lib/random32: convert selftest to KUnit

Convert the existing prandom selftest (lib/random32.c) to use the KUnit
framework (lib/tests/random32_kunit.c).  Unlike typical KUnit tests, this
file is directly #included into lib/random32.c.

The new test:
- Removes the legacy CONFIG_RANDOM32_SELFTEST from lib/random32.c.
- Adds CONFIG_PRANDOM_KUNIT_TEST (defaulting to KUNIT_ALL_TESTS).
- Moves the test logic to lib/tests/random32_kunit.c.

This commit is verified by `./tools/testing/kunit/kunit.py run`
with the .kunit/.kunitconfig:

CONFIG_KUNIT=y
CONFIG_PRANDOM_KUNIT_TEST=y

Link: https://lore.kernel.org/20260703050100.23944-1-note351@hotmail.com
Signed-off-by: Kir Chou <note351@hotmail.com>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kir Chou
2026-07-30 19:50:06 -07:00
committed by Andrew Morton
parent 13a2f5084f
commit 7426929241
5 changed files with 202 additions and 180 deletions
-6
View File
@@ -159,12 +159,6 @@ config AUDIT_COMPAT_GENERIC
depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
default y
config RANDOM32_SELFTEST
bool "PRNG perform self test on init"
help
This option enables the 32 bit PRNG library functions to perform a
self test on initialization.
#
# compression support is select'ed if needed
#
+9
View File
@@ -3548,6 +3548,15 @@ config GLOB_KUNIT_TEST
If unsure, say N
config PRANDOM_KUNIT_TEST
tristate "KUnit test for prandom" if !KUNIT_ALL_TESTS
depends on KUNIT
default KUNIT_ALL_TESTS
help
Enable this option to test the prandom functions at runtime.
If unsure, say N
endif # RUNTIME_TESTING_MENU
config ARCH_USE_MEMTEST
+10 -174
View File
@@ -41,6 +41,7 @@
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/unaligned.h>
#include <kunit/visibility.h>
/**
* prandom_u32_state - seeded pseudo-random number generator.
@@ -92,7 +93,14 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes)
}
EXPORT_SYMBOL(prandom_bytes_state);
static void prandom_warmup(struct rnd_state *state)
/*
* Only declared here so that it has a prototype when made
* non-static for KUnit testing (avoids -Wmissing-prototypes).
*/
#if IS_ENABLED(CONFIG_KUNIT)
void prandom_warmup(struct rnd_state *state);
#endif
VISIBLE_IF_KUNIT void prandom_warmup(struct rnd_state *state)
{
/* Calling RNG ten times to satisfy recurrence condition */
prandom_u32_state(state);
@@ -106,6 +114,7 @@ static void prandom_warmup(struct rnd_state *state)
prandom_u32_state(state);
prandom_u32_state(state);
}
EXPORT_SYMBOL_IF_KUNIT(prandom_warmup);
void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state)
{
@@ -125,176 +134,3 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state)
}
}
EXPORT_SYMBOL(prandom_seed_full_state);
#ifdef CONFIG_RANDOM32_SELFTEST
static struct prandom_test1 {
u32 seed;
u32 result;
} test1[] = {
{ 1U, 3484351685U },
{ 2U, 2623130059U },
{ 3U, 3125133893U },
{ 4U, 984847254U },
};
static struct prandom_test2 {
u32 seed;
u32 iteration;
u32 result;
} test2[] = {
/* Test cases against taus113 from GSL library. */
{ 931557656U, 959U, 2975593782U },
{ 1339693295U, 876U, 3887776532U },
{ 1545556285U, 961U, 1615538833U },
{ 601730776U, 723U, 1776162651U },
{ 1027516047U, 687U, 511983079U },
{ 416526298U, 700U, 916156552U },
{ 1395522032U, 652U, 2222063676U },
{ 366221443U, 617U, 2992857763U },
{ 1539836965U, 714U, 3783265725U },
{ 556206671U, 994U, 799626459U },
{ 684907218U, 799U, 367789491U },
{ 2121230701U, 931U, 2115467001U },
{ 1668516451U, 644U, 3620590685U },
{ 768046066U, 883U, 2034077390U },
{ 1989159136U, 833U, 1195767305U },
{ 536585145U, 996U, 3577259204U },
{ 1008129373U, 642U, 1478080776U },
{ 1740775604U, 939U, 1264980372U },
{ 1967883163U, 508U, 10734624U },
{ 1923019697U, 730U, 3821419629U },
{ 442079932U, 560U, 3440032343U },
{ 1961302714U, 845U, 841962572U },
{ 2030205964U, 962U, 1325144227U },
{ 1160407529U, 507U, 240940858U },
{ 635482502U, 779U, 4200489746U },
{ 1252788931U, 699U, 867195434U },
{ 1961817131U, 719U, 668237657U },
{ 1071468216U, 983U, 917876630U },
{ 1281848367U, 932U, 1003100039U },
{ 582537119U, 780U, 1127273778U },
{ 1973672777U, 853U, 1071368872U },
{ 1896756996U, 762U, 1127851055U },
{ 847917054U, 500U, 1717499075U },
{ 1240520510U, 951U, 2849576657U },
{ 1685071682U, 567U, 1961810396U },
{ 1516232129U, 557U, 3173877U },
{ 1208118903U, 612U, 1613145022U },
{ 1817269927U, 693U, 4279122573U },
{ 1510091701U, 717U, 638191229U },
{ 365916850U, 807U, 600424314U },
{ 399324359U, 702U, 1803598116U },
{ 1318480274U, 779U, 2074237022U },
{ 697758115U, 840U, 1483639402U },
{ 1696507773U, 840U, 577415447U },
{ 2081979121U, 981U, 3041486449U },
{ 955646687U, 742U, 3846494357U },
{ 1250683506U, 749U, 836419859U },
{ 595003102U, 534U, 366794109U },
{ 47485338U, 558U, 3521120834U },
{ 619433479U, 610U, 3991783875U },
{ 704096520U, 518U, 4139493852U },
{ 1712224984U, 606U, 2393312003U },
{ 1318233152U, 922U, 3880361134U },
{ 855572992U, 761U, 1472974787U },
{ 64721421U, 703U, 683860550U },
{ 678931758U, 840U, 380616043U },
{ 692711973U, 778U, 1382361947U },
{ 677703619U, 530U, 2826914161U },
{ 92393223U, 586U, 1522128471U },
{ 1222592920U, 743U, 3466726667U },
{ 358288986U, 695U, 1091956998U },
{ 1935056945U, 958U, 514864477U },
{ 735675993U, 990U, 1294239989U },
{ 1560089402U, 897U, 2238551287U },
{ 70616361U, 829U, 22483098U },
{ 368234700U, 731U, 2913875084U },
{ 20221190U, 879U, 1564152970U },
{ 539444654U, 682U, 1835141259U },
{ 1314987297U, 840U, 1801114136U },
{ 2019295544U, 645U, 3286438930U },
{ 469023838U, 716U, 1637918202U },
{ 1843754496U, 653U, 2562092152U },
{ 400672036U, 809U, 4264212785U },
{ 404722249U, 965U, 2704116999U },
{ 600702209U, 758U, 584979986U },
{ 519953954U, 667U, 2574436237U },
{ 1658071126U, 694U, 2214569490U },
{ 420480037U, 749U, 3430010866U },
{ 690103647U, 969U, 3700758083U },
{ 1029424799U, 937U, 3787746841U },
{ 2012608669U, 506U, 3362628973U },
{ 1535432887U, 998U, 42610943U },
{ 1330635533U, 857U, 3040806504U },
{ 1223800550U, 539U, 3954229517U },
{ 1322411537U, 680U, 3223250324U },
{ 1877847898U, 945U, 2915147143U },
{ 1646356099U, 874U, 965988280U },
{ 805687536U, 744U, 4032277920U },
{ 1948093210U, 633U, 1346597684U },
{ 392609744U, 783U, 1636083295U },
{ 690241304U, 770U, 1201031298U },
{ 1360302965U, 696U, 1665394461U },
{ 1220090946U, 780U, 1316922812U },
{ 447092251U, 500U, 3438743375U },
{ 1613868791U, 592U, 828546883U },
{ 523430951U, 548U, 2552392304U },
{ 726692899U, 810U, 1656872867U },
{ 1364340021U, 836U, 3710513486U },
{ 1986257729U, 931U, 935013962U },
{ 407983964U, 921U, 728767059U },
};
static void prandom_state_selftest_seed(struct rnd_state *state, u32 seed)
{
#define LCG(x) ((x) * 69069U) /* super-duper LCG */
state->s1 = __seed(LCG(seed), 2U);
state->s2 = __seed(LCG(state->s1), 8U);
state->s3 = __seed(LCG(state->s2), 16U);
state->s4 = __seed(LCG(state->s3), 128U);
}
static int __init prandom_state_selftest(void)
{
int i, j, errors = 0, runs = 0;
bool error = false;
for (i = 0; i < ARRAY_SIZE(test1); i++) {
struct rnd_state state;
prandom_state_selftest_seed(&state, test1[i].seed);
prandom_warmup(&state);
if (test1[i].result != prandom_u32_state(&state))
error = true;
}
if (error)
pr_warn("prandom: seed boundary self test failed\n");
else
pr_info("prandom: seed boundary self test passed\n");
for (i = 0; i < ARRAY_SIZE(test2); i++) {
struct rnd_state state;
prandom_state_selftest_seed(&state, test2[i].seed);
prandom_warmup(&state);
for (j = 0; j < test2[i].iteration - 1; j++)
prandom_u32_state(&state);
if (test2[i].result != prandom_u32_state(&state))
errors++;
runs++;
cond_resched();
}
if (errors)
pr_warn("prandom: %d/%d self tests failed\n", errors, runs);
else
pr_info("prandom: %d self tests passed\n", runs);
return 0;
}
core_initcall(prandom_state_selftest);
#endif
+1
View File
@@ -43,6 +43,7 @@ CFLAGS_overflow_kunit.o = $(call cc-disable-warning, tautological-constant-out-o
obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o
# GCC < 12.1 can miscompile errptr() test when branch profiling is enabled.
CFLAGS_printf_kunit.o += -DDISABLE_BRANCH_PROFILING
obj-$(CONFIG_PRANDOM_KUNIT_TEST) += random32_kunit.o
obj-$(CONFIG_PRINTF_KUNIT_TEST) += printf_kunit.o
obj-$(CONFIG_RANDSTRUCT_KUNIT_TEST) += randstruct_kunit.o
obj-$(CONFIG_SCANF_KUNIT_TEST) += scanf_kunit.o
+182
View File
@@ -0,0 +1,182 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Test cases for random32 functions.
*/
#include <linux/prandom.h>
#include <kunit/test.h>
/* prandom_warmup() is static in lib/random32.c; exposed for testing only. */
void prandom_warmup(struct rnd_state *state);
static const struct prandom_test1 {
u32 seed;
u32 result;
} test1[] = {
{ 1U, 3484351685U },
{ 2U, 2623130059U },
{ 3U, 3125133893U },
{ 4U, 984847254U },
};
static const struct prandom_test2 {
u32 seed;
u32 iteration;
u32 result;
} test2[] = {
/* Test cases against taus113 from GSL library. */
{ 931557656U, 959U, 2975593782U },
{ 1339693295U, 876U, 3887776532U },
{ 1545556285U, 961U, 1615538833U },
{ 601730776U, 723U, 1776162651U },
{ 1027516047U, 687U, 511983079U },
{ 416526298U, 700U, 916156552U },
{ 1395522032U, 652U, 2222063676U },
{ 366221443U, 617U, 2992857763U },
{ 1539836965U, 714U, 3783265725U },
{ 556206671U, 994U, 799626459U },
{ 684907218U, 799U, 367789491U },
{ 2121230701U, 931U, 2115467001U },
{ 1668516451U, 644U, 3620590685U },
{ 768046066U, 883U, 2034077390U },
{ 1989159136U, 833U, 1195767305U },
{ 536585145U, 996U, 3577259204U },
{ 1008129373U, 642U, 1478080776U },
{ 1740775604U, 939U, 1264980372U },
{ 1967883163U, 508U, 10734624U },
{ 1923019697U, 730U, 3821419629U },
{ 442079932U, 560U, 3440032343U },
{ 1961302714U, 845U, 841962572U },
{ 2030205964U, 962U, 1325144227U },
{ 1160407529U, 507U, 240940858U },
{ 635482502U, 779U, 4200489746U },
{ 1252788931U, 699U, 867195434U },
{ 1961817131U, 719U, 668237657U },
{ 1071468216U, 983U, 917876630U },
{ 1281848367U, 932U, 1003100039U },
{ 582537119U, 780U, 1127273778U },
{ 1973672777U, 853U, 1071368872U },
{ 1896756996U, 762U, 1127851055U },
{ 847917054U, 500U, 1717499075U },
{ 1240520510U, 951U, 2849576657U },
{ 1685071682U, 567U, 1961810396U },
{ 1516232129U, 557U, 3173877U },
{ 1208118903U, 612U, 1613145022U },
{ 1817269927U, 693U, 4279122573U },
{ 1510091701U, 717U, 638191229U },
{ 365916850U, 807U, 600424314U },
{ 399324359U, 702U, 1803598116U },
{ 1318480274U, 779U, 2074237022U },
{ 697758115U, 840U, 1483639402U },
{ 1696507773U, 840U, 577415447U },
{ 2081979121U, 981U, 3041486449U },
{ 955646687U, 742U, 3846494357U },
{ 1250683506U, 749U, 836419859U },
{ 595003102U, 534U, 366794109U },
{ 47485338U, 558U, 3521120834U },
{ 619433479U, 610U, 3991783875U },
{ 704096520U, 518U, 4139493852U },
{ 1712224984U, 606U, 2393312003U },
{ 1318233152U, 922U, 3880361134U },
{ 855572992U, 761U, 1472974787U },
{ 64721421U, 703U, 683860550U },
{ 678931758U, 840U, 380616043U },
{ 692711973U, 778U, 1382361947U },
{ 677703619U, 530U, 2826914161U },
{ 92393223U, 586U, 1522128471U },
{ 1222592920U, 743U, 3466726667U },
{ 358288986U, 695U, 1091956998U },
{ 1935056945U, 958U, 514864477U },
{ 735675993U, 990U, 1294239989U },
{ 1560089402U, 897U, 2238551287U },
{ 70616361U, 829U, 22483098U },
{ 368234700U, 731U, 2913875084U },
{ 20221190U, 879U, 1564152970U },
{ 539444654U, 682U, 1835141259U },
{ 1314987297U, 840U, 1801114136U },
{ 2019295544U, 645U, 3286438930U },
{ 469023838U, 716U, 1637918202U },
{ 1843754496U, 653U, 2562092152U },
{ 400672036U, 809U, 4264212785U },
{ 404722249U, 965U, 2704116999U },
{ 600702209U, 758U, 584979986U },
{ 519953954U, 667U, 2574436237U },
{ 1658071126U, 694U, 2214569490U },
{ 420480037U, 749U, 3430010866U },
{ 690103647U, 969U, 3700758083U },
{ 1029424799U, 937U, 3787746841U },
{ 2012608669U, 506U, 3362628973U },
{ 1535432887U, 998U, 42610943U },
{ 1330635533U, 857U, 3040806504U },
{ 1223800550U, 539U, 3954229517U },
{ 1322411537U, 680U, 3223250324U },
{ 1877847898U, 945U, 2915147143U },
{ 1646356099U, 874U, 965988280U },
{ 805687536U, 744U, 4032277920U },
{ 1948093210U, 633U, 1346597684U },
{ 392609744U, 783U, 1636083295U },
{ 690241304U, 770U, 1201031298U },
{ 1360302965U, 696U, 1665394461U },
{ 1220090946U, 780U, 1316922812U },
{ 447092251U, 500U, 3438743375U },
{ 1613868791U, 592U, 828546883U },
{ 523430951U, 548U, 2552392304U },
{ 726692899U, 810U, 1656872867U },
{ 1364340021U, 836U, 3710513486U },
{ 1986257729U, 931U, 935013962U },
{ 407983964U, 921U, 728767059U },
};
static void prandom_state_test_seed(struct rnd_state *state, u32 seed)
{
#define LCG(x) ((x) * 69069U) /* super-duper LCG */
state->s1 = __seed(LCG(seed), 2U);
state->s2 = __seed(LCG(state->s1), 8U);
state->s3 = __seed(LCG(state->s2), 16U);
state->s4 = __seed(LCG(state->s3), 128U);
}
static void test_prandom_seed_boundary(struct kunit *test)
{
int i;
struct rnd_state state;
for (i = 0; i < ARRAY_SIZE(test1); i++) {
prandom_state_test_seed(&state, test1[i].seed);
prandom_warmup(&state);
KUNIT_EXPECT_EQ(test, test1[i].result, prandom_u32_state(&state));
}
}
static void test_prandom_taus113(struct kunit *test)
{
int i, j;
struct rnd_state state;
for (i = 0; i < ARRAY_SIZE(test2); i++) {
prandom_state_test_seed(&state, test2[i].seed);
prandom_warmup(&state);
for (j = 0; j < test2[i].iteration - 1; j++)
prandom_u32_state(&state);
KUNIT_EXPECT_EQ(test, test2[i].result, prandom_u32_state(&state));
}
}
static struct kunit_case prandom_test_cases[] = {
KUNIT_CASE(test_prandom_seed_boundary),
KUNIT_CASE(test_prandom_taus113),
{}
};
static struct kunit_suite prandom_test_suite = {
.name = "prandom",
.test_cases = prandom_test_cases,
};
kunit_test_suite(prandom_test_suite);
MODULE_DESCRIPTION("KUnit test for prandom");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");