arch/arm64/include/asm/mte-kasan.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2020 ARM Ltd.
   4  */
   5 #ifndef __ASM_MTE_KASAN_H
   6 #define __ASM_MTE_KASAN_H
   7
   8 #include <asm/mte-def.h>
   9
  10 #ifndef __ASSEMBLY__
  11
  12 #include <linux/types.h>
  13
  14 /*
  15  * The functions below are meant to be used only for the
  16  * KASAN_HW_TAGS interface defined in asm/memory.h.
  17  */
  18 #ifdef CONFIG_ARM64_MTE
  19
  20 static inline u8 mte_get_ptr_tag(void *ptr)
  21 {
  22         /* Note: The format of KASAN tags is 0xF<x> */
  23         u8 tag = 0xF0 | (u8)(((u64)(ptr)) >> MTE_TAG_SHIFT);
  24
  25         return tag;
  26 }
  27
  28 u8 mte_get_mem_tag(void *addr);
  29 u8 mte_get_random_tag(void);
  30 void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag);
  31
  32 void mte_enable_kernel(void);
  33 void mte_init_tags(u64 max_tag);
  34
  35 #else /* CONFIG_ARM64_MTE */
  36
  37 static inline u8 mte_get_ptr_tag(void *ptr)
  38 {
  39         return 0xFF;
  40 }
  41
  42 static inline u8 mte_get_mem_tag(void *addr)
  43 {
  44         return 0xFF;
  45 }
  46 static inline u8 mte_get_random_tag(void)
  47 {
  48         return 0xFF;
  49 }
  50 static inline void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag)
  51 {
  52         return addr;
  53 }
  54
  55 static inline void mte_enable_kernel(void)
  56 {
  57 }
  58
  59 static inline void mte_init_tags(u64 max_tag)
  60 {
  61 }
  62
  63 #endif /* CONFIG_ARM64_MTE */
  64
  65 #endif /* __ASSEMBLY__ */
  66
  67 #endif /* __ASM_MTE_KASAN_H  */