LXR linux/arch/arm64/include/asm/mte.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (C) 2020 ARM Ltd.
   4 */
   5#ifndef __ASM_MTE_H
   6#define __ASM_MTE_H
   7
   8#include <asm/compiler.h>
   9#include <asm/mte-def.h>
  10
  11#ifndef __ASSEMBLY__
  12
  13#include <linux/bitfield.h>
  14#include <linux/page-flags.h>
  15#include <linux/types.h>
  16
  17#include <asm/pgtable-types.h>
  18
  19void mte_clear_page_tags(void *addr);
  20unsigned long mte_copy_tags_from_user(void *to, const void __user *from,
  21                                      unsigned long n);
  22unsigned long mte_copy_tags_to_user(void __user *to, void *from,
  23                                    unsigned long n);
  24int mte_save_tags(struct page *page);
  25void mte_save_page_tags(const void *page_addr, void *tag_storage);
  26bool mte_restore_tags(swp_entry_t entry, struct page *page);
  27void mte_restore_page_tags(void *page_addr, const void *tag_storage);
  28void mte_invalidate_tags(int type, pgoff_t offset);
  29void mte_invalidate_tags_area(int type);
  30void *mte_allocate_tag_storage(void);
  31void mte_free_tag_storage(char *storage);
  32
  33#ifdef CONFIG_ARM64_MTE
  34
  35/* track which pages have valid allocation tags */
  36#define PG_mte_tagged   PG_arch_2
  37
  38void mte_zero_clear_page_tags(void *addr);
  39void mte_sync_tags(pte_t old_pte, pte_t pte);
  40void mte_copy_page_tags(void *kto, const void *kfrom);
  41void mte_thread_init_user(void);
  42void mte_thread_switch(struct task_struct *next);
  43void mte_suspend_enter(void);
  44long set_mte_ctrl(struct task_struct *task, unsigned long arg);
  45long get_mte_ctrl(struct task_struct *task);
  46int mte_ptrace_copy_tags(struct task_struct *child, long request,
  47                         unsigned long addr, unsigned long data);
  48
  49#else /* CONFIG_ARM64_MTE */
  50
  51/* unused if !CONFIG_ARM64_MTE, silence the compiler */
  52#define PG_mte_tagged   0
  53
  54static inline void mte_zero_clear_page_tags(void *addr)
  55{
  56}
  57static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
  58{
  59}
  60static inline void mte_copy_page_tags(void *kto, const void *kfrom)
  61{
  62}
  63static inline void mte_thread_init_user(void)
  64{
  65}
  66static inline void mte_thread_switch(struct task_struct *next)
  67{
  68}
  69static inline void mte_suspend_enter(void)
  70{
  71}
  72static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
  73{
  74        return 0;
  75}
  76static inline long get_mte_ctrl(struct task_struct *task)
  77{
  78        return 0;
  79}
  80static inline int mte_ptrace_copy_tags(struct task_struct *child,
  81                                       long request, unsigned long addr,
  82                                       unsigned long data)
  83{
  84        return -EIO;
  85}
  86
  87#endif /* CONFIG_ARM64_MTE */
  88
  89#ifdef CONFIG_KASAN_HW_TAGS
  90/* Whether the MTE asynchronous mode is enabled. */
  91DECLARE_STATIC_KEY_FALSE(mte_async_mode);
  92
  93static inline bool system_uses_mte_async_mode(void)
  94{
  95        return static_branch_unlikely(&mte_async_mode);
  96}
  97
  98void mte_check_tfsr_el1(void);
  99
 100static inline void mte_check_tfsr_entry(void)
 101{
 102        if (!system_supports_mte())
 103                return;
 104
 105        mte_check_tfsr_el1();
 106}
 107
 108static inline void mte_check_tfsr_exit(void)
 109{
 110        if (!system_supports_mte())
 111                return;
 112
 113        /*
 114         * The asynchronous faults are sync'ed automatically with
 115         * TFSR_EL1 on kernel entry but for exit an explicit dsb()
 116         * is required.
 117         */
 118        dsb(nsh);
 119        isb();
 120
 121        mte_check_tfsr_el1();
 122}
 123#else
 124static inline bool system_uses_mte_async_mode(void)
 125{
 126        return false;
 127}
 128static inline void mte_check_tfsr_el1(void)
 129{
 130}
 131static inline void mte_check_tfsr_entry(void)
 132{
 133}
 134static inline void mte_check_tfsr_exit(void)
 135{
 136}
 137#endif /* CONFIG_KASAN_HW_TAGS */
 138
 139#endif /* __ASSEMBLY__ */
 140#endif /* __ASM_MTE_H  */
 141