On 05/08/2018 08:20 PM, Andrey Konovalov wrote:
> diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
> index 69552a39951d..47023daf5606 100644
> --- a/scripts/Makefile.kasan
> +++ b/scripts/Makefile.kasan
> @@ -1,5 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
> -ifdef CONFIG_KASAN
> +ifdef CONFIG_KASAN_GENERIC
> ifdef CONFIG_KASAN_INLINE
> call_threshold := 10000
> else
> @@ -45,3 +45,28 @@ endif
> CFLAGS_KASAN_NOSANITIZE := -fno-builtin
>
> endif
> +
> +ifdef CONFIG_KASAN_HW
> +
> +ifdef CONFIG_KASAN_INLINE
> + instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
> +else
> + instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1
> +endif
> +
> +CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-hwaddress
> +
> +ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
> + ifneq ($(CONFIG_COMPILE_TEST),y)
> + $(warning Cannot use CONFIG_KASAN_HW: \
> + -fsanitize=hwaddress is not supported by compiler)
> + endif
> +else
> + CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-hwaddress \
> + -mllvm -hwasan-instrument-stack=0 \
> + $(instrumentation_flags))
> +endif
So this code does the following:
1) Warn if compiler doesn't support -fsanitize=kernel-hwaddress
2) Compile the kernel with all necessary set of the '-fsanitize=kernel-hwaddress -mllvm -hwasan-*' flags if compiler supports all of them.
3) Compile the kernel with empty CFLAGS_KASAN without a warning if compiler supports 'fsanitize=kernel-hwaddress',
but doesn't support the rest '-mllvm -hwasan-*' flags.
The last one is just nonsense.
> +
> +CFLAGS_KASAN_NOSANITIZE := -fno-builtin
> +
Does it really has to declared twice?
