1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2 #ifndef __BPF_CORE_READ_H__
3 #define __BPF_CORE_READ_H__
4 
5 /*
6  * enum bpf_field_info_kind is passed as a second argument into
7  * __builtin_preserve_field_info() built-in to get a specific aspect of
8  * a field, captured as a first argument. __builtin_preserve_field_info(field,
9  * info_kind) returns __u32 integer and produces BTF field relocation, which
10  * is understood and processed by libbpf during BPF object loading. See
11  * selftests/bpf for examples.
12  */
13 enum bpf_field_info_kind {
14 	BPF_FIELD_BYTE_OFFSET = 0,	/* field byte offset */
15 	BPF_FIELD_BYTE_SIZE = 1,
16 	BPF_FIELD_EXISTS = 2,		/* field existence in target kernel */
17 	BPF_FIELD_SIGNED = 3,
18 	BPF_FIELD_LSHIFT_U64 = 4,
19 	BPF_FIELD_RSHIFT_U64 = 5,
20 };
21 
22 /* second argument to __builtin_btf_type_id() built-in */
23 enum bpf_type_id_kind {
24 	BPF_TYPE_ID_LOCAL = 0,		/* BTF type ID in local program */
25 	BPF_TYPE_ID_TARGET = 1,		/* BTF type ID in target kernel */
26 };
27 
28 /* second argument to __builtin_preserve_type_info() built-in */
29 enum bpf_type_info_kind {
30 	BPF_TYPE_EXISTS = 0,		/* type existence in target kernel */
31 	BPF_TYPE_SIZE = 1,		/* type size in target kernel */
32 	BPF_TYPE_MATCHES = 2,		/* type match in target kernel */
33 };
34 
35 /* second argument to __builtin_preserve_enum_value() built-in */
36 enum bpf_enum_value_kind {
37 	BPF_ENUMVAL_EXISTS = 0,		/* enum value existence in kernel */
38 	BPF_ENUMVAL_VALUE = 1,		/* enum value value relocation */
39 };
40 
41 #define __CORE_RELO(src, field, info)					      \
42 	__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
43 
44 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
45 #define __CORE_BITFIELD_PROBE_READ(dst, src, fld)			      \
46 	bpf_probe_read_kernel(						      \
47 			(void *)dst,				      \
48 			__CORE_RELO(src, fld, BYTE_SIZE),		      \
49 			(const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
50 #else
51 /* semantics of LSHIFT_64 assumes loading values into low-ordered bytes, so
52  * for big-endian we need to adjust destination pointer accordingly, based on
53  * field byte size
54  */
55 #define __CORE_BITFIELD_PROBE_READ(dst, src, fld)			      \
56 	bpf_probe_read_kernel(						      \
57 			(void *)dst + (8 - __CORE_RELO(src, fld, BYTE_SIZE)), \
58 			__CORE_RELO(src, fld, BYTE_SIZE),		      \
59 			(const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
60 #endif
61 
62 /*
63  * Extract bitfield, identified by s->field, and return its value as u64.
64  * All this is done in relocatable manner, so bitfield changes such as
65  * signedness, bit size, offset changes, this will be handled automatically.
66  * This version of macro is using bpf_probe_read_kernel() to read underlying
67  * integer storage. Macro functions as an expression and its return type is
68  * bpf_probe_read_kernel()'s return value: 0, on success, <0 on error.
69  */
70 #define BPF_CORE_READ_BITFIELD_PROBED(s, field) ({			      \
71 	unsigned long long val = 0;					      \
72 									      \
73 	__CORE_BITFIELD_PROBE_READ(&val, s, field);			      \
74 	val <<= __CORE_RELO(s, field, LSHIFT_U64);			      \
75 	if (__CORE_RELO(s, field, SIGNED))				      \
76 		val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64);  \
77 	else								      \
78 		val = val >> __CORE_RELO(s, field, RSHIFT_U64);		      \
79 	val;								      \
80 })
81 
82 /*
83  * Extract bitfield, identified by s->field, and return its value as u64.
84  * This version of macro is using direct memory reads and should be used from
85  * BPF program types that support such functionality (e.g., typed raw
86  * tracepoints).
87  */
88 #define BPF_CORE_READ_BITFIELD(s, field) ({				      \
89 	const void *p = (const void *)s + __CORE_RELO(s, field, BYTE_OFFSET); \
90 	unsigned long long val;						      \
91 									      \
92 	/* This is a so-called barrier_var() operation that makes specified   \
93 	 * variable "a black box" for optimizing compiler.		      \
94 	 * It forces compiler to perform BYTE_OFFSET relocation on p and use  \
95 	 * its calculated value in the switch below, instead of applying      \
96 	 * the same relocation 4 times for each individual memory load.       \
97 	 */								      \
98 	asm volatile("" : "=r"(p) : "0"(p));				      \
99 									      \
100 	switch (__CORE_RELO(s, field, BYTE_SIZE)) {			      \
101 	case 1: val = *(const unsigned char *)p; break;			      \
102 	case 2: val = *(const unsigned short *)p; break;		      \
103 	case 4: val = *(const unsigned int *)p; break;			      \
104 	case 8: val = *(const unsigned long long *)p; break;		      \
105 	}								      \
106 	val <<= __CORE_RELO(s, field, LSHIFT_U64);			      \
107 	if (__CORE_RELO(s, field, SIGNED))				      \
108 		val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64);  \
109 	else								      \
110 		val = val >> __CORE_RELO(s, field, RSHIFT_U64);		      \
111 	val;								      \
112 })
113 
114 #define ___bpf_field_ref1(field)	(field)
115 #define ___bpf_field_ref2(type, field)	(((typeof(type) *)0)->field)
116 #define ___bpf_field_ref(args...)					    \
117 	___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
118 
119 /*
120  * Convenience macro to check that field actually exists in target kernel's.
121  * Returns:
122  *    1, if matching field is present in target kernel;
123  *    0, if no matching field found.
124  *
125  * Supports two forms:
126  *   - field reference through variable access:
127  *     bpf_core_field_exists(p->my_field);
128  *   - field reference through type and field names:
129  *     bpf_core_field_exists(struct my_type, my_field).
130  */
131 #define bpf_core_field_exists(field...)					    \
132 	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
133 
134 /*
135  * Convenience macro to get the byte size of a field. Works for integers,
136  * struct/unions, pointers, arrays, and enums.
137  *
138  * Supports two forms:
139  *   - field reference through variable access:
140  *     bpf_core_field_size(p->my_field);
141  *   - field reference through type and field names:
142  *     bpf_core_field_size(struct my_type, my_field).
143  */
144 #define bpf_core_field_size(field...)					    \
145 	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_SIZE)
146 
147 /*
148  * Convenience macro to get field's byte offset.
149  *
150  * Supports two forms:
151  *   - field reference through variable access:
152  *     bpf_core_field_offset(p->my_field);
153  *   - field reference through type and field names:
154  *     bpf_core_field_offset(struct my_type, my_field).
155  */
156 #define bpf_core_field_offset(field...)					    \
157 	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_OFFSET)
158 
159 /*
160  * Convenience macro to get BTF type ID of a specified type, using a local BTF
161  * information. Return 32-bit unsigned integer with type ID from program's own
162  * BTF. Always succeeds.
163  */
164 #define bpf_core_type_id_local(type)					    \
165 	__builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_LOCAL)
166 
167 /*
168  * Convenience macro to get BTF type ID of a target kernel's type that matches
169  * specified local type.
170  * Returns:
171  *    - valid 32-bit unsigned type ID in kernel BTF;
172  *    - 0, if no matching type was found in a target kernel BTF.
173  */
174 #define bpf_core_type_id_kernel(type)					    \
175 	__builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_TARGET)
176 
177 /*
178  * Convenience macro to check that provided named type
179  * (struct/union/enum/typedef) exists in a target kernel.
180  * Returns:
181  *    1, if such type is present in target kernel's BTF;
182  *    0, if no matching type is found.
183  */
184 #define bpf_core_type_exists(type)					    \
185 	__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
186 
187 /*
188  * Convenience macro to check that provided named type
189  * (struct/union/enum/typedef) "matches" that in a target kernel.
190  * Returns:
191  *    1, if the type matches in the target kernel's BTF;
192  *    0, if the type does not match any in the target kernel
193  */
194 #define bpf_core_type_matches(type)					    \
195 	__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_MATCHES)
196 
197 /*
198  * Convenience macro to get the byte size of a provided named type
199  * (struct/union/enum/typedef) in a target kernel.
200  * Returns:
201  *    >= 0 size (in bytes), if type is present in target kernel's BTF;
202  *    0, if no matching type is found.
203  */
204 #define bpf_core_type_size(type)					    \
205 	__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
206 
207 /*
208  * Convenience macro to check that provided enumerator value is defined in
209  * a target kernel.
210  * Returns:
211  *    1, if specified enum type and its enumerator value are present in target
212  *    kernel's BTF;
213  *    0, if no matching enum and/or enum value within that enum is found.
214  */
215 #define bpf_core_enum_value_exists(enum_type, enum_value)		    \
216 	__builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_EXISTS)
217 
218 /*
219  * Convenience macro to get the integer value of an enumerator value in
220  * a target kernel.
221  * Returns:
222  *    64-bit value, if specified enum type and its enumerator value are
223  *    present in target kernel's BTF;
224  *    0, if no matching enum and/or enum value within that enum is found.
225  */
226 #define bpf_core_enum_value(enum_type, enum_value)			    \
227 	__builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_VALUE)
228 
229 /*
230  * bpf_core_read() abstracts away bpf_probe_read_kernel() call and captures
231  * offset relocation for source address using __builtin_preserve_access_index()
232  * built-in, provided by Clang.
233  *
234  * __builtin_preserve_access_index() takes as an argument an expression of
235  * taking an address of a field within struct/union. It makes compiler emit
236  * a relocation, which records BTF type ID describing root struct/union and an
237  * accessor string which describes exact embedded field that was used to take
238  * an address. See detailed description of this relocation format and
239  * semantics in comments to struct bpf_field_reloc in libbpf_internal.h.
240  *
241  * This relocation allows libbpf to adjust BPF instruction to use correct
242  * actual field offset, based on target kernel BTF type that matches original
243  * (local) BTF, used to record relocation.
244  */
245 #define bpf_core_read(dst, sz, src)					    \
246 	bpf_probe_read_kernel(dst, sz, (const void *)__builtin_preserve_access_index(src))
247 
248 /* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */
249 #define bpf_core_read_user(dst, sz, src)				    \
250 	bpf_probe_read_user(dst, sz, (const void *)__builtin_preserve_access_index(src))
251 /*
252  * bpf_core_read_str() is a thin wrapper around bpf_probe_read_str()
253  * additionally emitting BPF CO-RE field relocation for specified source
254  * argument.
255  */
256 #define bpf_core_read_str(dst, sz, src)					    \
257 	bpf_probe_read_kernel_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
258 
259 /* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */
260 #define bpf_core_read_user_str(dst, sz, src)				    \
261 	bpf_probe_read_user_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
262 
263 #define ___concat(a, b) a ## b
264 #define ___apply(fn, n) ___concat(fn, n)
265 #define ___nth(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, __11, N, ...) N
266 
267 /*
268  * return number of provided arguments; used for switch-based variadic macro
269  * definitions (see ___last, ___arrow, etc below)
270  */
271 #define ___narg(...) ___nth(_, ##__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
272 /*
273  * return 0 if no arguments are passed, N - otherwise; used for
274  * recursively-defined macros to specify termination (0) case, and generic
275  * (N) case (e.g., ___read_ptrs, ___core_read)
276  */
277 #define ___empty(...) ___nth(_, ##__VA_ARGS__, N, N, N, N, N, N, N, N, N, N, 0)
278 
279 #define ___last1(x) x
280 #define ___last2(a, x) x
281 #define ___last3(a, b, x) x
282 #define ___last4(a, b, c, x) x
283 #define ___last5(a, b, c, d, x) x
284 #define ___last6(a, b, c, d, e, x) x
285 #define ___last7(a, b, c, d, e, f, x) x
286 #define ___last8(a, b, c, d, e, f, g, x) x
287 #define ___last9(a, b, c, d, e, f, g, h, x) x
288 #define ___last10(a, b, c, d, e, f, g, h, i, x) x
289 #define ___last(...) ___apply(___last, ___narg(__VA_ARGS__))(__VA_ARGS__)
290 
291 #define ___nolast2(a, _) a
292 #define ___nolast3(a, b, _) a, b
293 #define ___nolast4(a, b, c, _) a, b, c
294 #define ___nolast5(a, b, c, d, _) a, b, c, d
295 #define ___nolast6(a, b, c, d, e, _) a, b, c, d, e
296 #define ___nolast7(a, b, c, d, e, f, _) a, b, c, d, e, f
297 #define ___nolast8(a, b, c, d, e, f, g, _) a, b, c, d, e, f, g
298 #define ___nolast9(a, b, c, d, e, f, g, h, _) a, b, c, d, e, f, g, h
299 #define ___nolast10(a, b, c, d, e, f, g, h, i, _) a, b, c, d, e, f, g, h, i
300 #define ___nolast(...) ___apply(___nolast, ___narg(__VA_ARGS__))(__VA_ARGS__)
301 
302 #define ___arrow1(a) a
303 #define ___arrow2(a, b) a->b
304 #define ___arrow3(a, b, c) a->b->c
305 #define ___arrow4(a, b, c, d) a->b->c->d
306 #define ___arrow5(a, b, c, d, e) a->b->c->d->e
307 #define ___arrow6(a, b, c, d, e, f) a->b->c->d->e->f
308 #define ___arrow7(a, b, c, d, e, f, g) a->b->c->d->e->f->g
309 #define ___arrow8(a, b, c, d, e, f, g, h) a->b->c->d->e->f->g->h
310 #define ___arrow9(a, b, c, d, e, f, g, h, i) a->b->c->d->e->f->g->h->i
311 #define ___arrow10(a, b, c, d, e, f, g, h, i, j) a->b->c->d->e->f->g->h->i->j
312 #define ___arrow(...) ___apply(___arrow, ___narg(__VA_ARGS__))(__VA_ARGS__)
313 
314 #define ___type(...) typeof(___arrow(__VA_ARGS__))
315 
316 #define ___read(read_fn, dst, src_type, src, accessor)			    \
317 	read_fn((void *)(dst), sizeof(*(dst)), &((src_type)(src))->accessor)
318 
319 /* "recursively" read a sequence of inner pointers using local __t var */
320 #define ___rd_first(fn, src, a) ___read(fn, &__t, ___type(src), src, a);
321 #define ___rd_last(fn, ...)						    \
322 	___read(fn, &__t, ___type(___nolast(__VA_ARGS__)), __t, ___last(__VA_ARGS__));
323 #define ___rd_p1(fn, ...) const void *__t; ___rd_first(fn, __VA_ARGS__)
324 #define ___rd_p2(fn, ...) ___rd_p1(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
325 #define ___rd_p3(fn, ...) ___rd_p2(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
326 #define ___rd_p4(fn, ...) ___rd_p3(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
327 #define ___rd_p5(fn, ...) ___rd_p4(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
328 #define ___rd_p6(fn, ...) ___rd_p5(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
329 #define ___rd_p7(fn, ...) ___rd_p6(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
330 #define ___rd_p8(fn, ...) ___rd_p7(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
331 #define ___rd_p9(fn, ...) ___rd_p8(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
332 #define ___read_ptrs(fn, src, ...)					    \
333 	___apply(___rd_p, ___narg(__VA_ARGS__))(fn, src, __VA_ARGS__)
334 
335 #define ___core_read0(fn, fn_ptr, dst, src, a)				    \
336 	___read(fn, dst, ___type(src), src, a);
337 #define ___core_readN(fn, fn_ptr, dst, src, ...)			    \
338 	___read_ptrs(fn_ptr, src, ___nolast(__VA_ARGS__))		    \
339 	___read(fn, dst, ___type(src, ___nolast(__VA_ARGS__)), __t,	    \
340 		___last(__VA_ARGS__));
341 #define ___core_read(fn, fn_ptr, dst, src, a, ...)			    \
342 	___apply(___core_read, ___empty(__VA_ARGS__))(fn, fn_ptr, dst,	    \
343 						      src, a, ##__VA_ARGS__)
344 
345 /*
346  * BPF_CORE_READ_INTO() is a more performance-conscious variant of
347  * BPF_CORE_READ(), in which final field is read into user-provided storage.
348  * See BPF_CORE_READ() below for more details on general usage.
349  */
350 #define BPF_CORE_READ_INTO(dst, src, a, ...) ({				    \
351 	___core_read(bpf_core_read, bpf_core_read,			    \
352 		     dst, (src), a, ##__VA_ARGS__)			    \
353 })
354 
355 /*
356  * Variant of BPF_CORE_READ_INTO() for reading from user-space memory.
357  *
358  * NOTE: see comments for BPF_CORE_READ_USER() about the proper types use.
359  */
360 #define BPF_CORE_READ_USER_INTO(dst, src, a, ...) ({			    \
361 	___core_read(bpf_core_read_user, bpf_core_read_user,		    \
362 		     dst, (src), a, ##__VA_ARGS__)			    \
363 })
364 
365 /* Non-CO-RE variant of BPF_CORE_READ_INTO() */
366 #define BPF_PROBE_READ_INTO(dst, src, a, ...) ({			    \
367 	___core_read(bpf_probe_read, bpf_probe_read,			    \
368 		     dst, (src), a, ##__VA_ARGS__)			    \
369 })
370 
371 /* Non-CO-RE variant of BPF_CORE_READ_USER_INTO().
372  *
373  * As no CO-RE relocations are emitted, source types can be arbitrary and are
374  * not restricted to kernel types only.
375  */
376 #define BPF_PROBE_READ_USER_INTO(dst, src, a, ...) ({			    \
377 	___core_read(bpf_probe_read_user, bpf_probe_read_user,		    \
378 		     dst, (src), a, ##__VA_ARGS__)			    \
379 })
380 
381 /*
382  * BPF_CORE_READ_STR_INTO() does same "pointer chasing" as
383  * BPF_CORE_READ() for intermediate pointers, but then executes (and returns
384  * corresponding error code) bpf_core_read_str() for final string read.
385  */
386 #define BPF_CORE_READ_STR_INTO(dst, src, a, ...) ({			    \
387 	___core_read(bpf_core_read_str, bpf_core_read,			    \
388 		     dst, (src), a, ##__VA_ARGS__)			    \
389 })
390 
391 /*
392  * Variant of BPF_CORE_READ_STR_INTO() for reading from user-space memory.
393  *
394  * NOTE: see comments for BPF_CORE_READ_USER() about the proper types use.
395  */
396 #define BPF_CORE_READ_USER_STR_INTO(dst, src, a, ...) ({		    \
397 	___core_read(bpf_core_read_user_str, bpf_core_read_user,	    \
398 		     dst, (src), a, ##__VA_ARGS__)			    \
399 })
400 
401 /* Non-CO-RE variant of BPF_CORE_READ_STR_INTO() */
402 #define BPF_PROBE_READ_STR_INTO(dst, src, a, ...) ({			    \
403 	___core_read(bpf_probe_read_str, bpf_probe_read,		    \
404 		     dst, (src), a, ##__VA_ARGS__)			    \
405 })
406 
407 /*
408  * Non-CO-RE variant of BPF_CORE_READ_USER_STR_INTO().
409  *
410  * As no CO-RE relocations are emitted, source types can be arbitrary and are
411  * not restricted to kernel types only.
412  */
413 #define BPF_PROBE_READ_USER_STR_INTO(dst, src, a, ...) ({		    \
414 	___core_read(bpf_probe_read_user_str, bpf_probe_read_user,	    \
415 		     dst, (src), a, ##__VA_ARGS__)			    \
416 })
417 
418 /*
419  * BPF_CORE_READ() is used to simplify BPF CO-RE relocatable read, especially
420  * when there are few pointer chasing steps.
421  * E.g., what in non-BPF world (or in BPF w/ BCC) would be something like:
422  *	int x = s->a.b.c->d.e->f->g;
423  * can be succinctly achieved using BPF_CORE_READ as:
424  *	int x = BPF_CORE_READ(s, a.b.c, d.e, f, g);
425  *
426  * BPF_CORE_READ will decompose above statement into 4 bpf_core_read (BPF
427  * CO-RE relocatable bpf_probe_read_kernel() wrapper) calls, logically
428  * equivalent to:
429  * 1. const void *__t = s->a.b.c;
430  * 2. __t = __t->d.e;
431  * 3. __t = __t->f;
432  * 4. return __t->g;
433  *
434  * Equivalence is logical, because there is a heavy type casting/preservation
435  * involved, as well as all the reads are happening through
436  * bpf_probe_read_kernel() calls using __builtin_preserve_access_index() to
437  * emit CO-RE relocations.
438  *
439  * N.B. Only up to 9 "field accessors" are supported, which should be more
440  * than enough for any practical purpose.
441  */
442 #define BPF_CORE_READ(src, a, ...) ({					    \
443 	___type((src), a, ##__VA_ARGS__) __r;				    \
444 	BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__);		    \
445 	__r;								    \
446 })
447 
448 /*
449  * Variant of BPF_CORE_READ() for reading from user-space memory.
450  *
451  * NOTE: all the source types involved are still *kernel types* and need to
452  * exist in kernel (or kernel module) BTF, otherwise CO-RE relocation will
453  * fail. Custom user types are not relocatable with CO-RE.
454  * The typical situation in which BPF_CORE_READ_USER() might be used is to
455  * read kernel UAPI types from the user-space memory passed in as a syscall
456  * input argument.
457  */
458 #define BPF_CORE_READ_USER(src, a, ...) ({				    \
459 	___type((src), a, ##__VA_ARGS__) __r;				    \
460 	BPF_CORE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__);		    \
461 	__r;								    \
462 })
463 
464 /* Non-CO-RE variant of BPF_CORE_READ() */
465 #define BPF_PROBE_READ(src, a, ...) ({					    \
466 	___type((src), a, ##__VA_ARGS__) __r;				    \
467 	BPF_PROBE_READ_INTO(&__r, (src), a, ##__VA_ARGS__);		    \
468 	__r;								    \
469 })
470 
471 /*
472  * Non-CO-RE variant of BPF_CORE_READ_USER().
473  *
474  * As no CO-RE relocations are emitted, source types can be arbitrary and are
475  * not restricted to kernel types only.
476  */
477 #define BPF_PROBE_READ_USER(src, a, ...) ({				    \
478 	___type((src), a, ##__VA_ARGS__) __r;				    \
479 	BPF_PROBE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__);	    \
480 	__r;								    \
481 })
482 
483 #endif
484 
485