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f1d3cbfa SRG |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __TRACE_PROBE_KERNEL_H_ | |
3 | #define __TRACE_PROBE_KERNEL_H_ | |
4 | ||
5 | /* | |
6 | * This depends on trace_probe.h, but can not include it due to | |
7 | * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c. | |
8 | * Which means that any other user must include trace_probe.h before including | |
9 | * this file. | |
10 | */ | |
11 | /* Return the length of string -- including null terminal byte */ | |
12 | static nokprobe_inline int | |
672a2bf8 | 13 | fetch_store_strlen_user(unsigned long addr) |
f1d3cbfa SRG |
14 | { |
15 | const void __user *uaddr = (__force const void __user *)addr; | |
16 | ||
4ed8f337 | 17 | return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); |
f1d3cbfa SRG |
18 | } |
19 | ||
20 | /* Return the length of string -- including null terminal byte */ | |
21 | static nokprobe_inline int | |
672a2bf8 | 22 | fetch_store_strlen(unsigned long addr) |
f1d3cbfa SRG |
23 | { |
24 | int ret, len = 0; | |
25 | u8 c; | |
26 | ||
27 | #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
28 | if (addr < TASK_SIZE) | |
672a2bf8 | 29 | return fetch_store_strlen_user(addr); |
f1d3cbfa SRG |
30 | #endif |
31 | ||
32 | do { | |
33 | ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); | |
34 | len++; | |
35 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
36 | ||
4ed8f337 | 37 | return (ret < 0) ? ret : len; |
f1d3cbfa SRG |
38 | } |
39 | ||
797311bc MHG |
40 | static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void *base) |
41 | { | |
42 | if (ret < 0) | |
43 | ret = 0; | |
44 | *(u32 *)dest = make_data_loc(ret, __dest - base); | |
45 | } | |
46 | ||
f1d3cbfa SRG |
47 | /* |
48 | * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf | |
49 | * with max length and relative data location. | |
50 | */ | |
51 | static nokprobe_inline int | |
672a2bf8 | 52 | fetch_store_string_user(unsigned long addr, void *dest, void *base) |
f1d3cbfa SRG |
53 | { |
54 | const void __user *uaddr = (__force const void __user *)addr; | |
55 | int maxlen = get_loc_len(*(u32 *)dest); | |
56 | void *__dest; | |
57 | long ret; | |
58 | ||
59 | if (unlikely(!maxlen)) | |
60 | return -ENOMEM; | |
61 | ||
62 | __dest = get_loc_data(dest, base); | |
63 | ||
64 | ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); | |
797311bc | 65 | set_data_loc(ret, dest, __dest, base); |
f1d3cbfa SRG |
66 | |
67 | return ret; | |
68 | } | |
69 | ||
70 | /* | |
71 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
72 | * length and relative data location. | |
73 | */ | |
74 | static nokprobe_inline int | |
672a2bf8 | 75 | fetch_store_string(unsigned long addr, void *dest, void *base) |
f1d3cbfa SRG |
76 | { |
77 | int maxlen = get_loc_len(*(u32 *)dest); | |
78 | void *__dest; | |
79 | long ret; | |
80 | ||
81 | #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
82 | if ((unsigned long)addr < TASK_SIZE) | |
672a2bf8 | 83 | return fetch_store_string_user(addr, dest, base); |
f1d3cbfa SRG |
84 | #endif |
85 | ||
86 | if (unlikely(!maxlen)) | |
87 | return -ENOMEM; | |
88 | ||
89 | __dest = get_loc_data(dest, base); | |
90 | ||
91 | /* | |
92 | * Try to get string again, since the string can be changed while | |
93 | * probing. | |
94 | */ | |
95 | ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); | |
797311bc | 96 | set_data_loc(ret, dest, __dest, base); |
f1d3cbfa SRG |
97 | |
98 | return ret; | |
99 | } | |
100 | ||
672a2bf8 SC |
101 | static nokprobe_inline int |
102 | probe_mem_read_user(void *dest, void *src, size_t size) | |
103 | { | |
104 | const void __user *uaddr = (__force const void __user *)src; | |
105 | ||
106 | return copy_from_user_nofault(dest, uaddr, size); | |
107 | } | |
108 | ||
109 | static nokprobe_inline int | |
110 | probe_mem_read(void *dest, void *src, size_t size) | |
111 | { | |
112 | #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
113 | if ((unsigned long)src < TASK_SIZE) | |
114 | return probe_mem_read_user(dest, src, size); | |
115 | #endif | |
116 | return copy_from_kernel_nofault(dest, src, size); | |
117 | } | |
118 | ||
f1d3cbfa | 119 | #endif /* __TRACE_PROBE_KERNEL_H_ */ |