On Wed, Nov 7, 2018 at 6:04 PM, Mark Rutland <mark.rutland@xxxxxxx> wrote: > On Tue, Nov 06, 2018 at 06:30:20PM +0100, Andrey Konovalov wrote: >> This commit splits the current CONFIG_KASAN config option into two: >> 1. CONFIG_KASAN_GENERIC, that enables the generic KASAN mode (the one >> that exists now); >> 2. CONFIG_KASAN_SW_TAGS, that enables the software tag-based KASAN mode. >> >> The name CONFIG_KASAN_SW_TAGS is chosen as in the future we will have >> another hardware tag-based KASAN mode, that will rely on hardware memory >> tagging support in arm64. >> >> With CONFIG_KASAN_SW_TAGS enabled, compiler options are changed to >> instrument kernel files with -fsantize=kernel-hwaddress (except the ones >> for which KASAN_SANITIZE := n is set). >> >> Both CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS support both >> CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes. >> >> This commit also adds empty placeholder (for now) implementation of >> tag-based KASAN specific hooks inserted by the compiler and adjusts >> common hooks implementation to compile correctly with each of the >> config options. >> >> Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> >> Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> >> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> >> --- >> arch/arm64/Kconfig | 1 + >> include/linux/compiler-clang.h | 5 +- >> include/linux/compiler-gcc.h | 6 ++ >> include/linux/compiler_attributes.h | 13 ----- >> include/linux/kasan.h | 16 ++++-- >> lib/Kconfig.kasan | 87 +++++++++++++++++++++++------ >> mm/kasan/Makefile | 6 +- >> mm/kasan/generic.c | 2 +- >> mm/kasan/kasan.h | 3 +- >> mm/kasan/tags.c | 75 +++++++++++++++++++++++++ >> mm/slub.c | 2 +- >> scripts/Makefile.kasan | 27 ++++++++- >> 12 files changed, 201 insertions(+), 42 deletions(-) >> create mode 100644 mm/kasan/tags.c >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index 787d7850e064..8b331dcfb48e 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -111,6 +111,7 @@ config ARM64 >> select HAVE_ARCH_JUMP_LABEL >> select HAVE_ARCH_JUMP_LABEL_RELATIVE >> select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) >> + select HAVE_ARCH_KASAN_SW_TAGS if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) > > Given this relies on a compiler feature, can we please gate this on > compiler feature detection? e.g. in some common Kconfig have: > > select CC_HAS_ASAN_HWADDRESS if $(cc-option -fsanitize=kernel-hwaddress) > > ... and on arm64 we can do: > > select HAVE_ARCH_KASAN_SW_TAGS if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) > > ... and core KASAN Kconfig can have: > > config KASAN_SW_TAGS > depends on HAVE_ARCH_KASAN_SW_TAGS > depends on CC_HAS_ASAN_HWADDRESS > > [...] > >> +ifeq ($(call cc-option, $(CFLAGS_KASAN) -Werror),) >> + ifneq ($(CONFIG_COMPILE_TEST),y) >> + $(warning Cannot use CONFIG_KASAN_SW_TAGS: \ >> + -fsanitize=hwaddress is not supported by compiler) >> + endif >> +endif > > ... and then this warning shouldn't be possible, and can go. Will do in v11, thanks!
