From: Victor Chibotaru <tchibo@xxxxxxxxxx> Subject: Makefile: support flag -fsanitizer-coverage=trace-cmp The flag enables Clang instrumentation of comparison operations (currently not supported by GCC). This instrumentation is needed by the new KCOV device to collect comparison operands. Link: http://lkml.kernel.org/r/20171011095459.70721-2-glider@xxxxxxxxxx Signed-off-by: Victor Chibotaru <tchibo@xxxxxxxxxx> Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Alexander Popov <alex.popov@xxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Cc: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx> Cc: <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Makefile | 3 +-- lib/Kconfig.debug | 10 ++++++++++ scripts/Makefile.kcov | 7 +++++++ 3 files changed, 18 insertions(+), 2 deletions(-) diff -puN lib/Kconfig.debug~makefile-support-flag-fsanitizer-coverage=trace-cmp lib/Kconfig.debug --- a/lib/Kconfig.debug~makefile-support-flag-fsanitizer-coverage=trace-cmp +++ a/lib/Kconfig.debug @@ -756,6 +756,16 @@ config KCOV For more details, see Documentation/dev-tools/kcov.rst. +config KCOV_ENABLE_COMPARISONS + bool "Enable comparison operands collection by KCOV" + depends on KCOV + default n + help + KCOV also exposes operands of every comparison in the instrumented + code along with operand sizes and PCs of the comparison instructions. + These operands can be used by fuzzing engines to improve the quality + of fuzzing coverage. + config KCOV_INSTRUMENT_ALL bool "Instrument all code by default" depends on KCOV diff -puN Makefile~makefile-support-flag-fsanitizer-coverage=trace-cmp Makefile --- a/Makefile~makefile-support-flag-fsanitizer-coverage=trace-cmp +++ a/Makefile @@ -375,8 +375,6 @@ CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) - # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ @@ -659,6 +657,7 @@ ifeq ($(shell $(CONFIG_SHELL) $(srctree) KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO endif +include scripts/Makefile.kcov include scripts/Makefile.gcc-plugins ifdef CONFIG_READABLE_ASM diff -puN /dev/null scripts/Makefile.kcov --- /dev/null +++ a/scripts/Makefile.kcov @@ -0,0 +1,7 @@ +ifdef CONFIG_KCOV +CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) +ifeq ($(CONFIG_KCOV_ENABLE_COMPARISONS),y) +CFLAGS_KCOV += $(call cc-option,-fsanitize-coverage=trace-cmp,) +endif + +endif _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
