From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- lib/tests/random32_kunit.c | 182 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 lib/tests/random32_kunit.c (limited to 'lib/tests/random32_kunit.c') diff --git a/lib/tests/random32_kunit.c b/lib/tests/random32_kunit.c new file mode 100644 index 000000000..0b4af2b09 --- /dev/null +++ b/lib/tests/random32_kunit.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for random32 functions. + */ + +#include +#include + +/* 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"); -- cgit v1.3.1