1
2#ifndef __BPF_CORE_READ_H__
3#define __BPF_CORE_READ_H__
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11
12
13enum bpf_field_info_kind {
14 BPF_FIELD_BYTE_OFFSET = 0,
15 BPF_FIELD_BYTE_SIZE = 1,
16 BPF_FIELD_EXISTS = 2,
17 BPF_FIELD_SIGNED = 3,
18 BPF_FIELD_LSHIFT_U64 = 4,
19 BPF_FIELD_RSHIFT_U64 = 5,
20};
21
22
23enum bpf_type_id_kind {
24 BPF_TYPE_ID_LOCAL = 0,
25 BPF_TYPE_ID_TARGET = 1,
26};
27
28
29enum bpf_type_info_kind {
30 BPF_TYPE_EXISTS = 0,
31 BPF_TYPE_SIZE = 1,
32};
33
34
35enum bpf_enum_value_kind {
36 BPF_ENUMVAL_EXISTS = 0,
37 BPF_ENUMVAL_VALUE = 1,
38};
39
40#define __CORE_RELO(src, field, info) \
41 __builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
42
43#if __BYTE_ORDER == __LITTLE_ENDIAN
44#define __CORE_BITFIELD_PROBE_READ(dst, src, fld) \
45 bpf_probe_read_kernel( \
46 (void *)dst, \
47 __CORE_RELO(src, fld, BYTE_SIZE), \
48 (const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
49#else
50
51
52
53
54#define __CORE_BITFIELD_PROBE_READ(dst, src, fld) \
55 bpf_probe_read_kernel( \
56 (void *)dst + (8 - __CORE_RELO(src, fld, BYTE_SIZE)), \
57 __CORE_RELO(src, fld, BYTE_SIZE), \
58 (const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
59#endif
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67
68
69#define BPF_CORE_READ_BITFIELD_PROBED(s, field) ({ \
70 unsigned long long val = 0; \
71 \
72 __CORE_BITFIELD_PROBE_READ(&val, s, field); \
73 val <<= __CORE_RELO(s, field, LSHIFT_U64); \
74 if (__CORE_RELO(s, field, SIGNED)) \
75 val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64); \
76 else \
77 val = val >> __CORE_RELO(s, field, RSHIFT_U64); \
78 val; \
79})
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84
85
86
87#define BPF_CORE_READ_BITFIELD(s, field) ({ \
88 const void *p = (const void *)s + __CORE_RELO(s, field, BYTE_OFFSET); \
89 unsigned long long val; \
90 \
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96 \
97 asm volatile("" : "=r"(p) : "0"(p)); \
98 \
99 switch (__CORE_RELO(s, field, BYTE_SIZE)) { \
100 case 1: val = *(const unsigned char *)p; break; \
101 case 2: val = *(const unsigned short *)p; break; \
102 case 4: val = *(const unsigned int *)p; break; \
103 case 8: val = *(const unsigned long long *)p; break; \
104 } \
105 val <<= __CORE_RELO(s, field, LSHIFT_U64); \
106 if (__CORE_RELO(s, field, SIGNED)) \
107 val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64); \
108 else \
109 val = val >> __CORE_RELO(s, field, RSHIFT_U64); \
110 val; \
111})
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117
118
119#define bpf_core_field_exists(field) \
120 __builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
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125
126#define bpf_core_field_size(field) \
127 __builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
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133
134#define bpf_core_type_id_local(type) \
135 __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_LOCAL)
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142
143
144#define bpf_core_type_id_kernel(type) \
145 __builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_TARGET)
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153
154#define bpf_core_type_exists(type) \
155 __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
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163
164#define bpf_core_type_size(type) \
165 __builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
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174
175#define bpf_core_enum_value_exists(enum_type, enum_value) \
176 __builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_EXISTS)
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185
186#define bpf_core_enum_value(enum_type, enum_value) \
187 __builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_VALUE)
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204
205#define bpf_core_read(dst, sz, src) \
206 bpf_probe_read_kernel(dst, sz, (const void *)__builtin_preserve_access_index(src))
207
208
209#define bpf_core_read_user(dst, sz, src) \
210 bpf_probe_read_user(dst, sz, (const void *)__builtin_preserve_access_index(src))
211
212
213
214
215
216#define bpf_core_read_str(dst, sz, src) \
217 bpf_probe_read_kernel_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
218
219
220#define bpf_core_read_user_str(dst, sz, src) \
221 bpf_probe_read_user_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
222
223#define ___concat(a, b) a ## b
224#define ___apply(fn, n) ___concat(fn, n)
225#define ___nth(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, __11, N, ...) N
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229
230
231#define ___narg(...) ___nth(_, ##__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
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236
237#define ___empty(...) ___nth(_, ##__VA_ARGS__, N, N, N, N, N, N, N, N, N, N, 0)
238
239#define ___last1(x) x
240#define ___last2(a, x) x
241#define ___last3(a, b, x) x
242#define ___last4(a, b, c, x) x
243#define ___last5(a, b, c, d, x) x
244#define ___last6(a, b, c, d, e, x) x
245#define ___last7(a, b, c, d, e, f, x) x
246#define ___last8(a, b, c, d, e, f, g, x) x
247#define ___last9(a, b, c, d, e, f, g, h, x) x
248#define ___last10(a, b, c, d, e, f, g, h, i, x) x
249#define ___last(...) ___apply(___last, ___narg(__VA_ARGS__))(__VA_ARGS__)
250
251#define ___nolast2(a, _) a
252#define ___nolast3(a, b, _) a, b
253#define ___nolast4(a, b, c, _) a, b, c
254#define ___nolast5(a, b, c, d, _) a, b, c, d
255#define ___nolast6(a, b, c, d, e, _) a, b, c, d, e
256#define ___nolast7(a, b, c, d, e, f, _) a, b, c, d, e, f
257#define ___nolast8(a, b, c, d, e, f, g, _) a, b, c, d, e, f, g
258#define ___nolast9(a, b, c, d, e, f, g, h, _) a, b, c, d, e, f, g, h
259#define ___nolast10(a, b, c, d, e, f, g, h, i, _) a, b, c, d, e, f, g, h, i
260#define ___nolast(...) ___apply(___nolast, ___narg(__VA_ARGS__))(__VA_ARGS__)
261
262#define ___arrow1(a) a
263#define ___arrow2(a, b) a->b
264#define ___arrow3(a, b, c) a->b->c
265#define ___arrow4(a, b, c, d) a->b->c->d
266#define ___arrow5(a, b, c, d, e) a->b->c->d->e
267#define ___arrow6(a, b, c, d, e, f) a->b->c->d->e->f
268#define ___arrow7(a, b, c, d, e, f, g) a->b->c->d->e->f->g
269#define ___arrow8(a, b, c, d, e, f, g, h) a->b->c->d->e->f->g->h
270#define ___arrow9(a, b, c, d, e, f, g, h, i) a->b->c->d->e->f->g->h->i
271#define ___arrow10(a, b, c, d, e, f, g, h, i, j) a->b->c->d->e->f->g->h->i->j
272#define ___arrow(...) ___apply(___arrow, ___narg(__VA_ARGS__))(__VA_ARGS__)
273
274#define ___type(...) typeof(___arrow(__VA_ARGS__))
275
276#define ___read(read_fn, dst, src_type, src, accessor) \
277 read_fn((void *)(dst), sizeof(*(dst)), &((src_type)(src))->accessor)
278
279
280#define ___rd_first(fn, src, a) ___read(fn, &__t, ___type(src), src, a);
281#define ___rd_last(fn, ...) \
282 ___read(fn, &__t, ___type(___nolast(__VA_ARGS__)), __t, ___last(__VA_ARGS__));
283#define ___rd_p1(fn, ...) const void *__t; ___rd_first(fn, __VA_ARGS__)
284#define ___rd_p2(fn, ...) ___rd_p1(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
285#define ___rd_p3(fn, ...) ___rd_p2(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
286#define ___rd_p4(fn, ...) ___rd_p3(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
287#define ___rd_p5(fn, ...) ___rd_p4(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
288#define ___rd_p6(fn, ...) ___rd_p5(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
289#define ___rd_p7(fn, ...) ___rd_p6(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
290#define ___rd_p8(fn, ...) ___rd_p7(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
291#define ___rd_p9(fn, ...) ___rd_p8(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
292#define ___read_ptrs(fn, src, ...) \
293 ___apply(___rd_p, ___narg(__VA_ARGS__))(fn, src, __VA_ARGS__)
294
295#define ___core_read0(fn, fn_ptr, dst, src, a) \
296 ___read(fn, dst, ___type(src), src, a);
297#define ___core_readN(fn, fn_ptr, dst, src, ...) \
298 ___read_ptrs(fn_ptr, src, ___nolast(__VA_ARGS__)) \
299 ___read(fn, dst, ___type(src, ___nolast(__VA_ARGS__)), __t, \
300 ___last(__VA_ARGS__));
301#define ___core_read(fn, fn_ptr, dst, src, a, ...) \
302 ___apply(___core_read, ___empty(__VA_ARGS__))(fn, fn_ptr, dst, \
303 src, a, ##__VA_ARGS__)
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308
309
310#define BPF_CORE_READ_INTO(dst, src, a, ...) ({ \
311 ___core_read(bpf_core_read, bpf_core_read, \
312 dst, (src), a, ##__VA_ARGS__) \
313})
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319
320#define BPF_CORE_READ_USER_INTO(dst, src, a, ...) ({ \
321 ___core_read(bpf_core_read_user, bpf_core_read_user, \
322 dst, (src), a, ##__VA_ARGS__) \
323})
324
325
326#define BPF_PROBE_READ_INTO(dst, src, a, ...) ({ \
327 ___core_read(bpf_probe_read, bpf_probe_read, \
328 dst, (src), a, ##__VA_ARGS__) \
329})
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335
336#define BPF_PROBE_READ_USER_INTO(dst, src, a, ...) ({ \
337 ___core_read(bpf_probe_read_user, bpf_probe_read_user, \
338 dst, (src), a, ##__VA_ARGS__) \
339})
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345
346#define BPF_CORE_READ_STR_INTO(dst, src, a, ...) ({ \
347 ___core_read(bpf_core_read_str, bpf_core_read, \
348 dst, (src), a, ##__VA_ARGS__) \
349})
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355
356#define BPF_CORE_READ_USER_STR_INTO(dst, src, a, ...) ({ \
357 ___core_read(bpf_core_read_user_str, bpf_core_read_user, \
358 dst, (src), a, ##__VA_ARGS__) \
359})
360
361
362#define BPF_PROBE_READ_STR_INTO(dst, src, a, ...) ({ \
363 ___core_read(bpf_probe_read_str, bpf_probe_read, \
364 dst, (src), a, ##__VA_ARGS__) \
365})
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372
373#define BPF_PROBE_READ_USER_STR_INTO(dst, src, a, ...) ({ \
374 ___core_read(bpf_probe_read_user_str, bpf_probe_read_user, \
375 dst, (src), a, ##__VA_ARGS__) \
376})
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402#define BPF_CORE_READ(src, a, ...) ({ \
403 ___type((src), a, ##__VA_ARGS__) __r; \
404 BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \
405 __r; \
406})
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417
418#define BPF_CORE_READ_USER(src, a, ...) ({ \
419 ___type((src), a, ##__VA_ARGS__) __r; \
420 BPF_CORE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \
421 __r; \
422})
423
424
425#define BPF_PROBE_READ(src, a, ...) ({ \
426 ___type((src), a, ##__VA_ARGS__) __r; \
427 BPF_PROBE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \
428 __r; \
429})
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435
436
437#define BPF_PROBE_READ_USER(src, a, ...) ({ \
438 ___type((src), a, ##__VA_ARGS__) __r; \
439 BPF_PROBE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \
440 __r; \
441})
442
443#endif
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445