Hi Ilya, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 5e63226c72287bc6c6724d4fc7e157af0e3d7908 commit: e37b3dd063a1a68e28a7cfaf77c84c472112e330 [3881/10945] s390: enable KCSAN config: s390-buildonly-randconfig-r005-20210829 (attached as .config) compiler: s390-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=e37b3dd063a1a68e28a7cfaf77c84c472112e330 git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout e37b3dd063a1a68e28a7cfaf77c84c472112e330 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): kernel/kcsan/kcsan_test.c: In function 'test_atomic_builtins': >> kernel/kcsan/kcsan_test.c:945:17: warning: 'atomic_thread_fence' is not supported with '-fsanitize=thread' [-Wtsan] 945 | __atomic_thread_fence(__ATOMIC_SEQ_CST); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +945 kernel/kcsan/kcsan_test.c 1fe84fd4a4027a kernel/kcsan/kcsan-test.c Marco Elver 2020-05-05 901 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 902 /* f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 903 * Test atomic builtins work and required instrumentation functions exist. We f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 904 * also test that KCSAN understands they're atomic by racing with them via f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 905 * test_kernel_atomic_builtins(), and expect no reports. f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 906 * f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 907 * The atomic builtins _SHOULD NOT_ be used in normal kernel code! f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 908 */ f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 909 static void test_atomic_builtins(struct kunit *test) f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 910 { f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 911 bool match_never = false; f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 912 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 913 begin_test_checks(test_kernel_atomic_builtins, test_kernel_atomic_builtins); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 914 do { f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 915 long tmp; f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 916 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 917 kcsan_enable_current(); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 918 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 919 __atomic_store_n(&test_var, 42L, __ATOMIC_RELAXED); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 920 KUNIT_EXPECT_EQ(test, 42L, __atomic_load_n(&test_var, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 921 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 922 KUNIT_EXPECT_EQ(test, 42L, __atomic_exchange_n(&test_var, 20, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 923 KUNIT_EXPECT_EQ(test, 20L, test_var); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 924 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 925 tmp = 20L; f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 926 KUNIT_EXPECT_TRUE(test, __atomic_compare_exchange_n(&test_var, &tmp, 30L, f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 927 0, __ATOMIC_RELAXED, f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 928 __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 929 KUNIT_EXPECT_EQ(test, tmp, 20L); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 930 KUNIT_EXPECT_EQ(test, test_var, 30L); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 931 KUNIT_EXPECT_FALSE(test, __atomic_compare_exchange_n(&test_var, &tmp, 40L, f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 932 1, __ATOMIC_RELAXED, f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 933 __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 934 KUNIT_EXPECT_EQ(test, tmp, 30L); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 935 KUNIT_EXPECT_EQ(test, test_var, 30L); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 936 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 937 KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_add(&test_var, 1, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 938 KUNIT_EXPECT_EQ(test, 31L, __atomic_fetch_sub(&test_var, 1, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 939 KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_and(&test_var, 0xf, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 940 KUNIT_EXPECT_EQ(test, 14L, __atomic_fetch_xor(&test_var, 0xf, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 941 KUNIT_EXPECT_EQ(test, 1L, __atomic_fetch_or(&test_var, 0xf0, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 942 KUNIT_EXPECT_EQ(test, 241L, __atomic_fetch_nand(&test_var, 0xf, __ATOMIC_RELAXED)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 943 KUNIT_EXPECT_EQ(test, -2L, test_var); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 944 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 @945 __atomic_thread_fence(__ATOMIC_SEQ_CST); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 946 __atomic_signal_fence(__ATOMIC_SEQ_CST); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 947 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 948 kcsan_disable_current(); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 949 f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 950 match_never = report_available(); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 951 } while (!end_test_checks(match_never)); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 952 KUNIT_EXPECT_FALSE(test, match_never); f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 953 } f9ea6319313547 kernel/kcsan/kcsan-test.c Marco Elver 2020-07-03 954 :::::: The code at line 945 was first introduced by commit :::::: f9ea63193135473ed6b6ff06f016eb6248100041 kcsan: Add atomic builtin test case :::::: TO: Marco Elver :::::: CC: Paul E. McKenney --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org