + { 1560089402U, 897U, 2238551287U }, + { 70616361U, 829U, 22483098U }, + { 368234700U, 731U, 2913875084U }, + { 20221190U, 879U, 1564152970U }, + { 539444654U, 682U, 1835141259U }, + { 1314987297U, 840U, 1801114136U }, + { 2019295544U, 645U, 3286438930U }, + { 469023838U, 716U, 1637918202U }, + { 1843754496U, 653U, 2562092152U }, + { 400672036U, 809U, 4264212785U }, + { 404722249U, 965U, 2704116999U }, + { 600702209U, 758U, 584979986U }, + { 519953954U, 667U, 2574436237U }, + { 1658071126U, 694U, 2214569490U }, + { 420480037U, 749U, 3430010866U }, + { 690103647U, 969U, 3700758083U }, + { 1029424799U, 937U, 3787746841U }, + { 2012608669U, 506U, 3362628973U }, + { 1535432887U, 998U, 42610943U }, + { 1330635533U, 857U, 3040806504U }, + { 1223800550U, 539U, 3954229517U }, + { 1322411537U, 680U, 3223250324U }, + { 1877847898U, 945U, 2915147143U }, + { 1646356099U, 874U, 965988280U }, + { 805687536U, 744U, 4032277920U }, + { 1948093210U, 633U, 1346597684U }, + { 392609744U, 783U, 1636083295U }, + { 690241304U, 770U, 1201031298U }, + { 1360302965U, 696U, 1665394461U }, + { 1220090946U, 780U, 1316922812U }, + { 447092251U, 500U, 3438743375U }, + { 1613868791U, 592U, 828546883U }, + { 523430951U, 548U, 2552392304U }, + { 726692899U, 810U, 1656872867U }, + { 1364340021U, 836U, 3710513486U }, + { 1986257729U, 931U, 935013962U }, + { 407983964U, 921U, 728767059U }, +}; + +static void __init prandom_state_selftest(void) +{ + int i, j, errors = 0, runs = 0; + bool error = false; + + for (i = 0; i < ARRAY_SIZE(test1); i++) { + struct rnd_state state; + + prandom_seed_early(&state, test1[i].seed, false); + prandom_warmup(&state); + + if (test1[i].result != prandom_u32_state(&state)) + error = true; + } + + if (error) + pr_warn("prandom: seed boundary self test failed\n"); + else + pr_info("prandom: seed boundary self test passed\n"); + + for (i = 0; i < ARRAY_SIZE(test2); i++) { + struct rnd_state state; + + prandom_seed_early(&state, test2[i].seed, false); + prandom_warmup(&state); + + for (j = 0; j < test2[i].iteration - 1; j++) + prandom_u32_state(&state); + + if (test2[i].result != prandom_u32_state(&state)) + errors++; + + runs++; + cond_resched(); + } + + if (errors) + pr_warn("prandom: %d/%d self tests failed\n", errors, runs); + else + pr_info("prandom: %d self tests passed\n", runs); +} +#endif