>From dc78cee3b9a88e756555152ab621940cf2abe78f Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 21 Jun 2018 11:25:02 -0700 Subject: [PATCH 1/3] random, random_r: merge from glibc * lib/random.c, lib/random_r.c: Include libc-config.h if !_LIBC, not config.h unilaterally. * lib/random.c: Do not include stdint.h or time.h; not needed. Include libc-lock.h if _LIBC, and define substitute macros otherwise. (unsafe_state): Rename from generator. All uses changed. Use C99-style initializers. (__random, __srandom, __initstate, __setstate): Rename from non-underscored version, but define it to non-underscored version on Gnulib. Add a lock. * lib/random_r.c (__srandom_r, __initstate_r, __setstate_r, __random_r): Likewise. Do not include ; not needed since stdlib.h defines int32_t. (weak_alias, __set_errno) [!_LIBC]: Remove; now done by libc-config. (__srandom_r): Use int32_t instead of long int where int32_t will do. (__random_r): Use uint32 to fix glibc bug 17343. * modules/random, modules/random_r (Depends-on): Add libc-config. Depend on stdint only if $HAVE_RANDOM = 0. --- ChangeLog | 22 +++++ lib/random.c | 221 ++++++++++++++++++++++++++++++++++++----------- lib/random_r.c | 76 +++++++--------- modules/random | 3 +- modules/random_r | 3 +- 5 files changed, 231 insertions(+), 94 deletions(-) diff --git a/ChangeLog b/ChangeLog index ac3fcab6a..7be60f1c3 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,25 @@ +2018-06-21 Paul Eggert + + random, random_r: merge from glibc + * lib/random.c, lib/random_r.c: + Include libc-config.h if !_LIBC, not config.h unilaterally. + * lib/random.c: + Do not include stdint.h or time.h; not needed. + Include libc-lock.h if _LIBC, and define substitute macros otherwise. + (unsafe_state): Rename from generator. All uses changed. + Use C99-style initializers. + (__random, __srandom, __initstate, __setstate): Rename from + non-underscored version, but define it to non-underscored version + on Gnulib. Add a lock. + * lib/random_r.c (__srandom_r, __initstate_r, __setstate_r, __random_r): + Likewise. + Do not include ; not needed since stdlib.h defines int32_t. + (weak_alias, __set_errno) [!_LIBC]: Remove; now done by libc-config. + (__srandom_r): Use int32_t instead of long int where int32_t will do. + (__random_r): Use uint32 to fix glibc bug 17343. + * modules/random, modules/random_r (Depends-on): Add libc-config. + Depend on stdint only if $HAVE_RANDOM = 0. + 2018-06-19 Jim Meyering README-release: also run any check-very-expensive tests diff --git a/lib/random.c b/lib/random.c index 758aeec40..d14b82084 100644 --- a/lib/random.c +++ b/lib/random.c @@ -1,18 +1,18 @@ -/* Family of functions for random integers. - Copyright (C) 1995-1997, 2000-2002, 2012-2018 Free Software Foundation, Inc. +/* Copyright (C) 1995-2018 Free Software Foundation, Inc. - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. - This program is distributed in the hope that it will be useful, + The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program. If not, see . */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ /* * This is derived from the Berkeley source: @@ -38,7 +38,7 @@ may be used to endorse or promote products derived from this software without specific prior written permission. - THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS OR CONTRIBUTORS BE LIABLE @@ -50,16 +50,62 @@ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.*/ -#include +#ifndef _LIBC +# include +#endif /* Specification. */ #include -#include -#include - -/* This file can assume the 'struct random_data' and associated *_r functions - from gnulib. */ +#ifdef _LIBC +# include +#else +/* Allow memory races; that's random enough. */ +# define __libc_lock_define_initialized(class, name) +# define __libc_lock_lock(name) ((void) 0) +# define __libc_lock_unlock(name) ((void) 0) +#endif + +/* An improved random number generation package. In addition to the standard + rand()/srand() like interface, this package also has a special state info + interface. The initstate() routine is called with a seed, an array of + bytes, and a count of how many bytes are being passed in; this array is + then initialized to contain information for random number generation with + that much state information. Good sizes for the amount of state + information are 32, 64, 128, and 256 bytes. The state can be switched by + calling the setstate() function with the same array as was initialized + with initstate(). By default, the package runs with 128 bytes of state + information and generates far better random numbers than a linear + congruential generator. If the amount of state information is less than + 32 bytes, a simple linear congruential R.N.G. is used. Internally, the + state information is treated as an array of longs; the zeroth element of + the array is the type of R.N.G. being used (small integer); the remainder + of the array is the state information for the R.N.G. Thus, 32 bytes of + state information will give 7 longs worth of state information, which will + allow a degree seven polynomial. (Note: The zeroth word of state + information also has some other information stored in it; see setstate + for details). The random number generation technique is a linear feedback + shift register approach, employing trinomials (since there are fewer terms + to sum up that way). In this approach, the least significant bit of all + the numbers in the state table will act as a linear feedback shift register, + and will have period 2^deg - 1 (where deg is the degree of the polynomial + being used, assuming that the polynomial is irreducible and primitive). + The higher order bits will have longer periods, since their values are + also influenced by pseudo-random carries out of the lower bits. The + total period of the generator is approximately deg*(2**deg - 1); thus + doubling the amount of state information has a vast influence on the + period of the generator. Note: The deg*(2**deg - 1) is an approximation + only good for large deg, when the period of the shift register is the + dominant factor. With deg equal to seven, the period is actually much + longer than the 7*(2**7 - 1) predicted by this formula. */ + + + +/* For each of the currently supported random number generators, we have a + break value on the amount of state information (you need at least this many + bytes of state info to support this random number generator), a degree for + the polynomial (actually a trinomial) that the R.N.G. is based on, and + separation between the two lower order coefficients of the trinomial. */ /* Linear congruential. */ #define TYPE_0 0 @@ -91,11 +137,13 @@ #define DEG_4 63 #define SEP_4 1 + /* Array versions of the above information to make code run faster. Relies on fact that TYPE_i == i. */ #define MAX_TYPES 5 /* Max number of types above. */ + /* Initially, everything is set up as if from: initstate(1, randtbl, 128); Note that this initialization takes advantage of the fact that srandom @@ -118,10 +166,11 @@ static int32_t randtbl[DEG_3 + 1] = -205601318, }; -static struct random_data generator = + +static struct random_data unsafe_state = { /* FPTR and RPTR are two pointers into the state info, a front and a rear - pointer. These two pointers are always rand_sep places aparts, as they + pointer. These two pointers are always rand_sep places apart, as they cycle through the state information. (Yes, this does mean we could get away with just one pointer, but the code for random is more efficient this way). The pointers are left positioned as they would be from the call: @@ -130,8 +179,8 @@ static struct random_data generator = in the initialization of randtbl) because the state table pointer is set to point to randtbl[1] (as explained below).) */ - /* fptr */ &randtbl[SEP_3 + 1], - /* rptr */ &randtbl[1], + .fptr = &randtbl[SEP_3 + 1], + .rptr = &randtbl[1], /* The following things are the pointer to the state information table, the type of the current generator, the degree of the current polynomial @@ -143,45 +192,119 @@ static struct random_data generator = indexing every time to find the address of the last element to see if the front and rear pointers have wrapped. */ - /* state */ &randtbl[1], + .state = &randtbl[1], - /* rand_type */ TYPE_3, - /* rand_deg */ DEG_3, - /* rand_sep */ SEP_3, + .rand_type = TYPE_3, + .rand_deg = DEG_3, + .rand_sep = SEP_3, - /* end_ptr */ &randtbl[sizeof (randtbl) / sizeof (randtbl[0])] + .end_ptr = &randtbl[sizeof (randtbl) / sizeof (randtbl[0])] }; - -long -random (void) + +/* POSIX.1c requires that there is mutual exclusion for the 'rand' and + 'srand' functions to prevent concurrent calls from modifying common + data. */ +__libc_lock_define_initialized (static, lock) + +/* Initialize the random number generator based on the given seed. If the + type is the trivial no-state-information type, just remember the seed. + Otherwise, initializes state[] based on the given "seed" via a linear + congruential generator. Then, the pointers are set to known locations + that are exactly rand_sep places apart. Lastly, it cycles the state + information a given number of times to get rid of any initial dependencies + introduced by the L.C.R.N.G. Note that the initialization of randtbl[] + for default usage relies on values produced by this routine. */ +void +__srandom (unsigned int x) { - int32_t val; - - if (random_r (&generator, &val) < 0) - abort (); /* should not happen */ - return val; + __libc_lock_lock (lock); + (void) __srandom_r (x, &unsafe_state); + __libc_lock_unlock (lock); } -void -srandom (unsigned int seed) +weak_alias (__srandom, srandom) +weak_alias (__srandom, srand) + +/* 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 the break values for the different R.N.G.'s, we choose + the best (largest) 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. + 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. + Returns a pointer to the old state. */ +char * +__initstate (unsigned int seed, char *arg_state, size_t n) { - (void) srandom_r (seed, &generator); /* may fail! */ + int32_t *ostate; + int ret; + + __libc_lock_lock (lock); + + ostate = &unsafe_state.state[-1]; + + ret = __initstate_r (seed, arg_state, n, &unsafe_state); + + __libc_lock_unlock (lock); + + return ret == -1 ? NULL : (char *) ostate; } +weak_alias (__initstate, initstate) + +/* Restore the state from the given state array. + Note: It is important that we also remember the locations of the pointers + in the current state information, and restore the locations of the pointers + from the old state information. This is done by multiplexing the pointer + location into the zeroth word of the state information. Note that due + to the order in which things are done, it is OK to call setstate with the + same state as the current state + Returns a pointer to the old state information. */ char * -initstate (unsigned int seed, char *buf, size_t buf_size) +__setstate (char *arg_state) { - char *old_state = (char *) ((int32_t *) generator.state - 1); - if (initstate_r (seed, buf, buf_size, &generator) < 0) - return NULL; /* failed */ - return old_state; + int32_t *ostate; + + __libc_lock_lock (lock); + + ostate = &unsafe_state.state[-1]; + + if (__setstate_r (arg_state, &unsafe_state) < 0) + ostate = NULL; + + __libc_lock_unlock (lock); + + return (char *) ostate; } -char * -setstate (char *arg_state) +weak_alias (__setstate, setstate) + +/* If we are using the trivial TYPE_0 R.N.G., just do the old linear + congruential bit. Otherwise, we do our fancy trinomial stuff, which is the + same in all the other cases due to all the global variables that have been + set up. The basic operation is to add the number at the rear pointer into + the one at the front pointer. Then both pointers are advanced to the next + location cyclically in the table. The value returned is the sum generated, + reduced to 31 bits by throwing away the "least random" low bit. + Note: The code takes advantage of the fact that both the front and + rear pointers can't wrap on the same call by not testing the rear + pointer if the front one has wrapped. Returns a 31-bit random number. */ + +long int +__random (void) { - char *old_state = (char *) ((int32_t *) generator.state - 1); - if (setstate_r (arg_state, &generator) < 0) - return NULL; /* failed */ - return old_state; + int32_t retval; + + __libc_lock_lock (lock); + + (void) __random_r (&unsafe_state, &retval); + + __libc_lock_unlock (lock); + + return retval; } + +weak_alias (__random, random) diff --git a/lib/random_r.c b/lib/random_r.c index 697ca5fdb..fba07bb98 100644 --- a/lib/random_r.c +++ b/lib/random_r.c @@ -1,18 +1,19 @@ /* - Copyright (C) 1995, 2005, 2008-2018 Free Software Foundation, Inc. + Copyright (C) 1995-2018 Free Software Foundation, Inc. - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. - This program is distributed in the hope that it will be useful, + The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program. If not, see . */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ /* Copyright (C) 1983 Regents of the University of California. @@ -50,12 +51,18 @@ * Rewritten to be reentrant by Ulrich Drepper, 1995 */ +#ifndef _LIBC /* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc optimizes away the buf == NULL, arg_state == NULL, result == NULL tests below. */ -#define _GL_ARG_NONNULL(params) +# define _GL_ARG_NONNULL(params) -#include +# include +# define __srandom_r srandom_r +# define __initstate_r initstate_r +# define __setstate_r setstate_r +# define __random_r random_r +#endif /* Specification. */ #include @@ -63,7 +70,6 @@ #include #include #include -#include /* An improved random number generation package. In addition to the standard @@ -155,14 +161,6 @@ static const struct random_poly_info random_poly_info = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 } }; -#ifndef _LIBC -# define weak_alias(local, symbol) -# define __set_errno(e) errno = (e) -# define __srandom_r srandom_r -# define __initstate_r initstate_r -# define __setstate_r setstate_r -# define __random_r random_r -#endif @@ -180,7 +178,7 @@ __srandom_r (unsigned int seed, struct random_data *buf) int type; int32_t *state; long int i; - long int word; + int32_t word; int32_t *dst; int kc; @@ -242,21 +240,15 @@ weak_alias (__srandom_r, srandom_r) lose this information and will be able to restart with setstate. 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. - Returns a pointer to the old state. */ + Returns 0 on success, non-zero on failure. */ int __initstate_r (unsigned int seed, char *arg_state, size_t n, struct random_data *buf) { - int32_t *old_state; - int32_t *state; - int type; - int degree; - int separation; - if (buf == NULL) goto fail; - old_state = buf->state; + int32_t *old_state = buf->state; if (old_state != NULL) { int old_type = buf->rand_type; @@ -266,27 +258,26 @@ __initstate_r (unsigned int seed, char *arg_state, size_t n, old_state[-1] = (MAX_TYPES * (buf->rptr - old_state)) + old_type; } + int type; if (n >= BREAK_3) type = n < BREAK_4 ? TYPE_3 : TYPE_4; else if (n < BREAK_1) { if (n < BREAK_0) - { - __set_errno (EINVAL); - goto fail; - } + goto fail; + type = TYPE_0; } else type = n < BREAK_2 ? TYPE_1 : TYPE_2; - degree = random_poly_info.degrees[type]; - separation = random_poly_info.seps[type]; + int degree = random_poly_info.degrees[type]; + int separation = random_poly_info.seps[type]; buf->rand_type = type; buf->rand_sep = separation; buf->rand_deg = degree; - state = &((int32_t *) arg_state)[1]; /* First location. */ + int32_t *state = &((int32_t *) arg_state)[1]; /* First location. */ /* Must set END_PTR before srandom. */ buf->end_ptr = &state[degree]; @@ -314,7 +305,7 @@ weak_alias (__initstate_r, initstate_r) location into the zeroth word of the state information. Note that due to the order in which things are done, it is OK to call setstate with the same state as the current state - Returns a pointer to the old state information. */ + Returns 0 on success, non-zero on failure. */ int __setstate_r (char *arg_state, struct random_data *buf) { @@ -385,8 +376,7 @@ __random_r (struct random_data *buf, int32_t *result) if (buf->rand_type == TYPE_0) { - int32_t val = state[0]; - val = ((state[0] * 1103515245) + 12345) & 0x7fffffff; + int32_t val = ((state[0] * 1103515245U) + 12345U) & 0x7fffffff; state[0] = val; *result = val; } @@ -395,11 +385,11 @@ __random_r (struct random_data *buf, int32_t *result) int32_t *fptr = buf->fptr; int32_t *rptr = buf->rptr; int32_t *end_ptr = buf->end_ptr; - int32_t val; + uint32_t val; - val = *fptr += *rptr; + val = *fptr += (uint32_t) *rptr; /* Chucking least random bit. */ - *result = (val >> 1) & 0x7fffffff; + *result = val >> 1; ++fptr; if (fptr >= end_ptr) { diff --git a/modules/random b/modules/random index 631a8e555..706096bed 100644 --- a/modules/random +++ b/modules/random @@ -6,8 +6,9 @@ lib/random.c m4/random.m4 Depends-on: +libc-config [test $HAVE_RANDOM = 0] stdlib -stdint +stdint [test $HAVE_RANDOM = 0] random_r [test $HAVE_RANDOM = 0] configure.ac: diff --git a/modules/random_r b/modules/random_r index 52a884279..52becd597 100644 --- a/modules/random_r +++ b/modules/random_r @@ -6,8 +6,9 @@ lib/random_r.c m4/random_r.m4 Depends-on: +libc-config [test $HAVE_RANDOM_R = 0 || test $REPLACE_RANDOM_R = 1] stdlib -stdint +stdint [test $HAVE_RANDOM_R = 0 || test $REPLACE_RANDOM_R = 1] configure.ac: gl_FUNC_RANDOM_R -- 2.17.1