Allow architectures to override KASAN_TAG_KERNEL in asm/kasan.h. This is needed on RISC-V, which supports 57-bit virtual addresses and 7-bit pointer tags. For consistency, move the arm64 MTE definition of KASAN_TAG_MIN to asm/kasan.h, since it is also architecture-dependent; RISC-V's equivalent extension is expected to support 7-bit hardware memory tags. Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx> Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx> --- (no changes since v1) arch/arm64/include/asm/kasan.h | 6 ++++-- arch/arm64/include/asm/uaccess.h | 1 + include/linux/kasan-tags.h | 13 ++++++++----- 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h index e1b57c13f8a4..4ab419df8b93 100644 --- a/arch/arm64/include/asm/kasan.h +++ b/arch/arm64/include/asm/kasan.h @@ -6,8 +6,10 @@ #include <linux/linkage.h> #include <asm/memory.h> -#include <asm/mte-kasan.h> -#include <asm/pgtable-types.h> + +#ifdef CONFIG_KASAN_HW_TAGS +#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ +#endif #define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) #define arch_kasan_reset_tag(addr) __tag_reset(addr) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 1aa4ecb73429..8f700a7dd2cd 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -22,6 +22,7 @@ #include <asm/cpufeature.h> #include <asm/mmu.h> #include <asm/mte.h> +#include <asm/mte-kasan.h> #include <asm/ptrace.h> #include <asm/memory.h> #include <asm/extable.h> diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h index 4f85f562512c..e07c896f95d3 100644 --- a/include/linux/kasan-tags.h +++ b/include/linux/kasan-tags.h @@ -2,13 +2,16 @@ #ifndef _LINUX_KASAN_TAGS_H #define _LINUX_KASAN_TAGS_H +#include <asm/kasan.h> + +#ifndef KASAN_TAG_KERNEL #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ -#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ -#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ +#endif + +#define KASAN_TAG_INVALID (KASAN_TAG_KERNEL - 1) /* inaccessible memory tag */ +#define KASAN_TAG_MAX (KASAN_TAG_KERNEL - 2) /* maximum value for random tags */ -#ifdef CONFIG_KASAN_HW_TAGS -#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ -#else +#ifndef KASAN_TAG_MIN #define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ #endif -- 2.45.1
