From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id C55416B0275 for ; Tue, 10 Oct 2017 11:27:42 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id u78so5690642wmd.13 for ; Tue, 10 Oct 2017 08:27:42 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id b11sor2875863wmb.67.2017.10.10.08.27.41 for (Google Transport Security); Tue, 10 Oct 2017 08:27:41 -0700 (PDT) From: Alexander Potapenko Subject: [PATCH v3 2/3] Makefile: support flag -fsanitizer-coverage=trace-cmp Date: Tue, 10 Oct 2017 17:27:30 +0200 Message-Id: <20171010152731.26031-2-glider@google.com> In-Reply-To: <20171010152731.26031-1-glider@google.com> References: <20171010152731.26031-1-glider@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, mark.rutland@arm.com, alex.popov@linux.com, aryabinin@virtuozzo.com, quentin.casasnovas@oracle.com, dvyukov@google.com, andreyknvl@google.com, keescook@chromium.org, vegard.nossum@oracle.com Cc: syzkaller@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org From: Victor Chibotaru 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. Signed-off-by: Victor Chibotaru Signed-off-by: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Konovalov Cc: Andrew Morton Cc: Mark Rutland Cc: Alexander Popov Cc: Andrey Ryabinin Cc: Kees Cook Cc: Vegard Nossum Cc: Quentin Casasnovas Cc: syzkaller@googlegroups.com Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- Clang instrumentation: https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-data-flow v3: - Andrey Ryabinin's comments: reinstated scripts/Makefile.kcov and moved CFLAGS_KCOV there, dropped CFLAGS_KCOV_COMPS - allow building with GCC v2: - updated KCOV_ENABLE_COMPARISONS description --- Makefile | 3 +-- lib/Kconfig.debug | 10 ++++++++++ scripts/Makefile.kcov | 7 +++++++ scripts/Makefile.lib | 6 ++++++ 4 files changed, 24 insertions(+), 2 deletions(-) create mode 100644 scripts/Makefile.kcov diff --git a/Makefile b/Makefile index 2835863bdd5a..43f642167d68 100644 --- a/Makefile +++ b/Makefile @@ -373,8 +373,6 @@ CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) - # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ @@ -657,6 +655,7 @@ ifeq ($(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 2689b7c50c52..a10eb4e34719 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -759,6 +759,16 @@ 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 diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 5e975fee0f5b..7ddd5932c832 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -142,6 +142,12 @@ _c_flags += $(if $(patsubst n%,, \ $(CFLAGS_KCOV)) endif +ifeq ($(CONFIG_KCOV_ENABLE_COMPARISONS),y) +_c_flags += $(if $(patsubst n%,, \ + $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ + $(CFLAGS_KCOV_COMPS)) +endif + # If building the kernel in a separate objtree expand all occurrences # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/'). -- 2.14.2.920.gcf0c67979c-goog -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org