From 4185b3b92792eaec5869266e594338343421ffb0 Mon Sep 17 00:00:00 2001 From: Petteri Aimonen Date: Thu, 18 Jun 2020 16:37:37 +0200 Subject: selftests/fpu: Add an FPU selftest Add a selftest for the usage of FPU code in kernel mode. Currently only implemented for x86. In the future, kernel FPU testing could be unified between the different architectures supporting it. [ bp: - Split out from a conglomerate patch, put comments over statements. - run the test only on debugfs write. - Add bare-minimum run_test_fpu.sh, run 1000 iterations on all CPUs by default. - Add conditionally -msse2 so that clang doesn't generate library calls. - Use cc-option to detect gcc 7.1 not supporting -mpreferred-stack-boundary=3 (amluto). - Document stuff so that we don't forget. - Fix: ld: lib/test_fpu.o: in function `test_fpu_get': >> test_fpu.c:(.text+0x16e): undefined reference to `__sanitizer_cov_trace_cmpd' >> ld: test_fpu.c:(.text+0x1a7): undefined reference to `__sanitizer_cov_trace_cmpd' ld: test_fpu.c:(.text+0x1e0): undefined reference to `__sanitizer_cov_trace_cmpd' ] Reported-by: kernel test robot Signed-off-by: Petteri Aimonen Signed-off-by: Borislav Petkov Reviewed-by: Nick Desaulniers Link: https://lkml.kernel.org/r/20200624114646.28953-3-bp@alien8.de --- lib/Kconfig.debug | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 9ad9210d70a1..5842885ab184 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2307,6 +2307,17 @@ config TEST_HMM If unsure, say N. +config TEST_FPU + tristate "Test floating point operations in kernel space" + depends on X86 && !KCOV_INSTRUMENT_ALL + help + Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu + which will trigger a sequence of floating point operations. This is used + for self-testing floating point control register setting in + kernel_fpu_begin(). + + If unsure, say N. + endif # RUNTIME_TESTING_MENU config MEMTEST -- cgit v1.2.3