linux-stable/arch/arm64/include/asm/kasan.h
Andrey Konovalov 2cb3427642 arm64: kasan: simplify and inline MTE functions
This change provides a simpler implementation of mte_get_mem_tag(),
mte_get_random_tag(), and mte_set_mem_tag_range().

Simplifications include removing system_supports_mte() checks as these
functions are onlye called from KASAN runtime that had already checked
system_supports_mte().  Besides that, size and address alignment checks
are removed from mte_set_mem_tag_range(), as KASAN now does those.

This change also moves these functions into the asm/mte-kasan.h header and
implements mte_set_mem_tag_range() via inline assembly to avoid
unnecessary functions calls.

[vincenzo.frascino@arm.com: fix warning in mte_get_random_tag()]
  Link: https://lkml.kernel.org/r/20210211152208.23811-1-vincenzo.frascino@arm.com

Link: https://lkml.kernel.org/r/a26121b294fdf76e369cb7a74351d1c03a908930.1612546384.git.andreyknvl@google.com
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:03 -08:00

48 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_KASAN_H
#define __ASM_KASAN_H
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <asm/memory.h>
#include <asm/mte-kasan.h>
#include <asm/pgtable-types.h>
#define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag)
#define arch_kasan_reset_tag(addr) __tag_reset(addr)
#define arch_kasan_get_tag(addr) __tag_get(addr)
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
void kasan_init(void);
/*
* KASAN_SHADOW_START: beginning of the kernel virtual addresses.
* KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
* where N = (1 << KASAN_SHADOW_SCALE_SHIFT).
*
* KASAN_SHADOW_OFFSET:
* This value is used to map an address to the corresponding shadow
* address by the following formula:
* shadow_addr = (address >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
*
* (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) shadow addresses that lie in range
* [KASAN_SHADOW_OFFSET, KASAN_SHADOW_END) cover all 64-bits of virtual
* addresses. So KASAN_SHADOW_OFFSET should satisfy the following equation:
* KASAN_SHADOW_OFFSET = KASAN_SHADOW_END -
* (1ULL << (64 - KASAN_SHADOW_SCALE_SHIFT))
*/
#define _KASAN_SHADOW_START(va) (KASAN_SHADOW_END - (1UL << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
#define KASAN_SHADOW_START _KASAN_SHADOW_START(vabits_actual)
void kasan_copy_shadow(pgd_t *pgdir);
asmlinkage void kasan_early_init(void);
#else
static inline void kasan_init(void) { }
static inline void kasan_copy_shadow(pgd_t *pgdir) { }
#endif
#endif
#endif