Linux kernel mirror (for testing)
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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 *
19 * Instrument a regular read access. The instrumentation should be inserted
20 * before the actual read happens.
21 *
22 * @ptr address of access
23 * @size size of access
24 */
25static __always_inline void instrument_read(const volatile void *v, size_t size)
26{
27 kasan_check_read(v, size);
28 kcsan_check_read(v, size);
29}
30
31/**
32 * instrument_write - instrument regular write access
33 *
34 * Instrument a regular write access. The instrumentation should be inserted
35 * before the actual write happens.
36 *
37 * @ptr address of access
38 * @size size of access
39 */
40static __always_inline void instrument_write(const volatile void *v, size_t size)
41{
42 kasan_check_write(v, size);
43 kcsan_check_write(v, size);
44}
45
46/**
47 * instrument_read_write - instrument regular read-write access
48 *
49 * Instrument a regular write access. The instrumentation should be inserted
50 * before the actual write happens.
51 *
52 * @ptr address of access
53 * @size size of access
54 */
55static __always_inline void instrument_read_write(const volatile void *v, size_t size)
56{
57 kasan_check_write(v, size);
58 kcsan_check_read_write(v, size);
59}
60
61/**
62 * instrument_atomic_read - instrument atomic read access
63 *
64 * Instrument an atomic read access. The instrumentation should be inserted
65 * before the actual read happens.
66 *
67 * @ptr address of access
68 * @size size of access
69 */
70static __always_inline void instrument_atomic_read(const volatile void *v, size_t size)
71{
72 kasan_check_read(v, size);
73 kcsan_check_atomic_read(v, size);
74}
75
76/**
77 * instrument_atomic_write - instrument atomic write access
78 *
79 * Instrument an atomic write access. The instrumentation should be inserted
80 * before the actual write happens.
81 *
82 * @ptr address of access
83 * @size size of access
84 */
85static __always_inline void instrument_atomic_write(const volatile void *v, size_t size)
86{
87 kasan_check_write(v, size);
88 kcsan_check_atomic_write(v, size);
89}
90
91/**
92 * instrument_atomic_read_write - instrument atomic read-write access
93 *
94 * Instrument an atomic read-write access. The instrumentation should be
95 * inserted before the actual write happens.
96 *
97 * @ptr address of access
98 * @size size of access
99 */
100static __always_inline void instrument_atomic_read_write(const volatile void *v, size_t size)
101{
102 kasan_check_write(v, size);
103 kcsan_check_atomic_read_write(v, size);
104}
105
106/**
107 * instrument_copy_to_user - instrument reads of copy_to_user
108 *
109 * Instrument reads from kernel memory, that are due to copy_to_user (and
110 * variants). The instrumentation must be inserted before the accesses.
111 *
112 * @to destination address
113 * @from source address
114 * @n number of bytes to copy
115 */
116static __always_inline void
117instrument_copy_to_user(void __user *to, const void *from, unsigned long n)
118{
119 kasan_check_read(from, n);
120 kcsan_check_read(from, n);
121 kmsan_copy_to_user(to, from, n, 0);
122}
123
124/**
125 * instrument_copy_from_user_before - add instrumentation before copy_from_user
126 *
127 * Instrument writes to kernel memory, that are due to copy_from_user (and
128 * variants). The instrumentation should be inserted before the accesses.
129 *
130 * @to destination address
131 * @from source address
132 * @n number of bytes to copy
133 */
134static __always_inline void
135instrument_copy_from_user_before(const void *to, const void __user *from, unsigned long n)
136{
137 kasan_check_write(to, n);
138 kcsan_check_write(to, n);
139}
140
141/**
142 * instrument_copy_from_user_after - add instrumentation after copy_from_user
143 *
144 * Instrument writes to kernel memory, that are due to copy_from_user (and
145 * variants). The instrumentation should be inserted after the accesses.
146 *
147 * @to destination address
148 * @from source address
149 * @n number of bytes to copy
150 * @left number of bytes not copied (as returned by copy_from_user)
151 */
152static __always_inline void
153instrument_copy_from_user_after(const void *to, const void __user *from,
154 unsigned long n, unsigned long left)
155{
156 kmsan_unpoison_memory(to, n - left);
157}
158
159/**
160 * instrument_get_user() - add instrumentation to get_user()-like macros
161 *
162 * get_user() and friends are fragile, so it may depend on the implementation
163 * whether the instrumentation happens before or after the data is copied from
164 * the userspace.
165 *
166 * @to destination variable, may not be address-taken
167 */
168#define instrument_get_user(to) \
169({ \
170 u64 __tmp = (u64)(to); \
171 kmsan_unpoison_memory(&__tmp, sizeof(__tmp)); \
172 to = __tmp; \
173})
174
175
176/**
177 * instrument_put_user() - add instrumentation to put_user()-like macros
178 *
179 * put_user() and friends are fragile, so it may depend on the implementation
180 * whether the instrumentation happens before or after the data is copied from
181 * the userspace.
182 *
183 * @from source address
184 * @ptr userspace pointer to copy to
185 * @size number of bytes to copy
186 */
187#define instrument_put_user(from, ptr, size) \
188({ \
189 kmsan_copy_to_user(ptr, &from, sizeof(from), 0); \
190})
191
192#endif /* _LINUX_INSTRUMENTED_H */