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 extern u64 gcr_kernel_excl; 20 21 void mte_clear_page_tags(void *addr); 22 unsigned long mte_copy_tags_from_user(void *to, const void __user *from, 23 unsigned long n); 24 unsigned long mte_copy_tags_to_user(void __user *to, void *from, 25 unsigned long n); 26 int mte_save_tags(struct page *page); 27 void mte_save_page_tags(const void *page_addr, void *tag_storage); 28 bool mte_restore_tags(swp_entry_t entry, struct page *page); 29 void mte_restore_page_tags(void *page_addr, const void *tag_storage); 30 void mte_invalidate_tags(int type, pgoff_t offset); 31 void mte_invalidate_tags_area(int type); 32 void *mte_allocate_tag_storage(void); 33 void mte_free_tag_storage(char *storage); 34 35 #ifdef CONFIG_ARM64_MTE 36 37 /* track which pages have valid allocation tags */ 38 #define PG_mte_tagged PG_arch_2 39 40 void mte_sync_tags(pte_t *ptep, pte_t pte); 41 void mte_copy_page_tags(void *kto, const void *kfrom); 42 void mte_thread_init_user(void); 43 void mte_thread_switch(struct task_struct *next); 44 void mte_suspend_enter(void); 45 void mte_suspend_exit(void); 46 long set_mte_ctrl(struct task_struct *task, unsigned long arg); 47 long get_mte_ctrl(struct task_struct *task); 48 int mte_ptrace_copy_tags(struct task_struct *child, long request, 49 unsigned long addr, unsigned long data); 50 51 #else /* CONFIG_ARM64_MTE */ 52 53 /* unused if !CONFIG_ARM64_MTE, silence the compiler */ 54 #define PG_mte_tagged 0 55 56 static inline void mte_sync_tags(pte_t *ptep, pte_t pte) 57 { 58 } 59 static inline void mte_copy_page_tags(void *kto, const void *kfrom) 60 { 61 } 62 static inline void mte_thread_init_user(void) 63 { 64 } 65 static inline void mte_thread_switch(struct task_struct *next) 66 { 67 } 68 static inline void mte_suspend_enter(void) 69 { 70 } 71 static inline void mte_suspend_exit(void) 72 { 73 } 74 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg) 75 { 76 return 0; 77 } 78 static inline long get_mte_ctrl(struct task_struct *task) 79 { 80 return 0; 81 } 82 static inline int mte_ptrace_copy_tags(struct task_struct *child, 83 long request, unsigned long addr, 84 unsigned long data) 85 { 86 return -EIO; 87 } 88 89 #endif /* CONFIG_ARM64_MTE */ 90 91 #ifdef CONFIG_KASAN_HW_TAGS 92 /* Whether the MTE asynchronous mode is enabled. */ 93 DECLARE_STATIC_KEY_FALSE(mte_async_mode); 94 95 static inline bool system_uses_mte_async_mode(void) 96 { 97 return static_branch_unlikely(&mte_async_mode); 98 } 99 100 void mte_check_tfsr_el1(void); 101 102 static inline void mte_check_tfsr_entry(void) 103 { 104 mte_check_tfsr_el1(); 105 } 106 107 static inline void mte_check_tfsr_exit(void) 108 { 109 /* 110 * The asynchronous faults are sync'ed automatically with 111 * TFSR_EL1 on kernel entry but for exit an explicit dsb() 112 * is required. 113 */ 114 dsb(nsh); 115 isb(); 116 117 mte_check_tfsr_el1(); 118 } 119 #else 120 static inline bool system_uses_mte_async_mode(void) 121 { 122 return false; 123 } 124 static inline void mte_check_tfsr_el1(void) 125 { 126 } 127 static inline void mte_check_tfsr_entry(void) 128 { 129 } 130 static inline void mte_check_tfsr_exit(void) 131 { 132 } 133 #endif /* CONFIG_KASAN_HW_TAGS */ 134 135 #endif /* __ASSEMBLY__ */ 136 #endif /* __ASM_MTE_H */ 137