From d677a4d6019385488e794cc47bd3d6f9c2aab874 Mon Sep 17 00:00:00 2001 From: Victor Chibotaru <tchibo@google.com> Date: Fri, 17 Nov 2017 15:30:50 -0800 Subject: [PATCH] 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@google.com Signed-off-by: Victor Chibotaru <tchibo@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- Makefile | 3 +-- lib/Kconfig.debug | 10 ++++++++++ scripts/Makefile.kcov | 7 +++++++ 3 files changed, 18 insertions(+), 2 deletions(-) create mode 100644 scripts/Makefile.kcov diff --git a/Makefile b/Makefile index 763ab35df12ac..ccb7d5b2fbf5f 100644 --- a/Makefile +++ b/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)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLA KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO endif +include scripts/Makefile.kcov include scripts/Makefile.gcc-plugins ifdef CONFIG_READABLE_ASM diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ce813731269f6..947d3e2ed5c2f 100644 --- a/lib/Kconfig.debug +++ b/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 --git a/scripts/Makefile.kcov b/scripts/Makefile.kcov new file mode 100644 index 0000000000000..5cc72037e4234 --- /dev/null +++ b/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 -- GitLab