1 /* 2 * probe-finder.c : C expression to kprobe event converter 3 * 4 * Written by Masami Hiramatsu <mhiramat@redhat.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 * 20 */ 21 22 #include <sys/utsname.h> 23 #include <sys/types.h> 24 #include <sys/stat.h> 25 #include <fcntl.h> 26 #include <errno.h> 27 #include <stdio.h> 28 #include <unistd.h> 29 #include <getopt.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <stdarg.h> 33 #include <dwarf-regs.h> 34 35 #include <linux/bitops.h> 36 #include "event.h" 37 #include "dso.h" 38 #include "debug.h" 39 #include "intlist.h" 40 #include "util.h" 41 #include "symbol.h" 42 #include "probe-finder.h" 43 44 /* Kprobe tracer basic type is up to u64 */ 45 #define MAX_BASIC_TYPE_BITS 64 46 47 /* Dwarf FL wrappers */ 48 static char *debuginfo_path; /* Currently dummy */ 49 50 static const Dwfl_Callbacks offline_callbacks = { 51 .find_debuginfo = dwfl_standard_find_debuginfo, 52 .debuginfo_path = &debuginfo_path, 53 54 .section_address = dwfl_offline_section_address, 55 56 /* We use this table for core files too. */ 57 .find_elf = dwfl_build_id_find_elf, 58 }; 59 60 /* Get a Dwarf from offline image */ 61 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg, 62 const char *path) 63 { 64 int fd; 65 66 fd = open(path, O_RDONLY); 67 if (fd < 0) 68 return fd; 69 70 dbg->dwfl = dwfl_begin(&offline_callbacks); 71 if (!dbg->dwfl) 72 goto error; 73 74 dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd); 75 if (!dbg->mod) 76 goto error; 77 78 dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias); 79 if (!dbg->dbg) 80 goto error; 81 82 return 0; 83 error: 84 if (dbg->dwfl) 85 dwfl_end(dbg->dwfl); 86 else 87 close(fd); 88 memset(dbg, 0, sizeof(*dbg)); 89 90 return -ENOENT; 91 } 92 93 static struct debuginfo *__debuginfo__new(const char *path) 94 { 95 struct debuginfo *dbg = zalloc(sizeof(*dbg)); 96 if (!dbg) 97 return NULL; 98 99 if (debuginfo__init_offline_dwarf(dbg, path) < 0) 100 zfree(&dbg); 101 if (dbg) 102 pr_debug("Open Debuginfo file: %s\n", path); 103 return dbg; 104 } 105 106 enum dso_binary_type distro_dwarf_types[] = { 107 DSO_BINARY_TYPE__FEDORA_DEBUGINFO, 108 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO, 109 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO, 110 DSO_BINARY_TYPE__BUILDID_DEBUGINFO, 111 DSO_BINARY_TYPE__NOT_FOUND, 112 }; 113 114 struct debuginfo *debuginfo__new(const char *path) 115 { 116 enum dso_binary_type *type; 117 char buf[PATH_MAX], nil = '\0'; 118 struct dso *dso; 119 struct debuginfo *dinfo = NULL; 120 121 /* Try to open distro debuginfo files */ 122 dso = dso__new(path); 123 if (!dso) 124 goto out; 125 126 for (type = distro_dwarf_types; 127 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND; 128 type++) { 129 if (dso__read_binary_type_filename(dso, *type, &nil, 130 buf, PATH_MAX) < 0) 131 continue; 132 dinfo = __debuginfo__new(buf); 133 } 134 dso__delete(dso); 135 136 out: 137 /* if failed to open all distro debuginfo, open given binary */ 138 return dinfo ? : __debuginfo__new(path); 139 } 140 141 void debuginfo__delete(struct debuginfo *dbg) 142 { 143 if (dbg) { 144 if (dbg->dwfl) 145 dwfl_end(dbg->dwfl); 146 free(dbg); 147 } 148 } 149 150 /* 151 * Probe finder related functions 152 */ 153 154 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs) 155 { 156 struct probe_trace_arg_ref *ref; 157 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 158 if (ref != NULL) 159 ref->offset = offs; 160 return ref; 161 } 162 163 /* 164 * Convert a location into trace_arg. 165 * If tvar == NULL, this just checks variable can be converted. 166 * If fentry == true and vr_die is a parameter, do huristic search 167 * for the location fuzzed by function entry mcount. 168 */ 169 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, 170 Dwarf_Op *fb_ops, Dwarf_Die *sp_die, 171 struct probe_trace_arg *tvar) 172 { 173 Dwarf_Attribute attr; 174 Dwarf_Addr tmp = 0; 175 Dwarf_Op *op; 176 size_t nops; 177 unsigned int regn; 178 Dwarf_Word offs = 0; 179 bool ref = false; 180 const char *regs; 181 int ret; 182 183 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL) 184 goto static_var; 185 186 /* TODO: handle more than 1 exprs */ 187 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) 188 return -EINVAL; /* Broken DIE ? */ 189 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) { 190 ret = dwarf_entrypc(sp_die, &tmp); 191 if (ret || addr != tmp || 192 dwarf_tag(vr_die) != DW_TAG_formal_parameter || 193 dwarf_highpc(sp_die, &tmp)) 194 return -ENOENT; 195 /* 196 * This is fuzzed by fentry mcount. We try to find the 197 * parameter location at the earliest address. 198 */ 199 for (addr += 1; addr <= tmp; addr++) { 200 if (dwarf_getlocation_addr(&attr, addr, &op, 201 &nops, 1) > 0) 202 goto found; 203 } 204 return -ENOENT; 205 } 206 found: 207 if (nops == 0) 208 /* TODO: Support const_value */ 209 return -ENOENT; 210 211 if (op->atom == DW_OP_addr) { 212 static_var: 213 if (!tvar) 214 return 0; 215 /* Static variables on memory (not stack), make @varname */ 216 ret = strlen(dwarf_diename(vr_die)); 217 tvar->value = zalloc(ret + 2); 218 if (tvar->value == NULL) 219 return -ENOMEM; 220 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die)); 221 tvar->ref = alloc_trace_arg_ref((long)offs); 222 if (tvar->ref == NULL) 223 return -ENOMEM; 224 return 0; 225 } 226 227 /* If this is based on frame buffer, set the offset */ 228 if (op->atom == DW_OP_fbreg) { 229 if (fb_ops == NULL) 230 return -ENOTSUP; 231 ref = true; 232 offs = op->number; 233 op = &fb_ops[0]; 234 } 235 236 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) { 237 regn = op->atom - DW_OP_breg0; 238 offs += op->number; 239 ref = true; 240 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) { 241 regn = op->atom - DW_OP_reg0; 242 } else if (op->atom == DW_OP_bregx) { 243 regn = op->number; 244 offs += op->number2; 245 ref = true; 246 } else if (op->atom == DW_OP_regx) { 247 regn = op->number; 248 } else { 249 pr_debug("DW_OP %x is not supported.\n", op->atom); 250 return -ENOTSUP; 251 } 252 253 if (!tvar) 254 return 0; 255 256 regs = get_arch_regstr(regn); 257 if (!regs) { 258 /* This should be a bug in DWARF or this tool */ 259 pr_warning("Mapping for the register number %u " 260 "missing on this architecture.\n", regn); 261 return -ERANGE; 262 } 263 264 tvar->value = strdup(regs); 265 if (tvar->value == NULL) 266 return -ENOMEM; 267 268 if (ref) { 269 tvar->ref = alloc_trace_arg_ref((long)offs); 270 if (tvar->ref == NULL) 271 return -ENOMEM; 272 } 273 return 0; 274 } 275 276 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long)) 277 278 static int convert_variable_type(Dwarf_Die *vr_die, 279 struct probe_trace_arg *tvar, 280 const char *cast) 281 { 282 struct probe_trace_arg_ref **ref_ptr = &tvar->ref; 283 Dwarf_Die type; 284 char buf[16]; 285 int bsize, boffs, total; 286 int ret; 287 288 /* TODO: check all types */ 289 if (cast && strcmp(cast, "string") != 0) { 290 /* Non string type is OK */ 291 tvar->type = strdup(cast); 292 return (tvar->type == NULL) ? -ENOMEM : 0; 293 } 294 295 bsize = dwarf_bitsize(vr_die); 296 if (bsize > 0) { 297 /* This is a bitfield */ 298 boffs = dwarf_bitoffset(vr_die); 299 total = dwarf_bytesize(vr_die); 300 if (boffs < 0 || total < 0) 301 return -ENOENT; 302 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs, 303 BYTES_TO_BITS(total)); 304 goto formatted; 305 } 306 307 if (die_get_real_type(vr_die, &type) == NULL) { 308 pr_warning("Failed to get a type information of %s.\n", 309 dwarf_diename(vr_die)); 310 return -ENOENT; 311 } 312 313 pr_debug("%s type is %s.\n", 314 dwarf_diename(vr_die), dwarf_diename(&type)); 315 316 if (cast && strcmp(cast, "string") == 0) { /* String type */ 317 ret = dwarf_tag(&type); 318 if (ret != DW_TAG_pointer_type && 319 ret != DW_TAG_array_type) { 320 pr_warning("Failed to cast into string: " 321 "%s(%s) is not a pointer nor array.\n", 322 dwarf_diename(vr_die), dwarf_diename(&type)); 323 return -EINVAL; 324 } 325 if (die_get_real_type(&type, &type) == NULL) { 326 pr_warning("Failed to get a type" 327 " information.\n"); 328 return -ENOENT; 329 } 330 if (ret == DW_TAG_pointer_type) { 331 while (*ref_ptr) 332 ref_ptr = &(*ref_ptr)->next; 333 /* Add new reference with offset +0 */ 334 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); 335 if (*ref_ptr == NULL) { 336 pr_warning("Out of memory error\n"); 337 return -ENOMEM; 338 } 339 } 340 if (!die_compare_name(&type, "char") && 341 !die_compare_name(&type, "unsigned char")) { 342 pr_warning("Failed to cast into string: " 343 "%s is not (unsigned) char *.\n", 344 dwarf_diename(vr_die)); 345 return -EINVAL; 346 } 347 tvar->type = strdup(cast); 348 return (tvar->type == NULL) ? -ENOMEM : 0; 349 } 350 351 ret = dwarf_bytesize(&type); 352 if (ret <= 0) 353 /* No size ... try to use default type */ 354 return 0; 355 ret = BYTES_TO_BITS(ret); 356 357 /* Check the bitwidth */ 358 if (ret > MAX_BASIC_TYPE_BITS) { 359 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n", 360 dwarf_diename(&type), MAX_BASIC_TYPE_BITS); 361 ret = MAX_BASIC_TYPE_BITS; 362 } 363 ret = snprintf(buf, 16, "%c%d", 364 die_is_signed_type(&type) ? 's' : 'u', ret); 365 366 formatted: 367 if (ret < 0 || ret >= 16) { 368 if (ret >= 16) 369 ret = -E2BIG; 370 pr_warning("Failed to convert variable type: %s\n", 371 strerror(-ret)); 372 return ret; 373 } 374 tvar->type = strdup(buf); 375 if (tvar->type == NULL) 376 return -ENOMEM; 377 return 0; 378 } 379 380 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, 381 struct perf_probe_arg_field *field, 382 struct probe_trace_arg_ref **ref_ptr, 383 Dwarf_Die *die_mem) 384 { 385 struct probe_trace_arg_ref *ref = *ref_ptr; 386 Dwarf_Die type; 387 Dwarf_Word offs; 388 int ret, tag; 389 390 pr_debug("converting %s in %s\n", field->name, varname); 391 if (die_get_real_type(vr_die, &type) == NULL) { 392 pr_warning("Failed to get the type of %s.\n", varname); 393 return -ENOENT; 394 } 395 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type)); 396 tag = dwarf_tag(&type); 397 398 if (field->name[0] == '[' && 399 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) { 400 if (field->next) 401 /* Save original type for next field */ 402 memcpy(die_mem, &type, sizeof(*die_mem)); 403 /* Get the type of this array */ 404 if (die_get_real_type(&type, &type) == NULL) { 405 pr_warning("Failed to get the type of %s.\n", varname); 406 return -ENOENT; 407 } 408 pr_debug2("Array real type: (%x)\n", 409 (unsigned)dwarf_dieoffset(&type)); 410 if (tag == DW_TAG_pointer_type) { 411 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 412 if (ref == NULL) 413 return -ENOMEM; 414 if (*ref_ptr) 415 (*ref_ptr)->next = ref; 416 else 417 *ref_ptr = ref; 418 } 419 ref->offset += dwarf_bytesize(&type) * field->index; 420 if (!field->next) 421 /* Save vr_die for converting types */ 422 memcpy(die_mem, vr_die, sizeof(*die_mem)); 423 goto next; 424 } else if (tag == DW_TAG_pointer_type) { 425 /* Check the pointer and dereference */ 426 if (!field->ref) { 427 pr_err("Semantic error: %s must be referred by '->'\n", 428 field->name); 429 return -EINVAL; 430 } 431 /* Get the type pointed by this pointer */ 432 if (die_get_real_type(&type, &type) == NULL) { 433 pr_warning("Failed to get the type of %s.\n", varname); 434 return -ENOENT; 435 } 436 /* Verify it is a data structure */ 437 tag = dwarf_tag(&type); 438 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { 439 pr_warning("%s is not a data structure nor an union.\n", 440 varname); 441 return -EINVAL; 442 } 443 444 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 445 if (ref == NULL) 446 return -ENOMEM; 447 if (*ref_ptr) 448 (*ref_ptr)->next = ref; 449 else 450 *ref_ptr = ref; 451 } else { 452 /* Verify it is a data structure */ 453 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { 454 pr_warning("%s is not a data structure nor an union.\n", 455 varname); 456 return -EINVAL; 457 } 458 if (field->name[0] == '[') { 459 pr_err("Semantic error: %s is not a pointor" 460 " nor array.\n", varname); 461 return -EINVAL; 462 } 463 if (field->ref) { 464 pr_err("Semantic error: %s must be referred by '.'\n", 465 field->name); 466 return -EINVAL; 467 } 468 if (!ref) { 469 pr_warning("Structure on a register is not " 470 "supported yet.\n"); 471 return -ENOTSUP; 472 } 473 } 474 475 if (die_find_member(&type, field->name, die_mem) == NULL) { 476 pr_warning("%s(type:%s) has no member %s.\n", varname, 477 dwarf_diename(&type), field->name); 478 return -EINVAL; 479 } 480 481 /* Get the offset of the field */ 482 if (tag == DW_TAG_union_type) { 483 offs = 0; 484 } else { 485 ret = die_get_data_member_location(die_mem, &offs); 486 if (ret < 0) { 487 pr_warning("Failed to get the offset of %s.\n", 488 field->name); 489 return ret; 490 } 491 } 492 ref->offset += (long)offs; 493 494 next: 495 /* Converting next field */ 496 if (field->next) 497 return convert_variable_fields(die_mem, field->name, 498 field->next, &ref, die_mem); 499 else 500 return 0; 501 } 502 503 /* Show a variables in kprobe event format */ 504 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) 505 { 506 Dwarf_Die die_mem; 507 int ret; 508 509 pr_debug("Converting variable %s into trace event.\n", 510 dwarf_diename(vr_die)); 511 512 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, 513 &pf->sp_die, pf->tvar); 514 if (ret == -ENOENT) 515 pr_err("Failed to find the location of %s at this address.\n" 516 " Perhaps, it has been optimized out.\n", pf->pvar->var); 517 else if (ret == -ENOTSUP) 518 pr_err("Sorry, we don't support this variable location yet.\n"); 519 else if (pf->pvar->field) { 520 ret = convert_variable_fields(vr_die, pf->pvar->var, 521 pf->pvar->field, &pf->tvar->ref, 522 &die_mem); 523 vr_die = &die_mem; 524 } 525 if (ret == 0) 526 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); 527 /* *expr will be cached in libdw. Don't free it. */ 528 return ret; 529 } 530 531 /* Find a variable in a scope DIE */ 532 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf) 533 { 534 Dwarf_Die vr_die; 535 char buf[32], *ptr; 536 int ret = 0; 537 538 if (!is_c_varname(pf->pvar->var)) { 539 /* Copy raw parameters */ 540 pf->tvar->value = strdup(pf->pvar->var); 541 if (pf->tvar->value == NULL) 542 return -ENOMEM; 543 if (pf->pvar->type) { 544 pf->tvar->type = strdup(pf->pvar->type); 545 if (pf->tvar->type == NULL) 546 return -ENOMEM; 547 } 548 if (pf->pvar->name) { 549 pf->tvar->name = strdup(pf->pvar->name); 550 if (pf->tvar->name == NULL) 551 return -ENOMEM; 552 } else 553 pf->tvar->name = NULL; 554 return 0; 555 } 556 557 if (pf->pvar->name) 558 pf->tvar->name = strdup(pf->pvar->name); 559 else { 560 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32); 561 if (ret < 0) 562 return ret; 563 ptr = strchr(buf, ':'); /* Change type separator to _ */ 564 if (ptr) 565 *ptr = '_'; 566 pf->tvar->name = strdup(buf); 567 } 568 if (pf->tvar->name == NULL) 569 return -ENOMEM; 570 571 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var); 572 /* Search child die for local variables and parameters. */ 573 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) { 574 /* Search again in global variables */ 575 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die)) 576 ret = -ENOENT; 577 } 578 if (ret >= 0) 579 ret = convert_variable(&vr_die, pf); 580 581 if (ret < 0) 582 pr_warning("Failed to find '%s' in this function.\n", 583 pf->pvar->var); 584 return ret; 585 } 586 587 /* Convert subprogram DIE to trace point */ 588 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, 589 Dwarf_Addr paddr, bool retprobe, 590 struct probe_trace_point *tp) 591 { 592 Dwarf_Addr eaddr, highaddr; 593 GElf_Sym sym; 594 const char *symbol; 595 596 /* Verify the address is correct */ 597 if (dwarf_entrypc(sp_die, &eaddr) != 0) { 598 pr_warning("Failed to get entry address of %s\n", 599 dwarf_diename(sp_die)); 600 return -ENOENT; 601 } 602 if (dwarf_highpc(sp_die, &highaddr) != 0) { 603 pr_warning("Failed to get end address of %s\n", 604 dwarf_diename(sp_die)); 605 return -ENOENT; 606 } 607 if (paddr > highaddr) { 608 pr_warning("Offset specified is greater than size of %s\n", 609 dwarf_diename(sp_die)); 610 return -EINVAL; 611 } 612 613 /* Get an appropriate symbol from symtab */ 614 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); 615 if (!symbol) { 616 pr_warning("Failed to find symbol at 0x%lx\n", 617 (unsigned long)paddr); 618 return -ENOENT; 619 } 620 tp->offset = (unsigned long)(paddr - sym.st_value); 621 tp->address = (unsigned long)paddr; 622 tp->symbol = strdup(symbol); 623 if (!tp->symbol) 624 return -ENOMEM; 625 626 /* Return probe must be on the head of a subprogram */ 627 if (retprobe) { 628 if (eaddr != paddr) { 629 pr_warning("Return probe must be on the head of" 630 " a real function.\n"); 631 return -EINVAL; 632 } 633 tp->retprobe = true; 634 } 635 636 return 0; 637 } 638 639 /* Call probe_finder callback with scope DIE */ 640 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) 641 { 642 Dwarf_Attribute fb_attr; 643 size_t nops; 644 int ret; 645 646 if (!sc_die) { 647 pr_err("Caller must pass a scope DIE. Program error.\n"); 648 return -EINVAL; 649 } 650 651 /* If not a real subprogram, find a real one */ 652 if (!die_is_func_def(sc_die)) { 653 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { 654 pr_warning("Failed to find probe point in any " 655 "functions.\n"); 656 return -ENOENT; 657 } 658 } else 659 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die)); 660 661 /* Get the frame base attribute/ops from subprogram */ 662 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr); 663 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); 664 if (ret <= 0 || nops == 0) { 665 pf->fb_ops = NULL; 666 #if _ELFUTILS_PREREQ(0, 142) 667 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && 668 pf->cfi != NULL) { 669 Dwarf_Frame *frame; 670 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || 671 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { 672 pr_warning("Failed to get call frame on 0x%jx\n", 673 (uintmax_t)pf->addr); 674 return -ENOENT; 675 } 676 #endif 677 } 678 679 /* Call finder's callback handler */ 680 ret = pf->callback(sc_die, pf); 681 682 /* *pf->fb_ops will be cached in libdw. Don't free it. */ 683 pf->fb_ops = NULL; 684 685 return ret; 686 } 687 688 struct find_scope_param { 689 const char *function; 690 const char *file; 691 int line; 692 int diff; 693 Dwarf_Die *die_mem; 694 bool found; 695 }; 696 697 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data) 698 { 699 struct find_scope_param *fsp = data; 700 const char *file; 701 int lno; 702 703 /* Skip if declared file name does not match */ 704 if (fsp->file) { 705 file = dwarf_decl_file(fn_die); 706 if (!file || strcmp(fsp->file, file) != 0) 707 return 0; 708 } 709 /* If the function name is given, that's what user expects */ 710 if (fsp->function) { 711 if (die_compare_name(fn_die, fsp->function)) { 712 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); 713 fsp->found = true; 714 return 1; 715 } 716 } else { 717 /* With the line number, find the nearest declared DIE */ 718 dwarf_decl_line(fn_die, &lno); 719 if (lno < fsp->line && fsp->diff > fsp->line - lno) { 720 /* Keep a candidate and continue */ 721 fsp->diff = fsp->line - lno; 722 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); 723 fsp->found = true; 724 } 725 } 726 return 0; 727 } 728 729 /* Find an appropriate scope fits to given conditions */ 730 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem) 731 { 732 struct find_scope_param fsp = { 733 .function = pf->pev->point.function, 734 .file = pf->fname, 735 .line = pf->lno, 736 .diff = INT_MAX, 737 .die_mem = die_mem, 738 .found = false, 739 }; 740 741 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp); 742 743 return fsp.found ? die_mem : NULL; 744 } 745 746 static int probe_point_line_walker(const char *fname, int lineno, 747 Dwarf_Addr addr, void *data) 748 { 749 struct probe_finder *pf = data; 750 Dwarf_Die *sc_die, die_mem; 751 int ret; 752 753 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0) 754 return 0; 755 756 pf->addr = addr; 757 sc_die = find_best_scope(pf, &die_mem); 758 if (!sc_die) { 759 pr_warning("Failed to find scope of probe point.\n"); 760 return -ENOENT; 761 } 762 763 ret = call_probe_finder(sc_die, pf); 764 765 /* Continue if no error, because the line will be in inline function */ 766 return ret < 0 ? ret : 0; 767 } 768 769 /* Find probe point from its line number */ 770 static int find_probe_point_by_line(struct probe_finder *pf) 771 { 772 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf); 773 } 774 775 /* Find lines which match lazy pattern */ 776 static int find_lazy_match_lines(struct intlist *list, 777 const char *fname, const char *pat) 778 { 779 FILE *fp; 780 char *line = NULL; 781 size_t line_len; 782 ssize_t len; 783 int count = 0, linenum = 1; 784 785 fp = fopen(fname, "r"); 786 if (!fp) { 787 pr_warning("Failed to open %s: %s\n", fname, strerror(errno)); 788 return -errno; 789 } 790 791 while ((len = getline(&line, &line_len, fp)) > 0) { 792 793 if (line[len - 1] == '\n') 794 line[len - 1] = '\0'; 795 796 if (strlazymatch(line, pat)) { 797 intlist__add(list, linenum); 798 count++; 799 } 800 linenum++; 801 } 802 803 if (ferror(fp)) 804 count = -errno; 805 free(line); 806 fclose(fp); 807 808 if (count == 0) 809 pr_debug("No matched lines found in %s.\n", fname); 810 return count; 811 } 812 813 static int probe_point_lazy_walker(const char *fname, int lineno, 814 Dwarf_Addr addr, void *data) 815 { 816 struct probe_finder *pf = data; 817 Dwarf_Die *sc_die, die_mem; 818 int ret; 819 820 if (!intlist__has_entry(pf->lcache, lineno) || 821 strtailcmp(fname, pf->fname) != 0) 822 return 0; 823 824 pr_debug("Probe line found: line:%d addr:0x%llx\n", 825 lineno, (unsigned long long)addr); 826 pf->addr = addr; 827 pf->lno = lineno; 828 sc_die = find_best_scope(pf, &die_mem); 829 if (!sc_die) { 830 pr_warning("Failed to find scope of probe point.\n"); 831 return -ENOENT; 832 } 833 834 ret = call_probe_finder(sc_die, pf); 835 836 /* 837 * Continue if no error, because the lazy pattern will match 838 * to other lines 839 */ 840 return ret < 0 ? ret : 0; 841 } 842 843 /* Find probe points from lazy pattern */ 844 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf) 845 { 846 int ret = 0; 847 848 if (intlist__empty(pf->lcache)) { 849 /* Matching lazy line pattern */ 850 ret = find_lazy_match_lines(pf->lcache, pf->fname, 851 pf->pev->point.lazy_line); 852 if (ret <= 0) 853 return ret; 854 } 855 856 return die_walk_lines(sp_die, probe_point_lazy_walker, pf); 857 } 858 859 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) 860 { 861 struct probe_finder *pf = data; 862 struct perf_probe_point *pp = &pf->pev->point; 863 Dwarf_Addr addr; 864 int ret; 865 866 if (pp->lazy_line) 867 ret = find_probe_point_lazy(in_die, pf); 868 else { 869 /* Get probe address */ 870 if (dwarf_entrypc(in_die, &addr) != 0) { 871 pr_warning("Failed to get entry address of %s.\n", 872 dwarf_diename(in_die)); 873 return -ENOENT; 874 } 875 pf->addr = addr; 876 pf->addr += pp->offset; 877 pr_debug("found inline addr: 0x%jx\n", 878 (uintmax_t)pf->addr); 879 880 ret = call_probe_finder(in_die, pf); 881 } 882 883 return ret; 884 } 885 886 /* Callback parameter with return value for libdw */ 887 struct dwarf_callback_param { 888 void *data; 889 int retval; 890 }; 891 892 /* Search function from function name */ 893 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) 894 { 895 struct dwarf_callback_param *param = data; 896 struct probe_finder *pf = param->data; 897 struct perf_probe_point *pp = &pf->pev->point; 898 899 /* Check tag and diename */ 900 if (!die_is_func_def(sp_die) || 901 !die_compare_name(sp_die, pp->function)) 902 return DWARF_CB_OK; 903 904 /* Check declared file */ 905 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) 906 return DWARF_CB_OK; 907 908 pf->fname = dwarf_decl_file(sp_die); 909 if (pp->line) { /* Function relative line */ 910 dwarf_decl_line(sp_die, &pf->lno); 911 pf->lno += pp->line; 912 param->retval = find_probe_point_by_line(pf); 913 } else if (!dwarf_func_inline(sp_die)) { 914 /* Real function */ 915 if (pp->lazy_line) 916 param->retval = find_probe_point_lazy(sp_die, pf); 917 else { 918 if (dwarf_entrypc(sp_die, &pf->addr) != 0) { 919 pr_warning("Failed to get entry address of " 920 "%s.\n", dwarf_diename(sp_die)); 921 param->retval = -ENOENT; 922 return DWARF_CB_ABORT; 923 } 924 pf->addr += pp->offset; 925 /* TODO: Check the address in this function */ 926 param->retval = call_probe_finder(sp_die, pf); 927 } 928 } else 929 /* Inlined function: search instances */ 930 param->retval = die_walk_instances(sp_die, 931 probe_point_inline_cb, (void *)pf); 932 933 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */ 934 } 935 936 static int find_probe_point_by_func(struct probe_finder *pf) 937 { 938 struct dwarf_callback_param _param = {.data = (void *)pf, 939 .retval = 0}; 940 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0); 941 return _param.retval; 942 } 943 944 struct pubname_callback_param { 945 char *function; 946 char *file; 947 Dwarf_Die *cu_die; 948 Dwarf_Die *sp_die; 949 int found; 950 }; 951 952 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data) 953 { 954 struct pubname_callback_param *param = data; 955 956 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) { 957 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram) 958 return DWARF_CB_OK; 959 960 if (die_compare_name(param->sp_die, param->function)) { 961 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die)) 962 return DWARF_CB_OK; 963 964 if (param->file && 965 strtailcmp(param->file, dwarf_decl_file(param->sp_die))) 966 return DWARF_CB_OK; 967 968 param->found = 1; 969 return DWARF_CB_ABORT; 970 } 971 } 972 973 return DWARF_CB_OK; 974 } 975 976 /* Find probe points from debuginfo */ 977 static int debuginfo__find_probes(struct debuginfo *dbg, 978 struct probe_finder *pf) 979 { 980 struct perf_probe_point *pp = &pf->pev->point; 981 Dwarf_Off off, noff; 982 size_t cuhl; 983 Dwarf_Die *diep; 984 int ret = 0; 985 986 #if _ELFUTILS_PREREQ(0, 142) 987 /* Get the call frame information from this dwarf */ 988 pf->cfi = dwarf_getcfi(dbg->dbg); 989 #endif 990 991 off = 0; 992 pf->lcache = intlist__new(NULL); 993 if (!pf->lcache) 994 return -ENOMEM; 995 996 /* Fastpath: lookup by function name from .debug_pubnames section */ 997 if (pp->function) { 998 struct pubname_callback_param pubname_param = { 999 .function = pp->function, 1000 .file = pp->file, 1001 .cu_die = &pf->cu_die, 1002 .sp_die = &pf->sp_die, 1003 .found = 0, 1004 }; 1005 struct dwarf_callback_param probe_param = { 1006 .data = pf, 1007 }; 1008 1009 dwarf_getpubnames(dbg->dbg, pubname_search_cb, 1010 &pubname_param, 0); 1011 if (pubname_param.found) { 1012 ret = probe_point_search_cb(&pf->sp_die, &probe_param); 1013 if (ret) 1014 goto found; 1015 } 1016 } 1017 1018 /* Loop on CUs (Compilation Unit) */ 1019 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { 1020 /* Get the DIE(Debugging Information Entry) of this CU */ 1021 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die); 1022 if (!diep) 1023 continue; 1024 1025 /* Check if target file is included. */ 1026 if (pp->file) 1027 pf->fname = cu_find_realpath(&pf->cu_die, pp->file); 1028 else 1029 pf->fname = NULL; 1030 1031 if (!pp->file || pf->fname) { 1032 if (pp->function) 1033 ret = find_probe_point_by_func(pf); 1034 else if (pp->lazy_line) 1035 ret = find_probe_point_lazy(NULL, pf); 1036 else { 1037 pf->lno = pp->line; 1038 ret = find_probe_point_by_line(pf); 1039 } 1040 if (ret < 0) 1041 break; 1042 } 1043 off = noff; 1044 } 1045 1046 found: 1047 intlist__delete(pf->lcache); 1048 pf->lcache = NULL; 1049 1050 return ret; 1051 } 1052 1053 struct local_vars_finder { 1054 struct probe_finder *pf; 1055 struct perf_probe_arg *args; 1056 int max_args; 1057 int nargs; 1058 int ret; 1059 }; 1060 1061 /* Collect available variables in this scope */ 1062 static int copy_variables_cb(Dwarf_Die *die_mem, void *data) 1063 { 1064 struct local_vars_finder *vf = data; 1065 struct probe_finder *pf = vf->pf; 1066 int tag; 1067 1068 tag = dwarf_tag(die_mem); 1069 if (tag == DW_TAG_formal_parameter || 1070 tag == DW_TAG_variable) { 1071 if (convert_variable_location(die_mem, vf->pf->addr, 1072 vf->pf->fb_ops, &pf->sp_die, 1073 NULL) == 0) { 1074 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem); 1075 if (vf->args[vf->nargs].var == NULL) { 1076 vf->ret = -ENOMEM; 1077 return DIE_FIND_CB_END; 1078 } 1079 pr_debug(" %s", vf->args[vf->nargs].var); 1080 vf->nargs++; 1081 } 1082 } 1083 1084 if (dwarf_haspc(die_mem, vf->pf->addr)) 1085 return DIE_FIND_CB_CONTINUE; 1086 else 1087 return DIE_FIND_CB_SIBLING; 1088 } 1089 1090 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf, 1091 struct perf_probe_arg *args) 1092 { 1093 Dwarf_Die die_mem; 1094 int i; 1095 int n = 0; 1096 struct local_vars_finder vf = {.pf = pf, .args = args, 1097 .max_args = MAX_PROBE_ARGS, .ret = 0}; 1098 1099 for (i = 0; i < pf->pev->nargs; i++) { 1100 /* var never be NULL */ 1101 if (strcmp(pf->pev->args[i].var, "$vars") == 0) { 1102 pr_debug("Expanding $vars into:"); 1103 vf.nargs = n; 1104 /* Special local variables */ 1105 die_find_child(sc_die, copy_variables_cb, (void *)&vf, 1106 &die_mem); 1107 pr_debug(" (%d)\n", vf.nargs - n); 1108 if (vf.ret < 0) 1109 return vf.ret; 1110 n = vf.nargs; 1111 } else { 1112 /* Copy normal argument */ 1113 args[n] = pf->pev->args[i]; 1114 n++; 1115 } 1116 } 1117 return n; 1118 } 1119 1120 /* Add a found probe point into trace event list */ 1121 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) 1122 { 1123 struct trace_event_finder *tf = 1124 container_of(pf, struct trace_event_finder, pf); 1125 struct probe_trace_event *tev; 1126 struct perf_probe_arg *args; 1127 int ret, i; 1128 1129 /* Check number of tevs */ 1130 if (tf->ntevs == tf->max_tevs) { 1131 pr_warning("Too many( > %d) probe point found.\n", 1132 tf->max_tevs); 1133 return -ERANGE; 1134 } 1135 tev = &tf->tevs[tf->ntevs++]; 1136 1137 /* Trace point should be converted from subprogram DIE */ 1138 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr, 1139 pf->pev->point.retprobe, &tev->point); 1140 if (ret < 0) 1141 return ret; 1142 1143 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, 1144 tev->point.offset); 1145 1146 /* Expand special probe argument if exist */ 1147 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS); 1148 if (args == NULL) 1149 return -ENOMEM; 1150 1151 ret = expand_probe_args(sc_die, pf, args); 1152 if (ret < 0) 1153 goto end; 1154 1155 tev->nargs = ret; 1156 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); 1157 if (tev->args == NULL) { 1158 ret = -ENOMEM; 1159 goto end; 1160 } 1161 1162 /* Find each argument */ 1163 for (i = 0; i < tev->nargs; i++) { 1164 pf->pvar = &args[i]; 1165 pf->tvar = &tev->args[i]; 1166 /* Variable should be found from scope DIE */ 1167 ret = find_variable(sc_die, pf); 1168 if (ret != 0) 1169 break; 1170 } 1171 1172 end: 1173 free(args); 1174 return ret; 1175 } 1176 1177 /* Find probe_trace_events specified by perf_probe_event from debuginfo */ 1178 int debuginfo__find_trace_events(struct debuginfo *dbg, 1179 struct perf_probe_event *pev, 1180 struct probe_trace_event **tevs, int max_tevs) 1181 { 1182 struct trace_event_finder tf = { 1183 .pf = {.pev = pev, .callback = add_probe_trace_event}, 1184 .mod = dbg->mod, .max_tevs = max_tevs}; 1185 int ret; 1186 1187 /* Allocate result tevs array */ 1188 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs); 1189 if (*tevs == NULL) 1190 return -ENOMEM; 1191 1192 tf.tevs = *tevs; 1193 tf.ntevs = 0; 1194 1195 ret = debuginfo__find_probes(dbg, &tf.pf); 1196 if (ret < 0) { 1197 zfree(tevs); 1198 return ret; 1199 } 1200 1201 return (ret < 0) ? ret : tf.ntevs; 1202 } 1203 1204 #define MAX_VAR_LEN 64 1205 1206 /* Collect available variables in this scope */ 1207 static int collect_variables_cb(Dwarf_Die *die_mem, void *data) 1208 { 1209 struct available_var_finder *af = data; 1210 struct variable_list *vl; 1211 char buf[MAX_VAR_LEN]; 1212 int tag, ret; 1213 1214 vl = &af->vls[af->nvls - 1]; 1215 1216 tag = dwarf_tag(die_mem); 1217 if (tag == DW_TAG_formal_parameter || 1218 tag == DW_TAG_variable) { 1219 ret = convert_variable_location(die_mem, af->pf.addr, 1220 af->pf.fb_ops, &af->pf.sp_die, 1221 NULL); 1222 if (ret == 0) { 1223 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN); 1224 pr_debug2("Add new var: %s\n", buf); 1225 if (ret > 0) 1226 strlist__add(vl->vars, buf); 1227 } 1228 } 1229 1230 if (af->child && dwarf_haspc(die_mem, af->pf.addr)) 1231 return DIE_FIND_CB_CONTINUE; 1232 else 1233 return DIE_FIND_CB_SIBLING; 1234 } 1235 1236 /* Add a found vars into available variables list */ 1237 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf) 1238 { 1239 struct available_var_finder *af = 1240 container_of(pf, struct available_var_finder, pf); 1241 struct variable_list *vl; 1242 Dwarf_Die die_mem; 1243 int ret; 1244 1245 /* Check number of tevs */ 1246 if (af->nvls == af->max_vls) { 1247 pr_warning("Too many( > %d) probe point found.\n", af->max_vls); 1248 return -ERANGE; 1249 } 1250 vl = &af->vls[af->nvls++]; 1251 1252 /* Trace point should be converted from subprogram DIE */ 1253 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr, 1254 pf->pev->point.retprobe, &vl->point); 1255 if (ret < 0) 1256 return ret; 1257 1258 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol, 1259 vl->point.offset); 1260 1261 /* Find local variables */ 1262 vl->vars = strlist__new(true, NULL); 1263 if (vl->vars == NULL) 1264 return -ENOMEM; 1265 af->child = true; 1266 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem); 1267 1268 /* Find external variables */ 1269 if (!af->externs) 1270 goto out; 1271 /* Don't need to search child DIE for externs. */ 1272 af->child = false; 1273 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem); 1274 1275 out: 1276 if (strlist__empty(vl->vars)) { 1277 strlist__delete(vl->vars); 1278 vl->vars = NULL; 1279 } 1280 1281 return ret; 1282 } 1283 1284 /* Find available variables at given probe point */ 1285 int debuginfo__find_available_vars_at(struct debuginfo *dbg, 1286 struct perf_probe_event *pev, 1287 struct variable_list **vls, 1288 int max_vls, bool externs) 1289 { 1290 struct available_var_finder af = { 1291 .pf = {.pev = pev, .callback = add_available_vars}, 1292 .mod = dbg->mod, 1293 .max_vls = max_vls, .externs = externs}; 1294 int ret; 1295 1296 /* Allocate result vls array */ 1297 *vls = zalloc(sizeof(struct variable_list) * max_vls); 1298 if (*vls == NULL) 1299 return -ENOMEM; 1300 1301 af.vls = *vls; 1302 af.nvls = 0; 1303 1304 ret = debuginfo__find_probes(dbg, &af.pf); 1305 if (ret < 0) { 1306 /* Free vlist for error */ 1307 while (af.nvls--) { 1308 zfree(&af.vls[af.nvls].point.symbol); 1309 strlist__delete(af.vls[af.nvls].vars); 1310 } 1311 zfree(vls); 1312 return ret; 1313 } 1314 1315 return (ret < 0) ? ret : af.nvls; 1316 } 1317 1318 /* Reverse search */ 1319 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr, 1320 struct perf_probe_point *ppt) 1321 { 1322 Dwarf_Die cudie, spdie, indie; 1323 Dwarf_Addr _addr = 0, baseaddr = 0; 1324 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp; 1325 int baseline = 0, lineno = 0, ret = 0; 1326 1327 /* Adjust address with bias */ 1328 addr += dbg->bias; 1329 1330 /* Find cu die */ 1331 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) { 1332 pr_warning("Failed to find debug information for address %lx\n", 1333 addr); 1334 ret = -EINVAL; 1335 goto end; 1336 } 1337 1338 /* Find a corresponding line (filename and lineno) */ 1339 cu_find_lineinfo(&cudie, addr, &fname, &lineno); 1340 /* Don't care whether it failed or not */ 1341 1342 /* Find a corresponding function (name, baseline and baseaddr) */ 1343 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) { 1344 /* Get function entry information */ 1345 func = basefunc = dwarf_diename(&spdie); 1346 if (!func || 1347 dwarf_entrypc(&spdie, &baseaddr) != 0 || 1348 dwarf_decl_line(&spdie, &baseline) != 0) { 1349 lineno = 0; 1350 goto post; 1351 } 1352 1353 fname = dwarf_decl_file(&spdie); 1354 if (addr == (unsigned long)baseaddr) { 1355 /* Function entry - Relative line number is 0 */ 1356 lineno = baseline; 1357 goto post; 1358 } 1359 1360 /* Track down the inline functions step by step */ 1361 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr, 1362 &indie)) { 1363 /* There is an inline function */ 1364 if (dwarf_entrypc(&indie, &_addr) == 0 && 1365 _addr == addr) { 1366 /* 1367 * addr is at an inline function entry. 1368 * In this case, lineno should be the call-site 1369 * line number. (overwrite lineinfo) 1370 */ 1371 lineno = die_get_call_lineno(&indie); 1372 fname = die_get_call_file(&indie); 1373 break; 1374 } else { 1375 /* 1376 * addr is in an inline function body. 1377 * Since lineno points one of the lines 1378 * of the inline function, baseline should 1379 * be the entry line of the inline function. 1380 */ 1381 tmp = dwarf_diename(&indie); 1382 if (!tmp || 1383 dwarf_decl_line(&indie, &baseline) != 0) 1384 break; 1385 func = tmp; 1386 spdie = indie; 1387 } 1388 } 1389 /* Verify the lineno and baseline are in a same file */ 1390 tmp = dwarf_decl_file(&spdie); 1391 if (!tmp || strcmp(tmp, fname) != 0) 1392 lineno = 0; 1393 } 1394 1395 post: 1396 /* Make a relative line number or an offset */ 1397 if (lineno) 1398 ppt->line = lineno - baseline; 1399 else if (basefunc) { 1400 ppt->offset = addr - (unsigned long)baseaddr; 1401 func = basefunc; 1402 } 1403 1404 /* Duplicate strings */ 1405 if (func) { 1406 ppt->function = strdup(func); 1407 if (ppt->function == NULL) { 1408 ret = -ENOMEM; 1409 goto end; 1410 } 1411 } 1412 if (fname) { 1413 ppt->file = strdup(fname); 1414 if (ppt->file == NULL) { 1415 zfree(&ppt->function); 1416 ret = -ENOMEM; 1417 goto end; 1418 } 1419 } 1420 end: 1421 if (ret == 0 && (fname || func)) 1422 ret = 1; /* Found a point */ 1423 return ret; 1424 } 1425 1426 /* Add a line and store the src path */ 1427 static int line_range_add_line(const char *src, unsigned int lineno, 1428 struct line_range *lr) 1429 { 1430 /* Copy source path */ 1431 if (!lr->path) { 1432 lr->path = strdup(src); 1433 if (lr->path == NULL) 1434 return -ENOMEM; 1435 } 1436 return intlist__add(lr->line_list, lineno); 1437 } 1438 1439 static int line_range_walk_cb(const char *fname, int lineno, 1440 Dwarf_Addr addr __maybe_unused, 1441 void *data) 1442 { 1443 struct line_finder *lf = data; 1444 1445 if ((strtailcmp(fname, lf->fname) != 0) || 1446 (lf->lno_s > lineno || lf->lno_e < lineno)) 1447 return 0; 1448 1449 if (line_range_add_line(fname, lineno, lf->lr) < 0) 1450 return -EINVAL; 1451 1452 return 0; 1453 } 1454 1455 /* Find line range from its line number */ 1456 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf) 1457 { 1458 int ret; 1459 1460 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf); 1461 1462 /* Update status */ 1463 if (ret >= 0) 1464 if (!intlist__empty(lf->lr->line_list)) 1465 ret = lf->found = 1; 1466 else 1467 ret = 0; /* Lines are not found */ 1468 else { 1469 zfree(&lf->lr->path); 1470 } 1471 return ret; 1472 } 1473 1474 static int line_range_inline_cb(Dwarf_Die *in_die, void *data) 1475 { 1476 find_line_range_by_line(in_die, data); 1477 1478 /* 1479 * We have to check all instances of inlined function, because 1480 * some execution paths can be optimized out depends on the 1481 * function argument of instances 1482 */ 1483 return 0; 1484 } 1485 1486 /* Search function definition from function name */ 1487 static int line_range_search_cb(Dwarf_Die *sp_die, void *data) 1488 { 1489 struct dwarf_callback_param *param = data; 1490 struct line_finder *lf = param->data; 1491 struct line_range *lr = lf->lr; 1492 1493 /* Check declared file */ 1494 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) 1495 return DWARF_CB_OK; 1496 1497 if (die_is_func_def(sp_die) && 1498 die_compare_name(sp_die, lr->function)) { 1499 lf->fname = dwarf_decl_file(sp_die); 1500 dwarf_decl_line(sp_die, &lr->offset); 1501 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); 1502 lf->lno_s = lr->offset + lr->start; 1503 if (lf->lno_s < 0) /* Overflow */ 1504 lf->lno_s = INT_MAX; 1505 lf->lno_e = lr->offset + lr->end; 1506 if (lf->lno_e < 0) /* Overflow */ 1507 lf->lno_e = INT_MAX; 1508 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e); 1509 lr->start = lf->lno_s; 1510 lr->end = lf->lno_e; 1511 if (dwarf_func_inline(sp_die)) 1512 param->retval = die_walk_instances(sp_die, 1513 line_range_inline_cb, lf); 1514 else 1515 param->retval = find_line_range_by_line(sp_die, lf); 1516 return DWARF_CB_ABORT; 1517 } 1518 return DWARF_CB_OK; 1519 } 1520 1521 static int find_line_range_by_func(struct line_finder *lf) 1522 { 1523 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0}; 1524 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0); 1525 return param.retval; 1526 } 1527 1528 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr) 1529 { 1530 struct line_finder lf = {.lr = lr, .found = 0}; 1531 int ret = 0; 1532 Dwarf_Off off = 0, noff; 1533 size_t cuhl; 1534 Dwarf_Die *diep; 1535 const char *comp_dir; 1536 1537 /* Fastpath: lookup by function name from .debug_pubnames section */ 1538 if (lr->function) { 1539 struct pubname_callback_param pubname_param = { 1540 .function = lr->function, .file = lr->file, 1541 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0}; 1542 struct dwarf_callback_param line_range_param = { 1543 .data = (void *)&lf, .retval = 0}; 1544 1545 dwarf_getpubnames(dbg->dbg, pubname_search_cb, 1546 &pubname_param, 0); 1547 if (pubname_param.found) { 1548 line_range_search_cb(&lf.sp_die, &line_range_param); 1549 if (lf.found) 1550 goto found; 1551 } 1552 } 1553 1554 /* Loop on CUs (Compilation Unit) */ 1555 while (!lf.found && ret >= 0) { 1556 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, 1557 NULL, NULL, NULL) != 0) 1558 break; 1559 1560 /* Get the DIE(Debugging Information Entry) of this CU */ 1561 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die); 1562 if (!diep) 1563 continue; 1564 1565 /* Check if target file is included. */ 1566 if (lr->file) 1567 lf.fname = cu_find_realpath(&lf.cu_die, lr->file); 1568 else 1569 lf.fname = 0; 1570 1571 if (!lr->file || lf.fname) { 1572 if (lr->function) 1573 ret = find_line_range_by_func(&lf); 1574 else { 1575 lf.lno_s = lr->start; 1576 lf.lno_e = lr->end; 1577 ret = find_line_range_by_line(NULL, &lf); 1578 } 1579 } 1580 off = noff; 1581 } 1582 1583 found: 1584 /* Store comp_dir */ 1585 if (lf.found) { 1586 comp_dir = cu_get_comp_dir(&lf.cu_die); 1587 if (comp_dir) { 1588 lr->comp_dir = strdup(comp_dir); 1589 if (!lr->comp_dir) 1590 ret = -ENOMEM; 1591 } 1592 } 1593 1594 pr_debug("path: %s\n", lr->path); 1595 return (ret < 0) ? ret : lf.found; 1596 } 1597 1598