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. Thanks, Mark.
