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authorVictor Chibotaru <tchibo@google.com>2017-11-17 15:30:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-17 16:10:04 -0800
commitd677a4d6019385488e794cc47bd3d6f9c2aab874 (patch)
tree5c94f48e2a9acfb553a359c30bcbb2c0f76ba266
parentkcov: support comparison operands collection (diff)
downloadlinux-dev-d677a4d6019385488e794cc47bd3d6f9c2aab874.tar.xz
linux-dev-d677a4d6019385488e794cc47bd3d6f9c2aab874.zip
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>
-rw-r--r--Makefile3
-rw-r--r--lib/Kconfig.debug10
-rw-r--r--scripts/Makefile.kcov7
3 files changed, 18 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index 763ab35df12a..ccb7d5b2fbf5 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 ce813731269f..947d3e2ed5c2 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 000000000000..5cc72037e423
--- /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