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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