From: Dmitry Vyukov <dvyukov@google.com>
To: akpm@linux-foundation.org, linux-mm@kvack.org
Cc: tchibo@google.com, Mark Rutland <mark.rutland@arm.com>,
Alexander Popov <alex.popov@linux.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Kees Cook <keescook@chromium.org>,
Vegard Nossum <vegard.nossum@oracle.com>,
Quentin Casasnovas <quentin.casasnovas@oracle.com>,
syzkaller@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] Makefile: support flag -fsanitizer-coverage=trace-cmp
Date: Wed, 30 Aug 2017 18:23:30 +0200 [thread overview]
Message-ID: <81a8c78be80eb29f339959b0076f7cb7114e0bcb.1504109849.git.dvyukov@google.com> (raw)
In-Reply-To: <cover.1504109849.git.dvyukov@google.com>
In-Reply-To: <cover.1504109849.git.dvyukov@google.com>
From: Victor Chibotaru <tchibo@google.com>
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 <tchibo@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
Clang instrumentation:
https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-data-flow
---
Makefile | 5 +++--
lib/Kconfig.debug | 8 ++++++++
scripts/Makefile.kcov | 6 ++++++
scripts/Makefile.lib | 6 ++++++
4 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index f9703f3223eb..bb117c42a785 100644
--- a/Makefile
+++ b/Makefile
@@ -374,7 +374,7 @@ 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,)
-
+CFLAGS_KCOV_COMPS := $(call cc-option,-fsanitize-coverage=trace-cmp,)
# Use USERINCLUDE when you must reference the UAPI directories only.
USERINCLUDE := \
@@ -420,7 +420,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
-export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN
+export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KCOV_COMPS CFLAGS_KASAN CFLAGS_UBSAN
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
@@ -822,6 +822,7 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
KBUILD_ARFLAGS := $(call ar-option,D)
include scripts/Makefile.kasan
+include scripts/Makefile.kcov
include scripts/Makefile.extrawarn
include scripts/Makefile.ubsan
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d7e3f0bfe91e..85fc0db2e8af 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -777,6 +777,14 @@ config KCOV
For more details, see Documentation/dev-tools/kcov.rst.
+config KCOV_ENABLE_COMPARISONS
+ bool "Enable comparison operands collection by KCOV"
+ depends on KCOV
+ default n
+ help
+ KCOV also exposes operands of every comparison in instrumented code.
+ Note: currently only available if compiled with Clang.
+
config KCOV_INSTRUMENT_ALL
bool "Instrument all code by default"
depends on KCOV
diff --git a/scripts/Makefile.kcov b/scripts/Makefile.kcov
new file mode 100644
index 000000000000..5d6e644cefed
--- /dev/null
+++ b/scripts/Makefile.kcov
@@ -0,0 +1,6 @@
+ifeq ($(CONFIG_KCOV_ENABLE_COMPARISONS),y)
+ifneq ($(cc-name),clang)
+ $(warning Cannot use CONFIG_KCOV_ENABLE_COMPARISONS: \
+ -fsanitize=trace-cmp is not supported by compiler)
+endif
+endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 58c05e5d9870..bb38cd33e15c 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 '/').
--
2.14.1.581.gf28d330327-goog
next prev parent reply other threads:[~2017-08-30 16:23 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1504109849.git.dvyukov@google.com>
2017-08-30 16:23 ` [PATCH 1/3] kcov: support comparison operands collection Dmitry Vyukov
2017-08-30 18:23 ` Mark Rutland
2017-08-30 19:04 ` Alexander Potapenko
2017-08-30 19:08 ` Dmitry Vyukov
2017-08-31 9:31 ` Mark Rutland
2017-09-12 17:41 ` Dmitry Vyukov
2017-08-31 13:27 ` Andrey Konovalov
[not found] ` <CAPZ9YJZUPYs8nbwG9aO1uCfr7vPY7PNr1WPpvOxP8d+vkMiDJw@mail.gmail.com>
2017-09-12 17:41 ` Dmitry Vyukov
2017-08-30 16:23 ` Dmitry Vyukov [this message]
2017-08-30 16:23 ` [PATCH 3/3] kcov: update documentation Dmitry Vyukov
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