kasan/Makefile: support LLVM style asan parameters
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"), thus
we currently we don't use inline/globals/stack instrumentation when
building the kernel with clang.
Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to enable
all KASAN features.
Link: http://lkml.kernel.org/r/20171204191735.132544-3-paullawrence@google.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 94c9e65..ab85095 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -10,10 +10,7 @@
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
-CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
- -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
- --param asan-stack=1 --param asan-globals=1 \
- --param asan-instrumentation-with-call-threshold=$(call_threshold))
+cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
ifneq ($(CONFIG_COMPILE_TEST),y)
@@ -21,13 +18,23 @@
-fsanitize=kernel-address is not supported by compiler)
endif
else
- ifeq ($(CFLAGS_KASAN),)
- ifneq ($(CONFIG_COMPILE_TEST),y)
- $(warning CONFIG_KASAN: compiler does not support all options.\
- Trying minimal configuration)
- endif
- CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
- endif
+ # -fasan-shadow-offset fails without -fsanitize
+ CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
+ -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET), \
+ $(call cc-option, -fsanitize=kernel-address \
+ -mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
+
+ ifeq ($(strip $(CFLAGS_KASAN_SHADOW)),)
+ CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
+ else
+ # Now add all the compiler specific options that are valid standalone
+ CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
+ $(call cc-param,asan-globals=1) \
+ $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
+ $(call cc-param,asan-stack=1) \
+ $(call cc-param,asan-use-after-scope=1)
+ endif
+
endif
CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)