// SPDX-License-Identifier: GPL-2.0 /* * 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 <linux/types.h>#include <linux/percpu.h>#include <linux/export.h>#include <linux/jiffies.h>#include <linux/prandom.h>#include <linux/sched.h>#include <linux/bitops.h>#include <linux/slab.h>#include <linux/unaligned.h>/** * prandom_u32_state - seeded pseudo - random number generator . * @ state : pointer to state structure holding seeded state . * * This is used for pseudo - randomness with no outside seeding . * For more random results , use get_random_u32 ( ) . struct rnd_state *state)#define TAUSWORTHE(s, a, b, c, d) ((s & c) << d) ^ (((s << a) ^ s) >> b)6 U, 13 U, 4294967294 U, 18 U);2 U, 27 U, 4294967288 U, 2 U);13 U, 21 U, 4294967280 U, 7 U);3 U, 12 U, 4294967168 U, 13 U);return (state->s1 ^ state->s2 ^ state->s3 ^ state->s4);/** * prandom_bytes_state - get the requested number of pseudo - random bytes * * @ state : pointer to state structure holding seeded state . * @ buf : where to copy the pseudo - random bytes to * @ bytes : the requested number of bytes * * This is used for pseudo - randomness with no outside seeding . * For more random results , use get_random_bytes ( ) . void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes)while (bytes >= sizeof (u32)) {sizeof (u32);sizeof (u32);if (bytes > 0 ) {do {while (bytes > 0 );static void prandom_warmup(struct rnd_state *state)/* Calling RNG ten times to satisfy recurrence condition */ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state)int i;struct rnd_state *state = per_cpu_ptr(pcpu_state, i);4 ];sizeof (seeds));0 ], 2 U);1 ], 8 U);2 ], 16 U);3 ], 128 U);#ifdef CONFIG_RANDOM32_SELFTESTstatic struct prandom_test1 {1 U, 3484351685 U },2 U, 2623130059 U },3 U, 3125133893 U },4 U, 984847254 U },static struct prandom_test2 {/* Test cases against taus113 from GSL library. */ 931557656 U, 959 U, 2975593782 U },1339693295 U, 876 U, 3887776532 U },1545556285 U, 961 U, 1615538833 U },601730776 U, 723 U, 1776162651 U },1027516047 U, 687 U, 511983079 U },416526298 U, 700 U, 916156552 U },1395522032 U, 652 U, 2222063676 U },366221443 U, 617 U, 2992857763 U },1539836965 U, 714 U, 3783265725 U },556206671 U, 994 U, 799626459 U },684907218 U, 799 U, 367789491 U },2121230701 U, 931 U, 2115467001 U },1668516451 U, 644 U, 3620590685 U },768046066 U, 883 U, 2034077390 U },1989159136 U, 833 U, 1195767305 U },536585145 U, 996 U, 3577259204 U },1008129373 U, 642 U, 1478080776 U },1740775604 U, 939 U, 1264980372 U },1967883163 U, 508 U, 10734624 U },1923019697 U, 730 U, 3821419629 U },442079932 U, 560 U, 3440032343 U },1961302714 U, 845 U, 841962572 U },2030205964 U, 962 U, 1325144227 U },1160407529 U, 507 U, 240940858 U },635482502 U, 779 U, 4200489746 U },1252788931 U, 699 U, 867195434 U },1961817131 U, 719 U, 668237657 U },1071468216 U, 983 U, 917876630 U },1281848367 U, 932 U, 1003100039 U },582537119 U, 780 U, 1127273778 U },1973672777 U, 853 U, 1071368872 U },1896756996 U, 762 U, 1127851055 U },847917054 U, 500 U, 1717499075 U },1240520510 U, 951 U, 2849576657 U },1685071682 U, 567 U, 1961810396 U },1516232129 U, 557 U, 3173877 U },1208118903 U, 612 U, 1613145022 U },1817269927 U, 693 U, 4279122573 U },1510091701 U, 717 U, 638191229 U },365916850 U, 807 U, 600424314 U },399324359 U, 702 U, 1803598116 U },1318480274 U, 779 U, 2074237022 U },697758115 U, 840 U, 1483639402 U },1696507773 U, 840 U, 577415447 U },2081979121 U, 981 U, 3041486449 U },955646687 U, 742 U, 3846494357 U },1250683506 U, 749 U, 836419859 U },595003102 U, 534 U, 366794109 U },47485338 U, 558 U, 3521120834 U },619433479 U, 610 U, 3991783875 U },704096520 U, 518 U, 4139493852 U },1712224984 U, 606 U, 2393312003 U },1318233152 U, 922 U, 3880361134 U },855572992 U, 761 U, 1472974787 U },64721421 U, 703 U, 683860550 U },678931758 U, 840 U, 380616043 U },692711973 U, 778 U, 1382361947 U },677703619 U, 530 U, 2826914161 U },92393223 U, 586 U, 1522128471 U },1222592920 U, 743 U, 3466726667 U },358288986 U, 695 U, 1091956998 U },1935056945 U, 958 U, 514864477 U },735675993 U, 990 U, 1294239989 U },1560089402 U, 897 U, 2238551287 U },70616361 U, 829 U, 22483098 U },368234700 U, 731 U, 2913875084 U },20221190 U, 879 U, 1564152970 U },539444654 U, 682 U, 1835141259 U },1314987297 U, 840 U, 1801114136 U },2019295544 U, 645 U, 3286438930 U },469023838 U, 716 U, 1637918202 U },1843754496 U, 653 U, 2562092152 U },400672036 U, 809 U, 4264212785 U },404722249 U, 965 U, 2704116999 U },600702209 U, 758 U, 584979986 U },519953954 U, 667 U, 2574436237 U },1658071126 U, 694 U, 2214569490 U },420480037 U, 749 U, 3430010866 U },690103647 U, 969 U, 3700758083 U },1029424799 U, 937 U, 3787746841 U },2012608669 U, 506 U, 3362628973 U },1535432887 U, 998 U, 42610943 U },1330635533 U, 857 U, 3040806504 U },1223800550 U, 539 U, 3954229517 U },1322411537 U, 680 U, 3223250324 U },1877847898 U, 945 U, 2915147143 U },1646356099 U, 874 U, 965988280 U },805687536 U, 744 U, 4032277920 U },1948093210 U, 633 U, 1346597684 U },392609744 U, 783 U, 1636083295 U },690241304 U, 770 U, 1201031298 U },1360302965 U, 696 U, 1665394461 U },1220090946 U, 780 U, 1316922812 U },447092251 U, 500 U, 3438743375 U },1613868791 U, 592 U, 828546883 U },523430951 U, 548 U, 2552392304 U },726692899 U, 810 U, 1656872867 U },1364340021 U, 836 U, 3710513486 U },1986257729 U, 931 U, 935013962 U },407983964 U, 921 U, 728767059 U },static void prandom_state_selftest_seed(struct rnd_state *state, u32 seed)#define LCG(x) ((x) * 69069 U) /* super-duper LCG */ 2 U);8 U);16 U);128 U);static int __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;if (test1[i].result != prandom_u32_state(&state))true ;if (error)"prandom: seed boundary self test failed\n" );else "prandom: seed boundary self test passed\n" );for (i = 0 ; i < ARRAY_SIZE(test2); i++) {struct rnd_state state;for (j = 0 ; j < test2[i].iteration - 1 ; j++)if (test2[i].result != prandom_u32_state(&state))if (errors)"prandom: %d/%d self tests failed\n" , errors, runs);else "prandom: %d self tests passed\n" , runs);return 0 ;#endif
Messung V0.5 in Prozent C=97 H=74 G=86
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