1 /* 2 * probe-finder.c : C expression to kprobe event converter 3 * 4 * Written by Masami Hiramatsu <mhiramat (at) 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 "debug.h" 38 #include "util.h" 39 #include "symbol.h" 40 #include "probe-finder.h" 41 42 /* Kprobe tracer basic type is up to u64 */ 43 #define MAX_BASIC_TYPE_BITS 64 44 45 /* Line number list operations */ 46 47 /* Add a line to line number list */ 48 static int line_list__add_line(struct list_head *head, int line) 49 { 50 struct line_node *ln; 51 struct list_head *p; 52 53 /* Reverse search, because new line will be the last one */ 54 list_for_each_entry_reverse(ln, head, list) { 55 if (ln->line < line) { 56 p = &ln->list; 57 goto found; 58 } else if (ln->line == line) /* Already exist */ 59 return 1; 60 } 61 /* List is empty, or the smallest entry */ 62 p = head; 63 found: 64 pr_debug("line list: add a line %u\n", line); 65 ln = zalloc(sizeof(struct line_node)); 66 if (ln == NULL) 67 return -ENOMEM; 68 ln->line = line; 69 INIT_LIST_HEAD(&ln->list); 70 list_add(&ln->list, p); 71 return 0; 72 } 73 74 /* Check if the line in line number list */ 75 static int line_list__has_line(struct list_head *head, int line) 76 { 77 struct line_node *ln; 78 79 /* Reverse search, because new line will be the last one */ 80 list_for_each_entry(ln, head, list) 81 if (ln->line == line) 82 return 1; 83 84 return 0; 85 } 86 87 /* Init line number list */ 88 static void line_list__init(struct list_head *head) 89 { 90 INIT_LIST_HEAD(head); 91 } 92 93 /* Free line number list */ 94 static void line_list__free(struct list_head *head) 95 { 96 struct line_node *ln; 97 while (!list_empty(head)) { 98 ln = list_first_entry(head, struct line_node, list); 99 list_del(&ln->list); 100 free(ln); 101 } 102 } 103 104 /* Dwarf FL wrappers */ 105 static char *debuginfo_path; /* Currently dummy */ 106 107 static const Dwfl_Callbacks offline_callbacks = { 108 .find_debuginfo = dwfl_standard_find_debuginfo, 109 .debuginfo_path = &debuginfo_path, 110 111 .section_address = dwfl_offline_section_address, 112 113 /* We use this table for core files too. */ 114 .find_elf = dwfl_build_id_find_elf, 115 }; 116 117 /* Get a Dwarf from offline image */ 118 static int debuginfo__init_offline_dwarf(struct debuginfo *self, 119 const char *path) 120 { 121 int fd; 122 123 fd = open(path, O_RDONLY); 124 if (fd < 0) 125 return fd; 126 127 self->dwfl = dwfl_begin(&offline_callbacks); 128 if (!self->dwfl) 129 goto error; 130 131 self->mod = dwfl_report_offline(self->dwfl, "", "", fd); 132 if (!self->mod) 133 goto error; 134 135 self->dbg = dwfl_module_getdwarf(self->mod, &self->bias); 136 if (!self->dbg) 137 goto error; 138 139 return 0; 140 error: 141 if (self->dwfl) 142 dwfl_end(self->dwfl); 143 else 144 close(fd); 145 memset(self, 0, sizeof(*self)); 146 147 return -ENOENT; 148 } 149 150 /* 151 * ANDROID LOCAL PATCH 152 * Bionic doesn't have stdio_ext.h which is used by dwfl_linux_kernel_find_elf. 153 * So we just disable the new feature here even though we are pairing perf with 154 * elfutils 0.153 now. 155 */ 156 #if _ELFUTILS_PREREQ(0, 148) && 0 157 /* This method is buggy if elfutils is older than 0.148 */ 158 static int __linux_kernel_find_elf(Dwfl_Module *mod, 159 void **userdata, 160 const char *module_name, 161 Dwarf_Addr base, 162 char **file_name, Elf **elfp) 163 { 164 int fd; 165 const char *path = kernel_get_module_path(module_name); 166 167 pr_debug2("Use file %s for %s\n", path, module_name); 168 if (path) { 169 fd = open(path, O_RDONLY); 170 if (fd >= 0) { 171 *file_name = strdup(path); 172 return fd; 173 } 174 } 175 /* If failed, try to call standard method */ 176 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base, 177 file_name, elfp); 178 } 179 180 static const Dwfl_Callbacks kernel_callbacks = { 181 .find_debuginfo = dwfl_standard_find_debuginfo, 182 .debuginfo_path = &debuginfo_path, 183 184 .find_elf = __linux_kernel_find_elf, 185 .section_address = dwfl_linux_kernel_module_section_address, 186 }; 187 188 /* Get a Dwarf from live kernel image */ 189 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self, 190 Dwarf_Addr addr) 191 { 192 self->dwfl = dwfl_begin(&kernel_callbacks); 193 if (!self->dwfl) 194 return -EINVAL; 195 196 /* Load the kernel dwarves: Don't care the result here */ 197 dwfl_linux_kernel_report_kernel(self->dwfl); 198 dwfl_linux_kernel_report_modules(self->dwfl); 199 200 self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias); 201 /* Here, check whether we could get a real dwarf */ 202 if (!self->dbg) { 203 pr_debug("Failed to find kernel dwarf at %lx\n", 204 (unsigned long)addr); 205 dwfl_end(self->dwfl); 206 memset(self, 0, sizeof(*self)); 207 return -ENOENT; 208 } 209 210 return 0; 211 } 212 #else 213 /* With older elfutils, this just support kernel module... */ 214 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self, 215 Dwarf_Addr addr __maybe_unused) 216 { 217 const char *path = kernel_get_module_path("kernel"); 218 219 if (!path) { 220 pr_err("Failed to find vmlinux path\n"); 221 return -ENOENT; 222 } 223 224 pr_debug2("Use file %s for debuginfo\n", path); 225 return debuginfo__init_offline_dwarf(self, path); 226 } 227 #endif 228 229 struct debuginfo *debuginfo__new(const char *path) 230 { 231 struct debuginfo *self = zalloc(sizeof(struct debuginfo)); 232 if (!self) 233 return NULL; 234 235 if (debuginfo__init_offline_dwarf(self, path) < 0) { 236 free(self); 237 self = NULL; 238 } 239 240 return self; 241 } 242 243 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr) 244 { 245 struct debuginfo *self = zalloc(sizeof(struct debuginfo)); 246 if (!self) 247 return NULL; 248 249 if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) { 250 free(self); 251 self = NULL; 252 } 253 254 return self; 255 } 256 257 void debuginfo__delete(struct debuginfo *self) 258 { 259 if (self) { 260 if (self->dwfl) 261 dwfl_end(self->dwfl); 262 free(self); 263 } 264 } 265 266 /* 267 * Probe finder related functions 268 */ 269 270 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs) 271 { 272 struct probe_trace_arg_ref *ref; 273 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 274 if (ref != NULL) 275 ref->offset = offs; 276 return ref; 277 } 278 279 /* 280 * Convert a location into trace_arg. 281 * If tvar == NULL, this just checks variable can be converted. 282 */ 283 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, 284 Dwarf_Op *fb_ops, 285 struct probe_trace_arg *tvar) 286 { 287 Dwarf_Attribute attr; 288 Dwarf_Op *op; 289 size_t nops; 290 unsigned int regn; 291 Dwarf_Word offs = 0; 292 bool ref = false; 293 const char *regs; 294 int ret; 295 296 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL) 297 goto static_var; 298 299 /* TODO: handle more than 1 exprs */ 300 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL || 301 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 || 302 nops == 0) { 303 /* TODO: Support const_value */ 304 return -ENOENT; 305 } 306 307 if (op->atom == DW_OP_addr) { 308 static_var: 309 if (!tvar) 310 return 0; 311 /* Static variables on memory (not stack), make @varname */ 312 ret = strlen(dwarf_diename(vr_die)); 313 tvar->value = zalloc(ret + 2); 314 if (tvar->value == NULL) 315 return -ENOMEM; 316 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die)); 317 tvar->ref = alloc_trace_arg_ref((long)offs); 318 if (tvar->ref == NULL) 319 return -ENOMEM; 320 return 0; 321 } 322 323 /* If this is based on frame buffer, set the offset */ 324 if (op->atom == DW_OP_fbreg) { 325 if (fb_ops == NULL) 326 return -ENOTSUP; 327 ref = true; 328 offs = op->number; 329 op = &fb_ops[0]; 330 } 331 332 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) { 333 regn = op->atom - DW_OP_breg0; 334 offs += op->number; 335 ref = true; 336 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) { 337 regn = op->atom - DW_OP_reg0; 338 } else if (op->atom == DW_OP_bregx) { 339 regn = op->number; 340 offs += op->number2; 341 ref = true; 342 } else if (op->atom == DW_OP_regx) { 343 regn = op->number; 344 } else { 345 pr_debug("DW_OP %x is not supported.\n", op->atom); 346 return -ENOTSUP; 347 } 348 349 if (!tvar) 350 return 0; 351 352 regs = get_arch_regstr(regn); 353 if (!regs) { 354 /* This should be a bug in DWARF or this tool */ 355 pr_warning("Mapping for the register number %u " 356 "missing on this architecture.\n", regn); 357 return -ERANGE; 358 } 359 360 tvar->value = strdup(regs); 361 if (tvar->value == NULL) 362 return -ENOMEM; 363 364 if (ref) { 365 tvar->ref = alloc_trace_arg_ref((long)offs); 366 if (tvar->ref == NULL) 367 return -ENOMEM; 368 } 369 return 0; 370 } 371 372 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long)) 373 374 static int convert_variable_type(Dwarf_Die *vr_die, 375 struct probe_trace_arg *tvar, 376 const char *cast) 377 { 378 struct probe_trace_arg_ref **ref_ptr = &tvar->ref; 379 Dwarf_Die type; 380 char buf[16]; 381 int bsize, boffs, total; 382 int ret; 383 384 /* TODO: check all types */ 385 if (cast && strcmp(cast, "string") != 0) { 386 /* Non string type is OK */ 387 tvar->type = strdup(cast); 388 return (tvar->type == NULL) ? -ENOMEM : 0; 389 } 390 391 bsize = dwarf_bitsize(vr_die); 392 if (bsize > 0) { 393 /* This is a bitfield */ 394 boffs = dwarf_bitoffset(vr_die); 395 total = dwarf_bytesize(vr_die); 396 if (boffs < 0 || total < 0) 397 return -ENOENT; 398 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs, 399 BYTES_TO_BITS(total)); 400 goto formatted; 401 } 402 403 if (die_get_real_type(vr_die, &type) == NULL) { 404 pr_warning("Failed to get a type information of %s.\n", 405 dwarf_diename(vr_die)); 406 return -ENOENT; 407 } 408 409 pr_debug("%s type is %s.\n", 410 dwarf_diename(vr_die), dwarf_diename(&type)); 411 412 if (cast && strcmp(cast, "string") == 0) { /* String type */ 413 ret = dwarf_tag(&type); 414 if (ret != DW_TAG_pointer_type && 415 ret != DW_TAG_array_type) { 416 pr_warning("Failed to cast into string: " 417 "%s(%s) is not a pointer nor array.\n", 418 dwarf_diename(vr_die), dwarf_diename(&type)); 419 return -EINVAL; 420 } 421 if (die_get_real_type(&type, &type) == NULL) { 422 pr_warning("Failed to get a type" 423 " information.\n"); 424 return -ENOENT; 425 } 426 if (ret == DW_TAG_pointer_type) { 427 while (*ref_ptr) 428 ref_ptr = &(*ref_ptr)->next; 429 /* Add new reference with offset +0 */ 430 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); 431 if (*ref_ptr == NULL) { 432 pr_warning("Out of memory error\n"); 433 return -ENOMEM; 434 } 435 } 436 if (!die_compare_name(&type, "char") && 437 !die_compare_name(&type, "unsigned char")) { 438 pr_warning("Failed to cast into string: " 439 "%s is not (unsigned) char *.\n", 440 dwarf_diename(vr_die)); 441 return -EINVAL; 442 } 443 tvar->type = strdup(cast); 444 return (tvar->type == NULL) ? -ENOMEM : 0; 445 } 446 447 ret = dwarf_bytesize(&type); 448 if (ret <= 0) 449 /* No size ... try to use default type */ 450 return 0; 451 ret = BYTES_TO_BITS(ret); 452 453 /* Check the bitwidth */ 454 if (ret > MAX_BASIC_TYPE_BITS) { 455 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n", 456 dwarf_diename(&type), MAX_BASIC_TYPE_BITS); 457 ret = MAX_BASIC_TYPE_BITS; 458 } 459 ret = snprintf(buf, 16, "%c%d", 460 die_is_signed_type(&type) ? 's' : 'u', ret); 461 462 formatted: 463 if (ret < 0 || ret >= 16) { 464 if (ret >= 16) 465 ret = -E2BIG; 466 pr_warning("Failed to convert variable type: %s\n", 467 strerror(-ret)); 468 return ret; 469 } 470 tvar->type = strdup(buf); 471 if (tvar->type == NULL) 472 return -ENOMEM; 473 return 0; 474 } 475 476 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, 477 struct perf_probe_arg_field *field, 478 struct probe_trace_arg_ref **ref_ptr, 479 Dwarf_Die *die_mem) 480 { 481 struct probe_trace_arg_ref *ref = *ref_ptr; 482 Dwarf_Die type; 483 Dwarf_Word offs; 484 int ret, tag; 485 486 pr_debug("converting %s in %s\n", field->name, varname); 487 if (die_get_real_type(vr_die, &type) == NULL) { 488 pr_warning("Failed to get the type of %s.\n", varname); 489 return -ENOENT; 490 } 491 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type)); 492 tag = dwarf_tag(&type); 493 494 if (field->name[0] == '[' && 495 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) { 496 if (field->next) 497 /* Save original type for next field */ 498 memcpy(die_mem, &type, sizeof(*die_mem)); 499 /* Get the type of this array */ 500 if (die_get_real_type(&type, &type) == NULL) { 501 pr_warning("Failed to get the type of %s.\n", varname); 502 return -ENOENT; 503 } 504 pr_debug2("Array real type: (%x)\n", 505 (unsigned)dwarf_dieoffset(&type)); 506 if (tag == DW_TAG_pointer_type) { 507 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 508 if (ref == NULL) 509 return -ENOMEM; 510 if (*ref_ptr) 511 (*ref_ptr)->next = ref; 512 else 513 *ref_ptr = ref; 514 } 515 ref->offset += dwarf_bytesize(&type) * field->index; 516 if (!field->next) 517 /* Save vr_die for converting types */ 518 memcpy(die_mem, vr_die, sizeof(*die_mem)); 519 goto next; 520 } else if (tag == DW_TAG_pointer_type) { 521 /* Check the pointer and dereference */ 522 if (!field->ref) { 523 pr_err("Semantic error: %s must be referred by '->'\n", 524 field->name); 525 return -EINVAL; 526 } 527 /* Get the type pointed by this pointer */ 528 if (die_get_real_type(&type, &type) == NULL) { 529 pr_warning("Failed to get the type of %s.\n", varname); 530 return -ENOENT; 531 } 532 /* Verify it is a data structure */ 533 tag = dwarf_tag(&type); 534 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { 535 pr_warning("%s is not a data structure nor an union.\n", 536 varname); 537 return -EINVAL; 538 } 539 540 ref = zalloc(sizeof(struct probe_trace_arg_ref)); 541 if (ref == NULL) 542 return -ENOMEM; 543 if (*ref_ptr) 544 (*ref_ptr)->next = ref; 545 else 546 *ref_ptr = ref; 547 } else { 548 /* Verify it is a data structure */ 549 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { 550 pr_warning("%s is not a data structure nor an union.\n", 551 varname); 552 return -EINVAL; 553 } 554 if (field->name[0] == '[') { 555 pr_err("Semantic error: %s is not a pointor" 556 " nor array.\n", varname); 557 return -EINVAL; 558 } 559 if (field->ref) { 560 pr_err("Semantic error: %s must be referred by '.'\n", 561 field->name); 562 return -EINVAL; 563 } 564 if (!ref) { 565 pr_warning("Structure on a register is not " 566 "supported yet.\n"); 567 return -ENOTSUP; 568 } 569 } 570 571 if (die_find_member(&type, field->name, die_mem) == NULL) { 572 pr_warning("%s(tyep:%s) has no member %s.\n", varname, 573 dwarf_diename(&type), field->name); 574 return -EINVAL; 575 } 576 577 /* Get the offset of the field */ 578 if (tag == DW_TAG_union_type) { 579 offs = 0; 580 } else { 581 ret = die_get_data_member_location(die_mem, &offs); 582 if (ret < 0) { 583 pr_warning("Failed to get the offset of %s.\n", 584 field->name); 585 return ret; 586 } 587 } 588 ref->offset += (long)offs; 589 590 next: 591 /* Converting next field */ 592 if (field->next) 593 return convert_variable_fields(die_mem, field->name, 594 field->next, &ref, die_mem); 595 else 596 return 0; 597 } 598 599 /* Show a variables in kprobe event format */ 600 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) 601 { 602 Dwarf_Die die_mem; 603 int ret; 604 605 pr_debug("Converting variable %s into trace event.\n", 606 dwarf_diename(vr_die)); 607 608 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, 609 pf->tvar); 610 if (ret == -ENOENT) 611 pr_err("Failed to find the location of %s at this address.\n" 612 " Perhaps, it has been optimized out.\n", pf->pvar->var); 613 else if (ret == -ENOTSUP) 614 pr_err("Sorry, we don't support this variable location yet.\n"); 615 else if (pf->pvar->field) { 616 ret = convert_variable_fields(vr_die, pf->pvar->var, 617 pf->pvar->field, &pf->tvar->ref, 618 &die_mem); 619 vr_die = &die_mem; 620 } 621 if (ret == 0) 622 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); 623 /* *expr will be cached in libdw. Don't free it. */ 624 return ret; 625 } 626 627 /* Find a variable in a scope DIE */ 628 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf) 629 { 630 Dwarf_Die vr_die; 631 char buf[32], *ptr; 632 int ret = 0; 633 634 if (!is_c_varname(pf->pvar->var)) { 635 /* Copy raw parameters */ 636 pf->tvar->value = strdup(pf->pvar->var); 637 if (pf->tvar->value == NULL) 638 return -ENOMEM; 639 if (pf->pvar->type) { 640 pf->tvar->type = strdup(pf->pvar->type); 641 if (pf->tvar->type == NULL) 642 return -ENOMEM; 643 } 644 if (pf->pvar->name) { 645 pf->tvar->name = strdup(pf->pvar->name); 646 if (pf->tvar->name == NULL) 647 return -ENOMEM; 648 } else 649 pf->tvar->name = NULL; 650 return 0; 651 } 652 653 if (pf->pvar->name) 654 pf->tvar->name = strdup(pf->pvar->name); 655 else { 656 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32); 657 if (ret < 0) 658 return ret; 659 ptr = strchr(buf, ':'); /* Change type separator to _ */ 660 if (ptr) 661 *ptr = '_'; 662 pf->tvar->name = strdup(buf); 663 } 664 if (pf->tvar->name == NULL) 665 return -ENOMEM; 666 667 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var); 668 /* Search child die for local variables and parameters. */ 669 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) { 670 /* Search again in global variables */ 671 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die)) 672 ret = -ENOENT; 673 } 674 if (ret >= 0) 675 ret = convert_variable(&vr_die, pf); 676 677 if (ret < 0) 678 pr_warning("Failed to find '%s' in this function.\n", 679 pf->pvar->var); 680 return ret; 681 } 682 683 /* Convert subprogram DIE to trace point */ 684 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, 685 Dwarf_Addr paddr, bool retprobe, 686 struct probe_trace_point *tp) 687 { 688 Dwarf_Addr eaddr, highaddr; 689 GElf_Sym sym; 690 const char *symbol; 691 692 /* Verify the address is correct */ 693 if (dwarf_entrypc(sp_die, &eaddr) != 0) { 694 pr_warning("Failed to get entry address of %s\n", 695 dwarf_diename(sp_die)); 696 return -ENOENT; 697 } 698 if (dwarf_highpc(sp_die, &highaddr) != 0) { 699 pr_warning("Failed to get end address of %s\n", 700 dwarf_diename(sp_die)); 701 return -ENOENT; 702 } 703 if (paddr > highaddr) { 704 pr_warning("Offset specified is greater than size of %s\n", 705 dwarf_diename(sp_die)); 706 return -EINVAL; 707 } 708 709 /* Get an appropriate symbol from symtab */ 710 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); 711 if (!symbol) { 712 pr_warning("Failed to find symbol at 0x%lx\n", 713 (unsigned long)paddr); 714 return -ENOENT; 715 } 716 tp->offset = (unsigned long)(paddr - sym.st_value); 717 tp->symbol = strdup(symbol); 718 if (!tp->symbol) 719 return -ENOMEM; 720 721 /* Return probe must be on the head of a subprogram */ 722 if (retprobe) { 723 if (eaddr != paddr) { 724 pr_warning("Return probe must be on the head of" 725 " a real function.\n"); 726 return -EINVAL; 727 } 728 tp->retprobe = true; 729 } 730 731 return 0; 732 } 733 734 /* Call probe_finder callback with scope DIE */ 735 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) 736 { 737 Dwarf_Attribute fb_attr; 738 size_t nops; 739 int ret; 740 741 if (!sc_die) { 742 pr_err("Caller must pass a scope DIE. Program error.\n"); 743 return -EINVAL; 744 } 745 746 /* If not a real subprogram, find a real one */ 747 if (!die_is_func_def(sc_die)) { 748 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { 749 pr_warning("Failed to find probe point in any " 750 "functions.\n"); 751 return -ENOENT; 752 } 753 } else 754 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die)); 755 756 /* Get the frame base attribute/ops from subprogram */ 757 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr); 758 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); 759 if (ret <= 0 || nops == 0) { 760 pf->fb_ops = NULL; 761 #if _ELFUTILS_PREREQ(0, 142) 762 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && 763 pf->cfi != NULL) { 764 Dwarf_Frame *frame; 765 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || 766 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { 767 pr_warning("Failed to get call frame on 0x%jx\n", 768 (uintmax_t)pf->addr); 769 return -ENOENT; 770 } 771 #endif 772 } 773 774 /* Call finder's callback handler */ 775 ret = pf->callback(sc_die, pf); 776 777 /* *pf->fb_ops will be cached in libdw. Don't free it. */ 778 pf->fb_ops = NULL; 779 780 return ret; 781 } 782 783 struct find_scope_param { 784 const char *function; 785 const char *file; 786 int line; 787 int diff; 788 Dwarf_Die *die_mem; 789 bool found; 790 }; 791 792 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data) 793 { 794 struct find_scope_param *fsp = data; 795 const char *file; 796 int lno; 797 798 /* Skip if declared file name does not match */ 799 if (fsp->file) { 800 file = dwarf_decl_file(fn_die); 801 if (!file || strcmp(fsp->file, file) != 0) 802 return 0; 803 } 804 /* If the function name is given, that's what user expects */ 805 if (fsp->function) { 806 if (die_compare_name(fn_die, fsp->function)) { 807 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); 808 fsp->found = true; 809 return 1; 810 } 811 } else { 812 /* With the line number, find the nearest declared DIE */ 813 dwarf_decl_line(fn_die, &lno); 814 if (lno < fsp->line && fsp->diff > fsp->line - lno) { 815 /* Keep a candidate and continue */ 816 fsp->diff = fsp->line - lno; 817 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); 818 fsp->found = true; 819 } 820 } 821 return 0; 822 } 823 824 /* Find an appropriate scope fits to given conditions */ 825 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem) 826 { 827 struct find_scope_param fsp = { 828 .function = pf->pev->point.function, 829 .file = pf->fname, 830 .line = pf->lno, 831 .diff = INT_MAX, 832 .die_mem = die_mem, 833 .found = false, 834 }; 835 836 cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp); 837 838 return fsp.found ? die_mem : NULL; 839 } 840 841 static int probe_point_line_walker(const char *fname, int lineno, 842 Dwarf_Addr addr, void *data) 843 { 844 struct probe_finder *pf = data; 845 Dwarf_Die *sc_die, die_mem; 846 int ret; 847 848 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0) 849 return 0; 850 851 pf->addr = addr; 852 sc_die = find_best_scope(pf, &die_mem); 853 if (!sc_die) { 854 pr_warning("Failed to find scope of probe point.\n"); 855 return -ENOENT; 856 } 857 858 ret = call_probe_finder(sc_die, pf); 859 860 /* Continue if no error, because the line will be in inline function */ 861 return ret < 0 ? ret : 0; 862 } 863 864 /* Find probe point from its line number */ 865 static int find_probe_point_by_line(struct probe_finder *pf) 866 { 867 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf); 868 } 869 870 /* Find lines which match lazy pattern */ 871 static int find_lazy_match_lines(struct list_head *head, 872 const char *fname, const char *pat) 873 { 874 FILE *fp; 875 char *line = NULL; 876 size_t line_len; 877 ssize_t len; 878 int count = 0, linenum = 1; 879 880 fp = fopen(fname, "r"); 881 if (!fp) { 882 pr_warning("Failed to open %s: %s\n", fname, strerror(errno)); 883 return -errno; 884 } 885 886 while ((len = getline(&line, &line_len, fp)) > 0) { 887 888 if (line[len - 1] == '\n') 889 line[len - 1] = '\0'; 890 891 if (strlazymatch(line, pat)) { 892 line_list__add_line(head, linenum); 893 count++; 894 } 895 linenum++; 896 } 897 898 if (ferror(fp)) 899 count = -errno; 900 free(line); 901 fclose(fp); 902 903 if (count == 0) 904 pr_debug("No matched lines found in %s.\n", fname); 905 return count; 906 } 907 908 static int probe_point_lazy_walker(const char *fname, int lineno, 909 Dwarf_Addr addr, void *data) 910 { 911 struct probe_finder *pf = data; 912 Dwarf_Die *sc_die, die_mem; 913 int ret; 914 915 if (!line_list__has_line(&pf->lcache, lineno) || 916 strtailcmp(fname, pf->fname) != 0) 917 return 0; 918 919 pr_debug("Probe line found: line:%d addr:0x%llx\n", 920 lineno, (unsigned long long)addr); 921 pf->addr = addr; 922 pf->lno = lineno; 923 sc_die = find_best_scope(pf, &die_mem); 924 if (!sc_die) { 925 pr_warning("Failed to find scope of probe point.\n"); 926 return -ENOENT; 927 } 928 929 ret = call_probe_finder(sc_die, pf); 930 931 /* 932 * Continue if no error, because the lazy pattern will match 933 * to other lines 934 */ 935 return ret < 0 ? ret : 0; 936 } 937 938 /* Find probe points from lazy pattern */ 939 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf) 940 { 941 int ret = 0; 942 943 if (list_empty(&pf->lcache)) { 944 /* Matching lazy line pattern */ 945 ret = find_lazy_match_lines(&pf->lcache, pf->fname, 946 pf->pev->point.lazy_line); 947 if (ret <= 0) 948 return ret; 949 } 950 951 return die_walk_lines(sp_die, probe_point_lazy_walker, pf); 952 } 953 954 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) 955 { 956 struct probe_finder *pf = data; 957 struct perf_probe_point *pp = &pf->pev->point; 958 Dwarf_Addr addr; 959 int ret; 960 961 if (pp->lazy_line) 962 ret = find_probe_point_lazy(in_die, pf); 963 else { 964 /* Get probe address */ 965 if (dwarf_entrypc(in_die, &addr) != 0) { 966 pr_warning("Failed to get entry address of %s.\n", 967 dwarf_diename(in_die)); 968 return -ENOENT; 969 } 970 pf->addr = addr; 971 pf->addr += pp->offset; 972 pr_debug("found inline addr: 0x%jx\n", 973 (uintmax_t)pf->addr); 974 975 ret = call_probe_finder(in_die, pf); 976 } 977 978 return ret; 979 } 980 981 /* Callback parameter with return value for libdw */ 982 struct dwarf_callback_param { 983 void *data; 984 int retval; 985 }; 986 987 /* Search function from function name */ 988 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) 989 { 990 struct dwarf_callback_param *param = data; 991 struct probe_finder *pf = param->data; 992 struct perf_probe_point *pp = &pf->pev->point; 993 994 /* Check tag and diename */ 995 if (!die_is_func_def(sp_die) || 996 !die_compare_name(sp_die, pp->function)) 997 return DWARF_CB_OK; 998 999 /* Check declared file */ 1000 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) 1001 return DWARF_CB_OK; 1002 1003 pf->fname = dwarf_decl_file(sp_die); 1004 if (pp->line) { /* Function relative line */ 1005 dwarf_decl_line(sp_die, &pf->lno); 1006 pf->lno += pp->line; 1007 param->retval = find_probe_point_by_line(pf); 1008 } else if (!dwarf_func_inline(sp_die)) { 1009 /* Real function */ 1010 if (pp->lazy_line) 1011 param->retval = find_probe_point_lazy(sp_die, pf); 1012 else { 1013 if (dwarf_entrypc(sp_die, &pf->addr) != 0) { 1014 pr_warning("Failed to get entry address of " 1015 "%s.\n", dwarf_diename(sp_die)); 1016 param->retval = -ENOENT; 1017 return DWARF_CB_ABORT; 1018 } 1019 pf->addr += pp->offset; 1020 /* TODO: Check the address in this function */ 1021 param->retval = call_probe_finder(sp_die, pf); 1022 } 1023 } else 1024 /* Inlined function: search instances */ 1025 param->retval = die_walk_instances(sp_die, 1026 probe_point_inline_cb, (void *)pf); 1027 1028 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */ 1029 } 1030 1031 static int find_probe_point_by_func(struct probe_finder *pf) 1032 { 1033 struct dwarf_callback_param _param = {.data = (void *)pf, 1034 .retval = 0}; 1035 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0); 1036 return _param.retval; 1037 } 1038 1039 struct pubname_callback_param { 1040 char *function; 1041 char *file; 1042 Dwarf_Die *cu_die; 1043 Dwarf_Die *sp_die; 1044 int found; 1045 }; 1046 1047 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data) 1048 { 1049 struct pubname_callback_param *param = data; 1050 1051 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) { 1052 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram) 1053 return DWARF_CB_OK; 1054 1055 if (die_compare_name(param->sp_die, param->function)) { 1056 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die)) 1057 return DWARF_CB_OK; 1058 1059 if (param->file && 1060 strtailcmp(param->file, dwarf_decl_file(param->sp_die))) 1061 return DWARF_CB_OK; 1062 1063 param->found = 1; 1064 return DWARF_CB_ABORT; 1065 } 1066 } 1067 1068 return DWARF_CB_OK; 1069 } 1070 1071 /* Find probe points from debuginfo */ 1072 static int debuginfo__find_probes(struct debuginfo *self, 1073 struct probe_finder *pf) 1074 { 1075 struct perf_probe_point *pp = &pf->pev->point; 1076 Dwarf_Off off, noff; 1077 size_t cuhl; 1078 Dwarf_Die *diep; 1079 int ret = 0; 1080 1081 #if _ELFUTILS_PREREQ(0, 142) 1082 /* Get the call frame information from this dwarf */ 1083 pf->cfi = dwarf_getcfi(self->dbg); 1084 #endif 1085 1086 off = 0; 1087 line_list__init(&pf->lcache); 1088 1089 /* Fastpath: lookup by function name from .debug_pubnames section */ 1090 if (pp->function) { 1091 struct pubname_callback_param pubname_param = { 1092 .function = pp->function, 1093 .file = pp->file, 1094 .cu_die = &pf->cu_die, 1095 .sp_die = &pf->sp_die, 1096 .found = 0, 1097 }; 1098 struct dwarf_callback_param probe_param = { 1099 .data = pf, 1100 }; 1101 1102 dwarf_getpubnames(self->dbg, pubname_search_cb, 1103 &pubname_param, 0); 1104 if (pubname_param.found) { 1105 ret = probe_point_search_cb(&pf->sp_die, &probe_param); 1106 if (ret) 1107 goto found; 1108 } 1109 } 1110 1111 /* Loop on CUs (Compilation Unit) */ 1112 while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { 1113 /* Get the DIE(Debugging Information Entry) of this CU */ 1114 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die); 1115 if (!diep) 1116 continue; 1117 1118 /* Check if target file is included. */ 1119 if (pp->file) 1120 pf->fname = cu_find_realpath(&pf->cu_die, pp->file); 1121 else 1122 pf->fname = NULL; 1123 1124 if (!pp->file || pf->fname) { 1125 if (pp->function) 1126 ret = find_probe_point_by_func(pf); 1127 else if (pp->lazy_line) 1128 ret = find_probe_point_lazy(NULL, pf); 1129 else { 1130 pf->lno = pp->line; 1131 ret = find_probe_point_by_line(pf); 1132 } 1133 if (ret < 0) 1134 break; 1135 } 1136 off = noff; 1137 } 1138 1139 found: 1140 line_list__free(&pf->lcache); 1141 1142 return ret; 1143 } 1144 1145 /* Add a found probe point into trace event list */ 1146 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) 1147 { 1148 struct trace_event_finder *tf = 1149 container_of(pf, struct trace_event_finder, pf); 1150 struct probe_trace_event *tev; 1151 int ret, i; 1152 1153 /* Check number of tevs */ 1154 if (tf->ntevs == tf->max_tevs) { 1155 pr_warning("Too many( > %d) probe point found.\n", 1156 tf->max_tevs); 1157 return -ERANGE; 1158 } 1159 tev = &tf->tevs[tf->ntevs++]; 1160 1161 /* Trace point should be converted from subprogram DIE */ 1162 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr, 1163 pf->pev->point.retprobe, &tev->point); 1164 if (ret < 0) 1165 return ret; 1166 1167 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, 1168 tev->point.offset); 1169 1170 /* Find each argument */ 1171 tev->nargs = pf->pev->nargs; 1172 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); 1173 if (tev->args == NULL) 1174 return -ENOMEM; 1175 for (i = 0; i < pf->pev->nargs; i++) { 1176 pf->pvar = &pf->pev->args[i]; 1177 pf->tvar = &tev->args[i]; 1178 /* Variable should be found from scope DIE */ 1179 ret = find_variable(sc_die, pf); 1180 if (ret != 0) 1181 return ret; 1182 } 1183 1184 return 0; 1185 } 1186 1187 /* Find probe_trace_events specified by perf_probe_event from debuginfo */ 1188 int debuginfo__find_trace_events(struct debuginfo *self, 1189 struct perf_probe_event *pev, 1190 struct probe_trace_event **tevs, int max_tevs) 1191 { 1192 struct trace_event_finder tf = { 1193 .pf = {.pev = pev, .callback = add_probe_trace_event}, 1194 .mod = self->mod, .max_tevs = max_tevs}; 1195 int ret; 1196 1197 /* Allocate result tevs array */ 1198 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs); 1199 if (*tevs == NULL) 1200 return -ENOMEM; 1201 1202 tf.tevs = *tevs; 1203 tf.ntevs = 0; 1204 1205 ret = debuginfo__find_probes(self, &tf.pf); 1206 if (ret < 0) { 1207 free(*tevs); 1208 *tevs = NULL; 1209 return ret; 1210 } 1211 1212 return (ret < 0) ? ret : tf.ntevs; 1213 } 1214 1215 #define MAX_VAR_LEN 64 1216 1217 /* Collect available variables in this scope */ 1218 static int collect_variables_cb(Dwarf_Die *die_mem, void *data) 1219 { 1220 struct available_var_finder *af = data; 1221 struct variable_list *vl; 1222 char buf[MAX_VAR_LEN]; 1223 int tag, ret; 1224 1225 vl = &af->vls[af->nvls - 1]; 1226 1227 tag = dwarf_tag(die_mem); 1228 if (tag == DW_TAG_formal_parameter || 1229 tag == DW_TAG_variable) { 1230 ret = convert_variable_location(die_mem, af->pf.addr, 1231 af->pf.fb_ops, NULL); 1232 if (ret == 0) { 1233 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN); 1234 pr_debug2("Add new var: %s\n", buf); 1235 if (ret > 0) 1236 strlist__add(vl->vars, buf); 1237 } 1238 } 1239 1240 if (af->child && dwarf_haspc(die_mem, af->pf.addr)) 1241 return DIE_FIND_CB_CONTINUE; 1242 else 1243 return DIE_FIND_CB_SIBLING; 1244 } 1245 1246 /* Add a found vars into available variables list */ 1247 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf) 1248 { 1249 struct available_var_finder *af = 1250 container_of(pf, struct available_var_finder, pf); 1251 struct variable_list *vl; 1252 Dwarf_Die die_mem; 1253 int ret; 1254 1255 /* Check number of tevs */ 1256 if (af->nvls == af->max_vls) { 1257 pr_warning("Too many( > %d) probe point found.\n", af->max_vls); 1258 return -ERANGE; 1259 } 1260 vl = &af->vls[af->nvls++]; 1261 1262 /* Trace point should be converted from subprogram DIE */ 1263 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr, 1264 pf->pev->point.retprobe, &vl->point); 1265 if (ret < 0) 1266 return ret; 1267 1268 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol, 1269 vl->point.offset); 1270 1271 /* Find local variables */ 1272 vl->vars = strlist__new(true, NULL); 1273 if (vl->vars == NULL) 1274 return -ENOMEM; 1275 af->child = true; 1276 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem); 1277 1278 /* Find external variables */ 1279 if (!af->externs) 1280 goto out; 1281 /* Don't need to search child DIE for externs. */ 1282 af->child = false; 1283 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem); 1284 1285 out: 1286 if (strlist__empty(vl->vars)) { 1287 strlist__delete(vl->vars); 1288 vl->vars = NULL; 1289 } 1290 1291 return ret; 1292 } 1293 1294 /* Find available variables at given probe point */ 1295 int debuginfo__find_available_vars_at(struct debuginfo *self, 1296 struct perf_probe_event *pev, 1297 struct variable_list **vls, 1298 int max_vls, bool externs) 1299 { 1300 struct available_var_finder af = { 1301 .pf = {.pev = pev, .callback = add_available_vars}, 1302 .mod = self->mod, 1303 .max_vls = max_vls, .externs = externs}; 1304 int ret; 1305 1306 /* Allocate result vls array */ 1307 *vls = zalloc(sizeof(struct variable_list) * max_vls); 1308 if (*vls == NULL) 1309 return -ENOMEM; 1310 1311 af.vls = *vls; 1312 af.nvls = 0; 1313 1314 ret = debuginfo__find_probes(self, &af.pf); 1315 if (ret < 0) { 1316 /* Free vlist for error */ 1317 while (af.nvls--) { 1318 if (af.vls[af.nvls].point.symbol) 1319 free(af.vls[af.nvls].point.symbol); 1320 if (af.vls[af.nvls].vars) 1321 strlist__delete(af.vls[af.nvls].vars); 1322 } 1323 free(af.vls); 1324 *vls = NULL; 1325 return ret; 1326 } 1327 1328 return (ret < 0) ? ret : af.nvls; 1329 } 1330 1331 /* Reverse search */ 1332 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr, 1333 struct perf_probe_point *ppt) 1334 { 1335 Dwarf_Die cudie, spdie, indie; 1336 Dwarf_Addr _addr = 0, baseaddr = 0; 1337 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp; 1338 int baseline = 0, lineno = 0, ret = 0; 1339 1340 /* Adjust address with bias */ 1341 addr += self->bias; 1342 1343 /* Find cu die */ 1344 if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) { 1345 pr_warning("Failed to find debug information for address %lx\n", 1346 addr); 1347 ret = -EINVAL; 1348 goto end; 1349 } 1350 1351 /* Find a corresponding line (filename and lineno) */ 1352 cu_find_lineinfo(&cudie, addr, &fname, &lineno); 1353 /* Don't care whether it failed or not */ 1354 1355 /* Find a corresponding function (name, baseline and baseaddr) */ 1356 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) { 1357 /* Get function entry information */ 1358 func = basefunc = dwarf_diename(&spdie); 1359 if (!func || 1360 dwarf_entrypc(&spdie, &baseaddr) != 0 || 1361 dwarf_decl_line(&spdie, &baseline) != 0) { 1362 lineno = 0; 1363 goto post; 1364 } 1365 1366 fname = dwarf_decl_file(&spdie); 1367 if (addr == (unsigned long)baseaddr) { 1368 /* Function entry - Relative line number is 0 */ 1369 lineno = baseline; 1370 goto post; 1371 } 1372 1373 /* Track down the inline functions step by step */ 1374 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr, 1375 &indie)) { 1376 /* There is an inline function */ 1377 if (dwarf_entrypc(&indie, &_addr) == 0 && 1378 _addr == addr) { 1379 /* 1380 * addr is at an inline function entry. 1381 * In this case, lineno should be the call-site 1382 * line number. (overwrite lineinfo) 1383 */ 1384 lineno = die_get_call_lineno(&indie); 1385 fname = die_get_call_file(&indie); 1386 break; 1387 } else { 1388 /* 1389 * addr is in an inline function body. 1390 * Since lineno points one of the lines 1391 * of the inline function, baseline should 1392 * be the entry line of the inline function. 1393 */ 1394 tmp = dwarf_diename(&indie); 1395 if (!tmp || 1396 dwarf_decl_line(&indie, &baseline) != 0) 1397 break; 1398 func = tmp; 1399 spdie = indie; 1400 } 1401 } 1402 /* Verify the lineno and baseline are in a same file */ 1403 tmp = dwarf_decl_file(&spdie); 1404 if (!tmp || strcmp(tmp, fname) != 0) 1405 lineno = 0; 1406 } 1407 1408 post: 1409 /* Make a relative line number or an offset */ 1410 if (lineno) 1411 ppt->line = lineno - baseline; 1412 else if (basefunc) { 1413 ppt->offset = addr - (unsigned long)baseaddr; 1414 func = basefunc; 1415 } 1416 1417 /* Duplicate strings */ 1418 if (func) { 1419 ppt->function = strdup(func); 1420 if (ppt->function == NULL) { 1421 ret = -ENOMEM; 1422 goto end; 1423 } 1424 } 1425 if (fname) { 1426 ppt->file = strdup(fname); 1427 if (ppt->file == NULL) { 1428 if (ppt->function) { 1429 free(ppt->function); 1430 ppt->function = NULL; 1431 } 1432 ret = -ENOMEM; 1433 goto end; 1434 } 1435 } 1436 end: 1437 if (ret == 0 && (fname || func)) 1438 ret = 1; /* Found a point */ 1439 return ret; 1440 } 1441 1442 /* Add a line and store the src path */ 1443 static int line_range_add_line(const char *src, unsigned int lineno, 1444 struct line_range *lr) 1445 { 1446 /* Copy source path */ 1447 if (!lr->path) { 1448 lr->path = strdup(src); 1449 if (lr->path == NULL) 1450 return -ENOMEM; 1451 } 1452 return line_list__add_line(&lr->line_list, lineno); 1453 } 1454 1455 static int line_range_walk_cb(const char *fname, int lineno, 1456 Dwarf_Addr addr __maybe_unused, 1457 void *data) 1458 { 1459 struct line_finder *lf = data; 1460 1461 if ((strtailcmp(fname, lf->fname) != 0) || 1462 (lf->lno_s > lineno || lf->lno_e < lineno)) 1463 return 0; 1464 1465 if (line_range_add_line(fname, lineno, lf->lr) < 0) 1466 return -EINVAL; 1467 1468 return 0; 1469 } 1470 1471 /* Find line range from its line number */ 1472 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf) 1473 { 1474 int ret; 1475 1476 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf); 1477 1478 /* Update status */ 1479 if (ret >= 0) 1480 if (!list_empty(&lf->lr->line_list)) 1481 ret = lf->found = 1; 1482 else 1483 ret = 0; /* Lines are not found */ 1484 else { 1485 free(lf->lr->path); 1486 lf->lr->path = NULL; 1487 } 1488 return ret; 1489 } 1490 1491 static int line_range_inline_cb(Dwarf_Die *in_die, void *data) 1492 { 1493 find_line_range_by_line(in_die, data); 1494 1495 /* 1496 * We have to check all instances of inlined function, because 1497 * some execution paths can be optimized out depends on the 1498 * function argument of instances 1499 */ 1500 return 0; 1501 } 1502 1503 /* Search function definition from function name */ 1504 static int line_range_search_cb(Dwarf_Die *sp_die, void *data) 1505 { 1506 struct dwarf_callback_param *param = data; 1507 struct line_finder *lf = param->data; 1508 struct line_range *lr = lf->lr; 1509 1510 /* Check declared file */ 1511 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) 1512 return DWARF_CB_OK; 1513 1514 if (die_is_func_def(sp_die) && 1515 die_compare_name(sp_die, lr->function)) { 1516 lf->fname = dwarf_decl_file(sp_die); 1517 dwarf_decl_line(sp_die, &lr->offset); 1518 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); 1519 lf->lno_s = lr->offset + lr->start; 1520 if (lf->lno_s < 0) /* Overflow */ 1521 lf->lno_s = INT_MAX; 1522 lf->lno_e = lr->offset + lr->end; 1523 if (lf->lno_e < 0) /* Overflow */ 1524 lf->lno_e = INT_MAX; 1525 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e); 1526 lr->start = lf->lno_s; 1527 lr->end = lf->lno_e; 1528 if (dwarf_func_inline(sp_die)) 1529 param->retval = die_walk_instances(sp_die, 1530 line_range_inline_cb, lf); 1531 else 1532 param->retval = find_line_range_by_line(sp_die, lf); 1533 return DWARF_CB_ABORT; 1534 } 1535 return DWARF_CB_OK; 1536 } 1537 1538 static int find_line_range_by_func(struct line_finder *lf) 1539 { 1540 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0}; 1541 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0); 1542 return param.retval; 1543 } 1544 1545 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr) 1546 { 1547 struct line_finder lf = {.lr = lr, .found = 0}; 1548 int ret = 0; 1549 Dwarf_Off off = 0, noff; 1550 size_t cuhl; 1551 Dwarf_Die *diep; 1552 const char *comp_dir; 1553 1554 /* Fastpath: lookup by function name from .debug_pubnames section */ 1555 if (lr->function) { 1556 struct pubname_callback_param pubname_param = { 1557 .function = lr->function, .file = lr->file, 1558 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0}; 1559 struct dwarf_callback_param line_range_param = { 1560 .data = (void *)&lf, .retval = 0}; 1561 1562 dwarf_getpubnames(self->dbg, pubname_search_cb, 1563 &pubname_param, 0); 1564 if (pubname_param.found) { 1565 line_range_search_cb(&lf.sp_die, &line_range_param); 1566 if (lf.found) 1567 goto found; 1568 } 1569 } 1570 1571 /* Loop on CUs (Compilation Unit) */ 1572 while (!lf.found && ret >= 0) { 1573 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl, 1574 NULL, NULL, NULL) != 0) 1575 break; 1576 1577 /* Get the DIE(Debugging Information Entry) of this CU */ 1578 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die); 1579 if (!diep) 1580 continue; 1581 1582 /* Check if target file is included. */ 1583 if (lr->file) 1584 lf.fname = cu_find_realpath(&lf.cu_die, lr->file); 1585 else 1586 lf.fname = 0; 1587 1588 if (!lr->file || lf.fname) { 1589 if (lr->function) 1590 ret = find_line_range_by_func(&lf); 1591 else { 1592 lf.lno_s = lr->start; 1593 lf.lno_e = lr->end; 1594 ret = find_line_range_by_line(NULL, &lf); 1595 } 1596 } 1597 off = noff; 1598 } 1599 1600 found: 1601 /* Store comp_dir */ 1602 if (lf.found) { 1603 comp_dir = cu_get_comp_dir(&lf.cu_die); 1604 if (comp_dir) { 1605 lr->comp_dir = strdup(comp_dir); 1606 if (!lr->comp_dir) 1607 ret = -ENOMEM; 1608 } 1609 } 1610 1611 pr_debug("path: %s\n", lr->path); 1612 return (ret < 0) ? ret : lf.found; 1613 } 1614 1615
