Make CONFIG_KASAN_SW_TAGS available for x86 machines if they have ADDRESS_MASKING enabled (LAM) as that works similarly to Top-Byte Ignore (TBI) that allows the software tag-based mode on arm64 platform. Set scale macro based on KASAN mode: in software tag-based mode 32 bytes of memory map to one shadow byte and 16 in generic mode. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx> --- Changelog v2: - Remove KASAN dense code. arch/x86/Kconfig | 6 ++++++ arch/x86/boot/compressed/misc.h | 1 + arch/x86/include/asm/kasan.h | 2 +- arch/x86/kernel/setup.c | 2 ++ 4 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f4ef64bf824a..dc48eb5b664f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -195,6 +195,7 @@ config X86 select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KASAN_VMALLOC if X86_64 + select HAVE_ARCH_KASAN_SW_TAGS if ADDRESS_MASKING select HAVE_ARCH_KFENCE select HAVE_ARCH_KMSAN if X86_64 select HAVE_ARCH_KGDB @@ -402,6 +403,11 @@ config KASAN_SHADOW_OFFSET hex default 0xdffffc0000000000 if KASAN_GENERIC +config KASAN_SHADOW_SCALE_SHIFT + int + default 4 if KASAN_SW_TAGS + default 3 + config HAVE_INTEL_TXT def_bool y depends on INTEL_IOMMU && ACPI diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index dd8d1a85f671..f6a87e9ad200 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -13,6 +13,7 @@ #undef CONFIG_PARAVIRT_SPINLOCKS #undef CONFIG_KASAN #undef CONFIG_KASAN_GENERIC +#undef CONFIG_KASAN_SW_TAGS #define __NO_FORTIFY diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h index 4bfd3641af84..cfc31e4a2f70 100644 --- a/arch/x86/include/asm/kasan.h +++ b/arch/x86/include/asm/kasan.h @@ -6,7 +6,7 @@ #include <linux/kasan-tags.h> #include <linux/types.h> -#define KASAN_SHADOW_SCALE_SHIFT 3 +#define KASAN_SHADOW_SCALE_SHIFT CONFIG_KASAN_SHADOW_SCALE_SHIFT /* * Compiler uses shadow offset assuming that addresses start diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index cebee310e200..768990c573ea 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1124,6 +1124,8 @@ void __init setup_arch(char **cmdline_p) kasan_init(); + kasan_init_sw_tags(); + /* * Sync back kernel address range. * -- 2.47.1
