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
mte_zero_clear_page_tags(void * addr)54 static inline void mte_zero_clear_page_tags(void *addr)
55 {
56 }
mte_sync_tags(pte_t old_pte,pte_t pte)57 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
58 {
59 }
mte_copy_page_tags(void * kto,const void * kfrom)60 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
61 {
62 }
mte_thread_init_user(void)63 static inline void mte_thread_init_user(void)
64 {
65 }
mte_thread_switch(struct task_struct * next)66 static inline void mte_thread_switch(struct task_struct *next)
67 {
68 }
mte_suspend_enter(void)69 static inline void mte_suspend_enter(void)
70 {
71 }
set_mte_ctrl(struct task_struct * task,unsigned long arg)72 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
73 {
74 return 0;
75 }
get_mte_ctrl(struct task_struct * task)76 static inline long get_mte_ctrl(struct task_struct *task)
77 {
78 return 0;
79 }
mte_ptrace_copy_tags(struct task_struct * child,long request,unsigned long addr,unsigned long data)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
system_uses_mte_async_or_asymm_mode(void)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
mte_check_tfsr_entry(void)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
mte_check_tfsr_exit(void)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
system_uses_mte_async_or_asymm_mode(void)124 static inline bool system_uses_mte_async_or_asymm_mode(void)
125 {
126 return false;
127 }
mte_check_tfsr_el1(void)128 static inline void mte_check_tfsr_el1(void)
129 {
130 }
mte_check_tfsr_entry(void)131 static inline void mte_check_tfsr_entry(void)
132 {
133 }
mte_check_tfsr_exit(void)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