1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 /* Copyright (c) 2021 Facebook */ 3 #include <stdio.h> 4 #include <stdlib.h> 5 #include <string.h> 6 #include <errno.h> 7 #include <linux/filter.h> 8 #include <sys/param.h> 9 #include "btf.h" 10 #include "bpf.h" 11 #include "libbpf.h" 12 #include "libbpf_internal.h" 13 #include "hashmap.h" 14 #include "bpf_gen_internal.h" 15 #include "skel_internal.h" 16 #include <asm/byteorder.h> 17 18 #define MAX_USED_MAPS 64 19 #define MAX_USED_PROGS 32 20 #define MAX_KFUNC_DESCS 256 21 #define MAX_FD_ARRAY_SZ (MAX_USED_PROGS + MAX_KFUNC_DESCS) 22 23 /* The following structure describes the stack layout of the loader program. 24 * In addition R6 contains the pointer to context. 25 * R7 contains the result of the last sys_bpf command (typically error or FD). 26 * R9 contains the result of the last sys_close command. 27 * 28 * Naming convention: 29 * ctx - bpf program context 30 * stack - bpf program stack 31 * blob - bpf_attr-s, strings, insns, map data. 32 * All the bytes that loader prog will use for read/write. 33 */ 34 struct loader_stack { 35 __u32 btf_fd; 36 __u32 prog_fd[MAX_USED_PROGS]; 37 __u32 inner_map_fd; 38 }; 39 40 #define stack_off(field) \ 41 (__s16)(-sizeof(struct loader_stack) + offsetof(struct loader_stack, field)) 42 43 #define attr_field(attr, field) (attr + offsetof(union bpf_attr, field)) 44 45 static int realloc_insn_buf(struct bpf_gen *gen, __u32 size) 46 { 47 size_t off = gen->insn_cur - gen->insn_start; 48 void *insn_start; 49 50 if (gen->error) 51 return gen->error; 52 if (size > INT32_MAX || off + size > INT32_MAX) { 53 gen->error = -ERANGE; 54 return -ERANGE; 55 } 56 insn_start = realloc(gen->insn_start, off + size); 57 if (!insn_start) { 58 gen->error = -ENOMEM; 59 free(gen->insn_start); 60 gen->insn_start = NULL; 61 return -ENOMEM; 62 } 63 gen->insn_start = insn_start; 64 gen->insn_cur = insn_start + off; 65 return 0; 66 } 67 68 static int realloc_data_buf(struct bpf_gen *gen, __u32 size) 69 { 70 size_t off = gen->data_cur - gen->data_start; 71 void *data_start; 72 73 if (gen->error) 74 return gen->error; 75 if (size > INT32_MAX || off + size > INT32_MAX) { 76 gen->error = -ERANGE; 77 return -ERANGE; 78 } 79 data_start = realloc(gen->data_start, off + size); 80 if (!data_start) { 81 gen->error = -ENOMEM; 82 free(gen->data_start); 83 gen->data_start = NULL; 84 return -ENOMEM; 85 } 86 gen->data_start = data_start; 87 gen->data_cur = data_start + off; 88 return 0; 89 } 90 91 static void emit(struct bpf_gen *gen, struct bpf_insn insn) 92 { 93 if (realloc_insn_buf(gen, sizeof(insn))) 94 return; 95 memcpy(gen->insn_cur, &insn, sizeof(insn)); 96 gen->insn_cur += sizeof(insn); 97 } 98 99 static void emit2(struct bpf_gen *gen, struct bpf_insn insn1, struct bpf_insn insn2) 100 { 101 emit(gen, insn1); 102 emit(gen, insn2); 103 } 104 105 void bpf_gen__init(struct bpf_gen *gen, int log_level) 106 { 107 size_t stack_sz = sizeof(struct loader_stack); 108 int i; 109 110 gen->log_level = log_level; 111 /* save ctx pointer into R6 */ 112 emit(gen, BPF_MOV64_REG(BPF_REG_6, BPF_REG_1)); 113 114 /* bzero stack */ 115 emit(gen, BPF_MOV64_REG(BPF_REG_1, BPF_REG_10)); 116 emit(gen, BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -stack_sz)); 117 emit(gen, BPF_MOV64_IMM(BPF_REG_2, stack_sz)); 118 emit(gen, BPF_MOV64_IMM(BPF_REG_3, 0)); 119 emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel)); 120 121 /* jump over cleanup code */ 122 emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 123 /* size of cleanup code below */ 124 (stack_sz / 4) * 3 + 2)); 125 126 /* remember the label where all error branches will jump to */ 127 gen->cleanup_label = gen->insn_cur - gen->insn_start; 128 /* emit cleanup code: close all temp FDs */ 129 for (i = 0; i < stack_sz; i += 4) { 130 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -stack_sz + i)); 131 emit(gen, BPF_JMP_IMM(BPF_JSLE, BPF_REG_1, 0, 1)); 132 emit(gen, BPF_EMIT_CALL(BPF_FUNC_sys_close)); 133 } 134 /* R7 contains the error code from sys_bpf. Copy it into R0 and exit. */ 135 emit(gen, BPF_MOV64_REG(BPF_REG_0, BPF_REG_7)); 136 emit(gen, BPF_EXIT_INSN()); 137 } 138 139 static int add_data(struct bpf_gen *gen, const void *data, __u32 size) 140 { 141 __u32 size8 = roundup(size, 8); 142 __u64 zero = 0; 143 void *prev; 144 145 if (realloc_data_buf(gen, size8)) 146 return 0; 147 prev = gen->data_cur; 148 if (data) { 149 memcpy(gen->data_cur, data, size); 150 memcpy(gen->data_cur + size, &zero, size8 - size); 151 } else { 152 memset(gen->data_cur, 0, size8); 153 } 154 gen->data_cur += size8; 155 return prev - gen->data_start; 156 } 157 158 /* Get index for map_fd/btf_fd slot in reserved fd_array, or in data relative 159 * to start of fd_array. Caller can decide if it is usable or not. 160 */ 161 static int add_map_fd(struct bpf_gen *gen) 162 { 163 if (!gen->fd_array) 164 gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int)); 165 if (gen->nr_maps == MAX_USED_MAPS) { 166 pr_warn("Total maps exceeds %d\n", MAX_USED_MAPS); 167 gen->error = -E2BIG; 168 return 0; 169 } 170 return gen->nr_maps++; 171 } 172 173 static int add_kfunc_btf_fd(struct bpf_gen *gen) 174 { 175 int cur; 176 177 if (!gen->fd_array) 178 gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int)); 179 if (gen->nr_fd_array == MAX_KFUNC_DESCS) { 180 cur = add_data(gen, NULL, sizeof(int)); 181 return (cur - gen->fd_array) / sizeof(int); 182 } 183 return MAX_USED_MAPS + gen->nr_fd_array++; 184 } 185 186 static int blob_fd_array_off(struct bpf_gen *gen, int index) 187 { 188 return gen->fd_array + index * sizeof(int); 189 } 190 191 static int insn_bytes_to_bpf_size(__u32 sz) 192 { 193 switch (sz) { 194 case 8: return BPF_DW; 195 case 4: return BPF_W; 196 case 2: return BPF_H; 197 case 1: return BPF_B; 198 default: return -1; 199 } 200 } 201 202 /* *(u64 *)(blob + off) = (u64)(void *)(blob + data) */ 203 static void emit_rel_store(struct bpf_gen *gen, int off, int data) 204 { 205 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, 206 0, 0, 0, data)); 207 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 208 0, 0, 0, off)); 209 emit(gen, BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0)); 210 } 211 212 static void move_blob2blob(struct bpf_gen *gen, int off, int size, int blob_off) 213 { 214 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_2, BPF_PSEUDO_MAP_IDX_VALUE, 215 0, 0, 0, blob_off)); 216 emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_2, 0)); 217 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 218 0, 0, 0, off)); 219 emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_1, BPF_REG_0, 0)); 220 } 221 222 static void move_blob2ctx(struct bpf_gen *gen, int ctx_off, int size, int blob_off) 223 { 224 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 225 0, 0, 0, blob_off)); 226 emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_1, 0)); 227 emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_6, BPF_REG_0, ctx_off)); 228 } 229 230 static void move_ctx2blob(struct bpf_gen *gen, int off, int size, int ctx_off, 231 bool check_non_zero) 232 { 233 emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_6, ctx_off)); 234 if (check_non_zero) 235 /* If value in ctx is zero don't update the blob. 236 * For example: when ctx->map.max_entries == 0, keep default max_entries from bpf.c 237 */ 238 emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3)); 239 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 240 0, 0, 0, off)); 241 emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_1, BPF_REG_0, 0)); 242 } 243 244 static void move_stack2blob(struct bpf_gen *gen, int off, int size, int stack_off) 245 { 246 emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_10, stack_off)); 247 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 248 0, 0, 0, off)); 249 emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_1, BPF_REG_0, 0)); 250 } 251 252 static void move_stack2ctx(struct bpf_gen *gen, int ctx_off, int size, int stack_off) 253 { 254 emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_10, stack_off)); 255 emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_6, BPF_REG_0, ctx_off)); 256 } 257 258 static void emit_sys_bpf(struct bpf_gen *gen, int cmd, int attr, int attr_size) 259 { 260 emit(gen, BPF_MOV64_IMM(BPF_REG_1, cmd)); 261 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_2, BPF_PSEUDO_MAP_IDX_VALUE, 262 0, 0, 0, attr)); 263 emit(gen, BPF_MOV64_IMM(BPF_REG_3, attr_size)); 264 emit(gen, BPF_EMIT_CALL(BPF_FUNC_sys_bpf)); 265 /* remember the result in R7 */ 266 emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); 267 } 268 269 static bool is_simm16(__s64 value) 270 { 271 return value == (__s64)(__s16)value; 272 } 273 274 static void emit_check_err(struct bpf_gen *gen) 275 { 276 __s64 off = -(gen->insn_cur - gen->insn_start - gen->cleanup_label) / 8 - 1; 277 278 /* R7 contains result of last sys_bpf command. 279 * if (R7 < 0) goto cleanup; 280 */ 281 if (is_simm16(off)) { 282 emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, off)); 283 } else { 284 gen->error = -ERANGE; 285 emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, -1)); 286 } 287 } 288 289 /* reg1 and reg2 should not be R1 - R5. They can be R0, R6 - R10 */ 290 static void emit_debug(struct bpf_gen *gen, int reg1, int reg2, 291 const char *fmt, va_list args) 292 { 293 char buf[1024]; 294 int addr, len, ret; 295 296 if (!gen->log_level) 297 return; 298 ret = vsnprintf(buf, sizeof(buf), fmt, args); 299 if (ret < 1024 - 7 && reg1 >= 0 && reg2 < 0) 300 /* The special case to accommodate common debug_ret(): 301 * to avoid specifying BPF_REG_7 and adding " r=%%d" to 302 * prints explicitly. 303 */ 304 strcat(buf, " r=%d"); 305 len = strlen(buf) + 1; 306 addr = add_data(gen, buf, len); 307 308 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 309 0, 0, 0, addr)); 310 emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); 311 if (reg1 >= 0) 312 emit(gen, BPF_MOV64_REG(BPF_REG_3, reg1)); 313 if (reg2 >= 0) 314 emit(gen, BPF_MOV64_REG(BPF_REG_4, reg2)); 315 emit(gen, BPF_EMIT_CALL(BPF_FUNC_trace_printk)); 316 } 317 318 static void debug_regs(struct bpf_gen *gen, int reg1, int reg2, const char *fmt, ...) 319 { 320 va_list args; 321 322 va_start(args, fmt); 323 emit_debug(gen, reg1, reg2, fmt, args); 324 va_end(args); 325 } 326 327 static void debug_ret(struct bpf_gen *gen, const char *fmt, ...) 328 { 329 va_list args; 330 331 va_start(args, fmt); 332 emit_debug(gen, BPF_REG_7, -1, fmt, args); 333 va_end(args); 334 } 335 336 static void __emit_sys_close(struct bpf_gen *gen) 337 { 338 emit(gen, BPF_JMP_IMM(BPF_JSLE, BPF_REG_1, 0, 339 /* 2 is the number of the following insns 340 * * 6 is additional insns in debug_regs 341 */ 342 2 + (gen->log_level ? 6 : 0))); 343 emit(gen, BPF_MOV64_REG(BPF_REG_9, BPF_REG_1)); 344 emit(gen, BPF_EMIT_CALL(BPF_FUNC_sys_close)); 345 debug_regs(gen, BPF_REG_9, BPF_REG_0, "close(%%d) = %%d"); 346 } 347 348 static void emit_sys_close_stack(struct bpf_gen *gen, int stack_off) 349 { 350 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, stack_off)); 351 __emit_sys_close(gen); 352 } 353 354 static void emit_sys_close_blob(struct bpf_gen *gen, int blob_off) 355 { 356 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, 357 0, 0, 0, blob_off)); 358 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0)); 359 __emit_sys_close(gen); 360 } 361 362 int bpf_gen__finish(struct bpf_gen *gen) 363 { 364 int i; 365 366 emit_sys_close_stack(gen, stack_off(btf_fd)); 367 for (i = 0; i < gen->nr_progs; i++) 368 move_stack2ctx(gen, 369 sizeof(struct bpf_loader_ctx) + 370 sizeof(struct bpf_map_desc) * gen->nr_maps + 371 sizeof(struct bpf_prog_desc) * i + 372 offsetof(struct bpf_prog_desc, prog_fd), 4, 373 stack_off(prog_fd[i])); 374 for (i = 0; i < gen->nr_maps; i++) 375 move_blob2ctx(gen, 376 sizeof(struct bpf_loader_ctx) + 377 sizeof(struct bpf_map_desc) * i + 378 offsetof(struct bpf_map_desc, map_fd), 4, 379 blob_fd_array_off(gen, i)); 380 emit(gen, BPF_MOV64_IMM(BPF_REG_0, 0)); 381 emit(gen, BPF_EXIT_INSN()); 382 pr_debug("gen: finish %d\n", gen->error); 383 if (!gen->error) { 384 struct gen_loader_opts *opts = gen->opts; 385 386 opts->insns = gen->insn_start; 387 opts->insns_sz = gen->insn_cur - gen->insn_start; 388 opts->data = gen->data_start; 389 opts->data_sz = gen->data_cur - gen->data_start; 390 } 391 return gen->error; 392 } 393 394 void bpf_gen__free(struct bpf_gen *gen) 395 { 396 if (!gen) 397 return; 398 free(gen->data_start); 399 free(gen->insn_start); 400 free(gen); 401 } 402 403 void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data, 404 __u32 btf_raw_size) 405 { 406 int attr_size = offsetofend(union bpf_attr, btf_log_level); 407 int btf_data, btf_load_attr; 408 union bpf_attr attr; 409 410 memset(&attr, 0, attr_size); 411 pr_debug("gen: load_btf: size %d\n", btf_raw_size); 412 btf_data = add_data(gen, btf_raw_data, btf_raw_size); 413 414 attr.btf_size = btf_raw_size; 415 btf_load_attr = add_data(gen, &attr, attr_size); 416 417 /* populate union bpf_attr with user provided log details */ 418 move_ctx2blob(gen, attr_field(btf_load_attr, btf_log_level), 4, 419 offsetof(struct bpf_loader_ctx, log_level), false); 420 move_ctx2blob(gen, attr_field(btf_load_attr, btf_log_size), 4, 421 offsetof(struct bpf_loader_ctx, log_size), false); 422 move_ctx2blob(gen, attr_field(btf_load_attr, btf_log_buf), 8, 423 offsetof(struct bpf_loader_ctx, log_buf), false); 424 /* populate union bpf_attr with a pointer to the BTF data */ 425 emit_rel_store(gen, attr_field(btf_load_attr, btf), btf_data); 426 /* emit BTF_LOAD command */ 427 emit_sys_bpf(gen, BPF_BTF_LOAD, btf_load_attr, attr_size); 428 debug_ret(gen, "btf_load size %d", btf_raw_size); 429 emit_check_err(gen); 430 /* remember btf_fd in the stack, if successful */ 431 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, stack_off(btf_fd))); 432 } 433 434 void bpf_gen__map_create(struct bpf_gen *gen, 435 struct bpf_create_map_params *map_attr, int map_idx) 436 { 437 int attr_size = offsetofend(union bpf_attr, btf_vmlinux_value_type_id); 438 bool close_inner_map_fd = false; 439 int map_create_attr, idx; 440 union bpf_attr attr; 441 442 memset(&attr, 0, attr_size); 443 attr.map_type = map_attr->map_type; 444 attr.key_size = map_attr->key_size; 445 attr.value_size = map_attr->value_size; 446 attr.map_flags = map_attr->map_flags; 447 attr.map_extra = map_attr->map_extra; 448 memcpy(attr.map_name, map_attr->name, 449 min((unsigned)strlen(map_attr->name), BPF_OBJ_NAME_LEN - 1)); 450 attr.numa_node = map_attr->numa_node; 451 attr.map_ifindex = map_attr->map_ifindex; 452 attr.max_entries = map_attr->max_entries; 453 switch (attr.map_type) { 454 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 455 case BPF_MAP_TYPE_CGROUP_ARRAY: 456 case BPF_MAP_TYPE_STACK_TRACE: 457 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 458 case BPF_MAP_TYPE_HASH_OF_MAPS: 459 case BPF_MAP_TYPE_DEVMAP: 460 case BPF_MAP_TYPE_DEVMAP_HASH: 461 case BPF_MAP_TYPE_CPUMAP: 462 case BPF_MAP_TYPE_XSKMAP: 463 case BPF_MAP_TYPE_SOCKMAP: 464 case BPF_MAP_TYPE_SOCKHASH: 465 case BPF_MAP_TYPE_QUEUE: 466 case BPF_MAP_TYPE_STACK: 467 case BPF_MAP_TYPE_RINGBUF: 468 break; 469 default: 470 attr.btf_key_type_id = map_attr->btf_key_type_id; 471 attr.btf_value_type_id = map_attr->btf_value_type_id; 472 } 473 474 pr_debug("gen: map_create: %s idx %d type %d value_type_id %d\n", 475 attr.map_name, map_idx, map_attr->map_type, attr.btf_value_type_id); 476 477 map_create_attr = add_data(gen, &attr, attr_size); 478 if (attr.btf_value_type_id) 479 /* populate union bpf_attr with btf_fd saved in the stack earlier */ 480 move_stack2blob(gen, attr_field(map_create_attr, btf_fd), 4, 481 stack_off(btf_fd)); 482 switch (attr.map_type) { 483 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 484 case BPF_MAP_TYPE_HASH_OF_MAPS: 485 move_stack2blob(gen, attr_field(map_create_attr, inner_map_fd), 4, 486 stack_off(inner_map_fd)); 487 close_inner_map_fd = true; 488 break; 489 default: 490 break; 491 } 492 /* conditionally update max_entries */ 493 if (map_idx >= 0) 494 move_ctx2blob(gen, attr_field(map_create_attr, max_entries), 4, 495 sizeof(struct bpf_loader_ctx) + 496 sizeof(struct bpf_map_desc) * map_idx + 497 offsetof(struct bpf_map_desc, max_entries), 498 true /* check that max_entries != 0 */); 499 /* emit MAP_CREATE command */ 500 emit_sys_bpf(gen, BPF_MAP_CREATE, map_create_attr, attr_size); 501 debug_ret(gen, "map_create %s idx %d type %d value_size %d value_btf_id %d", 502 attr.map_name, map_idx, map_attr->map_type, attr.value_size, 503 attr.btf_value_type_id); 504 emit_check_err(gen); 505 /* remember map_fd in the stack, if successful */ 506 if (map_idx < 0) { 507 /* This bpf_gen__map_create() function is called with map_idx >= 0 508 * for all maps that libbpf loading logic tracks. 509 * It's called with -1 to create an inner map. 510 */ 511 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, 512 stack_off(inner_map_fd))); 513 } else if (map_idx != gen->nr_maps) { 514 gen->error = -EDOM; /* internal bug */ 515 return; 516 } else { 517 /* add_map_fd does gen->nr_maps++ */ 518 idx = add_map_fd(gen); 519 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 520 0, 0, 0, blob_fd_array_off(gen, idx))); 521 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_7, 0)); 522 } 523 if (close_inner_map_fd) 524 emit_sys_close_stack(gen, stack_off(inner_map_fd)); 525 } 526 527 void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *attach_name, 528 enum bpf_attach_type type) 529 { 530 const char *prefix; 531 int kind, ret; 532 533 btf_get_kernel_prefix_kind(type, &prefix, &kind); 534 gen->attach_kind = kind; 535 ret = snprintf(gen->attach_target, sizeof(gen->attach_target), "%s%s", 536 prefix, attach_name); 537 if (ret == sizeof(gen->attach_target)) 538 gen->error = -ENOSPC; 539 } 540 541 static void emit_find_attach_target(struct bpf_gen *gen) 542 { 543 int name, len = strlen(gen->attach_target) + 1; 544 545 pr_debug("gen: find_attach_tgt %s %d\n", gen->attach_target, gen->attach_kind); 546 name = add_data(gen, gen->attach_target, len); 547 548 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 549 0, 0, 0, name)); 550 emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); 551 emit(gen, BPF_MOV64_IMM(BPF_REG_3, gen->attach_kind)); 552 emit(gen, BPF_MOV64_IMM(BPF_REG_4, 0)); 553 emit(gen, BPF_EMIT_CALL(BPF_FUNC_btf_find_by_name_kind)); 554 emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); 555 debug_ret(gen, "find_by_name_kind(%s,%d)", 556 gen->attach_target, gen->attach_kind); 557 emit_check_err(gen); 558 /* if successful, btf_id is in lower 32-bit of R7 and 559 * btf_obj_fd is in upper 32-bit 560 */ 561 } 562 563 void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, 564 bool is_typeless, int kind, int insn_idx) 565 { 566 struct ksym_relo_desc *relo; 567 568 relo = libbpf_reallocarray(gen->relos, gen->relo_cnt + 1, sizeof(*relo)); 569 if (!relo) { 570 gen->error = -ENOMEM; 571 return; 572 } 573 gen->relos = relo; 574 relo += gen->relo_cnt; 575 relo->name = name; 576 relo->is_weak = is_weak; 577 relo->is_typeless = is_typeless; 578 relo->kind = kind; 579 relo->insn_idx = insn_idx; 580 gen->relo_cnt++; 581 } 582 583 /* returns existing ksym_desc with ref incremented, or inserts a new one */ 584 static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_desc *relo) 585 { 586 struct ksym_desc *kdesc; 587 588 for (int i = 0; i < gen->nr_ksyms; i++) { 589 if (!strcmp(gen->ksyms[i].name, relo->name)) { 590 gen->ksyms[i].ref++; 591 return &gen->ksyms[i]; 592 } 593 } 594 kdesc = libbpf_reallocarray(gen->ksyms, gen->nr_ksyms + 1, sizeof(*kdesc)); 595 if (!kdesc) { 596 gen->error = -ENOMEM; 597 return NULL; 598 } 599 gen->ksyms = kdesc; 600 kdesc = &gen->ksyms[gen->nr_ksyms++]; 601 kdesc->name = relo->name; 602 kdesc->kind = relo->kind; 603 kdesc->ref = 1; 604 kdesc->off = 0; 605 kdesc->insn = 0; 606 return kdesc; 607 } 608 609 /* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7} 610 * Returns result in BPF_REG_7 611 */ 612 static void emit_bpf_find_by_name_kind(struct bpf_gen *gen, struct ksym_relo_desc *relo) 613 { 614 int name_off, len = strlen(relo->name) + 1; 615 616 name_off = add_data(gen, relo->name, len); 617 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 618 0, 0, 0, name_off)); 619 emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); 620 emit(gen, BPF_MOV64_IMM(BPF_REG_3, relo->kind)); 621 emit(gen, BPF_MOV64_IMM(BPF_REG_4, 0)); 622 emit(gen, BPF_EMIT_CALL(BPF_FUNC_btf_find_by_name_kind)); 623 emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); 624 debug_ret(gen, "find_by_name_kind(%s,%d)", relo->name, relo->kind); 625 } 626 627 /* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7} 628 * Returns result in BPF_REG_7 629 * Returns u64 symbol addr in BPF_REG_9 630 */ 631 static void emit_bpf_kallsyms_lookup_name(struct bpf_gen *gen, struct ksym_relo_desc *relo) 632 { 633 int name_off, len = strlen(relo->name) + 1, res_off; 634 635 name_off = add_data(gen, relo->name, len); 636 res_off = add_data(gen, NULL, 8); /* res is u64 */ 637 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 638 0, 0, 0, name_off)); 639 emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); 640 emit(gen, BPF_MOV64_IMM(BPF_REG_3, 0)); 641 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_4, BPF_PSEUDO_MAP_IDX_VALUE, 642 0, 0, 0, res_off)); 643 emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_4)); 644 emit(gen, BPF_EMIT_CALL(BPF_FUNC_kallsyms_lookup_name)); 645 emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0)); 646 emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); 647 debug_ret(gen, "kallsyms_lookup_name(%s,%d)", relo->name, relo->kind); 648 } 649 650 /* Expects: 651 * BPF_REG_8 - pointer to instruction 652 * 653 * We need to reuse BTF fd for same symbol otherwise each relocation takes a new 654 * index, while kernel limits total kfunc BTFs to 256. For duplicate symbols, 655 * this would mean a new BTF fd index for each entry. By pairing symbol name 656 * with index, we get the insn->imm, insn->off pairing that kernel uses for 657 * kfunc_tab, which becomes the effective limit even though all of them may 658 * share same index in fd_array (such that kfunc_btf_tab has 1 element). 659 */ 660 static void emit_relo_kfunc_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn) 661 { 662 struct ksym_desc *kdesc; 663 int btf_fd_idx; 664 665 kdesc = get_ksym_desc(gen, relo); 666 if (!kdesc) 667 return; 668 /* try to copy from existing bpf_insn */ 669 if (kdesc->ref > 1) { 670 move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, 671 kdesc->insn + offsetof(struct bpf_insn, imm)); 672 move_blob2blob(gen, insn + offsetof(struct bpf_insn, off), 2, 673 kdesc->insn + offsetof(struct bpf_insn, off)); 674 goto log; 675 } 676 /* remember insn offset, so we can copy BTF ID and FD later */ 677 kdesc->insn = insn; 678 emit_bpf_find_by_name_kind(gen, relo); 679 if (!relo->is_weak) 680 emit_check_err(gen); 681 /* get index in fd_array to store BTF FD at */ 682 btf_fd_idx = add_kfunc_btf_fd(gen); 683 if (btf_fd_idx > INT16_MAX) { 684 pr_warn("BTF fd off %d for kfunc %s exceeds INT16_MAX, cannot process relocation\n", 685 btf_fd_idx, relo->name); 686 gen->error = -E2BIG; 687 return; 688 } 689 kdesc->off = btf_fd_idx; 690 /* set a default value for imm */ 691 emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0)); 692 /* skip success case store if ret < 0 */ 693 emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 1)); 694 /* store btf_id into insn[insn_idx].imm */ 695 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm))); 696 /* load fd_array slot pointer */ 697 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, 698 0, 0, 0, blob_fd_array_off(gen, btf_fd_idx))); 699 /* skip store of BTF fd if ret < 0 */ 700 emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 3)); 701 /* store BTF fd in slot */ 702 emit(gen, BPF_MOV64_REG(BPF_REG_9, BPF_REG_7)); 703 emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32)); 704 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_9, 0)); 705 /* set a default value for off */ 706 emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), 0)); 707 /* skip insn->off store if ret < 0 */ 708 emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 2)); 709 /* skip if vmlinux BTF */ 710 emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_9, 0, 1)); 711 /* store index into insn[insn_idx].off */ 712 emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), btf_fd_idx)); 713 log: 714 if (!gen->log_level) 715 return; 716 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8, 717 offsetof(struct bpf_insn, imm))); 718 emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, 719 offsetof(struct bpf_insn, off))); 720 debug_regs(gen, BPF_REG_7, BPF_REG_9, " func (%s:count=%d): imm: %%d, off: %%d", 721 relo->name, kdesc->ref); 722 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, 723 0, 0, 0, blob_fd_array_off(gen, kdesc->off))); 724 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_0, 0)); 725 debug_regs(gen, BPF_REG_9, -1, " func (%s:count=%d): btf_fd", 726 relo->name, kdesc->ref); 727 } 728 729 static void emit_ksym_relo_log(struct bpf_gen *gen, struct ksym_relo_desc *relo, 730 int ref) 731 { 732 if (!gen->log_level) 733 return; 734 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8, 735 offsetof(struct bpf_insn, imm))); 736 emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, sizeof(struct bpf_insn) + 737 offsetof(struct bpf_insn, imm))); 738 debug_regs(gen, BPF_REG_7, BPF_REG_9, " var t=%d w=%d (%s:count=%d): imm[0]: %%d, imm[1]: %%d", 739 relo->is_typeless, relo->is_weak, relo->name, ref); 740 emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code))); 741 debug_regs(gen, BPF_REG_9, -1, " var t=%d w=%d (%s:count=%d): insn.reg", 742 relo->is_typeless, relo->is_weak, relo->name, ref); 743 } 744 745 /* Expects: 746 * BPF_REG_8 - pointer to instruction 747 */ 748 static void emit_relo_ksym_typeless(struct bpf_gen *gen, 749 struct ksym_relo_desc *relo, int insn) 750 { 751 struct ksym_desc *kdesc; 752 753 kdesc = get_ksym_desc(gen, relo); 754 if (!kdesc) 755 return; 756 /* try to copy from existing ldimm64 insn */ 757 if (kdesc->ref > 1) { 758 move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, 759 kdesc->insn + offsetof(struct bpf_insn, imm)); 760 move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4, 761 kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)); 762 goto log; 763 } 764 /* remember insn offset, so we can copy ksym addr later */ 765 kdesc->insn = insn; 766 /* skip typeless ksym_desc in fd closing loop in cleanup_relos */ 767 kdesc->typeless = true; 768 emit_bpf_kallsyms_lookup_name(gen, relo); 769 emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_7, -ENOENT, 1)); 770 emit_check_err(gen); 771 /* store lower half of addr into insn[insn_idx].imm */ 772 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9, offsetof(struct bpf_insn, imm))); 773 /* store upper half of addr into insn[insn_idx + 1].imm */ 774 emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32)); 775 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9, 776 sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm))); 777 log: 778 emit_ksym_relo_log(gen, relo, kdesc->ref); 779 } 780 781 static __u32 src_reg_mask(void) 782 { 783 #if defined(__LITTLE_ENDIAN_BITFIELD) 784 return 0x0f; /* src_reg,dst_reg,... */ 785 #elif defined(__BIG_ENDIAN_BITFIELD) 786 return 0xf0; /* dst_reg,src_reg,... */ 787 #else 788 #error "Unsupported bit endianness, cannot proceed" 789 #endif 790 } 791 792 /* Expects: 793 * BPF_REG_8 - pointer to instruction 794 */ 795 static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn) 796 { 797 struct ksym_desc *kdesc; 798 __u32 reg_mask; 799 800 kdesc = get_ksym_desc(gen, relo); 801 if (!kdesc) 802 return; 803 /* try to copy from existing ldimm64 insn */ 804 if (kdesc->ref > 1) { 805 move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, 806 kdesc->insn + offsetof(struct bpf_insn, imm)); 807 move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4, 808 kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)); 809 emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_8, offsetof(struct bpf_insn, imm))); 810 /* jump over src_reg adjustment if imm is not 0 */ 811 emit(gen, BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0, 3)); 812 goto clear_src_reg; 813 } 814 /* remember insn offset, so we can copy BTF ID and FD later */ 815 kdesc->insn = insn; 816 emit_bpf_find_by_name_kind(gen, relo); 817 if (!relo->is_weak) 818 emit_check_err(gen); 819 /* set default values as 0 */ 820 emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0)); 821 emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 0)); 822 /* skip success case stores if ret < 0 */ 823 emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 4)); 824 /* store btf_id into insn[insn_idx].imm */ 825 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm))); 826 /* store btf_obj_fd into insn[insn_idx + 1].imm */ 827 emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32)); 828 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, 829 sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm))); 830 emit(gen, BPF_JMP_IMM(BPF_JSGE, BPF_REG_7, 0, 3)); 831 clear_src_reg: 832 /* clear bpf_object__relocate_data's src_reg assignment, otherwise we get a verifier failure */ 833 reg_mask = src_reg_mask(); 834 emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code))); 835 emit(gen, BPF_ALU32_IMM(BPF_AND, BPF_REG_9, reg_mask)); 836 emit(gen, BPF_STX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, offsetofend(struct bpf_insn, code))); 837 838 emit_ksym_relo_log(gen, relo, kdesc->ref); 839 } 840 841 static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns) 842 { 843 int insn; 844 845 pr_debug("gen: emit_relo (%d): %s at %d\n", relo->kind, relo->name, relo->insn_idx); 846 insn = insns + sizeof(struct bpf_insn) * relo->insn_idx; 847 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn)); 848 switch (relo->kind) { 849 case BTF_KIND_VAR: 850 if (relo->is_typeless) 851 emit_relo_ksym_typeless(gen, relo, insn); 852 else 853 emit_relo_ksym_btf(gen, relo, insn); 854 break; 855 case BTF_KIND_FUNC: 856 emit_relo_kfunc_btf(gen, relo, insn); 857 break; 858 default: 859 pr_warn("Unknown relocation kind '%d'\n", relo->kind); 860 gen->error = -EDOM; 861 return; 862 } 863 } 864 865 static void emit_relos(struct bpf_gen *gen, int insns) 866 { 867 int i; 868 869 for (i = 0; i < gen->relo_cnt; i++) 870 emit_relo(gen, gen->relos + i, insns); 871 } 872 873 static void cleanup_relos(struct bpf_gen *gen, int insns) 874 { 875 int i, insn; 876 877 for (i = 0; i < gen->nr_ksyms; i++) { 878 /* only close fds for typed ksyms and kfuncs */ 879 if (gen->ksyms[i].kind == BTF_KIND_VAR && !gen->ksyms[i].typeless) { 880 /* close fd recorded in insn[insn_idx + 1].imm */ 881 insn = gen->ksyms[i].insn; 882 insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm); 883 emit_sys_close_blob(gen, insn); 884 } else if (gen->ksyms[i].kind == BTF_KIND_FUNC) { 885 emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off)); 886 if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ) 887 gen->nr_fd_array--; 888 } 889 } 890 if (gen->nr_ksyms) { 891 free(gen->ksyms); 892 gen->nr_ksyms = 0; 893 gen->ksyms = NULL; 894 } 895 if (gen->relo_cnt) { 896 free(gen->relos); 897 gen->relo_cnt = 0; 898 gen->relos = NULL; 899 } 900 } 901 902 void bpf_gen__prog_load(struct bpf_gen *gen, 903 struct bpf_prog_load_params *load_attr, int prog_idx) 904 { 905 int attr_size = offsetofend(union bpf_attr, fd_array); 906 int prog_load_attr, license, insns, func_info, line_info; 907 union bpf_attr attr; 908 909 memset(&attr, 0, attr_size); 910 pr_debug("gen: prog_load: type %d insns_cnt %zd\n", 911 load_attr->prog_type, load_attr->insn_cnt); 912 /* add license string to blob of bytes */ 913 license = add_data(gen, load_attr->license, strlen(load_attr->license) + 1); 914 /* add insns to blob of bytes */ 915 insns = add_data(gen, load_attr->insns, 916 load_attr->insn_cnt * sizeof(struct bpf_insn)); 917 918 attr.prog_type = load_attr->prog_type; 919 attr.expected_attach_type = load_attr->expected_attach_type; 920 attr.attach_btf_id = load_attr->attach_btf_id; 921 attr.prog_ifindex = load_attr->prog_ifindex; 922 attr.kern_version = 0; 923 attr.insn_cnt = (__u32)load_attr->insn_cnt; 924 attr.prog_flags = load_attr->prog_flags; 925 926 attr.func_info_rec_size = load_attr->func_info_rec_size; 927 attr.func_info_cnt = load_attr->func_info_cnt; 928 func_info = add_data(gen, load_attr->func_info, 929 attr.func_info_cnt * attr.func_info_rec_size); 930 931 attr.line_info_rec_size = load_attr->line_info_rec_size; 932 attr.line_info_cnt = load_attr->line_info_cnt; 933 line_info = add_data(gen, load_attr->line_info, 934 attr.line_info_cnt * attr.line_info_rec_size); 935 936 memcpy(attr.prog_name, load_attr->name, 937 min((unsigned)strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1)); 938 prog_load_attr = add_data(gen, &attr, attr_size); 939 940 /* populate union bpf_attr with a pointer to license */ 941 emit_rel_store(gen, attr_field(prog_load_attr, license), license); 942 943 /* populate union bpf_attr with a pointer to instructions */ 944 emit_rel_store(gen, attr_field(prog_load_attr, insns), insns); 945 946 /* populate union bpf_attr with a pointer to func_info */ 947 emit_rel_store(gen, attr_field(prog_load_attr, func_info), func_info); 948 949 /* populate union bpf_attr with a pointer to line_info */ 950 emit_rel_store(gen, attr_field(prog_load_attr, line_info), line_info); 951 952 /* populate union bpf_attr fd_array with a pointer to data where map_fds are saved */ 953 emit_rel_store(gen, attr_field(prog_load_attr, fd_array), gen->fd_array); 954 955 /* populate union bpf_attr with user provided log details */ 956 move_ctx2blob(gen, attr_field(prog_load_attr, log_level), 4, 957 offsetof(struct bpf_loader_ctx, log_level), false); 958 move_ctx2blob(gen, attr_field(prog_load_attr, log_size), 4, 959 offsetof(struct bpf_loader_ctx, log_size), false); 960 move_ctx2blob(gen, attr_field(prog_load_attr, log_buf), 8, 961 offsetof(struct bpf_loader_ctx, log_buf), false); 962 /* populate union bpf_attr with btf_fd saved in the stack earlier */ 963 move_stack2blob(gen, attr_field(prog_load_attr, prog_btf_fd), 4, 964 stack_off(btf_fd)); 965 if (gen->attach_kind) { 966 emit_find_attach_target(gen); 967 /* populate union bpf_attr with btf_id and btf_obj_fd found by helper */ 968 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, 969 0, 0, 0, prog_load_attr)); 970 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, 971 offsetof(union bpf_attr, attach_btf_id))); 972 emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32)); 973 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, 974 offsetof(union bpf_attr, attach_btf_obj_fd))); 975 } 976 emit_relos(gen, insns); 977 /* emit PROG_LOAD command */ 978 emit_sys_bpf(gen, BPF_PROG_LOAD, prog_load_attr, attr_size); 979 debug_ret(gen, "prog_load %s insn_cnt %d", attr.prog_name, attr.insn_cnt); 980 /* successful or not, close btf module FDs used in extern ksyms and attach_btf_obj_fd */ 981 cleanup_relos(gen, insns); 982 if (gen->attach_kind) 983 emit_sys_close_blob(gen, 984 attr_field(prog_load_attr, attach_btf_obj_fd)); 985 emit_check_err(gen); 986 /* remember prog_fd in the stack, if successful */ 987 emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, 988 stack_off(prog_fd[gen->nr_progs]))); 989 gen->nr_progs++; 990 } 991 992 void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue, 993 __u32 value_size) 994 { 995 int attr_size = offsetofend(union bpf_attr, flags); 996 int map_update_attr, value, key; 997 union bpf_attr attr; 998 int zero = 0; 999 1000 memset(&attr, 0, attr_size); 1001 pr_debug("gen: map_update_elem: idx %d\n", map_idx); 1002 1003 value = add_data(gen, pvalue, value_size); 1004 key = add_data(gen, &zero, sizeof(zero)); 1005 1006 /* if (map_desc[map_idx].initial_value) 1007 * copy_from_user(value, initial_value, value_size); 1008 */ 1009 emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_6, 1010 sizeof(struct bpf_loader_ctx) + 1011 sizeof(struct bpf_map_desc) * map_idx + 1012 offsetof(struct bpf_map_desc, initial_value))); 1013 emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 4)); 1014 emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 1015 0, 0, 0, value)); 1016 emit(gen, BPF_MOV64_IMM(BPF_REG_2, value_size)); 1017 emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user)); 1018 1019 map_update_attr = add_data(gen, &attr, attr_size); 1020 move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4, 1021 blob_fd_array_off(gen, map_idx)); 1022 emit_rel_store(gen, attr_field(map_update_attr, key), key); 1023 emit_rel_store(gen, attr_field(map_update_attr, value), value); 1024 /* emit MAP_UPDATE_ELEM command */ 1025 emit_sys_bpf(gen, BPF_MAP_UPDATE_ELEM, map_update_attr, attr_size); 1026 debug_ret(gen, "update_elem idx %d value_size %d", map_idx, value_size); 1027 emit_check_err(gen); 1028 } 1029 1030 void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx) 1031 { 1032 int attr_size = offsetofend(union bpf_attr, map_fd); 1033 int map_freeze_attr; 1034 union bpf_attr attr; 1035 1036 memset(&attr, 0, attr_size); 1037 pr_debug("gen: map_freeze: idx %d\n", map_idx); 1038 map_freeze_attr = add_data(gen, &attr, attr_size); 1039 move_blob2blob(gen, attr_field(map_freeze_attr, map_fd), 4, 1040 blob_fd_array_off(gen, map_idx)); 1041 /* emit MAP_FREEZE command */ 1042 emit_sys_bpf(gen, BPF_MAP_FREEZE, map_freeze_attr, attr_size); 1043 debug_ret(gen, "map_freeze"); 1044 emit_check_err(gen); 1045 } 1046