1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 /*
4 * This header provides generic wrappers for memory access instrumentation that
5 * the compiler cannot emit for: KASAN, KCSAN, KMSAN.
6 */
7 #ifndef _LINUX_INSTRUMENTED_H
8 #define _LINUX_INSTRUMENTED_H
9
10 #include <linux/compiler.h>
11 #include <linux/kasan-checks.h>
12 #include <linux/kcsan-checks.h>
13 #include <linux/kmsan-checks.h>
14 #include <linux/types.h>
15
16 /**
17 * instrument_read - instrument regular read access
18 * @v: address of access
19 * @size: size of access
20 *
21 * Instrument a regular read access. The instrumentation should be inserted
22 * before the actual read happens.
23 */
instrument_read(const volatile void * v,size_t size)24 static __always_inline void instrument_read(const volatile void *v, size_t size)
25 {
26 kasan_check_read(v, size);
27 kcsan_check_read(v, size);
28 }
29
30 /**
31 * instrument_write - instrument regular write access
32 * @v: address of access
33 * @size: size of access
34 *
35 * Instrument a regular write access. The instrumentation should be inserted
36 * before the actual write happens.
37 */
instrument_write(const volatile void * v,size_t size)38 static __always_inline void instrument_write(const volatile void *v, size_t size)
39 {
40 kasan_check_write(v, size);
41 kcsan_check_write(v, size);
42 }
43
44 /**
45 * instrument_read_write - instrument regular read-write access
46 * @v: address of access
47 * @size: size of access
48 *
49 * Instrument a regular write access. The instrumentation should be inserted
50 * before the actual write happens.
51 */
instrument_read_write(const volatile void * v,size_t size)52 static __always_inline void instrument_read_write(const volatile void *v, size_t size)
53 {
54 kasan_check_write(v, size);
55 kcsan_check_read_write(v, size);
56 }
57
58 /**
59 * instrument_atomic_read - instrument atomic read access
60 * @v: address of access
61 * @size: size of access
62 *
63 * Instrument an atomic read access. The instrumentation should be inserted
64 * before the actual read happens.
65 */
instrument_atomic_read(const volatile void * v,size_t size)66 static __always_inline void instrument_atomic_read(const volatile void *v, size_t size)
67 {
68 kasan_check_read(v, size);
69 kcsan_check_atomic_read(v, size);
70 }
71
72 /**
73 * instrument_atomic_write - instrument atomic write access
74 * @v: address of access
75 * @size: size of access
76 *
77 * Instrument an atomic write access. The instrumentation should be inserted
78 * before the actual write happens.
79 */
instrument_atomic_write(const volatile void * v,size_t size)80 static __always_inline void instrument_atomic_write(const volatile void *v, size_t size)
81 {
82 kasan_check_write(v, size);
83 kcsan_check_atomic_write(v, size);
84 }
85
86 /**
87 * instrument_atomic_read_write - instrument atomic read-write access
88 * @v: address of access
89 * @size: size of access
90 *
91 * Instrument an atomic read-write access. The instrumentation should be
92 * inserted before the actual write happens.
93 */
instrument_atomic_read_write(const volatile void * v,size_t size)94 static __always_inline void instrument_atomic_read_write(const volatile void *v, size_t size)
95 {
96 kasan_check_write(v, size);
97 kcsan_check_atomic_read_write(v, size);
98 }
99
100 /**
101 * instrument_copy_to_user - instrument reads of copy_to_user
102 * @to: destination address
103 * @from: source address
104 * @n: number of bytes to copy
105 *
106 * Instrument reads from kernel memory, that are due to copy_to_user (and
107 * variants). The instrumentation must be inserted before the accesses.
108 */
109 static __always_inline void
instrument_copy_to_user(void __user * to,const void * from,unsigned long n)110 instrument_copy_to_user(void __user *to, const void *from, unsigned long n)
111 {
112 kasan_check_read(from, n);
113 kcsan_check_read(from, n);
114 kmsan_copy_to_user(to, from, n, 0);
115 }
116
117 /**
118 * instrument_copy_from_user_before - add instrumentation before copy_from_user
119 * @to: destination address
120 * @from: source address
121 * @n: number of bytes to copy
122 *
123 * Instrument writes to kernel memory, that are due to copy_from_user (and
124 * variants). The instrumentation should be inserted before the accesses.
125 */
126 static __always_inline void
instrument_copy_from_user_before(const void * to,const void __user * from,unsigned long n)127 instrument_copy_from_user_before(const void *to, const void __user *from, unsigned long n)
128 {
129 kasan_check_write(to, n);
130 kcsan_check_write(to, n);
131 }
132
133 /**
134 * instrument_copy_from_user_after - add instrumentation after copy_from_user
135 * @to: destination address
136 * @from: source address
137 * @n: number of bytes to copy
138 * @left: number of bytes not copied (as returned by copy_from_user)
139 *
140 * Instrument writes to kernel memory, that are due to copy_from_user (and
141 * variants). The instrumentation should be inserted after the accesses.
142 */
143 static __always_inline void
instrument_copy_from_user_after(const void * to,const void __user * from,unsigned long n,unsigned long left)144 instrument_copy_from_user_after(const void *to, const void __user *from,
145 unsigned long n, unsigned long left)
146 {
147 kmsan_unpoison_memory(to, n - left);
148 }
149
150 /**
151 * instrument_get_user() - add instrumentation to get_user()-like macros
152 * @to: destination variable, may not be address-taken
153 *
154 * get_user() and friends are fragile, so it may depend on the implementation
155 * whether the instrumentation happens before or after the data is copied from
156 * the userspace.
157 */
158 #define instrument_get_user(to) \
159 ({ \
160 u64 __tmp = (u64)(to); \
161 kmsan_unpoison_memory(&__tmp, sizeof(__tmp)); \
162 to = __tmp; \
163 })
164
165
166 /**
167 * instrument_put_user() - add instrumentation to put_user()-like macros
168 * @from: source address
169 * @ptr: userspace pointer to copy to
170 * @size: number of bytes to copy
171 *
172 * put_user() and friends are fragile, so it may depend on the implementation
173 * whether the instrumentation happens before or after the data is copied from
174 * the userspace.
175 */
176 #define instrument_put_user(from, ptr, size) \
177 ({ \
178 kmsan_copy_to_user(ptr, &from, sizeof(from), 0); \
179 })
180
181 #endif /* _LINUX_INSTRUMENTED_H */
182