linux

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 <lkp@intel.com> Signed-off-by: Petteri Aimonen <jpa@git.mail.kapsi.fi> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20200624114646.28953-3-bp@alien8.de 2020-06-18 16:37:37 +02:00