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 19 void mte_clear_page_tags(void *addr); 20 unsigned long mte_copy_tags_from_user(void *to, const void __user *from, 21 unsigned long n); 22 unsigned long mte_copy_tags_to_user(void __user *to, void *from, 23 unsigned long n); 24 int mte_save_tags(struct page *page); 25 void mte_save_page_tags(const void *page_addr, void *tag_storage); 26 bool mte_restore_tags(swp_entry_t entry, struct page *page); 27 void mte_restore_page_tags(void *page_addr, const void *tag_storage); 28 void mte_invalidate_tags(int type, pgoff_t offset); 29 void mte_invalidate_tags_area(int type); 30 void *mte_allocate_tag_storage(void); 31 void 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 38 void mte_zero_clear_page_tags(void *addr); 39 void mte_sync_tags(pte_t old_pte, pte_t pte); 40 void mte_copy_page_tags(void *kto, const void *kfrom); 41 void mte_thread_init_user(void); 42 void mte_thread_switch(struct task_struct *next); 43 void mte_suspend_enter(void); 44 long set_mte_ctrl(struct task_struct *task, unsigned long arg); 45 long get_mte_ctrl(struct task_struct *task); 46 int 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 54 static inline void mte_zero_clear_page_tags(void *addr) 55 { 56 } 57 static inline void mte_sync_tags(pte_t old_pte, pte_t pte) 58 { 59 } 60 static inline void mte_copy_page_tags(void *kto, const void *kfrom) 61 { 62 } 63 static inline void mte_thread_init_user(void) 64 { 65 } 66 static inline void mte_thread_switch(struct task_struct *next) 67 { 68 } 69 static inline void mte_suspend_enter(void) 70 { 71 } 72 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg) 73 { 74 return 0; 75 } 76 static inline long get_mte_ctrl(struct task_struct *task) 77 { 78 return 0; 79 } 80 static 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. */ 91 DECLARE_STATIC_KEY_FALSE(mte_async_or_asymm_mode); 92 93 static inline bool system_uses_mte_async_or_asymm_mode(void) 94 { 95 return static_branch_unlikely(&mte_async_or_asymm_mode); 96 } 97 98 void mte_check_tfsr_el1(void); 99 100 static inline void mte_check_tfsr_entry(void) 101 { 102 if (!system_supports_mte()) 103 return; 104 105 mte_check_tfsr_el1(); 106 } 107 108 static 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 124 static inline bool system_uses_mte_async_or_asymm_mode(void) 125 { 126 return false; 127 } 128 static inline void mte_check_tfsr_el1(void) 129 { 130 } 131 static inline void mte_check_tfsr_entry(void) 132 { 133 } 134 static 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