1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #ifndef _LINUX_BPF_VERIFIER_H 5 #define _LINUX_BPF_VERIFIER_H 1 6 7 #include <linux/bpf.h> /* for enum bpf_reg_type */ 8 #include <linux/btf.h> /* for struct btf and btf_id() */ 9 #include <linux/filter.h> /* for MAX_BPF_STACK */ 10 #include <linux/tnum.h> 11 12 /* Maximum variable offset umax_value permitted when resolving memory accesses. 13 * In practice this is far bigger than any realistic pointer offset; this limit 14 * ensures that umax_value + (int)off + (int)size cannot overflow a u64. 15 */ 16 #define BPF_MAX_VAR_OFF (1 << 29) 17 /* Maximum variable size permitted for ARG_CONST_SIZE[_OR_ZERO]. This ensures 18 * that converting umax_value to int cannot overflow. 19 */ 20 #define BPF_MAX_VAR_SIZ (1 << 29) 21 /* size of type_str_buf in bpf_verifier. */ 22 #define TYPE_STR_BUF_LEN 64 23 24 /* Liveness marks, used for registers and spilled-regs (in stack slots). 25 * Read marks propagate upwards until they find a write mark; they record that 26 * "one of this state's descendants read this reg" (and therefore the reg is 27 * relevant for states_equal() checks). 28 * Write marks collect downwards and do not propagate; they record that "the 29 * straight-line code that reached this state (from its parent) wrote this reg" 30 * (and therefore that reads propagated from this state or its descendants 31 * should not propagate to its parent). 32 * A state with a write mark can receive read marks; it just won't propagate 33 * them to its parent, since the write mark is a property, not of the state, 34 * but of the link between it and its parent. See mark_reg_read() and 35 * mark_stack_slot_read() in kernel/bpf/verifier.c. 36 */ 37 enum bpf_reg_liveness { 38 REG_LIVE_NONE = 0, /* reg hasn't been read or written this branch */ 39 REG_LIVE_READ32 = 0x1, /* reg was read, so we're sensitive to initial value */ 40 REG_LIVE_READ64 = 0x2, /* likewise, but full 64-bit content matters */ 41 REG_LIVE_READ = REG_LIVE_READ32 | REG_LIVE_READ64, 42 REG_LIVE_WRITTEN = 0x4, /* reg was written first, screening off later reads */ 43 REG_LIVE_DONE = 0x8, /* liveness won't be updating this register anymore */ 44 }; 45 46 struct bpf_reg_state { 47 /* Ordering of fields matters. See states_equal() */ 48 enum bpf_reg_type type; 49 /* Fixed part of pointer offset, pointer types only */ 50 s32 off; 51 union { 52 /* valid when type == PTR_TO_PACKET */ 53 int range; 54 55 /* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE | 56 * PTR_TO_MAP_VALUE_OR_NULL 57 */ 58 struct { 59 struct bpf_map *map_ptr; 60 /* To distinguish map lookups from outer map 61 * the map_uid is non-zero for registers 62 * pointing to inner maps. 63 */ 64 u32 map_uid; 65 }; 66 67 /* for PTR_TO_BTF_ID */ 68 struct { 69 struct btf *btf; 70 u32 btf_id; 71 }; 72 73 u32 mem_size; /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */ 74 75 /* For dynptr stack slots */ 76 struct { 77 enum bpf_dynptr_type type; 78 /* A dynptr is 16 bytes so it takes up 2 stack slots. 79 * We need to track which slot is the first slot 80 * to protect against cases where the user may try to 81 * pass in an address starting at the second slot of the 82 * dynptr. 83 */ 84 bool first_slot; 85 } dynptr; 86 87 /* Max size from any of the above. */ 88 struct { 89 unsigned long raw1; 90 unsigned long raw2; 91 } raw; 92 93 u32 subprogno; /* for PTR_TO_FUNC */ 94 }; 95 /* For PTR_TO_PACKET, used to find other pointers with the same variable 96 * offset, so they can share range knowledge. 97 * For PTR_TO_MAP_VALUE_OR_NULL this is used to share which map value we 98 * came from, when one is tested for != NULL. 99 * For PTR_TO_MEM_OR_NULL this is used to identify memory allocation 100 * for the purpose of tracking that it's freed. 101 * For PTR_TO_SOCKET this is used to share which pointers retain the 102 * same reference to the socket, to determine proper reference freeing. 103 * For stack slots that are dynptrs, this is used to track references to 104 * the dynptr to determine proper reference freeing. 105 */ 106 u32 id; 107 /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned 108 * from a pointer-cast helper, bpf_sk_fullsock() and 109 * bpf_tcp_sock(). 110 * 111 * Consider the following where "sk" is a reference counted 112 * pointer returned from "sk = bpf_sk_lookup_tcp();": 113 * 114 * 1: sk = bpf_sk_lookup_tcp(); 115 * 2: if (!sk) { return 0; } 116 * 3: fullsock = bpf_sk_fullsock(sk); 117 * 4: if (!fullsock) { bpf_sk_release(sk); return 0; } 118 * 5: tp = bpf_tcp_sock(fullsock); 119 * 6: if (!tp) { bpf_sk_release(sk); return 0; } 120 * 7: bpf_sk_release(sk); 121 * 8: snd_cwnd = tp->snd_cwnd; // verifier will complain 122 * 123 * After bpf_sk_release(sk) at line 7, both "fullsock" ptr and 124 * "tp" ptr should be invalidated also. In order to do that, 125 * the reg holding "fullsock" and "sk" need to remember 126 * the original refcounted ptr id (i.e. sk_reg->id) in ref_obj_id 127 * such that the verifier can reset all regs which have 128 * ref_obj_id matching the sk_reg->id. 129 * 130 * sk_reg->ref_obj_id is set to sk_reg->id at line 1. 131 * sk_reg->id will stay as NULL-marking purpose only. 132 * After NULL-marking is done, sk_reg->id can be reset to 0. 133 * 134 * After "fullsock = bpf_sk_fullsock(sk);" at line 3, 135 * fullsock_reg->ref_obj_id is set to sk_reg->ref_obj_id. 136 * 137 * After "tp = bpf_tcp_sock(fullsock);" at line 5, 138 * tp_reg->ref_obj_id is set to fullsock_reg->ref_obj_id 139 * which is the same as sk_reg->ref_obj_id. 140 * 141 * From the verifier perspective, if sk, fullsock and tp 142 * are not NULL, they are the same ptr with different 143 * reg->type. In particular, bpf_sk_release(tp) is also 144 * allowed and has the same effect as bpf_sk_release(sk). 145 */ 146 u32 ref_obj_id; 147 /* For scalar types (SCALAR_VALUE), this represents our knowledge of 148 * the actual value. 149 * For pointer types, this represents the variable part of the offset 150 * from the pointed-to object, and is shared with all bpf_reg_states 151 * with the same id as us. 152 */ 153 struct tnum var_off; 154 /* Used to determine if any memory access using this register will 155 * result in a bad access. 156 * These refer to the same value as var_off, not necessarily the actual 157 * contents of the register. 158 */ 159 s64 smin_value; /* minimum possible (s64)value */ 160 s64 smax_value; /* maximum possible (s64)value */ 161 u64 umin_value; /* minimum possible (u64)value */ 162 u64 umax_value; /* maximum possible (u64)value */ 163 s32 s32_min_value; /* minimum possible (s32)value */ 164 s32 s32_max_value; /* maximum possible (s32)value */ 165 u32 u32_min_value; /* minimum possible (u32)value */ 166 u32 u32_max_value; /* maximum possible (u32)value */ 167 /* parentage chain for liveness checking */ 168 struct bpf_reg_state *parent; 169 /* Inside the callee two registers can be both PTR_TO_STACK like 170 * R1=fp-8 and R2=fp-8, but one of them points to this function stack 171 * while another to the caller's stack. To differentiate them 'frameno' 172 * is used which is an index in bpf_verifier_state->frame[] array 173 * pointing to bpf_func_state. 174 */ 175 u32 frameno; 176 /* Tracks subreg definition. The stored value is the insn_idx of the 177 * writing insn. This is safe because subreg_def is used before any insn 178 * patching which only happens after main verification finished. 179 */ 180 s32 subreg_def; 181 enum bpf_reg_liveness live; 182 /* if (!precise && SCALAR_VALUE) min/max/tnum don't affect safety */ 183 bool precise; 184 }; 185 186 enum bpf_stack_slot_type { 187 STACK_INVALID, /* nothing was stored in this stack slot */ 188 STACK_SPILL, /* register spilled into stack */ 189 STACK_MISC, /* BPF program wrote some data into this slot */ 190 STACK_ZERO, /* BPF program wrote constant zero */ 191 /* A dynptr is stored in this stack slot. The type of dynptr 192 * is stored in bpf_stack_state->spilled_ptr.dynptr.type 193 */ 194 STACK_DYNPTR, 195 }; 196 197 #define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ 198 #define BPF_DYNPTR_SIZE sizeof(struct bpf_dynptr_kern) 199 #define BPF_DYNPTR_NR_SLOTS (BPF_DYNPTR_SIZE / BPF_REG_SIZE) 200 201 struct bpf_stack_state { 202 struct bpf_reg_state spilled_ptr; 203 u8 slot_type[BPF_REG_SIZE]; 204 }; 205 206 struct bpf_reference_state { 207 /* Track each reference created with a unique id, even if the same 208 * instruction creates the reference multiple times (eg, via CALL). 209 */ 210 int id; 211 /* Instruction where the allocation of this reference occurred. This 212 * is used purely to inform the user of a reference leak. 213 */ 214 int insn_idx; 215 /* There can be a case like: 216 * main (frame 0) 217 * cb (frame 1) 218 * func (frame 3) 219 * cb (frame 4) 220 * Hence for frame 4, if callback_ref just stored boolean, it would be 221 * impossible to distinguish nested callback refs. Hence store the 222 * frameno and compare that to callback_ref in check_reference_leak when 223 * exiting a callback function. 224 */ 225 int callback_ref; 226 }; 227 228 /* state of the program: 229 * type of all registers and stack info 230 */ 231 struct bpf_func_state { 232 struct bpf_reg_state regs[MAX_BPF_REG]; 233 /* index of call instruction that called into this func */ 234 int callsite; 235 /* stack frame number of this function state from pov of 236 * enclosing bpf_verifier_state. 237 * 0 = main function, 1 = first callee. 238 */ 239 u32 frameno; 240 /* subprog number == index within subprog_info 241 * zero == main subprog 242 */ 243 u32 subprogno; 244 /* Every bpf_timer_start will increment async_entry_cnt. 245 * It's used to distinguish: 246 * void foo(void) { for(;;); } 247 * void foo(void) { bpf_timer_set_callback(,foo); } 248 */ 249 u32 async_entry_cnt; 250 bool in_callback_fn; 251 struct tnum callback_ret_range; 252 bool in_async_callback_fn; 253 254 /* The following fields should be last. See copy_func_state() */ 255 int acquired_refs; 256 struct bpf_reference_state *refs; 257 int allocated_stack; 258 struct bpf_stack_state *stack; 259 }; 260 261 struct bpf_idx_pair { 262 u32 prev_idx; 263 u32 idx; 264 }; 265 266 struct bpf_id_pair { 267 u32 old; 268 u32 cur; 269 }; 270 271 /* Maximum number of register states that can exist at once */ 272 #define BPF_ID_MAP_SIZE (MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE) 273 #define MAX_CALL_FRAMES 8 274 struct bpf_verifier_state { 275 /* call stack tracking */ 276 struct bpf_func_state *frame[MAX_CALL_FRAMES]; 277 struct bpf_verifier_state *parent; 278 /* 279 * 'branches' field is the number of branches left to explore: 280 * 0 - all possible paths from this state reached bpf_exit or 281 * were safely pruned 282 * 1 - at least one path is being explored. 283 * This state hasn't reached bpf_exit 284 * 2 - at least two paths are being explored. 285 * This state is an immediate parent of two children. 286 * One is fallthrough branch with branches==1 and another 287 * state is pushed into stack (to be explored later) also with 288 * branches==1. The parent of this state has branches==1. 289 * The verifier state tree connected via 'parent' pointer looks like: 290 * 1 291 * 1 292 * 2 -> 1 (first 'if' pushed into stack) 293 * 1 294 * 2 -> 1 (second 'if' pushed into stack) 295 * 1 296 * 1 297 * 1 bpf_exit. 298 * 299 * Once do_check() reaches bpf_exit, it calls update_branch_counts() 300 * and the verifier state tree will look: 301 * 1 302 * 1 303 * 2 -> 1 (first 'if' pushed into stack) 304 * 1 305 * 1 -> 1 (second 'if' pushed into stack) 306 * 0 307 * 0 308 * 0 bpf_exit. 309 * After pop_stack() the do_check() will resume at second 'if'. 310 * 311 * If is_state_visited() sees a state with branches > 0 it means 312 * there is a loop. If such state is exactly equal to the current state 313 * it's an infinite loop. Note states_equal() checks for states 314 * equivalency, so two states being 'states_equal' does not mean 315 * infinite loop. The exact comparison is provided by 316 * states_maybe_looping() function. It's a stronger pre-check and 317 * much faster than states_equal(). 318 * 319 * This algorithm may not find all possible infinite loops or 320 * loop iteration count may be too high. 321 * In such cases BPF_COMPLEXITY_LIMIT_INSNS limit kicks in. 322 */ 323 u32 branches; 324 u32 insn_idx; 325 u32 curframe; 326 u32 active_spin_lock; 327 bool speculative; 328 329 /* first and last insn idx of this verifier state */ 330 u32 first_insn_idx; 331 u32 last_insn_idx; 332 /* jmp history recorded from first to last. 333 * backtracking is using it to go from last to first. 334 * For most states jmp_history_cnt is [0-3]. 335 * For loops can go up to ~40. 336 */ 337 struct bpf_idx_pair *jmp_history; 338 u32 jmp_history_cnt; 339 }; 340 341 #define bpf_get_spilled_reg(slot, frame) \ 342 (((slot < frame->allocated_stack / BPF_REG_SIZE) && \ 343 (frame->stack[slot].slot_type[0] == STACK_SPILL)) \ 344 ? &frame->stack[slot].spilled_ptr : NULL) 345 346 /* Iterate over 'frame', setting 'reg' to either NULL or a spilled register. */ 347 #define bpf_for_each_spilled_reg(iter, frame, reg) \ 348 for (iter = 0, reg = bpf_get_spilled_reg(iter, frame); \ 349 iter < frame->allocated_stack / BPF_REG_SIZE; \ 350 iter++, reg = bpf_get_spilled_reg(iter, frame)) 351 352 /* Invoke __expr over regsiters in __vst, setting __state and __reg */ 353 #define bpf_for_each_reg_in_vstate(__vst, __state, __reg, __expr) \ 354 ({ \ 355 struct bpf_verifier_state *___vstate = __vst; \ 356 int ___i, ___j; \ 357 for (___i = 0; ___i <= ___vstate->curframe; ___i++) { \ 358 struct bpf_reg_state *___regs; \ 359 __state = ___vstate->frame[___i]; \ 360 ___regs = __state->regs; \ 361 for (___j = 0; ___j < MAX_BPF_REG; ___j++) { \ 362 __reg = &___regs[___j]; \ 363 (void)(__expr); \ 364 } \ 365 bpf_for_each_spilled_reg(___j, __state, __reg) { \ 366 if (!__reg) \ 367 continue; \ 368 (void)(__expr); \ 369 } \ 370 } \ 371 }) 372 373 /* linked list of verifier states used to prune search */ 374 struct bpf_verifier_state_list { 375 struct bpf_verifier_state state; 376 struct bpf_verifier_state_list *next; 377 int miss_cnt, hit_cnt; 378 }; 379 380 struct bpf_loop_inline_state { 381 unsigned int initialized:1; /* set to true upon first entry */ 382 unsigned int fit_for_inline:1; /* true if callback function is the same 383 * at each call and flags are always zero 384 */ 385 u32 callback_subprogno; /* valid when fit_for_inline is true */ 386 }; 387 388 /* Possible states for alu_state member. */ 389 #define BPF_ALU_SANITIZE_SRC (1U << 0) 390 #define BPF_ALU_SANITIZE_DST (1U << 1) 391 #define BPF_ALU_NEG_VALUE (1U << 2) 392 #define BPF_ALU_NON_POINTER (1U << 3) 393 #define BPF_ALU_IMMEDIATE (1U << 4) 394 #define BPF_ALU_SANITIZE (BPF_ALU_SANITIZE_SRC | \ 395 BPF_ALU_SANITIZE_DST) 396 397 struct bpf_insn_aux_data { 398 union { 399 enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ 400 unsigned long map_ptr_state; /* pointer/poison value for maps */ 401 s32 call_imm; /* saved imm field of call insn */ 402 u32 alu_limit; /* limit for add/sub register with pointer */ 403 struct { 404 u32 map_index; /* index into used_maps[] */ 405 u32 map_off; /* offset from value base address */ 406 }; 407 struct { 408 enum bpf_reg_type reg_type; /* type of pseudo_btf_id */ 409 union { 410 struct { 411 struct btf *btf; 412 u32 btf_id; /* btf_id for struct typed var */ 413 }; 414 u32 mem_size; /* mem_size for non-struct typed var */ 415 }; 416 } btf_var; 417 /* if instruction is a call to bpf_loop this field tracks 418 * the state of the relevant registers to make decision about inlining 419 */ 420 struct bpf_loop_inline_state loop_inline_state; 421 }; 422 u64 map_key_state; /* constant (32 bit) key tracking for maps */ 423 int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ 424 u32 seen; /* this insn was processed by the verifier at env->pass_cnt */ 425 bool sanitize_stack_spill; /* subject to Spectre v4 sanitation */ 426 bool zext_dst; /* this insn zero extends dst reg */ 427 u8 alu_state; /* used in combination with alu_limit */ 428 429 /* below fields are initialized once */ 430 unsigned int orig_idx; /* original instruction index */ 431 bool prune_point; 432 }; 433 434 #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ 435 #define MAX_USED_BTFS 64 /* max number of BTFs accessed by one BPF program */ 436 437 #define BPF_VERIFIER_TMP_LOG_SIZE 1024 438 439 struct bpf_verifier_log { 440 u32 level; 441 char kbuf[BPF_VERIFIER_TMP_LOG_SIZE]; 442 char __user *ubuf; 443 u32 len_used; 444 u32 len_total; 445 }; 446 447 static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log) 448 { 449 return log->len_used >= log->len_total - 1; 450 } 451 452 #define BPF_LOG_LEVEL1 1 453 #define BPF_LOG_LEVEL2 2 454 #define BPF_LOG_STATS 4 455 #define BPF_LOG_LEVEL (BPF_LOG_LEVEL1 | BPF_LOG_LEVEL2) 456 #define BPF_LOG_MASK (BPF_LOG_LEVEL | BPF_LOG_STATS) 457 #define BPF_LOG_KERNEL (BPF_LOG_MASK + 1) /* kernel internal flag */ 458 #define BPF_LOG_MIN_ALIGNMENT 8U 459 #define BPF_LOG_ALIGNMENT 40U 460 461 static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) 462 { 463 return log && 464 ((log->level && log->ubuf && !bpf_verifier_log_full(log)) || 465 log->level == BPF_LOG_KERNEL); 466 } 467 468 static inline bool 469 bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log) 470 { 471 return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 && 472 log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK); 473 } 474 475 #define BPF_MAX_SUBPROGS 256 476 477 struct bpf_subprog_info { 478 /* 'start' has to be the first field otherwise find_subprog() won't work */ 479 u32 start; /* insn idx of function entry point */ 480 u32 linfo_idx; /* The idx to the main_prog->aux->linfo */ 481 u16 stack_depth; /* max. stack depth used by this function */ 482 bool has_tail_call; 483 bool tail_call_reachable; 484 bool has_ld_abs; 485 bool is_async_cb; 486 }; 487 488 /* single container for all structs 489 * one verifier_env per bpf_check() call 490 */ 491 struct bpf_verifier_env { 492 u32 insn_idx; 493 u32 prev_insn_idx; 494 struct bpf_prog *prog; /* eBPF program being verified */ 495 const struct bpf_verifier_ops *ops; 496 struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ 497 int stack_size; /* number of states to be processed */ 498 bool strict_alignment; /* perform strict pointer alignment checks */ 499 bool test_state_freq; /* test verifier with different pruning frequency */ 500 struct bpf_verifier_state *cur_state; /* current verifier state */ 501 struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ 502 struct bpf_verifier_state_list *free_list; 503 struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */ 504 struct btf_mod_pair used_btfs[MAX_USED_BTFS]; /* array of BTF's used by BPF program */ 505 u32 used_map_cnt; /* number of used maps */ 506 u32 used_btf_cnt; /* number of used BTF objects */ 507 u32 id_gen; /* used to generate unique reg IDs */ 508 bool explore_alu_limits; 509 bool allow_ptr_leaks; 510 bool allow_uninit_stack; 511 bool allow_ptr_to_map_access; 512 bool bpf_capable; 513 bool bypass_spec_v1; 514 bool bypass_spec_v4; 515 bool seen_direct_write; 516 struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ 517 const struct bpf_line_info *prev_linfo; 518 struct bpf_verifier_log log; 519 struct bpf_subprog_info subprog_info[BPF_MAX_SUBPROGS + 1]; 520 struct bpf_id_pair idmap_scratch[BPF_ID_MAP_SIZE]; 521 struct { 522 int *insn_state; 523 int *insn_stack; 524 int cur_stack; 525 } cfg; 526 u32 pass_cnt; /* number of times do_check() was called */ 527 u32 subprog_cnt; 528 /* number of instructions analyzed by the verifier */ 529 u32 prev_insn_processed, insn_processed; 530 /* number of jmps, calls, exits analyzed so far */ 531 u32 prev_jmps_processed, jmps_processed; 532 /* total verification time */ 533 u64 verification_time; 534 /* maximum number of verifier states kept in 'branching' instructions */ 535 u32 max_states_per_insn; 536 /* total number of allocated verifier states */ 537 u32 total_states; 538 /* some states are freed during program analysis. 539 * this is peak number of states. this number dominates kernel 540 * memory consumption during verification 541 */ 542 u32 peak_states; 543 /* longest register parentage chain walked for liveness marking */ 544 u32 longest_mark_read_walk; 545 bpfptr_t fd_array; 546 547 /* bit mask to keep track of whether a register has been accessed 548 * since the last time the function state was printed 549 */ 550 u32 scratched_regs; 551 /* Same as scratched_regs but for stack slots */ 552 u64 scratched_stack_slots; 553 u32 prev_log_len, prev_insn_print_len; 554 /* buffer used in reg_type_str() to generate reg_type string */ 555 char type_str_buf[TYPE_STR_BUF_LEN]; 556 }; 557 558 __printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log, 559 const char *fmt, va_list args); 560 __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env, 561 const char *fmt, ...); 562 __printf(2, 3) void bpf_log(struct bpf_verifier_log *log, 563 const char *fmt, ...); 564 565 static inline struct bpf_func_state *cur_func(struct bpf_verifier_env *env) 566 { 567 struct bpf_verifier_state *cur = env->cur_state; 568 569 return cur->frame[cur->curframe]; 570 } 571 572 static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env) 573 { 574 return cur_func(env)->regs; 575 } 576 577 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog); 578 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, 579 int insn_idx, int prev_insn_idx); 580 int bpf_prog_offload_finalize(struct bpf_verifier_env *env); 581 void 582 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, 583 struct bpf_insn *insn); 584 void 585 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt); 586 587 int check_ptr_off_reg(struct bpf_verifier_env *env, 588 const struct bpf_reg_state *reg, int regno); 589 int check_func_arg_reg_off(struct bpf_verifier_env *env, 590 const struct bpf_reg_state *reg, int regno, 591 enum bpf_arg_type arg_type); 592 int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, 593 u32 regno); 594 int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, 595 u32 regno, u32 mem_size); 596 bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, 597 struct bpf_reg_state *reg); 598 bool is_dynptr_type_expected(struct bpf_verifier_env *env, 599 struct bpf_reg_state *reg, 600 enum bpf_arg_type arg_type); 601 602 /* this lives here instead of in bpf.h because it needs to dereference tgt_prog */ 603 static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog, 604 struct btf *btf, u32 btf_id) 605 { 606 if (tgt_prog) 607 return ((u64)tgt_prog->aux->id << 32) | btf_id; 608 else 609 return ((u64)btf_obj_id(btf) << 32) | 0x80000000 | btf_id; 610 } 611 612 /* unpack the IDs from the key as constructed above */ 613 static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id) 614 { 615 if (obj_id) 616 *obj_id = key >> 32; 617 if (btf_id) 618 *btf_id = key & 0x7FFFFFFF; 619 } 620 621 int bpf_check_attach_target(struct bpf_verifier_log *log, 622 const struct bpf_prog *prog, 623 const struct bpf_prog *tgt_prog, 624 u32 btf_id, 625 struct bpf_attach_target_info *tgt_info); 626 void bpf_free_kfunc_btf_tab(struct bpf_kfunc_btf_tab *tab); 627 628 int mark_chain_precision(struct bpf_verifier_env *env, int regno); 629 630 #define BPF_BASE_TYPE_MASK GENMASK(BPF_BASE_TYPE_BITS - 1, 0) 631 632 /* extract base type from bpf_{arg, return, reg}_type. */ 633 static inline u32 base_type(u32 type) 634 { 635 return type & BPF_BASE_TYPE_MASK; 636 } 637 638 /* extract flags from an extended type. See bpf_type_flag in bpf.h. */ 639 static inline u32 type_flag(u32 type) 640 { 641 return type & ~BPF_BASE_TYPE_MASK; 642 } 643 644 /* only use after check_attach_btf_id() */ 645 static inline enum bpf_prog_type resolve_prog_type(struct bpf_prog *prog) 646 { 647 return prog->type == BPF_PROG_TYPE_EXT ? 648 prog->aux->dst_prog->type : prog->type; 649 } 650 651 #endif /* _LINUX_BPF_VERIFIER_H */ 652