From dd00a3c923ba94986efba2289c1b0e22b7c12c97 Mon Sep 17 00:00:00 2001 From: Timothy Arceri Date: Wed, 22 Mar 2017 10:48:57 +1100 Subject: [PATCH] util/rand_xor: add function to seed rand MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit V2: pass the seed to the seed function so that we can isolate its uses. Stop leaking fd when urandom couldn't be read. Reviewed-by: Grazvydas Ignotas Reviewed-by: Nicolai Hähnle --- src/gallium/drivers/radeon/r600_test_dma.c | 3 +- src/util/rand_xor.c | 65 ++++++++++++++++++++++ src/util/rand_xor.h | 4 ++ 3 files changed, 70 insertions(+), 2 deletions(-) diff --git a/src/gallium/drivers/radeon/r600_test_dma.c b/src/gallium/drivers/radeon/r600_test_dma.c index 8b4149af53c..3c23b093294 100644 --- a/src/gallium/drivers/radeon/r600_test_dma.c +++ b/src/gallium/drivers/radeon/r600_test_dma.c @@ -183,8 +183,7 @@ void r600_test_dma(struct r600_common_screen *rscreen) /* the seed for random test parameters */ srand(0x9b47d95b); /* the seed for random pixel data */ - seed_xorshift128plus[0] = 0x3bffb83978e24f88; - seed_xorshift128plus[1] = 0x9238d5d56c71cd35; + s_rand_xorshift128plus(seed_xorshift128plus, false); iterations = 1000000000; /* just kill it when you are bored */ num_partial_copies = 30; diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c index 07b4c22ee15..de05fa64b3c 100644 --- a/src/util/rand_xor.c +++ b/src/util/rand_xor.c @@ -1,3 +1,34 @@ +/* + * Copyright 2017 Timothy Arceri + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ + +#if defined(__linux__) +#include +#include +#else +#include +#endif + #include "rand_xor.h" /* Super fast random number generator. @@ -18,3 +49,37 @@ rand_xorshift128plus(uint64_t *seed) return s[1] + s0; } + +void +s_rand_xorshift128plus(uint64_t *seed, bool randomised_seed) +{ + if (!randomised_seed) + goto fixed_seed; + +#if defined(__linux__) + int fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) + goto fixed_seed; + + size_t seed_size = sizeof(uint64_t) * 2; + if (read(fd, seed, seed_size) != seed_size) { + close(fd); + goto fixed_seed; + } + + close(fd); + return; + +#else + seed[0] = 0x3bffb83978e24f88; + seed[1] = time(NULL); + + return; +#endif + +fixed_seed: + + /* Fallback to a fixed seed */ + seed[0] = 0x3bffb83978e24f88; + seed[1] = 0x9238d5d56c71cd35; +} diff --git a/src/util/rand_xor.h b/src/util/rand_xor.h index d5144e98230..532d549bcda 100644 --- a/src/util/rand_xor.h +++ b/src/util/rand_xor.h @@ -26,8 +26,12 @@ #define RAND_XOR_H #include +#include uint64_t rand_xorshift128plus(uint64_t *seed); +void +s_rand_xorshift128plus(uint64_t *seed, bool randomised_seed); + #endif /* RAND_XOR_H */ -- 2.30.2