From b3a7bb71bfcd56c8266af8cf2a5dee3802e7a449 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 4 Aug 2025 09:43:57 -0700 Subject: KUnit: Introduce ffs()-family tests Add KUnit tests for ffs()-family bit scanning functions: ffs(), __ffs(), fls(), __fls(), fls64(), __ffs64(), and ffz(). The tests validate mathematical relationships (e.g. ffs(x) == __ffs(x) + 1), and test zero values, power-of-2 patterns, maximum values, and sparse bit patterns. Build and run tested with everything I could reach with KUnit: $ ./tools/testing/kunit/kunit.py run --arch=x86_64 ffs $ ./tools/testing/kunit/kunit.py run --arch=i386 ffs $ ./tools/testing/kunit/kunit.py run --arch=arm64 --make_options "CROSS_COMPILE=aarch64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=arm --make_options "CROSS_COMPILE=arm-linux-gnueabihf-" ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpc ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpc32 ffs $ ./tools/testing/kunit/kunit.py run --arch=powerpcle ffs $ ./tools/testing/kunit/kunit.py run --arch=riscv --make_options "CROSS_COMPILE=riscv64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=riscv32 --make_options "CROSS_COMPILE=riscv64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=s390 --make_options "CROSS_COMPILE=s390x-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=m68k ffs $ ./tools/testing/kunit/kunit.py run --arch=loongarch ffs $ ./tools/testing/kunit/kunit.py run --arch=mips --make_options "CROSS_COMPILE=mipsel-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sparc --make_options "CROSS_COMPILE=sparc64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sparc64 --make_options "CROSS_COMPILE=sparc64-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=alpha --make_options "CROSS_COMPILE=alpha-linux-gnu-" ffs $ ./tools/testing/kunit/kunit.py run --arch=sh --make_options "CROSS_COMPILE=sh4-linux-gnu-" ffs Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250804164417.1612371-1-kees@kernel.org Signed-off-by: Kees Cook --- lib/Kconfig.debug | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index dc0e0c6ed075..2391872c7b3c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2479,6 +2479,20 @@ config STRING_HELPERS_KUNIT_TEST depends on KUNIT default KUNIT_ALL_TESTS +config FFS_KUNIT_TEST + tristate "KUnit test ffs-family functions at runtime" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This builds KUnit tests for ffs-family bit manipulation functions + including ffs(), __ffs(), fls(), __fls(), fls64(), and __ffs64(). + + These tests validate mathematical correctness, edge case handling, + and cross-architecture consistency of bit scanning functions. + + For more information on KUnit and unit tests in general, + please refer to Documentation/dev-tools/kunit/. + config TEST_KSTRTOX tristate "Test kstrto*() family of functions at runtime" -- cgit