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1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* | |
3 | * KMSAN checks to be used for one-off annotations in subsystems. | |
4 | * | |
5 | * Copyright (C) 2017-2022 Google LLC | |
6 | * Author: Alexander Potapenko <glider@google.com> | |
7 | * | |
8 | */ | |
9 | ||
10 | #ifndef _LINUX_KMSAN_CHECKS_H | |
11 | #define _LINUX_KMSAN_CHECKS_H | |
12 | ||
13 | #include <linux/types.h> | |
14 | ||
15 | #ifdef CONFIG_KMSAN | |
16 | ||
17 | /** | |
18 | * kmsan_poison_memory() - Mark the memory range as uninitialized. | |
19 | * @address: address to start with. | |
20 | * @size: size of buffer to poison. | |
21 | * @flags: GFP flags for allocations done by this function. | |
22 | * | |
23 | * Until other data is written to this range, KMSAN will treat it as | |
24 | * uninitialized. Error reports for this memory will reference the call site of | |
25 | * kmsan_poison_memory() as origin. | |
26 | */ | |
27 | void kmsan_poison_memory(const void *address, size_t size, gfp_t flags); | |
28 | ||
29 | /** | |
30 | * kmsan_unpoison_memory() - Mark the memory range as initialized. | |
31 | * @address: address to start with. | |
32 | * @size: size of buffer to unpoison. | |
33 | * | |
34 | * Until other data is written to this range, KMSAN will treat it as | |
35 | * initialized. | |
36 | */ | |
37 | void kmsan_unpoison_memory(const void *address, size_t size); | |
38 | ||
39 | /** | |
40 | * kmsan_check_memory() - Check the memory range for being initialized. | |
41 | * @address: address to start with. | |
42 | * @size: size of buffer to check. | |
43 | * | |
44 | * If any piece of the given range is marked as uninitialized, KMSAN will report | |
45 | * an error. | |
46 | */ | |
47 | void kmsan_check_memory(const void *address, size_t size); | |
48 | ||
75cf0290 AP |
49 | /** |
50 | * kmsan_copy_to_user() - Notify KMSAN about a data transfer to userspace. | |
51 | * @to: destination address in the userspace. | |
52 | * @from: source address in the kernel. | |
53 | * @to_copy: number of bytes to copy. | |
54 | * @left: number of bytes not copied. | |
55 | * | |
56 | * If this is a real userspace data transfer, KMSAN checks the bytes that were | |
57 | * actually copied to ensure there was no information leak. If @to belongs to | |
58 | * the kernel space (which is possible for compat syscalls), KMSAN just copies | |
59 | * the metadata. | |
60 | */ | |
61 | void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy, | |
62 | size_t left); | |
63 | ||
3429055f AP |
64 | /** |
65 | * kmsan_memmove() - Notify KMSAN about a data copy within kernel. | |
66 | * @to: destination address in the kernel. | |
67 | * @from: source address in the kernel. | |
68 | * @size: number of bytes to copy. | |
69 | * | |
70 | * Invoked after non-instrumented version (e.g. implemented using assembly | |
71 | * code) of memmove()/memcpy() is called, in order to copy KMSAN's metadata. | |
72 | */ | |
73 | void kmsan_memmove(void *to, const void *from, size_t to_copy); | |
74 | ||
f80be457 AP |
75 | #else |
76 | ||
77 | static inline void kmsan_poison_memory(const void *address, size_t size, | |
78 | gfp_t flags) | |
79 | { | |
80 | } | |
81 | static inline void kmsan_unpoison_memory(const void *address, size_t size) | |
82 | { | |
83 | } | |
84 | static inline void kmsan_check_memory(const void *address, size_t size) | |
85 | { | |
86 | } | |
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87 | static inline void kmsan_copy_to_user(void __user *to, const void *from, |
88 | size_t to_copy, size_t left) | |
89 | { | |
90 | } | |
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3429055f AP |
92 | static inline void kmsan_memmove(void *to, const void *from, size_t to_copy) |
93 | { | |
94 | } | |
95 | ||
f80be457 AP |
96 | #endif |
97 | ||
98 | #endif /* _LINUX_KMSAN_CHECKS_H */ |