| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Common code for probe-based Dynamic events. |
| 4 | * |
| 5 | * This code was copied from kernel/trace/trace_kprobe.c written by |
| 6 | * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> |
| 7 | * |
| 8 | * Updates to make this generic: |
| 9 | * Copyright (C) IBM Corporation, 2010-2011 |
| 10 | * Author: Srikar Dronamraju |
| 11 | */ |
| 12 | #define pr_fmt(fmt) "trace_probe: " fmt |
| 13 | |
| 14 | #include <linux/bpf.h> |
| 15 | #include <linux/fs.h> |
| 16 | #include "trace_btf.h" |
| 17 | |
| 18 | #include "trace_probe.h" |
| 19 | |
| 20 | #undef C |
| 21 | #define C(a, b) b |
| 22 | |
| 23 | static const char *trace_probe_err_text[] = { ERRORS }; |
| 24 | |
| 25 | static const char *reserved_field_names[] = { |
| 26 | "common_type", |
| 27 | "common_flags", |
| 28 | "common_preempt_count", |
| 29 | "common_pid", |
| 30 | "common_tgid", |
| 31 | FIELD_STRING_IP, |
| 32 | FIELD_STRING_RETIP, |
| 33 | FIELD_STRING_FUNC, |
| 34 | }; |
| 35 | |
| 36 | /* Printing in basic type function template */ |
| 37 | #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ |
| 38 | int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ |
| 39 | { \ |
| 40 | trace_seq_printf(s, fmt, *(type *)data); \ |
| 41 | return !trace_seq_has_overflowed(s); \ |
| 42 | } \ |
| 43 | const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; |
| 44 | |
| 45 | DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") |
| 46 | DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") |
| 47 | DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") |
| 48 | DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") |
| 49 | DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") |
| 50 | DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") |
| 51 | DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") |
| 52 | DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") |
| 53 | DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") |
| 54 | DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") |
| 55 | DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") |
| 56 | DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") |
| 57 | DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") |
| 58 | |
| 59 | int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) |
| 60 | { |
| 61 | trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); |
| 62 | return !trace_seq_has_overflowed(s); |
| 63 | } |
| 64 | const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; |
| 65 | |
| 66 | /* Print type function for string type */ |
| 67 | int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) |
| 68 | { |
| 69 | int len = *(u32 *)data >> 16; |
| 70 | |
| 71 | if (!len) |
| 72 | trace_seq_puts(s, FAULT_STRING); |
| 73 | else |
| 74 | trace_seq_printf(s, "\"%s\"", |
| 75 | (const char *)get_loc_data(data, ent)); |
| 76 | return !trace_seq_has_overflowed(s); |
| 77 | } |
| 78 | |
| 79 | const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; |
| 80 | |
| 81 | /* Fetch type information table */ |
| 82 | static const struct fetch_type probe_fetch_types[] = { |
| 83 | /* Special types */ |
| 84 | __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1, |
| 85 | "__data_loc char[]"), |
| 86 | __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1, |
| 87 | "__data_loc char[]"), |
| 88 | __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1, |
| 89 | "__data_loc char[]"), |
| 90 | /* Basic types */ |
| 91 | ASSIGN_FETCH_TYPE(u8, u8, 0), |
| 92 | ASSIGN_FETCH_TYPE(u16, u16, 0), |
| 93 | ASSIGN_FETCH_TYPE(u32, u32, 0), |
| 94 | ASSIGN_FETCH_TYPE(u64, u64, 0), |
| 95 | ASSIGN_FETCH_TYPE(s8, u8, 1), |
| 96 | ASSIGN_FETCH_TYPE(s16, u16, 1), |
| 97 | ASSIGN_FETCH_TYPE(s32, u32, 1), |
| 98 | ASSIGN_FETCH_TYPE(s64, u64, 1), |
| 99 | ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), |
| 100 | ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), |
| 101 | ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), |
| 102 | ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), |
| 103 | ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), |
| 104 | ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), |
| 105 | |
| 106 | ASSIGN_FETCH_TYPE_END |
| 107 | }; |
| 108 | |
| 109 | static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags) |
| 110 | { |
| 111 | int i; |
| 112 | |
| 113 | /* Reject the symbol/symstr for uprobes */ |
| 114 | if (type && (flags & TPARG_FL_USER) && |
| 115 | (!strcmp(type, "symbol") || !strcmp(type, "symstr"))) |
| 116 | return NULL; |
| 117 | |
| 118 | if (!type) |
| 119 | type = DEFAULT_FETCH_TYPE_STR; |
| 120 | |
| 121 | /* Special case: bitfield */ |
| 122 | if (*type == 'b') { |
| 123 | unsigned long bs; |
| 124 | |
| 125 | type = strchr(type, '/'); |
| 126 | if (!type) |
| 127 | goto fail; |
| 128 | |
| 129 | type++; |
| 130 | if (kstrtoul(type, 0, &bs)) |
| 131 | goto fail; |
| 132 | |
| 133 | switch (bs) { |
| 134 | case 8: |
| 135 | return find_fetch_type("u8", flags); |
| 136 | case 16: |
| 137 | return find_fetch_type("u16", flags); |
| 138 | case 32: |
| 139 | return find_fetch_type("u32", flags); |
| 140 | case 64: |
| 141 | return find_fetch_type("u64", flags); |
| 142 | default: |
| 143 | goto fail; |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | for (i = 0; probe_fetch_types[i].name; i++) { |
| 148 | if (strcmp(type, probe_fetch_types[i].name) == 0) |
| 149 | return &probe_fetch_types[i]; |
| 150 | } |
| 151 | |
| 152 | fail: |
| 153 | return NULL; |
| 154 | } |
| 155 | |
| 156 | static struct trace_probe_log trace_probe_log; |
| 157 | |
| 158 | void trace_probe_log_init(const char *subsystem, int argc, const char **argv) |
| 159 | { |
| 160 | trace_probe_log.subsystem = subsystem; |
| 161 | trace_probe_log.argc = argc; |
| 162 | trace_probe_log.argv = argv; |
| 163 | trace_probe_log.index = 0; |
| 164 | } |
| 165 | |
| 166 | void trace_probe_log_clear(void) |
| 167 | { |
| 168 | memset(&trace_probe_log, 0, sizeof(trace_probe_log)); |
| 169 | } |
| 170 | |
| 171 | void trace_probe_log_set_index(int index) |
| 172 | { |
| 173 | trace_probe_log.index = index; |
| 174 | } |
| 175 | |
| 176 | void __trace_probe_log_err(int offset, int err_type) |
| 177 | { |
| 178 | char *command, *p; |
| 179 | int i, len = 0, pos = 0; |
| 180 | |
| 181 | if (!trace_probe_log.argv) |
| 182 | return; |
| 183 | |
| 184 | /* Recalculate the length and allocate buffer */ |
| 185 | for (i = 0; i < trace_probe_log.argc; i++) { |
| 186 | if (i == trace_probe_log.index) |
| 187 | pos = len; |
| 188 | len += strlen(trace_probe_log.argv[i]) + 1; |
| 189 | } |
| 190 | command = kzalloc(len, GFP_KERNEL); |
| 191 | if (!command) |
| 192 | return; |
| 193 | |
| 194 | if (trace_probe_log.index >= trace_probe_log.argc) { |
| 195 | /** |
| 196 | * Set the error position is next to the last arg + space. |
| 197 | * Note that len includes the terminal null and the cursor |
| 198 | * appears at pos + 1. |
| 199 | */ |
| 200 | pos = len; |
| 201 | offset = 0; |
| 202 | } |
| 203 | |
| 204 | /* And make a command string from argv array */ |
| 205 | p = command; |
| 206 | for (i = 0; i < trace_probe_log.argc; i++) { |
| 207 | len = strlen(trace_probe_log.argv[i]); |
| 208 | strcpy(p, trace_probe_log.argv[i]); |
| 209 | p[len] = ' '; |
| 210 | p += len + 1; |
| 211 | } |
| 212 | *(p - 1) = '\0'; |
| 213 | |
| 214 | tracing_log_err(NULL, trace_probe_log.subsystem, command, |
| 215 | trace_probe_err_text, err_type, pos + offset); |
| 216 | |
| 217 | kfree(command); |
| 218 | } |
| 219 | |
| 220 | /* Split symbol and offset. */ |
| 221 | int traceprobe_split_symbol_offset(char *symbol, long *offset) |
| 222 | { |
| 223 | char *tmp; |
| 224 | int ret; |
| 225 | |
| 226 | if (!offset) |
| 227 | return -EINVAL; |
| 228 | |
| 229 | tmp = strpbrk(symbol, "+-"); |
| 230 | if (tmp) { |
| 231 | ret = kstrtol(tmp, 0, offset); |
| 232 | if (ret) |
| 233 | return ret; |
| 234 | *tmp = '\0'; |
| 235 | } else |
| 236 | *offset = 0; |
| 237 | |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | /* @buf must has MAX_EVENT_NAME_LEN size */ |
| 242 | int traceprobe_parse_event_name(const char **pevent, const char **pgroup, |
| 243 | char *buf, int offset) |
| 244 | { |
| 245 | const char *slash, *event = *pevent; |
| 246 | int len; |
| 247 | |
| 248 | slash = strchr(event, '/'); |
| 249 | if (!slash) |
| 250 | slash = strchr(event, '.'); |
| 251 | |
| 252 | if (slash) { |
| 253 | if (slash == event) { |
| 254 | trace_probe_log_err(offset, NO_GROUP_NAME); |
| 255 | return -EINVAL; |
| 256 | } |
| 257 | if (slash - event + 1 > MAX_EVENT_NAME_LEN) { |
| 258 | trace_probe_log_err(offset, GROUP_TOO_LONG); |
| 259 | return -EINVAL; |
| 260 | } |
| 261 | strscpy(buf, event, slash - event + 1); |
| 262 | if (!is_good_system_name(buf)) { |
| 263 | trace_probe_log_err(offset, BAD_GROUP_NAME); |
| 264 | return -EINVAL; |
| 265 | } |
| 266 | *pgroup = buf; |
| 267 | *pevent = slash + 1; |
| 268 | offset += slash - event + 1; |
| 269 | event = *pevent; |
| 270 | } |
| 271 | len = strlen(event); |
| 272 | if (len == 0) { |
| 273 | if (slash) { |
| 274 | *pevent = NULL; |
| 275 | return 0; |
| 276 | } |
| 277 | trace_probe_log_err(offset, NO_EVENT_NAME); |
| 278 | return -EINVAL; |
| 279 | } else if (len > MAX_EVENT_NAME_LEN) { |
| 280 | trace_probe_log_err(offset, EVENT_TOO_LONG); |
| 281 | return -EINVAL; |
| 282 | } |
| 283 | if (!is_good_name(event)) { |
| 284 | trace_probe_log_err(offset, BAD_EVENT_NAME); |
| 285 | return -EINVAL; |
| 286 | } |
| 287 | return 0; |
| 288 | } |
| 289 | |
| 290 | static int parse_trace_event_arg(char *arg, struct fetch_insn *code, |
| 291 | struct traceprobe_parse_context *ctx) |
| 292 | { |
| 293 | struct ftrace_event_field *field; |
| 294 | struct list_head *head; |
| 295 | |
| 296 | head = trace_get_fields(ctx->event); |
| 297 | list_for_each_entry(field, head, link) { |
| 298 | if (!strcmp(arg, field->name)) { |
| 299 | code->op = FETCH_OP_TP_ARG; |
| 300 | code->data = field; |
| 301 | return 0; |
| 302 | } |
| 303 | } |
| 304 | return -ENOENT; |
| 305 | } |
| 306 | |
| 307 | #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS |
| 308 | |
| 309 | static u32 btf_type_int(const struct btf_type *t) |
| 310 | { |
| 311 | return *(u32 *)(t + 1); |
| 312 | } |
| 313 | |
| 314 | static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) |
| 315 | { |
| 316 | const struct btf_type *real_type; |
| 317 | u32 intdata; |
| 318 | s32 tid; |
| 319 | |
| 320 | real_type = btf_type_skip_modifiers(btf, type->type, &tid); |
| 321 | if (!real_type) |
| 322 | return false; |
| 323 | |
| 324 | if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) |
| 325 | return false; |
| 326 | |
| 327 | intdata = btf_type_int(real_type); |
| 328 | return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) |
| 329 | && BTF_INT_BITS(intdata) == 8; |
| 330 | } |
| 331 | |
| 332 | static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) |
| 333 | { |
| 334 | const struct btf_type *real_type; |
| 335 | const struct btf_array *array; |
| 336 | u32 intdata; |
| 337 | s32 tid; |
| 338 | |
| 339 | if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) |
| 340 | return false; |
| 341 | |
| 342 | array = (const struct btf_array *)(type + 1); |
| 343 | |
| 344 | real_type = btf_type_skip_modifiers(btf, array->type, &tid); |
| 345 | |
| 346 | intdata = btf_type_int(real_type); |
| 347 | return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) |
| 348 | && BTF_INT_BITS(intdata) == 8; |
| 349 | } |
| 350 | |
| 351 | static int check_prepare_btf_string_fetch(char *typename, |
| 352 | struct fetch_insn **pcode, |
| 353 | struct traceprobe_parse_context *ctx) |
| 354 | { |
| 355 | struct btf *btf = ctx->btf; |
| 356 | |
| 357 | if (!btf || !ctx->last_type) |
| 358 | return 0; |
| 359 | |
| 360 | /* char [] does not need any change. */ |
| 361 | if (btf_type_is_char_array(btf, ctx->last_type)) |
| 362 | return 0; |
| 363 | |
| 364 | /* char * requires dereference the pointer. */ |
| 365 | if (btf_type_is_char_ptr(btf, ctx->last_type)) { |
| 366 | struct fetch_insn *code = *pcode + 1; |
| 367 | |
| 368 | if (code->op == FETCH_OP_END) { |
| 369 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 370 | return -E2BIG; |
| 371 | } |
| 372 | if (typename[0] == 'u') |
| 373 | code->op = FETCH_OP_UDEREF; |
| 374 | else |
| 375 | code->op = FETCH_OP_DEREF; |
| 376 | code->offset = 0; |
| 377 | *pcode = code; |
| 378 | return 0; |
| 379 | } |
| 380 | /* Other types are not available for string */ |
| 381 | trace_probe_log_err(ctx->offset, BAD_TYPE4STR); |
| 382 | return -EINVAL; |
| 383 | } |
| 384 | |
| 385 | static const char *fetch_type_from_btf_type(struct btf *btf, |
| 386 | const struct btf_type *type, |
| 387 | struct traceprobe_parse_context *ctx) |
| 388 | { |
| 389 | u32 intdata; |
| 390 | |
| 391 | /* TODO: const char * could be converted as a string */ |
| 392 | switch (BTF_INFO_KIND(type->info)) { |
| 393 | case BTF_KIND_ENUM: |
| 394 | /* enum is "int", so convert to "s32" */ |
| 395 | return "s32"; |
| 396 | case BTF_KIND_ENUM64: |
| 397 | return "s64"; |
| 398 | case BTF_KIND_PTR: |
| 399 | /* pointer will be converted to "x??" */ |
| 400 | if (IS_ENABLED(CONFIG_64BIT)) |
| 401 | return "x64"; |
| 402 | else |
| 403 | return "x32"; |
| 404 | case BTF_KIND_INT: |
| 405 | intdata = btf_type_int(type); |
| 406 | if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { |
| 407 | switch (BTF_INT_BITS(intdata)) { |
| 408 | case 8: |
| 409 | return "s8"; |
| 410 | case 16: |
| 411 | return "s16"; |
| 412 | case 32: |
| 413 | return "s32"; |
| 414 | case 64: |
| 415 | return "s64"; |
| 416 | } |
| 417 | } else { /* unsigned */ |
| 418 | switch (BTF_INT_BITS(intdata)) { |
| 419 | case 8: |
| 420 | return "u8"; |
| 421 | case 16: |
| 422 | return "u16"; |
| 423 | case 32: |
| 424 | return "u32"; |
| 425 | case 64: |
| 426 | return "u64"; |
| 427 | } |
| 428 | /* bitfield, size is encoded in the type */ |
| 429 | ctx->last_bitsize = BTF_INT_BITS(intdata); |
| 430 | ctx->last_bitoffs += BTF_INT_OFFSET(intdata); |
| 431 | return "u64"; |
| 432 | } |
| 433 | } |
| 434 | /* TODO: support other types */ |
| 435 | |
| 436 | return NULL; |
| 437 | } |
| 438 | |
| 439 | static int query_btf_context(struct traceprobe_parse_context *ctx) |
| 440 | { |
| 441 | const struct btf_param *param; |
| 442 | const struct btf_type *type; |
| 443 | struct btf *btf; |
| 444 | s32 nr; |
| 445 | |
| 446 | if (ctx->btf) |
| 447 | return 0; |
| 448 | |
| 449 | if (!ctx->funcname) |
| 450 | return -EINVAL; |
| 451 | |
| 452 | type = btf_find_func_proto(ctx->funcname, &btf); |
| 453 | if (!type) |
| 454 | return -ENOENT; |
| 455 | |
| 456 | ctx->btf = btf; |
| 457 | ctx->proto = type; |
| 458 | |
| 459 | /* ctx->params is optional, since func(void) will not have params. */ |
| 460 | nr = 0; |
| 461 | param = btf_get_func_param(type, &nr); |
| 462 | if (!IS_ERR_OR_NULL(param)) { |
| 463 | /* Hide the first 'data' argument of tracepoint */ |
| 464 | if (ctx->flags & TPARG_FL_TPOINT) { |
| 465 | nr--; |
| 466 | param++; |
| 467 | } |
| 468 | } |
| 469 | |
| 470 | if (nr > 0) { |
| 471 | ctx->nr_params = nr; |
| 472 | ctx->params = param; |
| 473 | } else { |
| 474 | ctx->nr_params = 0; |
| 475 | ctx->params = NULL; |
| 476 | } |
| 477 | |
| 478 | return 0; |
| 479 | } |
| 480 | |
| 481 | static void clear_btf_context(struct traceprobe_parse_context *ctx) |
| 482 | { |
| 483 | if (ctx->btf) { |
| 484 | btf_put(ctx->btf); |
| 485 | ctx->btf = NULL; |
| 486 | ctx->proto = NULL; |
| 487 | ctx->params = NULL; |
| 488 | ctx->nr_params = 0; |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | /* Return 1 if the field separater is arrow operator ('->') */ |
| 493 | static int split_next_field(char *varname, char **next_field, |
| 494 | struct traceprobe_parse_context *ctx) |
| 495 | { |
| 496 | char *field; |
| 497 | int ret = 0; |
| 498 | |
| 499 | field = strpbrk(varname, ".-"); |
| 500 | if (field) { |
| 501 | if (field[0] == '-' && field[1] == '>') { |
| 502 | field[0] = '\0'; |
| 503 | field += 2; |
| 504 | ret = 1; |
| 505 | } else if (field[0] == '.') { |
| 506 | field[0] = '\0'; |
| 507 | field += 1; |
| 508 | } else { |
| 509 | trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); |
| 510 | return -EINVAL; |
| 511 | } |
| 512 | *next_field = field; |
| 513 | } |
| 514 | |
| 515 | return ret; |
| 516 | } |
| 517 | |
| 518 | /* |
| 519 | * Parse the field of data structure. The @type must be a pointer type |
| 520 | * pointing the target data structure type. |
| 521 | */ |
| 522 | static int parse_btf_field(char *fieldname, const struct btf_type *type, |
| 523 | struct fetch_insn **pcode, struct fetch_insn *end, |
| 524 | struct traceprobe_parse_context *ctx) |
| 525 | { |
| 526 | struct fetch_insn *code = *pcode; |
| 527 | const struct btf_member *field; |
| 528 | u32 bitoffs, anon_offs; |
| 529 | char *next; |
| 530 | int is_ptr; |
| 531 | s32 tid; |
| 532 | |
| 533 | do { |
| 534 | /* Outer loop for solving arrow operator ('->') */ |
| 535 | if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { |
| 536 | trace_probe_log_err(ctx->offset, NO_PTR_STRCT); |
| 537 | return -EINVAL; |
| 538 | } |
| 539 | /* Convert a struct pointer type to a struct type */ |
| 540 | type = btf_type_skip_modifiers(ctx->btf, type->type, &tid); |
| 541 | if (!type) { |
| 542 | trace_probe_log_err(ctx->offset, BAD_BTF_TID); |
| 543 | return -EINVAL; |
| 544 | } |
| 545 | |
| 546 | bitoffs = 0; |
| 547 | do { |
| 548 | /* Inner loop for solving dot operator ('.') */ |
| 549 | next = NULL; |
| 550 | is_ptr = split_next_field(fieldname, &next, ctx); |
| 551 | if (is_ptr < 0) |
| 552 | return is_ptr; |
| 553 | |
| 554 | anon_offs = 0; |
| 555 | field = btf_find_struct_member(ctx->btf, type, fieldname, |
| 556 | &anon_offs); |
| 557 | if (IS_ERR(field)) { |
| 558 | trace_probe_log_err(ctx->offset, BAD_BTF_TID); |
| 559 | return PTR_ERR(field); |
| 560 | } |
| 561 | if (!field) { |
| 562 | trace_probe_log_err(ctx->offset, NO_BTF_FIELD); |
| 563 | return -ENOENT; |
| 564 | } |
| 565 | /* Add anonymous structure/union offset */ |
| 566 | bitoffs += anon_offs; |
| 567 | |
| 568 | /* Accumulate the bit-offsets of the dot-connected fields */ |
| 569 | if (btf_type_kflag(type)) { |
| 570 | bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); |
| 571 | ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); |
| 572 | } else { |
| 573 | bitoffs += field->offset; |
| 574 | ctx->last_bitsize = 0; |
| 575 | } |
| 576 | |
| 577 | type = btf_type_skip_modifiers(ctx->btf, field->type, &tid); |
| 578 | if (!type) { |
| 579 | trace_probe_log_err(ctx->offset, BAD_BTF_TID); |
| 580 | return -EINVAL; |
| 581 | } |
| 582 | |
| 583 | ctx->offset += next - fieldname; |
| 584 | fieldname = next; |
| 585 | } while (!is_ptr && fieldname); |
| 586 | |
| 587 | if (++code == end) { |
| 588 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 589 | return -EINVAL; |
| 590 | } |
| 591 | code->op = FETCH_OP_DEREF; /* TODO: user deref support */ |
| 592 | code->offset = bitoffs / 8; |
| 593 | *pcode = code; |
| 594 | |
| 595 | ctx->last_bitoffs = bitoffs % 8; |
| 596 | ctx->last_type = type; |
| 597 | } while (fieldname); |
| 598 | |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | static int __store_entry_arg(struct trace_probe *tp, int argnum); |
| 603 | |
| 604 | static int parse_btf_arg(char *varname, |
| 605 | struct fetch_insn **pcode, struct fetch_insn *end, |
| 606 | struct traceprobe_parse_context *ctx) |
| 607 | { |
| 608 | struct fetch_insn *code = *pcode; |
| 609 | const struct btf_param *params; |
| 610 | const struct btf_type *type; |
| 611 | char *field = NULL; |
| 612 | int i, is_ptr, ret; |
| 613 | u32 tid; |
| 614 | |
| 615 | if (WARN_ON_ONCE(!ctx->funcname)) |
| 616 | return -EINVAL; |
| 617 | |
| 618 | is_ptr = split_next_field(varname, &field, ctx); |
| 619 | if (is_ptr < 0) |
| 620 | return is_ptr; |
| 621 | if (!is_ptr && field) { |
| 622 | /* dot-connected field on an argument is not supported. */ |
| 623 | trace_probe_log_err(ctx->offset + field - varname, |
| 624 | NOSUP_DAT_ARG); |
| 625 | return -EOPNOTSUPP; |
| 626 | } |
| 627 | |
| 628 | if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { |
| 629 | code->op = FETCH_OP_RETVAL; |
| 630 | /* Check whether the function return type is not void */ |
| 631 | if (query_btf_context(ctx) == 0) { |
| 632 | if (ctx->proto->type == 0) { |
| 633 | trace_probe_log_err(ctx->offset, NO_RETVAL); |
| 634 | return -ENOENT; |
| 635 | } |
| 636 | tid = ctx->proto->type; |
| 637 | goto found; |
| 638 | } |
| 639 | if (field) { |
| 640 | trace_probe_log_err(ctx->offset + field - varname, |
| 641 | NO_BTF_ENTRY); |
| 642 | return -ENOENT; |
| 643 | } |
| 644 | return 0; |
| 645 | } |
| 646 | |
| 647 | if (!ctx->btf) { |
| 648 | ret = query_btf_context(ctx); |
| 649 | if (ret < 0 || ctx->nr_params == 0) { |
| 650 | trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); |
| 651 | return PTR_ERR(params); |
| 652 | } |
| 653 | } |
| 654 | params = ctx->params; |
| 655 | |
| 656 | for (i = 0; i < ctx->nr_params; i++) { |
| 657 | const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); |
| 658 | |
| 659 | if (name && !strcmp(name, varname)) { |
| 660 | if (tparg_is_function_entry(ctx->flags)) { |
| 661 | code->op = FETCH_OP_ARG; |
| 662 | if (ctx->flags & TPARG_FL_TPOINT) |
| 663 | code->param = i + 1; |
| 664 | else |
| 665 | code->param = i; |
| 666 | } else if (tparg_is_function_return(ctx->flags)) { |
| 667 | code->op = FETCH_OP_EDATA; |
| 668 | ret = __store_entry_arg(ctx->tp, i); |
| 669 | if (ret < 0) { |
| 670 | /* internal error */ |
| 671 | return ret; |
| 672 | } |
| 673 | code->offset = ret; |
| 674 | } |
| 675 | tid = params[i].type; |
| 676 | goto found; |
| 677 | } |
| 678 | } |
| 679 | trace_probe_log_err(ctx->offset, NO_BTFARG); |
| 680 | return -ENOENT; |
| 681 | |
| 682 | found: |
| 683 | type = btf_type_skip_modifiers(ctx->btf, tid, &tid); |
| 684 | if (!type) { |
| 685 | trace_probe_log_err(ctx->offset, BAD_BTF_TID); |
| 686 | return -EINVAL; |
| 687 | } |
| 688 | /* Initialize the last type information */ |
| 689 | ctx->last_type = type; |
| 690 | ctx->last_bitoffs = 0; |
| 691 | ctx->last_bitsize = 0; |
| 692 | if (field) { |
| 693 | ctx->offset += field - varname; |
| 694 | return parse_btf_field(field, type, pcode, end, ctx); |
| 695 | } |
| 696 | return 0; |
| 697 | } |
| 698 | |
| 699 | static const struct fetch_type *find_fetch_type_from_btf_type( |
| 700 | struct traceprobe_parse_context *ctx) |
| 701 | { |
| 702 | struct btf *btf = ctx->btf; |
| 703 | const char *typestr = NULL; |
| 704 | |
| 705 | if (btf && ctx->last_type) |
| 706 | typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); |
| 707 | |
| 708 | return find_fetch_type(typestr, ctx->flags); |
| 709 | } |
| 710 | |
| 711 | static int parse_btf_bitfield(struct fetch_insn **pcode, |
| 712 | struct traceprobe_parse_context *ctx) |
| 713 | { |
| 714 | struct fetch_insn *code = *pcode; |
| 715 | |
| 716 | if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) |
| 717 | return 0; |
| 718 | |
| 719 | code++; |
| 720 | if (code->op != FETCH_OP_NOP) { |
| 721 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 722 | return -EINVAL; |
| 723 | } |
| 724 | *pcode = code; |
| 725 | |
| 726 | code->op = FETCH_OP_MOD_BF; |
| 727 | code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); |
| 728 | code->rshift = 64 - ctx->last_bitsize; |
| 729 | code->basesize = 64 / 8; |
| 730 | return 0; |
| 731 | } |
| 732 | |
| 733 | #else |
| 734 | static void clear_btf_context(struct traceprobe_parse_context *ctx) |
| 735 | { |
| 736 | ctx->btf = NULL; |
| 737 | } |
| 738 | |
| 739 | static int query_btf_context(struct traceprobe_parse_context *ctx) |
| 740 | { |
| 741 | return -EOPNOTSUPP; |
| 742 | } |
| 743 | |
| 744 | static int parse_btf_arg(char *varname, |
| 745 | struct fetch_insn **pcode, struct fetch_insn *end, |
| 746 | struct traceprobe_parse_context *ctx) |
| 747 | { |
| 748 | trace_probe_log_err(ctx->offset, NOSUP_BTFARG); |
| 749 | return -EOPNOTSUPP; |
| 750 | } |
| 751 | |
| 752 | static int parse_btf_bitfield(struct fetch_insn **pcode, |
| 753 | struct traceprobe_parse_context *ctx) |
| 754 | { |
| 755 | trace_probe_log_err(ctx->offset, NOSUP_BTFARG); |
| 756 | return -EOPNOTSUPP; |
| 757 | } |
| 758 | |
| 759 | #define find_fetch_type_from_btf_type(ctx) \ |
| 760 | find_fetch_type(NULL, ctx->flags) |
| 761 | |
| 762 | static int check_prepare_btf_string_fetch(char *typename, |
| 763 | struct fetch_insn **pcode, |
| 764 | struct traceprobe_parse_context *ctx) |
| 765 | { |
| 766 | return 0; |
| 767 | } |
| 768 | |
| 769 | #endif |
| 770 | |
| 771 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
| 772 | |
| 773 | static int __store_entry_arg(struct trace_probe *tp, int argnum) |
| 774 | { |
| 775 | struct probe_entry_arg *earg = tp->entry_arg; |
| 776 | bool match = false; |
| 777 | int i, offset; |
| 778 | |
| 779 | if (!earg) { |
| 780 | earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL); |
| 781 | if (!earg) |
| 782 | return -ENOMEM; |
| 783 | earg->size = 2 * tp->nr_args + 1; |
| 784 | earg->code = kcalloc(earg->size, sizeof(struct fetch_insn), |
| 785 | GFP_KERNEL); |
| 786 | if (!earg->code) { |
| 787 | kfree(earg); |
| 788 | return -ENOMEM; |
| 789 | } |
| 790 | /* Fill the code buffer with 'end' to simplify it */ |
| 791 | for (i = 0; i < earg->size; i++) |
| 792 | earg->code[i].op = FETCH_OP_END; |
| 793 | tp->entry_arg = earg; |
| 794 | } |
| 795 | |
| 796 | offset = 0; |
| 797 | for (i = 0; i < earg->size - 1; i++) { |
| 798 | switch (earg->code[i].op) { |
| 799 | case FETCH_OP_END: |
| 800 | earg->code[i].op = FETCH_OP_ARG; |
| 801 | earg->code[i].param = argnum; |
| 802 | earg->code[i + 1].op = FETCH_OP_ST_EDATA; |
| 803 | earg->code[i + 1].offset = offset; |
| 804 | return offset; |
| 805 | case FETCH_OP_ARG: |
| 806 | match = (earg->code[i].param == argnum); |
| 807 | break; |
| 808 | case FETCH_OP_ST_EDATA: |
| 809 | offset = earg->code[i].offset; |
| 810 | if (match) |
| 811 | return offset; |
| 812 | offset += sizeof(unsigned long); |
| 813 | break; |
| 814 | default: |
| 815 | break; |
| 816 | } |
| 817 | } |
| 818 | return -ENOSPC; |
| 819 | } |
| 820 | |
| 821 | int traceprobe_get_entry_data_size(struct trace_probe *tp) |
| 822 | { |
| 823 | struct probe_entry_arg *earg = tp->entry_arg; |
| 824 | int i, size = 0; |
| 825 | |
| 826 | if (!earg) |
| 827 | return 0; |
| 828 | |
| 829 | for (i = 0; i < earg->size; i++) { |
| 830 | switch (earg->code[i].op) { |
| 831 | case FETCH_OP_END: |
| 832 | goto out; |
| 833 | case FETCH_OP_ST_EDATA: |
| 834 | size = earg->code[i].offset + sizeof(unsigned long); |
| 835 | break; |
| 836 | default: |
| 837 | break; |
| 838 | } |
| 839 | } |
| 840 | out: |
| 841 | return size; |
| 842 | } |
| 843 | |
| 844 | void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) |
| 845 | { |
| 846 | struct probe_entry_arg *earg = tp->entry_arg; |
| 847 | unsigned long val = 0; |
| 848 | int i; |
| 849 | |
| 850 | if (!earg) |
| 851 | return; |
| 852 | |
| 853 | for (i = 0; i < earg->size; i++) { |
| 854 | struct fetch_insn *code = &earg->code[i]; |
| 855 | |
| 856 | switch (code->op) { |
| 857 | case FETCH_OP_ARG: |
| 858 | val = regs_get_kernel_argument(regs, code->param); |
| 859 | break; |
| 860 | case FETCH_OP_ST_EDATA: |
| 861 | *(unsigned long *)((unsigned long)edata + code->offset) = val; |
| 862 | break; |
| 863 | case FETCH_OP_END: |
| 864 | goto end; |
| 865 | default: |
| 866 | break; |
| 867 | } |
| 868 | } |
| 869 | end: |
| 870 | return; |
| 871 | } |
| 872 | NOKPROBE_SYMBOL(store_trace_entry_data) |
| 873 | #endif |
| 874 | |
| 875 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) |
| 876 | |
| 877 | /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ |
| 878 | static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, |
| 879 | struct fetch_insn **pcode, |
| 880 | struct fetch_insn *end, |
| 881 | struct traceprobe_parse_context *ctx) |
| 882 | { |
| 883 | struct fetch_insn *code = *pcode; |
| 884 | int err = TP_ERR_BAD_VAR; |
| 885 | char *arg = orig_arg + 1; |
| 886 | unsigned long param; |
| 887 | int ret = 0; |
| 888 | int len; |
| 889 | |
| 890 | if (ctx->flags & TPARG_FL_TEVENT) { |
| 891 | if (code->data) |
| 892 | return -EFAULT; |
| 893 | ret = parse_trace_event_arg(arg, code, ctx); |
| 894 | if (!ret) |
| 895 | return 0; |
| 896 | if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { |
| 897 | code->op = FETCH_OP_COMM; |
| 898 | return 0; |
| 899 | } |
| 900 | /* backward compatibility */ |
| 901 | ctx->offset = 0; |
| 902 | goto inval; |
| 903 | } |
| 904 | |
| 905 | if (str_has_prefix(arg, "retval")) { |
| 906 | if (!(ctx->flags & TPARG_FL_RETURN)) { |
| 907 | err = TP_ERR_RETVAL_ON_PROBE; |
| 908 | goto inval; |
| 909 | } |
| 910 | if (!(ctx->flags & TPARG_FL_KERNEL) || |
| 911 | !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { |
| 912 | code->op = FETCH_OP_RETVAL; |
| 913 | return 0; |
| 914 | } |
| 915 | return parse_btf_arg(orig_arg, pcode, end, ctx); |
| 916 | } |
| 917 | |
| 918 | len = str_has_prefix(arg, "stack"); |
| 919 | if (len) { |
| 920 | |
| 921 | if (arg[len] == '\0') { |
| 922 | code->op = FETCH_OP_STACKP; |
| 923 | return 0; |
| 924 | } |
| 925 | |
| 926 | if (isdigit(arg[len])) { |
| 927 | ret = kstrtoul(arg + len, 10, ¶m); |
| 928 | if (ret) |
| 929 | goto inval; |
| 930 | |
| 931 | if ((ctx->flags & TPARG_FL_KERNEL) && |
| 932 | param > PARAM_MAX_STACK) { |
| 933 | err = TP_ERR_BAD_STACK_NUM; |
| 934 | goto inval; |
| 935 | } |
| 936 | code->op = FETCH_OP_STACK; |
| 937 | code->param = (unsigned int)param; |
| 938 | return 0; |
| 939 | } |
| 940 | goto inval; |
| 941 | } |
| 942 | |
| 943 | if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { |
| 944 | code->op = FETCH_OP_COMM; |
| 945 | return 0; |
| 946 | } |
| 947 | |
| 948 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
| 949 | len = str_has_prefix(arg, "arg"); |
| 950 | if (len) { |
| 951 | ret = kstrtoul(arg + len, 10, ¶m); |
| 952 | if (ret) |
| 953 | goto inval; |
| 954 | |
| 955 | if (!param || param > PARAM_MAX_STACK) { |
| 956 | err = TP_ERR_BAD_ARG_NUM; |
| 957 | goto inval; |
| 958 | } |
| 959 | param--; /* argN starts from 1, but internal arg[N] starts from 0 */ |
| 960 | |
| 961 | if (tparg_is_function_entry(ctx->flags)) { |
| 962 | code->op = FETCH_OP_ARG; |
| 963 | code->param = (unsigned int)param; |
| 964 | /* |
| 965 | * The tracepoint probe will probe a stub function, and the |
| 966 | * first parameter of the stub is a dummy and should be ignored. |
| 967 | */ |
| 968 | if (ctx->flags & TPARG_FL_TPOINT) |
| 969 | code->param++; |
| 970 | } else if (tparg_is_function_return(ctx->flags)) { |
| 971 | /* function entry argument access from return probe */ |
| 972 | ret = __store_entry_arg(ctx->tp, param); |
| 973 | if (ret < 0) /* This error should be an internal error */ |
| 974 | return ret; |
| 975 | |
| 976 | code->op = FETCH_OP_EDATA; |
| 977 | code->offset = ret; |
| 978 | } else { |
| 979 | err = TP_ERR_NOFENTRY_ARGS; |
| 980 | goto inval; |
| 981 | } |
| 982 | return 0; |
| 983 | } |
| 984 | #endif |
| 985 | |
| 986 | inval: |
| 987 | __trace_probe_log_err(ctx->offset, err); |
| 988 | return -EINVAL; |
| 989 | } |
| 990 | |
| 991 | static int str_to_immediate(char *str, unsigned long *imm) |
| 992 | { |
| 993 | if (isdigit(str[0])) |
| 994 | return kstrtoul(str, 0, imm); |
| 995 | else if (str[0] == '-') |
| 996 | return kstrtol(str, 0, (long *)imm); |
| 997 | else if (str[0] == '+') |
| 998 | return kstrtol(str + 1, 0, (long *)imm); |
| 999 | return -EINVAL; |
| 1000 | } |
| 1001 | |
| 1002 | static int __parse_imm_string(char *str, char **pbuf, int offs) |
| 1003 | { |
| 1004 | size_t len = strlen(str); |
| 1005 | |
| 1006 | if (str[len - 1] != '"') { |
| 1007 | trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); |
| 1008 | return -EINVAL; |
| 1009 | } |
| 1010 | *pbuf = kstrndup(str, len - 1, GFP_KERNEL); |
| 1011 | if (!*pbuf) |
| 1012 | return -ENOMEM; |
| 1013 | return 0; |
| 1014 | } |
| 1015 | |
| 1016 | /* Recursive argument parser */ |
| 1017 | static int |
| 1018 | parse_probe_arg(char *arg, const struct fetch_type *type, |
| 1019 | struct fetch_insn **pcode, struct fetch_insn *end, |
| 1020 | struct traceprobe_parse_context *ctx) |
| 1021 | { |
| 1022 | struct fetch_insn *code = *pcode; |
| 1023 | unsigned long param; |
| 1024 | int deref = FETCH_OP_DEREF; |
| 1025 | long offset = 0; |
| 1026 | char *tmp; |
| 1027 | int ret = 0; |
| 1028 | |
| 1029 | switch (arg[0]) { |
| 1030 | case '$': |
| 1031 | ret = parse_probe_vars(arg, type, pcode, end, ctx); |
| 1032 | break; |
| 1033 | |
| 1034 | case '%': /* named register */ |
| 1035 | if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { |
| 1036 | /* eprobe and fprobe do not handle registers */ |
| 1037 | trace_probe_log_err(ctx->offset, BAD_VAR); |
| 1038 | break; |
| 1039 | } |
| 1040 | ret = regs_query_register_offset(arg + 1); |
| 1041 | if (ret >= 0) { |
| 1042 | code->op = FETCH_OP_REG; |
| 1043 | code->param = (unsigned int)ret; |
| 1044 | ret = 0; |
| 1045 | } else |
| 1046 | trace_probe_log_err(ctx->offset, BAD_REG_NAME); |
| 1047 | break; |
| 1048 | |
| 1049 | case '@': /* memory, file-offset or symbol */ |
| 1050 | if (isdigit(arg[1])) { |
| 1051 | ret = kstrtoul(arg + 1, 0, ¶m); |
| 1052 | if (ret) { |
| 1053 | trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); |
| 1054 | break; |
| 1055 | } |
| 1056 | /* load address */ |
| 1057 | code->op = FETCH_OP_IMM; |
| 1058 | code->immediate = param; |
| 1059 | } else if (arg[1] == '+') { |
| 1060 | /* kprobes don't support file offsets */ |
| 1061 | if (ctx->flags & TPARG_FL_KERNEL) { |
| 1062 | trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); |
| 1063 | return -EINVAL; |
| 1064 | } |
| 1065 | ret = kstrtol(arg + 2, 0, &offset); |
| 1066 | if (ret) { |
| 1067 | trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); |
| 1068 | break; |
| 1069 | } |
| 1070 | |
| 1071 | code->op = FETCH_OP_FOFFS; |
| 1072 | code->immediate = (unsigned long)offset; // imm64? |
| 1073 | } else { |
| 1074 | /* uprobes don't support symbols */ |
| 1075 | if (!(ctx->flags & TPARG_FL_KERNEL)) { |
| 1076 | trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); |
| 1077 | return -EINVAL; |
| 1078 | } |
| 1079 | /* Preserve symbol for updating */ |
| 1080 | code->op = FETCH_NOP_SYMBOL; |
| 1081 | code->data = kstrdup(arg + 1, GFP_KERNEL); |
| 1082 | if (!code->data) |
| 1083 | return -ENOMEM; |
| 1084 | if (++code == end) { |
| 1085 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1086 | return -EINVAL; |
| 1087 | } |
| 1088 | code->op = FETCH_OP_IMM; |
| 1089 | code->immediate = 0; |
| 1090 | } |
| 1091 | /* These are fetching from memory */ |
| 1092 | if (++code == end) { |
| 1093 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1094 | return -EINVAL; |
| 1095 | } |
| 1096 | *pcode = code; |
| 1097 | code->op = FETCH_OP_DEREF; |
| 1098 | code->offset = offset; |
| 1099 | break; |
| 1100 | |
| 1101 | case '+': /* deref memory */ |
| 1102 | case '-': |
| 1103 | if (arg[1] == 'u') { |
| 1104 | deref = FETCH_OP_UDEREF; |
| 1105 | arg[1] = arg[0]; |
| 1106 | arg++; |
| 1107 | } |
| 1108 | if (arg[0] == '+') |
| 1109 | arg++; /* Skip '+', because kstrtol() rejects it. */ |
| 1110 | tmp = strchr(arg, '('); |
| 1111 | if (!tmp) { |
| 1112 | trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); |
| 1113 | return -EINVAL; |
| 1114 | } |
| 1115 | *tmp = '\0'; |
| 1116 | ret = kstrtol(arg, 0, &offset); |
| 1117 | if (ret) { |
| 1118 | trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); |
| 1119 | break; |
| 1120 | } |
| 1121 | ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); |
| 1122 | arg = tmp + 1; |
| 1123 | tmp = strrchr(arg, ')'); |
| 1124 | if (!tmp) { |
| 1125 | trace_probe_log_err(ctx->offset + strlen(arg), |
| 1126 | DEREF_OPEN_BRACE); |
| 1127 | return -EINVAL; |
| 1128 | } else { |
| 1129 | const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); |
| 1130 | int cur_offs = ctx->offset; |
| 1131 | |
| 1132 | *tmp = '\0'; |
| 1133 | ret = parse_probe_arg(arg, t2, &code, end, ctx); |
| 1134 | if (ret) |
| 1135 | break; |
| 1136 | ctx->offset = cur_offs; |
| 1137 | if (code->op == FETCH_OP_COMM || |
| 1138 | code->op == FETCH_OP_DATA) { |
| 1139 | trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); |
| 1140 | return -EINVAL; |
| 1141 | } |
| 1142 | if (++code == end) { |
| 1143 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1144 | return -EINVAL; |
| 1145 | } |
| 1146 | *pcode = code; |
| 1147 | |
| 1148 | code->op = deref; |
| 1149 | code->offset = offset; |
| 1150 | /* Reset the last type if used */ |
| 1151 | ctx->last_type = NULL; |
| 1152 | } |
| 1153 | break; |
| 1154 | case '\\': /* Immediate value */ |
| 1155 | if (arg[1] == '"') { /* Immediate string */ |
| 1156 | ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); |
| 1157 | if (ret) |
| 1158 | break; |
| 1159 | code->op = FETCH_OP_DATA; |
| 1160 | code->data = tmp; |
| 1161 | } else { |
| 1162 | ret = str_to_immediate(arg + 1, &code->immediate); |
| 1163 | if (ret) |
| 1164 | trace_probe_log_err(ctx->offset + 1, BAD_IMM); |
| 1165 | else |
| 1166 | code->op = FETCH_OP_IMM; |
| 1167 | } |
| 1168 | break; |
| 1169 | default: |
| 1170 | if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ |
| 1171 | if (!tparg_is_function_entry(ctx->flags) && |
| 1172 | !tparg_is_function_return(ctx->flags)) { |
| 1173 | trace_probe_log_err(ctx->offset, NOSUP_BTFARG); |
| 1174 | return -EINVAL; |
| 1175 | } |
| 1176 | ret = parse_btf_arg(arg, pcode, end, ctx); |
| 1177 | break; |
| 1178 | } |
| 1179 | } |
| 1180 | if (!ret && code->op == FETCH_OP_NOP) { |
| 1181 | /* Parsed, but do not find fetch method */ |
| 1182 | trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); |
| 1183 | ret = -EINVAL; |
| 1184 | } |
| 1185 | return ret; |
| 1186 | } |
| 1187 | |
| 1188 | /* Bitfield type needs to be parsed into a fetch function */ |
| 1189 | static int __parse_bitfield_probe_arg(const char *bf, |
| 1190 | const struct fetch_type *t, |
| 1191 | struct fetch_insn **pcode) |
| 1192 | { |
| 1193 | struct fetch_insn *code = *pcode; |
| 1194 | unsigned long bw, bo; |
| 1195 | char *tail; |
| 1196 | |
| 1197 | if (*bf != 'b') |
| 1198 | return 0; |
| 1199 | |
| 1200 | bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ |
| 1201 | |
| 1202 | if (bw == 0 || *tail != '@') |
| 1203 | return -EINVAL; |
| 1204 | |
| 1205 | bf = tail + 1; |
| 1206 | bo = simple_strtoul(bf, &tail, 0); |
| 1207 | |
| 1208 | if (tail == bf || *tail != '/') |
| 1209 | return -EINVAL; |
| 1210 | code++; |
| 1211 | if (code->op != FETCH_OP_NOP) |
| 1212 | return -EINVAL; |
| 1213 | *pcode = code; |
| 1214 | |
| 1215 | code->op = FETCH_OP_MOD_BF; |
| 1216 | code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); |
| 1217 | code->rshift = BYTES_TO_BITS(t->size) - bw; |
| 1218 | code->basesize = t->size; |
| 1219 | |
| 1220 | return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; |
| 1221 | } |
| 1222 | |
| 1223 | /* Split type part from @arg and return it. */ |
| 1224 | static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, |
| 1225 | struct traceprobe_parse_context *ctx) |
| 1226 | { |
| 1227 | char *t = NULL, *t2, *t3; |
| 1228 | int offs; |
| 1229 | |
| 1230 | t = strchr(arg, ':'); |
| 1231 | if (t) { |
| 1232 | *t++ = '\0'; |
| 1233 | t2 = strchr(t, '['); |
| 1234 | if (t2) { |
| 1235 | *t2++ = '\0'; |
| 1236 | t3 = strchr(t2, ']'); |
| 1237 | if (!t3) { |
| 1238 | offs = t2 + strlen(t2) - arg; |
| 1239 | |
| 1240 | trace_probe_log_err(ctx->offset + offs, |
| 1241 | ARRAY_NO_CLOSE); |
| 1242 | return ERR_PTR(-EINVAL); |
| 1243 | } else if (t3[1] != '\0') { |
| 1244 | trace_probe_log_err(ctx->offset + t3 + 1 - arg, |
| 1245 | BAD_ARRAY_SUFFIX); |
| 1246 | return ERR_PTR(-EINVAL); |
| 1247 | } |
| 1248 | *t3 = '\0'; |
| 1249 | if (kstrtouint(t2, 0, &parg->count) || !parg->count) { |
| 1250 | trace_probe_log_err(ctx->offset + t2 - arg, |
| 1251 | BAD_ARRAY_NUM); |
| 1252 | return ERR_PTR(-EINVAL); |
| 1253 | } |
| 1254 | if (parg->count > MAX_ARRAY_LEN) { |
| 1255 | trace_probe_log_err(ctx->offset + t2 - arg, |
| 1256 | ARRAY_TOO_BIG); |
| 1257 | return ERR_PTR(-EINVAL); |
| 1258 | } |
| 1259 | } |
| 1260 | } |
| 1261 | offs = t ? t - arg : 0; |
| 1262 | |
| 1263 | /* |
| 1264 | * Since $comm and immediate string can not be dereferenced, |
| 1265 | * we can find those by strcmp. But ignore for eprobes. |
| 1266 | */ |
| 1267 | if (!(ctx->flags & TPARG_FL_TEVENT) && |
| 1268 | (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || |
| 1269 | strncmp(arg, "\\\"", 2) == 0)) { |
| 1270 | /* The type of $comm must be "string", and not an array type. */ |
| 1271 | if (parg->count || (t && strcmp(t, "string"))) { |
| 1272 | trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); |
| 1273 | return ERR_PTR(-EINVAL); |
| 1274 | } |
| 1275 | parg->type = find_fetch_type("string", ctx->flags); |
| 1276 | } else |
| 1277 | parg->type = find_fetch_type(t, ctx->flags); |
| 1278 | |
| 1279 | if (!parg->type) { |
| 1280 | trace_probe_log_err(ctx->offset + offs, BAD_TYPE); |
| 1281 | return ERR_PTR(-EINVAL); |
| 1282 | } |
| 1283 | |
| 1284 | return t; |
| 1285 | } |
| 1286 | |
| 1287 | /* After parsing, adjust the fetch_insn according to the probe_arg */ |
| 1288 | static int finalize_fetch_insn(struct fetch_insn *code, |
| 1289 | struct probe_arg *parg, |
| 1290 | char *type, |
| 1291 | int type_offset, |
| 1292 | struct traceprobe_parse_context *ctx) |
| 1293 | { |
| 1294 | struct fetch_insn *scode; |
| 1295 | int ret; |
| 1296 | |
| 1297 | /* Store operation */ |
| 1298 | if (parg->type->is_string) { |
| 1299 | /* Check bad combination of the type and the last fetch_insn. */ |
| 1300 | if (!strcmp(parg->type->name, "symstr")) { |
| 1301 | if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && |
| 1302 | code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && |
| 1303 | code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { |
| 1304 | trace_probe_log_err(ctx->offset + type_offset, |
| 1305 | BAD_SYMSTRING); |
| 1306 | return -EINVAL; |
| 1307 | } |
| 1308 | } else { |
| 1309 | if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && |
| 1310 | code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && |
| 1311 | code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { |
| 1312 | trace_probe_log_err(ctx->offset + type_offset, |
| 1313 | BAD_STRING); |
| 1314 | return -EINVAL; |
| 1315 | } |
| 1316 | } |
| 1317 | |
| 1318 | if (!strcmp(parg->type->name, "symstr") || |
| 1319 | (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || |
| 1320 | code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || |
| 1321 | parg->count) { |
| 1322 | /* |
| 1323 | * IMM, DATA and COMM is pointing actual address, those |
| 1324 | * must be kept, and if parg->count != 0, this is an |
| 1325 | * array of string pointers instead of string address |
| 1326 | * itself. |
| 1327 | * For the symstr, it doesn't need to dereference, thus |
| 1328 | * it just get the value. |
| 1329 | */ |
| 1330 | code++; |
| 1331 | if (code->op != FETCH_OP_NOP) { |
| 1332 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1333 | return -EINVAL; |
| 1334 | } |
| 1335 | } |
| 1336 | |
| 1337 | /* If op == DEREF, replace it with STRING */ |
| 1338 | if (!strcmp(parg->type->name, "ustring") || |
| 1339 | code->op == FETCH_OP_UDEREF) |
| 1340 | code->op = FETCH_OP_ST_USTRING; |
| 1341 | else if (!strcmp(parg->type->name, "symstr")) |
| 1342 | code->op = FETCH_OP_ST_SYMSTR; |
| 1343 | else |
| 1344 | code->op = FETCH_OP_ST_STRING; |
| 1345 | code->size = parg->type->size; |
| 1346 | parg->dynamic = true; |
| 1347 | } else if (code->op == FETCH_OP_DEREF) { |
| 1348 | code->op = FETCH_OP_ST_MEM; |
| 1349 | code->size = parg->type->size; |
| 1350 | } else if (code->op == FETCH_OP_UDEREF) { |
| 1351 | code->op = FETCH_OP_ST_UMEM; |
| 1352 | code->size = parg->type->size; |
| 1353 | } else { |
| 1354 | code++; |
| 1355 | if (code->op != FETCH_OP_NOP) { |
| 1356 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1357 | return -E2BIG; |
| 1358 | } |
| 1359 | code->op = FETCH_OP_ST_RAW; |
| 1360 | code->size = parg->type->size; |
| 1361 | } |
| 1362 | |
| 1363 | /* Save storing fetch_insn. */ |
| 1364 | scode = code; |
| 1365 | |
| 1366 | /* Modify operation */ |
| 1367 | if (type != NULL) { |
| 1368 | /* Bitfield needs a special fetch_insn. */ |
| 1369 | ret = __parse_bitfield_probe_arg(type, parg->type, &code); |
| 1370 | if (ret) { |
| 1371 | trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); |
| 1372 | return ret; |
| 1373 | } |
| 1374 | } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && |
| 1375 | ctx->last_type) { |
| 1376 | /* If user not specified the type, try parsing BTF bitfield. */ |
| 1377 | ret = parse_btf_bitfield(&code, ctx); |
| 1378 | if (ret) |
| 1379 | return ret; |
| 1380 | } |
| 1381 | |
| 1382 | /* Loop(Array) operation */ |
| 1383 | if (parg->count) { |
| 1384 | if (scode->op != FETCH_OP_ST_MEM && |
| 1385 | scode->op != FETCH_OP_ST_STRING && |
| 1386 | scode->op != FETCH_OP_ST_USTRING) { |
| 1387 | trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); |
| 1388 | return -EINVAL; |
| 1389 | } |
| 1390 | code++; |
| 1391 | if (code->op != FETCH_OP_NOP) { |
| 1392 | trace_probe_log_err(ctx->offset, TOO_MANY_OPS); |
| 1393 | return -E2BIG; |
| 1394 | } |
| 1395 | code->op = FETCH_OP_LP_ARRAY; |
| 1396 | code->param = parg->count; |
| 1397 | } |
| 1398 | |
| 1399 | /* Finalize the fetch_insn array. */ |
| 1400 | code++; |
| 1401 | code->op = FETCH_OP_END; |
| 1402 | |
| 1403 | return 0; |
| 1404 | } |
| 1405 | |
| 1406 | /* String length checking wrapper */ |
| 1407 | static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, |
| 1408 | struct probe_arg *parg, |
| 1409 | struct traceprobe_parse_context *ctx) |
| 1410 | { |
| 1411 | struct fetch_insn *code, *tmp = NULL; |
| 1412 | char *type, *arg; |
| 1413 | int ret, len; |
| 1414 | |
| 1415 | len = strlen(argv); |
| 1416 | if (len > MAX_ARGSTR_LEN) { |
| 1417 | trace_probe_log_err(ctx->offset, ARG_TOO_LONG); |
| 1418 | return -E2BIG; |
| 1419 | } else if (len == 0) { |
| 1420 | trace_probe_log_err(ctx->offset, NO_ARG_BODY); |
| 1421 | return -EINVAL; |
| 1422 | } |
| 1423 | |
| 1424 | arg = kstrdup(argv, GFP_KERNEL); |
| 1425 | if (!arg) |
| 1426 | return -ENOMEM; |
| 1427 | |
| 1428 | parg->comm = kstrdup(arg, GFP_KERNEL); |
| 1429 | if (!parg->comm) { |
| 1430 | ret = -ENOMEM; |
| 1431 | goto out; |
| 1432 | } |
| 1433 | |
| 1434 | type = parse_probe_arg_type(arg, parg, ctx); |
| 1435 | if (IS_ERR(type)) { |
| 1436 | ret = PTR_ERR(type); |
| 1437 | goto out; |
| 1438 | } |
| 1439 | |
| 1440 | code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); |
| 1441 | if (!code) { |
| 1442 | ret = -ENOMEM; |
| 1443 | goto out; |
| 1444 | } |
| 1445 | code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; |
| 1446 | |
| 1447 | ctx->last_type = NULL; |
| 1448 | ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], |
| 1449 | ctx); |
| 1450 | if (ret < 0) |
| 1451 | goto fail; |
| 1452 | |
| 1453 | /* Update storing type if BTF is available */ |
| 1454 | if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && |
| 1455 | ctx->last_type) { |
| 1456 | if (!type) { |
| 1457 | parg->type = find_fetch_type_from_btf_type(ctx); |
| 1458 | } else if (strstr(type, "string")) { |
| 1459 | ret = check_prepare_btf_string_fetch(type, &code, ctx); |
| 1460 | if (ret) |
| 1461 | goto fail; |
| 1462 | } |
| 1463 | } |
| 1464 | parg->offset = *size; |
| 1465 | *size += parg->type->size * (parg->count ?: 1); |
| 1466 | |
| 1467 | if (parg->count) { |
| 1468 | len = strlen(parg->type->fmttype) + 6; |
| 1469 | parg->fmt = kmalloc(len, GFP_KERNEL); |
| 1470 | if (!parg->fmt) { |
| 1471 | ret = -ENOMEM; |
| 1472 | goto fail; |
| 1473 | } |
| 1474 | snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, |
| 1475 | parg->count); |
| 1476 | } |
| 1477 | |
| 1478 | ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); |
| 1479 | if (ret < 0) |
| 1480 | goto fail; |
| 1481 | |
| 1482 | for (; code < tmp + FETCH_INSN_MAX; code++) |
| 1483 | if (code->op == FETCH_OP_END) |
| 1484 | break; |
| 1485 | /* Shrink down the code buffer */ |
| 1486 | parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); |
| 1487 | if (!parg->code) |
| 1488 | ret = -ENOMEM; |
| 1489 | else |
| 1490 | memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); |
| 1491 | |
| 1492 | fail: |
| 1493 | if (ret < 0) { |
| 1494 | for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) |
| 1495 | if (code->op == FETCH_NOP_SYMBOL || |
| 1496 | code->op == FETCH_OP_DATA) |
| 1497 | kfree(code->data); |
| 1498 | } |
| 1499 | kfree(tmp); |
| 1500 | out: |
| 1501 | kfree(arg); |
| 1502 | |
| 1503 | return ret; |
| 1504 | } |
| 1505 | |
| 1506 | /* Return 1 if name is reserved or already used by another argument */ |
| 1507 | static int traceprobe_conflict_field_name(const char *name, |
| 1508 | struct probe_arg *args, int narg) |
| 1509 | { |
| 1510 | int i; |
| 1511 | |
| 1512 | for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) |
| 1513 | if (strcmp(reserved_field_names[i], name) == 0) |
| 1514 | return 1; |
| 1515 | |
| 1516 | for (i = 0; i < narg; i++) |
| 1517 | if (strcmp(args[i].name, name) == 0) |
| 1518 | return 1; |
| 1519 | |
| 1520 | return 0; |
| 1521 | } |
| 1522 | |
| 1523 | static char *generate_probe_arg_name(const char *arg, int idx) |
| 1524 | { |
| 1525 | char *name = NULL; |
| 1526 | const char *end; |
| 1527 | |
| 1528 | /* |
| 1529 | * If argument name is omitted, try arg as a name (BTF variable) |
| 1530 | * or "argN". |
| 1531 | */ |
| 1532 | if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { |
| 1533 | end = strchr(arg, ':'); |
| 1534 | if (!end) |
| 1535 | end = arg + strlen(arg); |
| 1536 | |
| 1537 | name = kmemdup_nul(arg, end - arg, GFP_KERNEL); |
| 1538 | if (!name || !is_good_name(name)) { |
| 1539 | kfree(name); |
| 1540 | name = NULL; |
| 1541 | } |
| 1542 | } |
| 1543 | |
| 1544 | if (!name) |
| 1545 | name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); |
| 1546 | |
| 1547 | return name; |
| 1548 | } |
| 1549 | |
| 1550 | int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, |
| 1551 | struct traceprobe_parse_context *ctx) |
| 1552 | { |
| 1553 | struct probe_arg *parg = &tp->args[i]; |
| 1554 | const char *body; |
| 1555 | |
| 1556 | ctx->tp = tp; |
| 1557 | body = strchr(arg, '='); |
| 1558 | if (body) { |
| 1559 | if (body - arg > MAX_ARG_NAME_LEN) { |
| 1560 | trace_probe_log_err(0, ARG_NAME_TOO_LONG); |
| 1561 | return -EINVAL; |
| 1562 | } else if (body == arg) { |
| 1563 | trace_probe_log_err(0, NO_ARG_NAME); |
| 1564 | return -EINVAL; |
| 1565 | } |
| 1566 | parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); |
| 1567 | body++; |
| 1568 | } else { |
| 1569 | parg->name = generate_probe_arg_name(arg, i); |
| 1570 | body = arg; |
| 1571 | } |
| 1572 | if (!parg->name) |
| 1573 | return -ENOMEM; |
| 1574 | |
| 1575 | if (!is_good_name(parg->name)) { |
| 1576 | trace_probe_log_err(0, BAD_ARG_NAME); |
| 1577 | return -EINVAL; |
| 1578 | } |
| 1579 | if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { |
| 1580 | trace_probe_log_err(0, USED_ARG_NAME); |
| 1581 | return -EINVAL; |
| 1582 | } |
| 1583 | ctx->offset = body - arg; |
| 1584 | /* Parse fetch argument */ |
| 1585 | return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); |
| 1586 | } |
| 1587 | |
| 1588 | void traceprobe_free_probe_arg(struct probe_arg *arg) |
| 1589 | { |
| 1590 | struct fetch_insn *code = arg->code; |
| 1591 | |
| 1592 | while (code && code->op != FETCH_OP_END) { |
| 1593 | if (code->op == FETCH_NOP_SYMBOL || |
| 1594 | code->op == FETCH_OP_DATA) |
| 1595 | kfree(code->data); |
| 1596 | code++; |
| 1597 | } |
| 1598 | kfree(arg->code); |
| 1599 | kfree(arg->name); |
| 1600 | kfree(arg->comm); |
| 1601 | kfree(arg->fmt); |
| 1602 | } |
| 1603 | |
| 1604 | static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, |
| 1605 | struct traceprobe_parse_context *ctx) |
| 1606 | { |
| 1607 | int i, found = 0; |
| 1608 | |
| 1609 | for (i = 0; i < argc; i++) |
| 1610 | if (str_has_prefix(argv[i], "$arg")) { |
| 1611 | trace_probe_log_set_index(i + 2); |
| 1612 | |
| 1613 | if (!tparg_is_function_entry(ctx->flags) && |
| 1614 | !tparg_is_function_return(ctx->flags)) { |
| 1615 | trace_probe_log_err(0, NOFENTRY_ARGS); |
| 1616 | return -EINVAL; |
| 1617 | } |
| 1618 | |
| 1619 | if (isdigit(argv[i][4])) { |
| 1620 | found = 1; |
| 1621 | continue; |
| 1622 | } |
| 1623 | |
| 1624 | if (argv[i][4] != '*') { |
| 1625 | trace_probe_log_err(0, BAD_VAR); |
| 1626 | return -EINVAL; |
| 1627 | } |
| 1628 | |
| 1629 | if (*args_idx >= 0 && *args_idx < argc) { |
| 1630 | trace_probe_log_err(0, DOUBLE_ARGS); |
| 1631 | return -EINVAL; |
| 1632 | } |
| 1633 | found = 1; |
| 1634 | *args_idx = i; |
| 1635 | } |
| 1636 | |
| 1637 | return found; |
| 1638 | } |
| 1639 | |
| 1640 | static int sprint_nth_btf_arg(int idx, const char *type, |
| 1641 | char *buf, int bufsize, |
| 1642 | struct traceprobe_parse_context *ctx) |
| 1643 | { |
| 1644 | const char *name; |
| 1645 | int ret; |
| 1646 | |
| 1647 | if (idx >= ctx->nr_params) { |
| 1648 | trace_probe_log_err(0, NO_BTFARG); |
| 1649 | return -ENOENT; |
| 1650 | } |
| 1651 | name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); |
| 1652 | if (!name) { |
| 1653 | trace_probe_log_err(0, NO_BTF_ENTRY); |
| 1654 | return -ENOENT; |
| 1655 | } |
| 1656 | ret = snprintf(buf, bufsize, "%s%s", name, type); |
| 1657 | if (ret >= bufsize) { |
| 1658 | trace_probe_log_err(0, ARGS_2LONG); |
| 1659 | return -E2BIG; |
| 1660 | } |
| 1661 | return ret; |
| 1662 | } |
| 1663 | |
| 1664 | /* Return new_argv which must be freed after use */ |
| 1665 | const char **traceprobe_expand_meta_args(int argc, const char *argv[], |
| 1666 | int *new_argc, char *buf, int bufsize, |
| 1667 | struct traceprobe_parse_context *ctx) |
| 1668 | { |
| 1669 | const struct btf_param *params = NULL; |
| 1670 | int i, j, n, used, ret, args_idx = -1; |
| 1671 | const char **new_argv = NULL; |
| 1672 | |
| 1673 | ret = argv_has_var_arg(argc, argv, &args_idx, ctx); |
| 1674 | if (ret < 0) |
| 1675 | return ERR_PTR(ret); |
| 1676 | |
| 1677 | if (!ret) { |
| 1678 | *new_argc = argc; |
| 1679 | return NULL; |
| 1680 | } |
| 1681 | |
| 1682 | ret = query_btf_context(ctx); |
| 1683 | if (ret < 0 || ctx->nr_params == 0) { |
| 1684 | if (args_idx != -1) { |
| 1685 | /* $arg* requires BTF info */ |
| 1686 | trace_probe_log_err(0, NOSUP_BTFARG); |
| 1687 | return (const char **)params; |
| 1688 | } |
| 1689 | *new_argc = argc; |
| 1690 | return NULL; |
| 1691 | } |
| 1692 | |
| 1693 | if (args_idx >= 0) |
| 1694 | *new_argc = argc + ctx->nr_params - 1; |
| 1695 | else |
| 1696 | *new_argc = argc; |
| 1697 | |
| 1698 | new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); |
| 1699 | if (!new_argv) |
| 1700 | return ERR_PTR(-ENOMEM); |
| 1701 | |
| 1702 | used = 0; |
| 1703 | for (i = 0, j = 0; i < argc; i++) { |
| 1704 | trace_probe_log_set_index(i + 2); |
| 1705 | if (i == args_idx) { |
| 1706 | for (n = 0; n < ctx->nr_params; n++) { |
| 1707 | ret = sprint_nth_btf_arg(n, "", buf + used, |
| 1708 | bufsize - used, ctx); |
| 1709 | if (ret < 0) |
| 1710 | goto error; |
| 1711 | |
| 1712 | new_argv[j++] = buf + used; |
| 1713 | used += ret + 1; |
| 1714 | } |
| 1715 | continue; |
| 1716 | } |
| 1717 | |
| 1718 | if (str_has_prefix(argv[i], "$arg")) { |
| 1719 | char *type = NULL; |
| 1720 | |
| 1721 | n = simple_strtoul(argv[i] + 4, &type, 10); |
| 1722 | if (type && !(*type == ':' || *type == '\0')) { |
| 1723 | trace_probe_log_err(0, BAD_VAR); |
| 1724 | ret = -ENOENT; |
| 1725 | goto error; |
| 1726 | } |
| 1727 | /* Note: $argN starts from $arg1 */ |
| 1728 | ret = sprint_nth_btf_arg(n - 1, type, buf + used, |
| 1729 | bufsize - used, ctx); |
| 1730 | if (ret < 0) |
| 1731 | goto error; |
| 1732 | new_argv[j++] = buf + used; |
| 1733 | used += ret + 1; |
| 1734 | } else |
| 1735 | new_argv[j++] = argv[i]; |
| 1736 | } |
| 1737 | |
| 1738 | return new_argv; |
| 1739 | |
| 1740 | error: |
| 1741 | kfree(new_argv); |
| 1742 | return ERR_PTR(ret); |
| 1743 | } |
| 1744 | |
| 1745 | /* @buf: *buf must be equal to NULL. Caller must to free *buf */ |
| 1746 | int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) |
| 1747 | { |
| 1748 | int i, used, ret; |
| 1749 | const int bufsize = MAX_DENTRY_ARGS_LEN; |
| 1750 | char *tmpbuf = NULL; |
| 1751 | |
| 1752 | if (*buf) |
| 1753 | return -EINVAL; |
| 1754 | |
| 1755 | used = 0; |
| 1756 | for (i = 0; i < argc; i++) { |
| 1757 | char *tmp; |
| 1758 | char *equal; |
| 1759 | size_t arg_len; |
| 1760 | |
| 1761 | if (!glob_match("*:%p[dD]", argv[i])) |
| 1762 | continue; |
| 1763 | |
| 1764 | if (!tmpbuf) { |
| 1765 | tmpbuf = kmalloc(bufsize, GFP_KERNEL); |
| 1766 | if (!tmpbuf) |
| 1767 | return -ENOMEM; |
| 1768 | } |
| 1769 | |
| 1770 | tmp = kstrdup(argv[i], GFP_KERNEL); |
| 1771 | if (!tmp) |
| 1772 | goto nomem; |
| 1773 | |
| 1774 | equal = strchr(tmp, '='); |
| 1775 | if (equal) |
| 1776 | *equal = '\0'; |
| 1777 | arg_len = strlen(argv[i]); |
| 1778 | tmp[arg_len - 4] = '\0'; |
| 1779 | if (argv[i][arg_len - 1] == 'd') |
| 1780 | ret = snprintf(tmpbuf + used, bufsize - used, |
| 1781 | "%s%s+0x0(+0x%zx(%s)):string", |
| 1782 | equal ? tmp : "", equal ? "=" : "", |
| 1783 | offsetof(struct dentry, d_name.name), |
| 1784 | equal ? equal + 1 : tmp); |
| 1785 | else |
| 1786 | ret = snprintf(tmpbuf + used, bufsize - used, |
| 1787 | "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", |
| 1788 | equal ? tmp : "", equal ? "=" : "", |
| 1789 | offsetof(struct dentry, d_name.name), |
| 1790 | offsetof(struct file, f_path.dentry), |
| 1791 | equal ? equal + 1 : tmp); |
| 1792 | |
| 1793 | kfree(tmp); |
| 1794 | if (ret >= bufsize - used) |
| 1795 | goto nomem; |
| 1796 | argv[i] = tmpbuf + used; |
| 1797 | used += ret + 1; |
| 1798 | } |
| 1799 | |
| 1800 | *buf = tmpbuf; |
| 1801 | return 0; |
| 1802 | nomem: |
| 1803 | kfree(tmpbuf); |
| 1804 | return -ENOMEM; |
| 1805 | } |
| 1806 | |
| 1807 | void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) |
| 1808 | { |
| 1809 | clear_btf_context(ctx); |
| 1810 | } |
| 1811 | |
| 1812 | int traceprobe_update_arg(struct probe_arg *arg) |
| 1813 | { |
| 1814 | struct fetch_insn *code = arg->code; |
| 1815 | long offset; |
| 1816 | char *tmp; |
| 1817 | char c; |
| 1818 | int ret = 0; |
| 1819 | |
| 1820 | while (code && code->op != FETCH_OP_END) { |
| 1821 | if (code->op == FETCH_NOP_SYMBOL) { |
| 1822 | if (code[1].op != FETCH_OP_IMM) |
| 1823 | return -EINVAL; |
| 1824 | |
| 1825 | tmp = strpbrk(code->data, "+-"); |
| 1826 | if (tmp) |
| 1827 | c = *tmp; |
| 1828 | ret = traceprobe_split_symbol_offset(code->data, |
| 1829 | &offset); |
| 1830 | if (ret) |
| 1831 | return ret; |
| 1832 | |
| 1833 | code[1].immediate = |
| 1834 | (unsigned long)kallsyms_lookup_name(code->data); |
| 1835 | if (tmp) |
| 1836 | *tmp = c; |
| 1837 | if (!code[1].immediate) |
| 1838 | return -ENOENT; |
| 1839 | code[1].immediate += offset; |
| 1840 | } |
| 1841 | code++; |
| 1842 | } |
| 1843 | return 0; |
| 1844 | } |
| 1845 | |
| 1846 | /* When len=0, we just calculate the needed length */ |
| 1847 | #define LEN_OR_ZERO (len ? len - pos : 0) |
| 1848 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, |
| 1849 | enum probe_print_type ptype) |
| 1850 | { |
| 1851 | struct probe_arg *parg; |
| 1852 | int i, j; |
| 1853 | int pos = 0; |
| 1854 | const char *fmt, *arg; |
| 1855 | |
| 1856 | switch (ptype) { |
| 1857 | case PROBE_PRINT_NORMAL: |
| 1858 | fmt = "(%lx)"; |
| 1859 | arg = ", REC->" FIELD_STRING_IP; |
| 1860 | break; |
| 1861 | case PROBE_PRINT_RETURN: |
| 1862 | fmt = "(%lx <- %lx)"; |
| 1863 | arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; |
| 1864 | break; |
| 1865 | case PROBE_PRINT_EVENT: |
| 1866 | fmt = ""; |
| 1867 | arg = ""; |
| 1868 | break; |
| 1869 | default: |
| 1870 | WARN_ON_ONCE(1); |
| 1871 | return 0; |
| 1872 | } |
| 1873 | |
| 1874 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); |
| 1875 | |
| 1876 | for (i = 0; i < tp->nr_args; i++) { |
| 1877 | parg = tp->args + i; |
| 1878 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); |
| 1879 | if (parg->count) { |
| 1880 | pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", |
| 1881 | parg->type->fmt); |
| 1882 | for (j = 1; j < parg->count; j++) |
| 1883 | pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", |
| 1884 | parg->type->fmt); |
| 1885 | pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); |
| 1886 | } else |
| 1887 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", |
| 1888 | parg->type->fmt); |
| 1889 | } |
| 1890 | |
| 1891 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); |
| 1892 | |
| 1893 | for (i = 0; i < tp->nr_args; i++) { |
| 1894 | parg = tp->args + i; |
| 1895 | if (parg->count) { |
| 1896 | if (parg->type->is_string) |
| 1897 | fmt = ", __get_str(%s[%d])"; |
| 1898 | else |
| 1899 | fmt = ", REC->%s[%d]"; |
| 1900 | for (j = 0; j < parg->count; j++) |
| 1901 | pos += snprintf(buf + pos, LEN_OR_ZERO, |
| 1902 | fmt, parg->name, j); |
| 1903 | } else { |
| 1904 | if (parg->type->is_string) |
| 1905 | fmt = ", __get_str(%s)"; |
| 1906 | else |
| 1907 | fmt = ", REC->%s"; |
| 1908 | pos += snprintf(buf + pos, LEN_OR_ZERO, |
| 1909 | fmt, parg->name); |
| 1910 | } |
| 1911 | } |
| 1912 | |
| 1913 | /* return the length of print_fmt */ |
| 1914 | return pos; |
| 1915 | } |
| 1916 | #undef LEN_OR_ZERO |
| 1917 | |
| 1918 | int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) |
| 1919 | { |
| 1920 | struct trace_event_call *call = trace_probe_event_call(tp); |
| 1921 | int len; |
| 1922 | char *print_fmt; |
| 1923 | |
| 1924 | /* First: called with 0 length to calculate the needed length */ |
| 1925 | len = __set_print_fmt(tp, NULL, 0, ptype); |
| 1926 | print_fmt = kmalloc(len + 1, GFP_KERNEL); |
| 1927 | if (!print_fmt) |
| 1928 | return -ENOMEM; |
| 1929 | |
| 1930 | /* Second: actually write the @print_fmt */ |
| 1931 | __set_print_fmt(tp, print_fmt, len + 1, ptype); |
| 1932 | call->print_fmt = print_fmt; |
| 1933 | |
| 1934 | return 0; |
| 1935 | } |
| 1936 | |
| 1937 | int traceprobe_define_arg_fields(struct trace_event_call *event_call, |
| 1938 | size_t offset, struct trace_probe *tp) |
| 1939 | { |
| 1940 | int ret, i; |
| 1941 | |
| 1942 | /* Set argument names as fields */ |
| 1943 | for (i = 0; i < tp->nr_args; i++) { |
| 1944 | struct probe_arg *parg = &tp->args[i]; |
| 1945 | const char *fmt = parg->type->fmttype; |
| 1946 | int size = parg->type->size; |
| 1947 | |
| 1948 | if (parg->fmt) |
| 1949 | fmt = parg->fmt; |
| 1950 | if (parg->count) |
| 1951 | size *= parg->count; |
| 1952 | ret = trace_define_field(event_call, fmt, parg->name, |
| 1953 | offset + parg->offset, size, |
| 1954 | parg->type->is_signed, |
| 1955 | FILTER_OTHER); |
| 1956 | if (ret) |
| 1957 | return ret; |
| 1958 | } |
| 1959 | return 0; |
| 1960 | } |
| 1961 | |
| 1962 | static void trace_probe_event_free(struct trace_probe_event *tpe) |
| 1963 | { |
| 1964 | kfree(tpe->class.system); |
| 1965 | kfree(tpe->call.name); |
| 1966 | kfree(tpe->call.print_fmt); |
| 1967 | kfree(tpe); |
| 1968 | } |
| 1969 | |
| 1970 | int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) |
| 1971 | { |
| 1972 | if (trace_probe_has_sibling(tp)) |
| 1973 | return -EBUSY; |
| 1974 | |
| 1975 | list_del_init(&tp->list); |
| 1976 | trace_probe_event_free(tp->event); |
| 1977 | |
| 1978 | tp->event = to->event; |
| 1979 | list_add_tail(&tp->list, trace_probe_probe_list(to)); |
| 1980 | |
| 1981 | return 0; |
| 1982 | } |
| 1983 | |
| 1984 | void trace_probe_unlink(struct trace_probe *tp) |
| 1985 | { |
| 1986 | list_del_init(&tp->list); |
| 1987 | if (list_empty(trace_probe_probe_list(tp))) |
| 1988 | trace_probe_event_free(tp->event); |
| 1989 | tp->event = NULL; |
| 1990 | } |
| 1991 | |
| 1992 | void trace_probe_cleanup(struct trace_probe *tp) |
| 1993 | { |
| 1994 | int i; |
| 1995 | |
| 1996 | for (i = 0; i < tp->nr_args; i++) |
| 1997 | traceprobe_free_probe_arg(&tp->args[i]); |
| 1998 | |
| 1999 | if (tp->entry_arg) { |
| 2000 | kfree(tp->entry_arg->code); |
| 2001 | kfree(tp->entry_arg); |
| 2002 | tp->entry_arg = NULL; |
| 2003 | } |
| 2004 | |
| 2005 | if (tp->event) |
| 2006 | trace_probe_unlink(tp); |
| 2007 | } |
| 2008 | |
| 2009 | int trace_probe_init(struct trace_probe *tp, const char *event, |
| 2010 | const char *group, bool alloc_filter, int nargs) |
| 2011 | { |
| 2012 | struct trace_event_call *call; |
| 2013 | size_t size = sizeof(struct trace_probe_event); |
| 2014 | int ret = 0; |
| 2015 | |
| 2016 | if (!event || !group) |
| 2017 | return -EINVAL; |
| 2018 | |
| 2019 | if (alloc_filter) |
| 2020 | size += sizeof(struct trace_uprobe_filter); |
| 2021 | |
| 2022 | tp->event = kzalloc(size, GFP_KERNEL); |
| 2023 | if (!tp->event) |
| 2024 | return -ENOMEM; |
| 2025 | |
| 2026 | INIT_LIST_HEAD(&tp->event->files); |
| 2027 | INIT_LIST_HEAD(&tp->event->class.fields); |
| 2028 | INIT_LIST_HEAD(&tp->event->probes); |
| 2029 | INIT_LIST_HEAD(&tp->list); |
| 2030 | list_add(&tp->list, &tp->event->probes); |
| 2031 | |
| 2032 | call = trace_probe_event_call(tp); |
| 2033 | call->class = &tp->event->class; |
| 2034 | call->name = kstrdup(event, GFP_KERNEL); |
| 2035 | if (!call->name) { |
| 2036 | ret = -ENOMEM; |
| 2037 | goto error; |
| 2038 | } |
| 2039 | |
| 2040 | tp->event->class.system = kstrdup(group, GFP_KERNEL); |
| 2041 | if (!tp->event->class.system) { |
| 2042 | ret = -ENOMEM; |
| 2043 | goto error; |
| 2044 | } |
| 2045 | |
| 2046 | tp->nr_args = nargs; |
| 2047 | /* Make sure pointers in args[] are NULL */ |
| 2048 | if (nargs) |
| 2049 | memset(tp->args, 0, sizeof(tp->args[0]) * nargs); |
| 2050 | |
| 2051 | return 0; |
| 2052 | |
| 2053 | error: |
| 2054 | trace_probe_cleanup(tp); |
| 2055 | return ret; |
| 2056 | } |
| 2057 | |
| 2058 | static struct trace_event_call * |
| 2059 | find_trace_event_call(const char *system, const char *event_name) |
| 2060 | { |
| 2061 | struct trace_event_call *tp_event; |
| 2062 | const char *name; |
| 2063 | |
| 2064 | list_for_each_entry(tp_event, &ftrace_events, list) { |
| 2065 | if (!tp_event->class->system || |
| 2066 | strcmp(system, tp_event->class->system)) |
| 2067 | continue; |
| 2068 | name = trace_event_name(tp_event); |
| 2069 | if (!name || strcmp(event_name, name)) |
| 2070 | continue; |
| 2071 | return tp_event; |
| 2072 | } |
| 2073 | |
| 2074 | return NULL; |
| 2075 | } |
| 2076 | |
| 2077 | int trace_probe_register_event_call(struct trace_probe *tp) |
| 2078 | { |
| 2079 | struct trace_event_call *call = trace_probe_event_call(tp); |
| 2080 | int ret; |
| 2081 | |
| 2082 | lockdep_assert_held(&event_mutex); |
| 2083 | |
| 2084 | if (find_trace_event_call(trace_probe_group_name(tp), |
| 2085 | trace_probe_name(tp))) |
| 2086 | return -EEXIST; |
| 2087 | |
| 2088 | ret = register_trace_event(&call->event); |
| 2089 | if (!ret) |
| 2090 | return -ENODEV; |
| 2091 | |
| 2092 | ret = trace_add_event_call(call); |
| 2093 | if (ret) |
| 2094 | unregister_trace_event(&call->event); |
| 2095 | |
| 2096 | return ret; |
| 2097 | } |
| 2098 | |
| 2099 | int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) |
| 2100 | { |
| 2101 | struct event_file_link *link; |
| 2102 | |
| 2103 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
| 2104 | if (!link) |
| 2105 | return -ENOMEM; |
| 2106 | |
| 2107 | link->file = file; |
| 2108 | INIT_LIST_HEAD(&link->list); |
| 2109 | list_add_tail_rcu(&link->list, &tp->event->files); |
| 2110 | trace_probe_set_flag(tp, TP_FLAG_TRACE); |
| 2111 | return 0; |
| 2112 | } |
| 2113 | |
| 2114 | struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, |
| 2115 | struct trace_event_file *file) |
| 2116 | { |
| 2117 | struct event_file_link *link; |
| 2118 | |
| 2119 | trace_probe_for_each_link(link, tp) { |
| 2120 | if (link->file == file) |
| 2121 | return link; |
| 2122 | } |
| 2123 | |
| 2124 | return NULL; |
| 2125 | } |
| 2126 | |
| 2127 | int trace_probe_remove_file(struct trace_probe *tp, |
| 2128 | struct trace_event_file *file) |
| 2129 | { |
| 2130 | struct event_file_link *link; |
| 2131 | |
| 2132 | link = trace_probe_get_file_link(tp, file); |
| 2133 | if (!link) |
| 2134 | return -ENOENT; |
| 2135 | |
| 2136 | list_del_rcu(&link->list); |
| 2137 | kvfree_rcu_mightsleep(link); |
| 2138 | |
| 2139 | if (list_empty(&tp->event->files)) |
| 2140 | trace_probe_clear_flag(tp, TP_FLAG_TRACE); |
| 2141 | |
| 2142 | return 0; |
| 2143 | } |
| 2144 | |
| 2145 | /* |
| 2146 | * Return the smallest index of different type argument (start from 1). |
| 2147 | * If all argument types and name are same, return 0. |
| 2148 | */ |
| 2149 | int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) |
| 2150 | { |
| 2151 | int i; |
| 2152 | |
| 2153 | /* In case of more arguments */ |
| 2154 | if (a->nr_args < b->nr_args) |
| 2155 | return a->nr_args + 1; |
| 2156 | if (a->nr_args > b->nr_args) |
| 2157 | return b->nr_args + 1; |
| 2158 | |
| 2159 | for (i = 0; i < a->nr_args; i++) { |
| 2160 | if ((b->nr_args <= i) || |
| 2161 | ((a->args[i].type != b->args[i].type) || |
| 2162 | (a->args[i].count != b->args[i].count) || |
| 2163 | strcmp(a->args[i].name, b->args[i].name))) |
| 2164 | return i + 1; |
| 2165 | } |
| 2166 | |
| 2167 | return 0; |
| 2168 | } |
| 2169 | |
| 2170 | bool trace_probe_match_command_args(struct trace_probe *tp, |
| 2171 | int argc, const char **argv) |
| 2172 | { |
| 2173 | char buf[MAX_ARGSTR_LEN + 1]; |
| 2174 | int i; |
| 2175 | |
| 2176 | if (tp->nr_args < argc) |
| 2177 | return false; |
| 2178 | |
| 2179 | for (i = 0; i < argc; i++) { |
| 2180 | snprintf(buf, sizeof(buf), "%s=%s", |
| 2181 | tp->args[i].name, tp->args[i].comm); |
| 2182 | if (strcmp(buf, argv[i])) |
| 2183 | return false; |
| 2184 | } |
| 2185 | return true; |
| 2186 | } |
| 2187 | |
| 2188 | int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) |
| 2189 | { |
| 2190 | int argc = 0, ret = 0; |
| 2191 | char **argv; |
| 2192 | |
| 2193 | argv = argv_split(GFP_KERNEL, raw_command, &argc); |
| 2194 | if (!argv) |
| 2195 | return -ENOMEM; |
| 2196 | |
| 2197 | if (argc) |
| 2198 | ret = createfn(argc, (const char **)argv); |
| 2199 | |
| 2200 | argv_free(argv); |
| 2201 | |
| 2202 | return ret; |
| 2203 | } |
| 2204 | |
| 2205 | int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, |
| 2206 | u8 *data, void *field) |
| 2207 | { |
| 2208 | void *p; |
| 2209 | int i, j; |
| 2210 | |
| 2211 | for (i = 0; i < nr_args; i++) { |
| 2212 | struct probe_arg *a = args + i; |
| 2213 | |
| 2214 | trace_seq_printf(s, " %s=", a->name); |
| 2215 | if (likely(!a->count)) { |
| 2216 | if (!a->type->print(s, data + a->offset, field)) |
| 2217 | return -ENOMEM; |
| 2218 | continue; |
| 2219 | } |
| 2220 | trace_seq_putc(s, '{'); |
| 2221 | p = data + a->offset; |
| 2222 | for (j = 0; j < a->count; j++) { |
| 2223 | if (!a->type->print(s, p, field)) |
| 2224 | return -ENOMEM; |
| 2225 | trace_seq_putc(s, j == a->count - 1 ? '}' : ','); |
| 2226 | p += a->type->size; |
| 2227 | } |
| 2228 | } |
| 2229 | return 0; |
| 2230 | } |