Commit d677a4d6 authored by Victor Chibotaru's avatar Victor Chibotaru Committed by Linus Torvalds
Browse files

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: default avatarVictor Chibotaru <tchibo@google.com>
Signed-off-by: default avatarAlexander 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ded97d2c

Makefile

+1 −2
Original line number Diff line number Diff line
@@ -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

lib/Kconfig.debug

+10 −0
Original line number Diff line number Diff line
@@ -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

scripts/Makefile.kcov

0 → 100644
+7 −0
Original line number Diff line number Diff line 
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

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