1 /* 2 * Linux Socket Filter Data Structures 3 */ 4 #ifndef __LINUX_FILTER_H__ 5 #define __LINUX_FILTER_H__ 6 7 #include <stdarg.h> 8 9 #include <linux/atomic.h> 10 #include <linux/refcount.h> 11 #include <linux/compat.h> 12 #include <linux/skbuff.h> 13 #include <linux/linkage.h> 14 #include <linux/printk.h> 15 #include <linux/workqueue.h> 16 #include <linux/sched.h> 17 #include <linux/capability.h> 18 #include <linux/cryptohash.h> 19 20 #include <net/sch_generic.h> 21 22 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 23 #include <asm/set_memory.h> 24 #endif 25 26 #include <uapi/linux/filter.h> 27 #include <uapi/linux/bpf.h> 28 29 struct sk_buff; 30 struct sock; 31 struct seccomp_data; 32 struct bpf_prog_aux; 33 34 /* ArgX, context and stack frame pointer register positions. Note, 35 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 36 * calls in BPF_CALL instruction. 37 */ 38 #define BPF_REG_ARG1 BPF_REG_1 39 #define BPF_REG_ARG2 BPF_REG_2 40 #define BPF_REG_ARG3 BPF_REG_3 41 #define BPF_REG_ARG4 BPF_REG_4 42 #define BPF_REG_ARG5 BPF_REG_5 43 #define BPF_REG_CTX BPF_REG_6 44 #define BPF_REG_FP BPF_REG_10 45 46 /* Additional register mappings for converted user programs. */ 47 #define BPF_REG_A BPF_REG_0 48 #define BPF_REG_X BPF_REG_7 49 #define BPF_REG_TMP BPF_REG_8 50 51 /* Kernel hidden auxiliary/helper register for hardening step. 52 * Only used by eBPF JITs. It's nothing more than a temporary 53 * register that JITs use internally, only that here it's part 54 * of eBPF instructions that have been rewritten for blinding 55 * constants. See JIT pre-step in bpf_jit_blind_constants(). 56 */ 57 #define BPF_REG_AX MAX_BPF_REG 58 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 59 60 /* unused opcode to mark special call to bpf_tail_call() helper */ 61 #define BPF_TAIL_CALL 0xf0 62 63 /* As per nm, we expose JITed images as text (code) section for 64 * kallsyms. That way, tools like perf can find it to match 65 * addresses. 66 */ 67 #define BPF_SYM_ELF_TYPE 't' 68 69 /* BPF program can access up to 512 bytes of stack space. */ 70 #define MAX_BPF_STACK 512 71 72 /* Helper macros for filter block array initializers. */ 73 74 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 75 76 #define BPF_ALU64_REG(OP, DST, SRC) \ 77 ((struct bpf_insn) { \ 78 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 79 .dst_reg = DST, \ 80 .src_reg = SRC, \ 81 .off = 0, \ 82 .imm = 0 }) 83 84 #define BPF_ALU32_REG(OP, DST, SRC) \ 85 ((struct bpf_insn) { \ 86 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 87 .dst_reg = DST, \ 88 .src_reg = SRC, \ 89 .off = 0, \ 90 .imm = 0 }) 91 92 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 93 94 #define BPF_ALU64_IMM(OP, DST, IMM) \ 95 ((struct bpf_insn) { \ 96 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 97 .dst_reg = DST, \ 98 .src_reg = 0, \ 99 .off = 0, \ 100 .imm = IMM }) 101 102 #define BPF_ALU32_IMM(OP, DST, IMM) \ 103 ((struct bpf_insn) { \ 104 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 105 .dst_reg = DST, \ 106 .src_reg = 0, \ 107 .off = 0, \ 108 .imm = IMM }) 109 110 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 111 112 #define BPF_ENDIAN(TYPE, DST, LEN) \ 113 ((struct bpf_insn) { \ 114 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 115 .dst_reg = DST, \ 116 .src_reg = 0, \ 117 .off = 0, \ 118 .imm = LEN }) 119 120 /* Short form of mov, dst_reg = src_reg */ 121 122 #define BPF_MOV64_REG(DST, SRC) \ 123 ((struct bpf_insn) { \ 124 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 125 .dst_reg = DST, \ 126 .src_reg = SRC, \ 127 .off = 0, \ 128 .imm = 0 }) 129 130 #define BPF_MOV32_REG(DST, SRC) \ 131 ((struct bpf_insn) { \ 132 .code = BPF_ALU | BPF_MOV | BPF_X, \ 133 .dst_reg = DST, \ 134 .src_reg = SRC, \ 135 .off = 0, \ 136 .imm = 0 }) 137 138 /* Short form of mov, dst_reg = imm32 */ 139 140 #define BPF_MOV64_IMM(DST, IMM) \ 141 ((struct bpf_insn) { \ 142 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 143 .dst_reg = DST, \ 144 .src_reg = 0, \ 145 .off = 0, \ 146 .imm = IMM }) 147 148 #define BPF_MOV32_IMM(DST, IMM) \ 149 ((struct bpf_insn) { \ 150 .code = BPF_ALU | BPF_MOV | BPF_K, \ 151 .dst_reg = DST, \ 152 .src_reg = 0, \ 153 .off = 0, \ 154 .imm = IMM }) 155 156 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 157 #define BPF_LD_IMM64(DST, IMM) \ 158 BPF_LD_IMM64_RAW(DST, 0, IMM) 159 160 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 161 ((struct bpf_insn) { \ 162 .code = BPF_LD | BPF_DW | BPF_IMM, \ 163 .dst_reg = DST, \ 164 .src_reg = SRC, \ 165 .off = 0, \ 166 .imm = (__u32) (IMM) }), \ 167 ((struct bpf_insn) { \ 168 .code = 0, /* zero is reserved opcode */ \ 169 .dst_reg = 0, \ 170 .src_reg = 0, \ 171 .off = 0, \ 172 .imm = ((__u64) (IMM)) >> 32 }) 173 174 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 175 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 176 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 177 178 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 179 180 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 181 ((struct bpf_insn) { \ 182 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 183 .dst_reg = DST, \ 184 .src_reg = SRC, \ 185 .off = 0, \ 186 .imm = IMM }) 187 188 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 189 ((struct bpf_insn) { \ 190 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 191 .dst_reg = DST, \ 192 .src_reg = SRC, \ 193 .off = 0, \ 194 .imm = IMM }) 195 196 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 197 198 #define BPF_LD_ABS(SIZE, IMM) \ 199 ((struct bpf_insn) { \ 200 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 201 .dst_reg = 0, \ 202 .src_reg = 0, \ 203 .off = 0, \ 204 .imm = IMM }) 205 206 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 207 208 #define BPF_LD_IND(SIZE, SRC, IMM) \ 209 ((struct bpf_insn) { \ 210 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 211 .dst_reg = 0, \ 212 .src_reg = SRC, \ 213 .off = 0, \ 214 .imm = IMM }) 215 216 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 217 218 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 219 ((struct bpf_insn) { \ 220 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 221 .dst_reg = DST, \ 222 .src_reg = SRC, \ 223 .off = OFF, \ 224 .imm = 0 }) 225 226 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 227 228 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 229 ((struct bpf_insn) { \ 230 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 231 .dst_reg = DST, \ 232 .src_reg = SRC, \ 233 .off = OFF, \ 234 .imm = 0 }) 235 236 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 237 238 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 239 ((struct bpf_insn) { \ 240 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 241 .dst_reg = DST, \ 242 .src_reg = SRC, \ 243 .off = OFF, \ 244 .imm = 0 }) 245 246 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 247 248 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 249 ((struct bpf_insn) { \ 250 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 251 .dst_reg = DST, \ 252 .src_reg = 0, \ 253 .off = OFF, \ 254 .imm = IMM }) 255 256 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 257 258 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 259 ((struct bpf_insn) { \ 260 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 261 .dst_reg = DST, \ 262 .src_reg = SRC, \ 263 .off = OFF, \ 264 .imm = 0 }) 265 266 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 267 268 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 269 ((struct bpf_insn) { \ 270 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 271 .dst_reg = DST, \ 272 .src_reg = 0, \ 273 .off = OFF, \ 274 .imm = IMM }) 275 276 /* Unconditional jumps, goto pc + off16 */ 277 278 #define BPF_JMP_A(OFF) \ 279 ((struct bpf_insn) { \ 280 .code = BPF_JMP | BPF_JA, \ 281 .dst_reg = 0, \ 282 .src_reg = 0, \ 283 .off = OFF, \ 284 .imm = 0 }) 285 286 /* Function call */ 287 288 #define BPF_EMIT_CALL(FUNC) \ 289 ((struct bpf_insn) { \ 290 .code = BPF_JMP | BPF_CALL, \ 291 .dst_reg = 0, \ 292 .src_reg = 0, \ 293 .off = 0, \ 294 .imm = ((FUNC) - __bpf_call_base) }) 295 296 /* Raw code statement block */ 297 298 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 299 ((struct bpf_insn) { \ 300 .code = CODE, \ 301 .dst_reg = DST, \ 302 .src_reg = SRC, \ 303 .off = OFF, \ 304 .imm = IMM }) 305 306 /* Program exit */ 307 308 #define BPF_EXIT_INSN() \ 309 ((struct bpf_insn) { \ 310 .code = BPF_JMP | BPF_EXIT, \ 311 .dst_reg = 0, \ 312 .src_reg = 0, \ 313 .off = 0, \ 314 .imm = 0 }) 315 316 /* Internal classic blocks for direct assignment */ 317 318 #define __BPF_STMT(CODE, K) \ 319 ((struct sock_filter) BPF_STMT(CODE, K)) 320 321 #define __BPF_JUMP(CODE, K, JT, JF) \ 322 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 323 324 #define bytes_to_bpf_size(bytes) \ 325 ({ \ 326 int bpf_size = -EINVAL; \ 327 \ 328 if (bytes == sizeof(u8)) \ 329 bpf_size = BPF_B; \ 330 else if (bytes == sizeof(u16)) \ 331 bpf_size = BPF_H; \ 332 else if (bytes == sizeof(u32)) \ 333 bpf_size = BPF_W; \ 334 else if (bytes == sizeof(u64)) \ 335 bpf_size = BPF_DW; \ 336 \ 337 bpf_size; \ 338 }) 339 340 #define BPF_SIZEOF(type) \ 341 ({ \ 342 const int __size = bytes_to_bpf_size(sizeof(type)); \ 343 BUILD_BUG_ON(__size < 0); \ 344 __size; \ 345 }) 346 347 #define BPF_FIELD_SIZEOF(type, field) \ 348 ({ \ 349 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 350 BUILD_BUG_ON(__size < 0); \ 351 __size; \ 352 }) 353 354 #define __BPF_MAP_0(m, v, ...) v 355 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 356 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 357 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 358 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 359 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 360 361 #define __BPF_REG_0(...) __BPF_PAD(5) 362 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 363 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 364 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 365 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 366 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 367 368 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 369 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 370 371 #define __BPF_CAST(t, a) \ 372 (__force t) \ 373 (__force \ 374 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 375 (unsigned long)0, (t)0))) a 376 #define __BPF_V void 377 #define __BPF_N 378 379 #define __BPF_DECL_ARGS(t, a) t a 380 #define __BPF_DECL_REGS(t, a) u64 a 381 382 #define __BPF_PAD(n) \ 383 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 384 u64, __ur_3, u64, __ur_4, u64, __ur_5) 385 386 #define BPF_CALL_x(x, name, ...) \ 387 static __always_inline \ 388 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 389 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 390 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 391 { \ 392 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 393 } \ 394 static __always_inline \ 395 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 396 397 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 398 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 399 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 400 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 401 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 402 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 403 404 #ifdef CONFIG_COMPAT 405 /* A struct sock_filter is architecture independent. */ 406 struct compat_sock_fprog { 407 u16 len; 408 compat_uptr_t filter; /* struct sock_filter * */ 409 }; 410 #endif 411 412 struct sock_fprog_kern { 413 u16 len; 414 struct sock_filter *filter; 415 }; 416 417 struct bpf_binary_header { 418 unsigned int pages; 419 u8 image[]; 420 }; 421 422 struct bpf_prog { 423 u16 pages; /* Number of allocated pages */ 424 kmemcheck_bitfield_begin(meta); 425 u16 jited:1, /* Is our filter JIT'ed? */ 426 locked:1, /* Program image locked? */ 427 gpl_compatible:1, /* Is filter GPL compatible? */ 428 cb_access:1, /* Is control block accessed? */ 429 dst_needed:1; /* Do we need dst entry? */ 430 kmemcheck_bitfield_end(meta); 431 enum bpf_prog_type type; /* Type of BPF program */ 432 u32 len; /* Number of filter blocks */ 433 u32 jited_len; /* Size of jited insns in bytes */ 434 u8 tag[BPF_TAG_SIZE]; 435 struct bpf_prog_aux *aux; /* Auxiliary fields */ 436 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 437 unsigned int (*bpf_func)(const void *ctx, 438 const struct bpf_insn *insn); 439 /* Instructions for interpreter */ 440 union { 441 struct sock_filter insns[0]; 442 struct bpf_insn insnsi[0]; 443 }; 444 }; 445 446 struct sk_filter { 447 refcount_t refcnt; 448 struct rcu_head rcu; 449 struct bpf_prog *prog; 450 }; 451 452 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 453 454 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 455 456 struct bpf_skb_data_end { 457 struct qdisc_skb_cb qdisc_cb; 458 void *data_end; 459 }; 460 461 struct xdp_buff { 462 void *data; 463 void *data_end; 464 void *data_hard_start; 465 }; 466 467 /* compute the linear packet data range [data, data_end) which 468 * will be accessed by cls_bpf, act_bpf and lwt programs 469 */ 470 static inline void bpf_compute_data_end(struct sk_buff *skb) 471 { 472 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 473 474 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 475 cb->data_end = skb->data + skb_headlen(skb); 476 } 477 478 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 479 { 480 /* eBPF programs may read/write skb->cb[] area to transfer meta 481 * data between tail calls. Since this also needs to work with 482 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 483 * 484 * In some socket filter cases, the cb unfortunately needs to be 485 * saved/restored so that protocol specific skb->cb[] data won't 486 * be lost. In any case, due to unpriviledged eBPF programs 487 * attached to sockets, we need to clear the bpf_skb_cb() area 488 * to not leak previous contents to user space. 489 */ 490 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 491 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 492 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 493 494 return qdisc_skb_cb(skb)->data; 495 } 496 497 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 498 struct sk_buff *skb) 499 { 500 u8 *cb_data = bpf_skb_cb(skb); 501 u8 cb_saved[BPF_SKB_CB_LEN]; 502 u32 res; 503 504 if (unlikely(prog->cb_access)) { 505 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 506 memset(cb_data, 0, sizeof(cb_saved)); 507 } 508 509 res = BPF_PROG_RUN(prog, skb); 510 511 if (unlikely(prog->cb_access)) 512 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 513 514 return res; 515 } 516 517 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 518 struct sk_buff *skb) 519 { 520 u8 *cb_data = bpf_skb_cb(skb); 521 522 if (unlikely(prog->cb_access)) 523 memset(cb_data, 0, BPF_SKB_CB_LEN); 524 525 return BPF_PROG_RUN(prog, skb); 526 } 527 528 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 529 struct xdp_buff *xdp) 530 { 531 /* Caller needs to hold rcu_read_lock() (!), otherwise program 532 * can be released while still running, or map elements could be 533 * freed early while still having concurrent users. XDP fastpath 534 * already takes rcu_read_lock() when fetching the program, so 535 * it's not necessary here anymore. 536 */ 537 return BPF_PROG_RUN(prog, xdp); 538 } 539 540 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 541 { 542 return prog->len * sizeof(struct bpf_insn); 543 } 544 545 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 546 { 547 return round_up(bpf_prog_insn_size(prog) + 548 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 549 } 550 551 static inline unsigned int bpf_prog_size(unsigned int proglen) 552 { 553 return max(sizeof(struct bpf_prog), 554 offsetof(struct bpf_prog, insns[proglen])); 555 } 556 557 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 558 { 559 /* When classic BPF programs have been loaded and the arch 560 * does not have a classic BPF JIT (anymore), they have been 561 * converted via bpf_migrate_filter() to eBPF and thus always 562 * have an unspec program type. 563 */ 564 return prog->type == BPF_PROG_TYPE_UNSPEC; 565 } 566 567 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 568 569 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 570 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 571 { 572 fp->locked = 1; 573 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 574 } 575 576 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 577 { 578 if (fp->locked) { 579 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 580 /* In case set_memory_rw() fails, we want to be the first 581 * to crash here instead of some random place later on. 582 */ 583 fp->locked = 0; 584 } 585 } 586 587 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 588 { 589 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 590 } 591 592 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 593 { 594 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 595 } 596 #else 597 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 598 { 599 } 600 601 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 602 { 603 } 604 605 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 606 { 607 } 608 609 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 610 { 611 } 612 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 613 614 static inline struct bpf_binary_header * 615 bpf_jit_binary_hdr(const struct bpf_prog *fp) 616 { 617 unsigned long real_start = (unsigned long)fp->bpf_func; 618 unsigned long addr = real_start & PAGE_MASK; 619 620 return (void *)addr; 621 } 622 623 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 624 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 625 { 626 return sk_filter_trim_cap(sk, skb, 1); 627 } 628 629 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 630 void bpf_prog_free(struct bpf_prog *fp); 631 632 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 633 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 634 gfp_t gfp_extra_flags); 635 void __bpf_prog_free(struct bpf_prog *fp); 636 637 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 638 { 639 bpf_prog_unlock_ro(fp); 640 __bpf_prog_free(fp); 641 } 642 643 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 644 unsigned int flen); 645 646 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 647 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 648 bpf_aux_classic_check_t trans, bool save_orig); 649 void bpf_prog_destroy(struct bpf_prog *fp); 650 651 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 652 int sk_attach_bpf(u32 ufd, struct sock *sk); 653 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 654 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 655 int sk_detach_filter(struct sock *sk); 656 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 657 unsigned int len); 658 659 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 660 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 661 662 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 663 664 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 665 void bpf_jit_compile(struct bpf_prog *prog); 666 bool bpf_helper_changes_pkt_data(void *func); 667 668 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 669 const struct bpf_insn *patch, u32 len); 670 void bpf_warn_invalid_xdp_action(u32 act); 671 672 #ifdef CONFIG_BPF_JIT 673 extern int bpf_jit_enable; 674 extern int bpf_jit_harden; 675 extern int bpf_jit_kallsyms; 676 677 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 678 679 struct bpf_binary_header * 680 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 681 unsigned int alignment, 682 bpf_jit_fill_hole_t bpf_fill_ill_insns); 683 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 684 685 void bpf_jit_free(struct bpf_prog *fp); 686 687 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 688 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 689 690 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 691 u32 pass, void *image) 692 { 693 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 694 proglen, pass, image, current->comm, task_pid_nr(current)); 695 696 if (image) 697 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 698 16, 1, image, proglen, false); 699 } 700 701 static inline bool bpf_jit_is_ebpf(void) 702 { 703 # ifdef CONFIG_HAVE_EBPF_JIT 704 return true; 705 # else 706 return false; 707 # endif 708 } 709 710 static inline bool ebpf_jit_enabled(void) 711 { 712 return bpf_jit_enable && bpf_jit_is_ebpf(); 713 } 714 715 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 716 { 717 return fp->jited && bpf_jit_is_ebpf(); 718 } 719 720 static inline bool bpf_jit_blinding_enabled(void) 721 { 722 /* These are the prerequisites, should someone ever have the 723 * idea to call blinding outside of them, we make sure to 724 * bail out. 725 */ 726 if (!bpf_jit_is_ebpf()) 727 return false; 728 if (!bpf_jit_enable) 729 return false; 730 if (!bpf_jit_harden) 731 return false; 732 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 733 return false; 734 735 return true; 736 } 737 738 static inline bool bpf_jit_kallsyms_enabled(void) 739 { 740 /* There are a couple of corner cases where kallsyms should 741 * not be enabled f.e. on hardening. 742 */ 743 if (bpf_jit_harden) 744 return false; 745 if (!bpf_jit_kallsyms) 746 return false; 747 if (bpf_jit_kallsyms == 1) 748 return true; 749 750 return false; 751 } 752 753 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 754 unsigned long *off, char *sym); 755 bool is_bpf_text_address(unsigned long addr); 756 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 757 char *sym); 758 759 static inline const char * 760 bpf_address_lookup(unsigned long addr, unsigned long *size, 761 unsigned long *off, char **modname, char *sym) 762 { 763 const char *ret = __bpf_address_lookup(addr, size, off, sym); 764 765 if (ret && modname) 766 *modname = NULL; 767 return ret; 768 } 769 770 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 771 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 772 773 #else /* CONFIG_BPF_JIT */ 774 775 static inline bool ebpf_jit_enabled(void) 776 { 777 return false; 778 } 779 780 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 781 { 782 return false; 783 } 784 785 static inline void bpf_jit_free(struct bpf_prog *fp) 786 { 787 bpf_prog_unlock_free(fp); 788 } 789 790 static inline bool bpf_jit_kallsyms_enabled(void) 791 { 792 return false; 793 } 794 795 static inline const char * 796 __bpf_address_lookup(unsigned long addr, unsigned long *size, 797 unsigned long *off, char *sym) 798 { 799 return NULL; 800 } 801 802 static inline bool is_bpf_text_address(unsigned long addr) 803 { 804 return false; 805 } 806 807 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 808 char *type, char *sym) 809 { 810 return -ERANGE; 811 } 812 813 static inline const char * 814 bpf_address_lookup(unsigned long addr, unsigned long *size, 815 unsigned long *off, char **modname, char *sym) 816 { 817 return NULL; 818 } 819 820 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 821 { 822 } 823 824 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 825 { 826 } 827 #endif /* CONFIG_BPF_JIT */ 828 829 #define BPF_ANC BIT(15) 830 831 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 832 { 833 switch (first->code) { 834 case BPF_RET | BPF_K: 835 case BPF_LD | BPF_W | BPF_LEN: 836 return false; 837 838 case BPF_LD | BPF_W | BPF_ABS: 839 case BPF_LD | BPF_H | BPF_ABS: 840 case BPF_LD | BPF_B | BPF_ABS: 841 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 842 return true; 843 return false; 844 845 default: 846 return true; 847 } 848 } 849 850 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 851 { 852 BUG_ON(ftest->code & BPF_ANC); 853 854 switch (ftest->code) { 855 case BPF_LD | BPF_W | BPF_ABS: 856 case BPF_LD | BPF_H | BPF_ABS: 857 case BPF_LD | BPF_B | BPF_ABS: 858 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 859 return BPF_ANC | SKF_AD_##CODE 860 switch (ftest->k) { 861 BPF_ANCILLARY(PROTOCOL); 862 BPF_ANCILLARY(PKTTYPE); 863 BPF_ANCILLARY(IFINDEX); 864 BPF_ANCILLARY(NLATTR); 865 BPF_ANCILLARY(NLATTR_NEST); 866 BPF_ANCILLARY(MARK); 867 BPF_ANCILLARY(QUEUE); 868 BPF_ANCILLARY(HATYPE); 869 BPF_ANCILLARY(RXHASH); 870 BPF_ANCILLARY(CPU); 871 BPF_ANCILLARY(ALU_XOR_X); 872 BPF_ANCILLARY(VLAN_TAG); 873 BPF_ANCILLARY(VLAN_TAG_PRESENT); 874 BPF_ANCILLARY(PAY_OFFSET); 875 BPF_ANCILLARY(RANDOM); 876 BPF_ANCILLARY(VLAN_TPID); 877 } 878 /* Fallthrough. */ 879 default: 880 return ftest->code; 881 } 882 } 883 884 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 885 int k, unsigned int size); 886 887 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 888 unsigned int size, void *buffer) 889 { 890 if (k >= 0) 891 return skb_header_pointer(skb, k, size, buffer); 892 893 return bpf_internal_load_pointer_neg_helper(skb, k, size); 894 } 895 896 static inline int bpf_tell_extensions(void) 897 { 898 return SKF_AD_MAX; 899 } 900 901 #endif /* __LINUX_FILTER_H__ */ 902