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_kernel, bpf_probe_read_kernel, \ 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_kernel_str, bpf_probe_read_kernel, \ 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
