From c7fea48876773603721f545f8c1a2f894291ef85 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 21 Jul 2017 06:19:14 -0700 Subject: lkdtm: Provide timing tests for atomic_t vs refcount_t While not a crash test, this does provide two tight atomic_t and refcount_t loops for performance comparisons: cd /sys/kernel/debug/provoke-crash perf stat -B -- cat <(echo ATOMIC_TIMING) > DIRECT perf stat -B -- cat <(echo REFCOUNT_TIMING) > DIRECT Looking a CPU cycles is the best way to example the fast-path (rather than instruction counts, since conditional jumps will be executed but will be negligible due to branch-prediction). Signed-off-by: Kees Cook --- drivers/misc/lkdtm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/misc/lkdtm.h') diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index 04ff8b23b3b0..063f5d651076 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/lkdtm.h @@ -61,6 +61,8 @@ void lkdtm_REFCOUNT_INC_NOT_ZERO_SATURATED(void); void lkdtm_REFCOUNT_ADD_NOT_ZERO_SATURATED(void); void lkdtm_REFCOUNT_DEC_AND_TEST_SATURATED(void); void lkdtm_REFCOUNT_SUB_AND_TEST_SATURATED(void); +void lkdtm_REFCOUNT_TIMING(void); +void lkdtm_ATOMIC_TIMING(void); /* lkdtm_rodata.c */ void lkdtm_rodata_do_nothing(void); -- cgit