Date: Wed, 29 Jan 2020 05:25:20 +0000 (UTC) From: Conrad Meyer <cem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r357246 - head/tests/sys/sys Message-ID: <202001290525.00T5PKKh017113@repo.freebsd.org>
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Author: cem Date: Wed Jan 29 05:25:20 2020 New Revision: 357246 URL: https://svnweb.freebsd.org/changeset/base/357246 Log: qmath(3) test: Replace overcomplicated abomination with arc4random(3) The horrific GENRAND construction bent over backwards to construct 64-bit signed integers from the 31-bit output of random(3) for about 20 numbers per test. Reproducibility wasn't a goal: random(3) was seeded with srandomdev(3). Speed is not a factor for generating 20 integers with arc4random(3). Range is not a factor: all uses did not bound the range beyond that of the full [INT64_MIN, INT64_MAX]. Just use arc4random(3). Reported by: Coverity CIDs: 1404809, 1404817, 1404838, 1404840 and about 6x other identical reports of dubious code relating to the construction Modified: head/tests/sys/sys/qmath_test.c Modified: head/tests/sys/sys/qmath_test.c ============================================================================== --- head/tests/sys/sys/qmath_test.c Wed Jan 29 04:42:46 2020 (r357245) +++ head/tests/sys/sys/qmath_test.c Wed Jan 29 05:25:20 2020 (r357246) @@ -47,25 +47,7 @@ #define QTEST_QITRUNC(q, iv) ((iv) >> Q_RPSHFT(q)) #define QTEST_FFACTOR 32.0 -#define bitsperrand 31 -#define GENRAND(a, lb, ub) \ -({ \ - int _rembits; \ - do { \ - _rembits = Q_BITSPERBASEUP(ub) + Q_LTZ(lb); \ - *(a) = (__typeof(*(a)))0; \ - while (_rembits > 0) { \ - *(a) |= (((uint64_t)random()) & \ - ((1ULL << (_rembits > bitsperrand ? \ - bitsperrand : _rembits)) - 1)); \ - *(a) <<= (_rembits - (_rembits > bitsperrand ? \ - bitsperrand : _rembits)); \ - _rembits -= bitsperrand; \ - } \ - *(a) += lb; \ - } while (*(a) < (lb) || (uint64_t)*(a) > (ub)); \ - *(a); \ -}) +#define GENRAND(a) arc4random_buf((a), sizeof(*(a))) /* * Smoke tests for basic qmath operations, such as initialization @@ -213,11 +195,9 @@ ATF_TC_BODY(qmulq_s64q, tc) #endif int error; - srandomdev(); - for (int i = 0; i < 10;) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXX: We cheat a bit, to stand any chance of multiplying @@ -278,12 +258,9 @@ ATF_TC_BODY(qdivq_s64q, tc) if (atf_tc_get_config_var_as_bool_wd(tc, "ci", false)) atf_tc_skip("https://bugs.freebsd.org/240219"); - - srandomdev(); - for (int i = 0; i < 10; i++) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -324,11 +301,9 @@ ATF_TC_BODY(qaddq_s64q, tc) double a_dbl, b_dbl, r_dbl, maxe_dbl, delta_dbl; int error; - srandomdev(); - for (int i = 0; i < 10;) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -372,11 +347,9 @@ ATF_TC_BODY(qsubq_s64q, tc) double a_dbl, b_dbl, r_dbl, maxe_dbl, delta_dbl; int error; - srandomdev(); - for (int i = 0; i < 10; i++) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -418,11 +391,9 @@ ATF_TC_BODY(qfraci_s64q, tc) int64_t a_int, b_int; int error; - srandomdev(); - for (int i = 0; i < 10;) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -465,11 +436,9 @@ ATF_TC_BODY(qmuli_s64q, tc) int64_t a_int, b_int; int error; - srandomdev(); - for (int i = 0; i < 10;) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -512,11 +481,9 @@ ATF_TC_BODY(qaddi_s64q, tc) int64_t a_int, b_int; int error; - srandomdev(); - for (int i = 0; i < 10;) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision. @@ -563,11 +530,9 @@ ATF_TC_BODY(qsubi_s64q, tc) int64_t a_int, b_int; int error; - srandomdev(); - for (int i = 0; i < 10; i++) { - GENRAND(&a_s64q, INT64_MIN, UINT64_MAX); - GENRAND(&b_s64q, INT64_MIN, UINT64_MAX); + GENRAND(&a_s64q); + GENRAND(&b_s64q); /* * XXXLAS: Until Qmath handles precision normalisation, only * test with equal precision.
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