Index: head/lib/libc/stdlib/random.h =================================================================== --- head/lib/libc/stdlib/random.h +++ head/lib/libc/stdlib/random.h @@ -0,0 +1,46 @@ +/*- + * Copyright 2020 Conrad Meyer . All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#pragma once + +/* A full instance of the random(3) generator. */ +struct __random_state { + uint32_t *rst_fptr; + uint32_t *rst_rptr; + uint32_t *rst_state; + int rst_type; + int rst_deg; + int rst_sep; + uint32_t *rst_end_ptr; + /* Flexible array member must be last. */ + uint32_t rst_randtbl[]; +}; + +int initstate_r(struct __random_state *, unsigned, uint32_t *, size_t); +long random_r(struct __random_state *); +void srandom_r(struct __random_state *, unsigned); +void srandomdev_r(struct __random_state *); Index: head/lib/libc/stdlib/random.c =================================================================== --- head/lib/libc/stdlib/random.c +++ head/lib/libc/stdlib/random.c @@ -38,10 +38,13 @@ #include "namespace.h" #include #include +#include #include #include #include "un-namespace.h" +#include "random.h" + /* * random.c: * @@ -144,19 +147,6 @@ static const int degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 }; static const int seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 }; -/* A full instance of the random(3) generator. */ -struct random_state { - uint32_t *rst_fptr; - uint32_t *rst_rptr; - uint32_t *rst_state; - int rst_type; - int rst_deg; - int rst_sep; - uint32_t *rst_end_ptr; - /* Flexible array member must be last. */ - uint32_t rst_randtbl[]; -}; - /* * Initially, everything is set up as if from: * @@ -170,7 +160,7 @@ * * MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3. */ -static struct random_state implicit = { +static struct __random_state implicit = { .rst_randtbl = { TYPE_3, 0x2cf41758, 0x27bb3711, 0x4916d4d1, 0x7b02f59f, 0x9b8e28eb, 0xc0e80269, @@ -257,25 +247,31 @@ * for default usage relies on values produced by this routine. */ void -srandom(unsigned int x) +srandom_r(struct __random_state *estate, unsigned x) { int i, lim; - implicit.rst_state[0] = (uint32_t)x; - if (implicit.rst_type == TYPE_0) + estate->rst_state[0] = (uint32_t)x; + if (estate->rst_type == TYPE_0) lim = NSHUFF; else { - for (i = 1; i < implicit.rst_deg; i++) - implicit.rst_state[i] = - parkmiller32(implicit.rst_state[i - 1]); - implicit.rst_fptr = &implicit.rst_state[implicit.rst_sep]; - implicit.rst_rptr = &implicit.rst_state[0]; - lim = 10 * implicit.rst_deg; + for (i = 1; i < estate->rst_deg; i++) + estate->rst_state[i] = + parkmiller32(estate->rst_state[i - 1]); + estate->rst_fptr = &estate->rst_state[estate->rst_sep]; + estate->rst_rptr = &estate->rst_state[0]; + lim = 10 * estate->rst_deg; } for (i = 0; i < lim; i++) - (void)random(); + (void)random_r(estate); } +void +srandom(unsigned x) +{ + srandom_r(&implicit, x); +} + /* * srandomdev: * @@ -289,20 +285,20 @@ * derived from the LC algorithm applied to a fixed seed. */ void -srandomdev(void) +srandomdev_r(struct __random_state *estate) { int mib[2]; size_t expected, len; - if (implicit.rst_type == TYPE_0) - len = sizeof(implicit.rst_state[0]); + if (estate->rst_type == TYPE_0) + len = sizeof(estate->rst_state[0]); else - len = implicit.rst_deg * sizeof(implicit.rst_state[0]); + len = estate->rst_deg * sizeof(estate->rst_state[0]); expected = len; mib[0] = CTL_KERN; mib[1] = KERN_ARND; - if (sysctl(mib, 2, implicit.rst_state, &len, NULL, 0) == -1 || + if (sysctl(mib, 2, estate->rst_state, &len, NULL, 0) == -1 || len != expected) { /* * The sysctl cannot fail. If it does fail on some FreeBSD @@ -313,14 +309,20 @@ abort(); } - if (implicit.rst_type != TYPE_0) { - implicit.rst_fptr = &implicit.rst_state[implicit.rst_sep]; - implicit.rst_rptr = &implicit.rst_state[0]; + if (estate->rst_type != TYPE_0) { + estate->rst_fptr = &estate->rst_state[estate->rst_sep]; + estate->rst_rptr = &estate->rst_state[0]; } } +void +srandomdev(void) +{ + srandomdev_r(&implicit); +} + /* - * initstate: + * initstate_r: * * Initialize the state information in the given array of n bytes for future * random number generation. Based on the number of bytes we are given, and @@ -328,65 +330,95 @@ * one we can and set things up for it. srandom() is then called to * initialize the state information. * - * Note that on return from srandom(), we set state[-1] to be the type - * multiplexed with the current value of the rear pointer; this is so - * successive calls to initstate() won't lose this information and will be - * able to restart with setstate(). + * Returns zero on success, or an error number on failure. * + * Note: There is no need for a setstate_r(); just use a new context. + */ +int +initstate_r(struct __random_state *estate, unsigned seed, uint32_t *arg_state, + size_t sz) +{ + if (sz < BREAK_0) + return (EINVAL); + + if (sz < BREAK_1) { + estate->rst_type = TYPE_0; + estate->rst_deg = DEG_0; + estate->rst_sep = SEP_0; + } else if (sz < BREAK_2) { + estate->rst_type = TYPE_1; + estate->rst_deg = DEG_1; + estate->rst_sep = SEP_1; + } else if (sz < BREAK_3) { + estate->rst_type = TYPE_2; + estate->rst_deg = DEG_2; + estate->rst_sep = SEP_2; + } else if (sz < BREAK_4) { + estate->rst_type = TYPE_3; + estate->rst_deg = DEG_3; + estate->rst_sep = SEP_3; + } else { + estate->rst_type = TYPE_4; + estate->rst_deg = DEG_4; + estate->rst_sep = SEP_4; + } + estate->rst_state = arg_state + 1; + estate->rst_end_ptr = &estate->rst_state[estate->rst_deg]; + srandom_r(estate, seed); + return (0); +} + +/* + * initstate: + * * Note: the first thing we do is save the current state, if any, just like * setstate() so that it doesn't matter when initstate is called. * + * Note that on return from initstate_r(), we set state[-1] to be the type + * multiplexed with the current value of the rear pointer; this is so + * successive calls to initstate() won't lose this information and will be able + * to restart with setstate(). + * * Returns a pointer to the old state. * - * Note: The Sparc platform requires that arg_state begin on an int - * word boundary; otherwise a bus error will occur. Even so, lint will - * complain about mis-alignment, but you should disregard these messages. + * Despite the misleading "char *" type, arg_state must alias an array of + * 32-bit unsigned integer values. Naturally, such an array is 32-bit aligned. + * Usually objects are naturally aligned to at least 32-bits on all platforms, + * but if you treat the provided 'state' as char* you may inadvertently + * misalign it. Don't do that. */ char * initstate(unsigned int seed, char *arg_state, size_t n) { char *ostate = (char *)(&implicit.rst_state[-1]); uint32_t *int_arg_state = (uint32_t *)arg_state; + int error; - if (n < BREAK_0) - return (NULL); + /* + * Persist rptr offset and rst_type in the first word of the prior + * state we are replacing. + */ if (implicit.rst_type == TYPE_0) implicit.rst_state[-1] = implicit.rst_type; else implicit.rst_state[-1] = MAX_TYPES * (implicit.rst_rptr - implicit.rst_state) + implicit.rst_type; - if (n < BREAK_1) { - implicit.rst_type = TYPE_0; - implicit.rst_deg = DEG_0; - implicit.rst_sep = SEP_0; - } else if (n < BREAK_2) { - implicit.rst_type = TYPE_1; - implicit.rst_deg = DEG_1; - implicit.rst_sep = SEP_1; - } else if (n < BREAK_3) { - implicit.rst_type = TYPE_2; - implicit.rst_deg = DEG_2; - implicit.rst_sep = SEP_2; - } else if (n < BREAK_4) { - implicit.rst_type = TYPE_3; - implicit.rst_deg = DEG_3; - implicit.rst_sep = SEP_3; - } else { - implicit.rst_type = TYPE_4; - implicit.rst_deg = DEG_4; - implicit.rst_sep = SEP_4; - } - implicit.rst_state = int_arg_state + 1; /* first location */ - /* must set end_ptr before srandom */ - implicit.rst_end_ptr = &implicit.rst_state[implicit.rst_deg]; - srandom(seed); + + error = initstate_r(&implicit, seed, int_arg_state, n); + if (error != 0) + return (NULL); + + /* + * Persist rptr offset and rst_type of the new state in its first word. + */ if (implicit.rst_type == TYPE_0) int_arg_state[0] = implicit.rst_type; else int_arg_state[0] = MAX_TYPES * (implicit.rst_rptr - implicit.rst_state) + implicit.rst_type; + return (ostate); } @@ -456,33 +488,39 @@ * Returns a 31-bit random number. */ long -random(void) +random_r(struct __random_state *estate) { uint32_t i; uint32_t *f, *r; - if (implicit.rst_type == TYPE_0) { - i = implicit.rst_state[0]; + if (estate->rst_type == TYPE_0) { + i = estate->rst_state[0]; i = parkmiller32(i); - implicit.rst_state[0] = i; + estate->rst_state[0] = i; } else { /* * Use local variables rather than static variables for speed. */ - f = implicit.rst_fptr; - r = implicit.rst_rptr; + f = estate->rst_fptr; + r = estate->rst_rptr; *f += *r; i = *f >> 1; /* chucking least random bit */ - if (++f >= implicit.rst_end_ptr) { - f = implicit.rst_state; + if (++f >= estate->rst_end_ptr) { + f = estate->rst_state; ++r; } - else if (++r >= implicit.rst_end_ptr) { - r = implicit.rst_state; + else if (++r >= estate->rst_end_ptr) { + r = estate->rst_state; } - implicit.rst_fptr = f; - implicit.rst_rptr = r; + estate->rst_fptr = f; + estate->rst_rptr = r; } return ((long)i); +} + +long +random(void) +{ + return (random_r(&implicit)); }