1/* 2 * dwarf-aux.c : libdw auxiliary interfaces 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 * 18 */ 19 20#include <stdbool.h> 21#include "util.h" 22#include "debug.h" 23#include "dwarf-aux.h" 24 25/** 26 * cu_find_realpath - Find the realpath of the target file 27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit) 28 * @fname: The tail filename of the target file 29 * 30 * Find the real(long) path of @fname in @cu_die. 31 */ 32const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname) 33{ 34 Dwarf_Files *files; 35 size_t nfiles, i; 36 const char *src = NULL; 37 int ret; 38 39 if (!fname) 40 return NULL; 41 42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles); 43 if (ret != 0) 44 return NULL; 45 46 for (i = 0; i < nfiles; i++) { 47 src = dwarf_filesrc(files, i, NULL, NULL); 48 if (strtailcmp(src, fname) == 0) 49 break; 50 } 51 if (i == nfiles) 52 return NULL; 53 return src; 54} 55 56/** 57 * cu_get_comp_dir - Get the path of compilation directory 58 * @cu_die: a CU DIE 59 * 60 * Get the path of compilation directory of given @cu_die. 61 * Since this depends on DW_AT_comp_dir, older gcc will not 62 * embedded it. In that case, this returns NULL. 63 */ 64const char *cu_get_comp_dir(Dwarf_Die *cu_die) 65{ 66 Dwarf_Attribute attr; 67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL) 68 return NULL; 69 return dwarf_formstring(&attr); 70} 71 72/** 73 * cu_find_lineinfo - Get a line number and file name for given address 74 * @cu_die: a CU DIE 75 * @addr: An address 76 * @fname: a pointer which returns the file name string 77 * @lineno: a pointer which returns the line number 78 * 79 * Find a line number and file name for @addr in @cu_die. 80 */ 81int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr, 82 const char **fname, int *lineno) 83{ 84 Dwarf_Line *line; 85 Dwarf_Addr laddr; 86 87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr); 88 if (line && dwarf_lineaddr(line, &laddr) == 0 && 89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) { 90 *fname = dwarf_linesrc(line, NULL, NULL); 91 if (!*fname) 92 /* line number is useless without filename */ 93 *lineno = 0; 94 } 95 96 return *lineno ?: -ENOENT; 97} 98 99static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data); 100 101/** 102 * cu_walk_functions_at - Walk on function DIEs at given address 103 * @cu_die: A CU DIE 104 * @addr: An address 105 * @callback: A callback which called with found DIEs 106 * @data: A user data 107 * 108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs 109 * should be subprogram or inlined-subroutines. 110 */ 111int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, 112 int (*callback)(Dwarf_Die *, void *), void *data) 113{ 114 Dwarf_Die die_mem; 115 Dwarf_Die *sc_die; 116 int ret = -ENOENT; 117 118 /* Inlined function could be recursive. Trace it until fail */ 119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem); 120 sc_die != NULL; 121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr, 122 &die_mem)) { 123 ret = callback(sc_die, data); 124 if (ret) 125 break; 126 } 127 128 return ret; 129 130} 131 132/** 133 * die_compare_name - Compare diename and tname 134 * @dw_die: a DIE 135 * @tname: a string of target name 136 * 137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name. 138 */ 139bool die_compare_name(Dwarf_Die *dw_die, const char *tname) 140{ 141 const char *name; 142 143 name = dwarf_diename(dw_die); 144 return name ? (strcmp(tname, name) == 0) : false; 145} 146 147/** 148 * die_match_name - Match diename and glob 149 * @dw_die: a DIE 150 * @glob: a string of target glob pattern 151 * 152 * Glob matching the name of @dw_die and @glob. Return false if matching fail. 153 */ 154bool die_match_name(Dwarf_Die *dw_die, const char *glob) 155{ 156 const char *name; 157 158 name = dwarf_diename(dw_die); 159 return name ? strglobmatch(name, glob) : false; 160} 161 162/** 163 * die_get_call_lineno - Get callsite line number of inline-function instance 164 * @in_die: a DIE of an inlined function instance 165 * 166 * Get call-site line number of @in_die. This means from where the inline 167 * function is called. 168 */ 169int die_get_call_lineno(Dwarf_Die *in_die) 170{ 171 Dwarf_Attribute attr; 172 Dwarf_Word ret; 173 174 if (!dwarf_attr(in_die, DW_AT_call_line, &attr)) 175 return -ENOENT; 176 177 dwarf_formudata(&attr, &ret); 178 return (int)ret; 179} 180 181/** 182 * die_get_type - Get type DIE 183 * @vr_die: a DIE of a variable 184 * @die_mem: where to store a type DIE 185 * 186 * Get a DIE of the type of given variable (@vr_die), and store 187 * it to die_mem. Return NULL if fails to get a type DIE. 188 */ 189Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 190{ 191 Dwarf_Attribute attr; 192 193 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) && 194 dwarf_formref_die(&attr, die_mem)) 195 return die_mem; 196 else 197 return NULL; 198} 199 200/* Get a type die, but skip qualifiers */ 201static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 202{ 203 int tag; 204 205 do { 206 vr_die = die_get_type(vr_die, die_mem); 207 if (!vr_die) 208 break; 209 tag = dwarf_tag(vr_die); 210 } while (tag == DW_TAG_const_type || 211 tag == DW_TAG_restrict_type || 212 tag == DW_TAG_volatile_type || 213 tag == DW_TAG_shared_type); 214 215 return vr_die; 216} 217 218/** 219 * die_get_real_type - Get a type die, but skip qualifiers and typedef 220 * @vr_die: a DIE of a variable 221 * @die_mem: where to store a type DIE 222 * 223 * Get a DIE of the type of given variable (@vr_die), and store 224 * it to die_mem. Return NULL if fails to get a type DIE. 225 * If the type is qualifiers (e.g. const) or typedef, this skips it 226 * and tries to find real type (structure or basic types, e.g. int). 227 */ 228Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 229{ 230 do { 231 vr_die = __die_get_real_type(vr_die, die_mem); 232 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef); 233 234 return vr_die; 235} 236 237/* Get attribute and translate it as a udata */ 238static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name, 239 Dwarf_Word *result) 240{ 241 Dwarf_Attribute attr; 242 243 if (dwarf_attr(tp_die, attr_name, &attr) == NULL || 244 dwarf_formudata(&attr, result) != 0) 245 return -ENOENT; 246 247 return 0; 248} 249 250/* Get attribute and translate it as a sdata */ 251static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name, 252 Dwarf_Sword *result) 253{ 254 Dwarf_Attribute attr; 255 256 if (dwarf_attr(tp_die, attr_name, &attr) == NULL || 257 dwarf_formsdata(&attr, result) != 0) 258 return -ENOENT; 259 260 return 0; 261} 262 263/** 264 * die_is_signed_type - Check whether a type DIE is signed or not 265 * @tp_die: a DIE of a type 266 * 267 * Get the encoding of @tp_die and return true if the encoding 268 * is signed. 269 */ 270bool die_is_signed_type(Dwarf_Die *tp_die) 271{ 272 Dwarf_Word ret; 273 274 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret)) 275 return false; 276 277 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed || 278 ret == DW_ATE_signed_fixed); 279} 280 281/** 282 * die_is_func_def - Ensure that this DIE is a subprogram and definition 283 * @dw_die: a DIE 284 * 285 * Ensure that this DIE is a subprogram and NOT a declaration. This 286 * returns true if @dw_die is a function definition. 287 **/ 288bool die_is_func_def(Dwarf_Die *dw_die) 289{ 290 Dwarf_Attribute attr; 291 292 return (dwarf_tag(dw_die) == DW_TAG_subprogram && 293 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL); 294} 295 296/** 297 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram 298 * @dw_die: a DIE 299 * 300 * Ensure that this DIE is an instance (which has an entry address). 301 * This returns true if @dw_die is a function instance. If not, you need to 302 * call die_walk_instances() to find actual instances. 303 **/ 304bool die_is_func_instance(Dwarf_Die *dw_die) 305{ 306 Dwarf_Addr tmp; 307 308 /* Actually gcc optimizes non-inline as like as inlined */ 309 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0; 310} 311/** 312 * die_get_data_member_location - Get the data-member offset 313 * @mb_die: a DIE of a member of a data structure 314 * @offs: The offset of the member in the data structure 315 * 316 * Get the offset of @mb_die in the data structure including @mb_die, and 317 * stores result offset to @offs. If any error occurs this returns errno. 318 */ 319int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) 320{ 321 Dwarf_Attribute attr; 322 Dwarf_Op *expr; 323 size_t nexpr; 324 int ret; 325 326 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) 327 return -ENOENT; 328 329 if (dwarf_formudata(&attr, offs) != 0) { 330 /* DW_AT_data_member_location should be DW_OP_plus_uconst */ 331 ret = dwarf_getlocation(&attr, &expr, &nexpr); 332 if (ret < 0 || nexpr == 0) 333 return -ENOENT; 334 335 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) { 336 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n", 337 expr[0].atom, nexpr); 338 return -ENOTSUP; 339 } 340 *offs = (Dwarf_Word)expr[0].number; 341 } 342 return 0; 343} 344 345/* Get the call file index number in CU DIE */ 346static int die_get_call_fileno(Dwarf_Die *in_die) 347{ 348 Dwarf_Sword idx; 349 350 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0) 351 return (int)idx; 352 else 353 return -ENOENT; 354} 355 356/* Get the declared file index number in CU DIE */ 357static int die_get_decl_fileno(Dwarf_Die *pdie) 358{ 359 Dwarf_Sword idx; 360 361 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) 362 return (int)idx; 363 else 364 return -ENOENT; 365} 366 367/** 368 * die_get_call_file - Get callsite file name of inlined function instance 369 * @in_die: a DIE of an inlined function instance 370 * 371 * Get call-site file name of @in_die. This means from which file the inline 372 * function is called. 373 */ 374const char *die_get_call_file(Dwarf_Die *in_die) 375{ 376 Dwarf_Die cu_die; 377 Dwarf_Files *files; 378 int idx; 379 380 idx = die_get_call_fileno(in_die); 381 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) || 382 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0) 383 return NULL; 384 385 return dwarf_filesrc(files, idx, NULL, NULL); 386} 387 388 389/** 390 * die_find_child - Generic DIE search function in DIE tree 391 * @rt_die: a root DIE 392 * @callback: a callback function 393 * @data: a user data passed to the callback function 394 * @die_mem: a buffer for result DIE 395 * 396 * Trace DIE tree from @rt_die and call @callback for each child DIE. 397 * If @callback returns DIE_FIND_CB_END, this stores the DIE into 398 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE, 399 * this continues to trace the tree. Optionally, @callback can return 400 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only 401 * the children and trace only the siblings respectively. 402 * Returns NULL if @callback can't find any appropriate DIE. 403 */ 404Dwarf_Die *die_find_child(Dwarf_Die *rt_die, 405 int (*callback)(Dwarf_Die *, void *), 406 void *data, Dwarf_Die *die_mem) 407{ 408 Dwarf_Die child_die; 409 int ret; 410 411 ret = dwarf_child(rt_die, die_mem); 412 if (ret != 0) 413 return NULL; 414 415 do { 416 ret = callback(die_mem, data); 417 if (ret == DIE_FIND_CB_END) 418 return die_mem; 419 420 if ((ret & DIE_FIND_CB_CHILD) && 421 die_find_child(die_mem, callback, data, &child_die)) { 422 memcpy(die_mem, &child_die, sizeof(Dwarf_Die)); 423 return die_mem; 424 } 425 } while ((ret & DIE_FIND_CB_SIBLING) && 426 dwarf_siblingof(die_mem, die_mem) == 0); 427 428 return NULL; 429} 430 431struct __addr_die_search_param { 432 Dwarf_Addr addr; 433 Dwarf_Die *die_mem; 434}; 435 436static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data) 437{ 438 struct __addr_die_search_param *ad = data; 439 Dwarf_Addr addr = 0; 440 441 if (dwarf_tag(fn_die) == DW_TAG_subprogram && 442 !dwarf_highpc(fn_die, &addr) && 443 addr == ad->addr) { 444 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); 445 return DWARF_CB_ABORT; 446 } 447 return DWARF_CB_OK; 448} 449 450/** 451 * die_find_tailfunc - Search for a non-inlined function with tail call at 452 * given address 453 * @cu_die: a CU DIE which including @addr 454 * @addr: target address 455 * @die_mem: a buffer for result DIE 456 * 457 * Search for a non-inlined function DIE with tail call at @addr. Stores the 458 * DIE to @die_mem and returns it if found. Returns NULL if failed. 459 */ 460Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, 461 Dwarf_Die *die_mem) 462{ 463 struct __addr_die_search_param ad; 464 ad.addr = addr; 465 ad.die_mem = die_mem; 466 /* dwarf_getscopes can't find subprogram. */ 467 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0)) 468 return NULL; 469 else 470 return die_mem; 471} 472 473/* die_find callback for non-inlined function search */ 474static int __die_search_func_cb(Dwarf_Die *fn_die, void *data) 475{ 476 struct __addr_die_search_param *ad = data; 477 478 /* 479 * Since a declaration entry doesn't has given pc, this always returns 480 * function definition entry. 481 */ 482 if (dwarf_tag(fn_die) == DW_TAG_subprogram && 483 dwarf_haspc(fn_die, ad->addr)) { 484 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); 485 return DWARF_CB_ABORT; 486 } 487 return DWARF_CB_OK; 488} 489 490/** 491 * die_find_realfunc - Search a non-inlined function at given address 492 * @cu_die: a CU DIE which including @addr 493 * @addr: target address 494 * @die_mem: a buffer for result DIE 495 * 496 * Search a non-inlined function DIE which includes @addr. Stores the 497 * DIE to @die_mem and returns it if found. Returns NULL if failed. 498 */ 499Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, 500 Dwarf_Die *die_mem) 501{ 502 struct __addr_die_search_param ad; 503 ad.addr = addr; 504 ad.die_mem = die_mem; 505 /* dwarf_getscopes can't find subprogram. */ 506 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0)) 507 return NULL; 508 else 509 return die_mem; 510} 511 512/* die_find callback for inline function search */ 513static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data) 514{ 515 Dwarf_Addr *addr = data; 516 517 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine && 518 dwarf_haspc(die_mem, *addr)) 519 return DIE_FIND_CB_END; 520 521 return DIE_FIND_CB_CONTINUE; 522} 523 524/** 525 * die_find_top_inlinefunc - Search the top inlined function at given address 526 * @sp_die: a subprogram DIE which including @addr 527 * @addr: target address 528 * @die_mem: a buffer for result DIE 529 * 530 * Search an inlined function DIE which includes @addr. Stores the 531 * DIE to @die_mem and returns it if found. Returns NULL if failed. 532 * Even if several inlined functions are expanded recursively, this 533 * doesn't trace it down, and returns the topmost one. 534 */ 535Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 536 Dwarf_Die *die_mem) 537{ 538 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); 539} 540 541/** 542 * die_find_inlinefunc - Search an inlined function at given address 543 * @sp_die: a subprogram DIE which including @addr 544 * @addr: target address 545 * @die_mem: a buffer for result DIE 546 * 547 * Search an inlined function DIE which includes @addr. Stores the 548 * DIE to @die_mem and returns it if found. Returns NULL if failed. 549 * If several inlined functions are expanded recursively, this trace 550 * it down and returns deepest one. 551 */ 552Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 553 Dwarf_Die *die_mem) 554{ 555 Dwarf_Die tmp_die; 556 557 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die); 558 if (!sp_die) 559 return NULL; 560 561 /* Inlined function could be recursive. Trace it until fail */ 562 while (sp_die) { 563 memcpy(die_mem, sp_die, sizeof(Dwarf_Die)); 564 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, 565 &tmp_die); 566 } 567 568 return die_mem; 569} 570 571struct __instance_walk_param { 572 void *addr; 573 int (*callback)(Dwarf_Die *, void *); 574 void *data; 575 int retval; 576}; 577 578static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) 579{ 580 struct __instance_walk_param *iwp = data; 581 Dwarf_Attribute attr_mem; 582 Dwarf_Die origin_mem; 583 Dwarf_Attribute *attr; 584 Dwarf_Die *origin; 585 int tmp; 586 587 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); 588 if (attr == NULL) 589 return DIE_FIND_CB_CONTINUE; 590 591 origin = dwarf_formref_die(attr, &origin_mem); 592 if (origin == NULL || origin->addr != iwp->addr) 593 return DIE_FIND_CB_CONTINUE; 594 595 /* Ignore redundant instances */ 596 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { 597 dwarf_decl_line(origin, &tmp); 598 if (die_get_call_lineno(inst) == tmp) { 599 tmp = die_get_decl_fileno(origin); 600 if (die_get_call_fileno(inst) == tmp) 601 return DIE_FIND_CB_CONTINUE; 602 } 603 } 604 605 iwp->retval = iwp->callback(inst, iwp->data); 606 607 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; 608} 609 610/** 611 * die_walk_instances - Walk on instances of given DIE 612 * @or_die: an abstract original DIE 613 * @callback: a callback function which is called with instance DIE 614 * @data: user data 615 * 616 * Walk on the instances of give @in_die. @in_die must be an inlined function 617 * declartion. This returns the return value of @callback if it returns 618 * non-zero value, or -ENOENT if there is no instance. 619 */ 620int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *), 621 void *data) 622{ 623 Dwarf_Die cu_die; 624 Dwarf_Die die_mem; 625 struct __instance_walk_param iwp = { 626 .addr = or_die->addr, 627 .callback = callback, 628 .data = data, 629 .retval = -ENOENT, 630 }; 631 632 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL) 633 return -ENOENT; 634 635 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem); 636 637 return iwp.retval; 638} 639 640/* Line walker internal parameters */ 641struct __line_walk_param { 642 bool recursive; 643 line_walk_callback_t callback; 644 void *data; 645 int retval; 646}; 647 648static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data) 649{ 650 struct __line_walk_param *lw = data; 651 Dwarf_Addr addr = 0; 652 const char *fname; 653 int lineno; 654 655 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) { 656 fname = die_get_call_file(in_die); 657 lineno = die_get_call_lineno(in_die); 658 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) { 659 lw->retval = lw->callback(fname, lineno, addr, lw->data); 660 if (lw->retval != 0) 661 return DIE_FIND_CB_END; 662 } 663 } 664 if (!lw->recursive) 665 /* Don't need to search recursively */ 666 return DIE_FIND_CB_SIBLING; 667 668 if (addr) { 669 fname = dwarf_decl_file(in_die); 670 if (fname && dwarf_decl_line(in_die, &lineno) == 0) { 671 lw->retval = lw->callback(fname, lineno, addr, lw->data); 672 if (lw->retval != 0) 673 return DIE_FIND_CB_END; 674 } 675 } 676 677 /* Continue to search nested inlined function call-sites */ 678 return DIE_FIND_CB_CONTINUE; 679} 680 681/* Walk on lines of blocks included in given DIE */ 682static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive, 683 line_walk_callback_t callback, void *data) 684{ 685 struct __line_walk_param lw = { 686 .recursive = recursive, 687 .callback = callback, 688 .data = data, 689 .retval = 0, 690 }; 691 Dwarf_Die die_mem; 692 Dwarf_Addr addr; 693 const char *fname; 694 int lineno; 695 696 /* Handle function declaration line */ 697 fname = dwarf_decl_file(sp_die); 698 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 && 699 dwarf_entrypc(sp_die, &addr) == 0) { 700 lw.retval = callback(fname, lineno, addr, data); 701 if (lw.retval != 0) 702 goto done; 703 } 704 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem); 705done: 706 return lw.retval; 707} 708 709static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data) 710{ 711 struct __line_walk_param *lw = data; 712 713 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data); 714 if (lw->retval != 0) 715 return DWARF_CB_ABORT; 716 717 return DWARF_CB_OK; 718} 719 720/** 721 * die_walk_lines - Walk on lines inside given DIE 722 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine) 723 * @callback: callback routine 724 * @data: user data 725 * 726 * Walk on all lines inside given @rt_die and call @callback on each line. 727 * If the @rt_die is a function, walk only on the lines inside the function, 728 * otherwise @rt_die must be a CU DIE. 729 * Note that this walks not only dwarf line list, but also function entries 730 * and inline call-site. 731 */ 732int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) 733{ 734 Dwarf_Lines *lines; 735 Dwarf_Line *line; 736 Dwarf_Addr addr; 737 const char *fname, *decf = NULL; 738 int lineno, ret = 0; 739 int decl = 0, inl; 740 Dwarf_Die die_mem, *cu_die; 741 size_t nlines, i; 742 743 /* Get the CU die */ 744 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) { 745 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL); 746 dwarf_decl_line(rt_die, &decl); 747 decf = dwarf_decl_file(rt_die); 748 } else 749 cu_die = rt_die; 750 if (!cu_die) { 751 pr_debug2("Failed to get CU from given DIE.\n"); 752 return -EINVAL; 753 } 754 755 /* Get lines list in the CU */ 756 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) { 757 pr_debug2("Failed to get source lines on this CU.\n"); 758 return -ENOENT; 759 } 760 pr_debug2("Get %zd lines from this CU\n", nlines); 761 762 /* Walk on the lines on lines list */ 763 for (i = 0; i < nlines; i++) { 764 line = dwarf_onesrcline(lines, i); 765 if (line == NULL || 766 dwarf_lineno(line, &lineno) != 0 || 767 dwarf_lineaddr(line, &addr) != 0) { 768 pr_debug2("Failed to get line info. " 769 "Possible error in debuginfo.\n"); 770 continue; 771 } 772 /* Filter lines based on address */ 773 if (rt_die != cu_die) { 774 /* 775 * Address filtering 776 * The line is included in given function, and 777 * no inline block includes it. 778 */ 779 if (!dwarf_haspc(rt_die, addr)) 780 continue; 781 if (die_find_inlinefunc(rt_die, addr, &die_mem)) { 782 dwarf_decl_line(&die_mem, &inl); 783 if (inl != decl || 784 decf != dwarf_decl_file(&die_mem)) 785 continue; 786 } 787 } 788 /* Get source line */ 789 fname = dwarf_linesrc(line, NULL, NULL); 790 791 ret = callback(fname, lineno, addr, data); 792 if (ret != 0) 793 return ret; 794 } 795 796 /* 797 * Dwarf lines doesn't include function declarations and inlined 798 * subroutines. We have to check functions list or given function. 799 */ 800 if (rt_die != cu_die) 801 /* 802 * Don't need walk functions recursively, because nested 803 * inlined functions don't have lines of the specified DIE. 804 */ 805 ret = __die_walk_funclines(rt_die, false, callback, data); 806 else { 807 struct __line_walk_param param = { 808 .callback = callback, 809 .data = data, 810 .retval = 0, 811 }; 812 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0); 813 ret = param.retval; 814 } 815 816 return ret; 817} 818 819struct __find_variable_param { 820 const char *name; 821 Dwarf_Addr addr; 822}; 823 824static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data) 825{ 826 struct __find_variable_param *fvp = data; 827 Dwarf_Attribute attr; 828 int tag; 829 830 tag = dwarf_tag(die_mem); 831 if ((tag == DW_TAG_formal_parameter || 832 tag == DW_TAG_variable) && 833 die_compare_name(die_mem, fvp->name) && 834 /* Does the DIE have location information or external instance? */ 835 (dwarf_attr(die_mem, DW_AT_external, &attr) || 836 dwarf_attr(die_mem, DW_AT_location, &attr))) 837 return DIE_FIND_CB_END; 838 if (dwarf_haspc(die_mem, fvp->addr)) 839 return DIE_FIND_CB_CONTINUE; 840 else 841 return DIE_FIND_CB_SIBLING; 842} 843 844/** 845 * die_find_variable_at - Find a given name variable at given address 846 * @sp_die: a function DIE 847 * @name: variable name 848 * @addr: address 849 * @die_mem: a buffer for result DIE 850 * 851 * Find a variable DIE called @name at @addr in @sp_die. 852 */ 853Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name, 854 Dwarf_Addr addr, Dwarf_Die *die_mem) 855{ 856 struct __find_variable_param fvp = { .name = name, .addr = addr}; 857 858 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp, 859 die_mem); 860} 861 862static int __die_find_member_cb(Dwarf_Die *die_mem, void *data) 863{ 864 const char *name = data; 865 866 if (dwarf_tag(die_mem) == DW_TAG_member) { 867 if (die_compare_name(die_mem, name)) 868 return DIE_FIND_CB_END; 869 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */ 870 Dwarf_Die type_die, tmp_die; 871 if (die_get_type(die_mem, &type_die) && 872 die_find_member(&type_die, name, &tmp_die)) 873 return DIE_FIND_CB_END; 874 } 875 } 876 return DIE_FIND_CB_SIBLING; 877} 878 879/** 880 * die_find_member - Find a given name member in a data structure 881 * @st_die: a data structure type DIE 882 * @name: member name 883 * @die_mem: a buffer for result DIE 884 * 885 * Find a member DIE called @name in @st_die. 886 */ 887Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, 888 Dwarf_Die *die_mem) 889{ 890 return die_find_child(st_die, __die_find_member_cb, (void *)name, 891 die_mem); 892} 893 894/** 895 * die_get_typename - Get the name of given variable DIE 896 * @vr_die: a variable DIE 897 * @buf: a strbuf for result type name 898 * 899 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded. 900 * and Return -ENOENT if failed to find type name. 901 * Note that the result will stores typedef name if possible, and stores 902 * "*(function_type)" if the type is a function pointer. 903 */ 904int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf) 905{ 906 Dwarf_Die type; 907 int tag, ret; 908 const char *tmp = ""; 909 910 if (__die_get_real_type(vr_die, &type) == NULL) 911 return -ENOENT; 912 913 tag = dwarf_tag(&type); 914 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type) 915 tmp = "*"; 916 else if (tag == DW_TAG_subroutine_type) { 917 /* Function pointer */ 918 strbuf_addf(buf, "(function_type)"); 919 return 0; 920 } else { 921 if (!dwarf_diename(&type)) 922 return -ENOENT; 923 if (tag == DW_TAG_union_type) 924 tmp = "union "; 925 else if (tag == DW_TAG_structure_type) 926 tmp = "struct "; 927 else if (tag == DW_TAG_enumeration_type) 928 tmp = "enum "; 929 /* Write a base name */ 930 strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type)); 931 return 0; 932 } 933 ret = die_get_typename(&type, buf); 934 if (ret == 0) 935 strbuf_addf(buf, "%s", tmp); 936 937 return ret; 938} 939 940/** 941 * die_get_varname - Get the name and type of given variable DIE 942 * @vr_die: a variable DIE 943 * @buf: a strbuf for type and variable name 944 * 945 * Get the name and type of @vr_die and stores it in @buf as "type\tname". 946 */ 947int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) 948{ 949 int ret; 950 951 ret = die_get_typename(vr_die, buf); 952 if (ret < 0) { 953 pr_debug("Failed to get type, make it unknown.\n"); 954 strbuf_addf(buf, "(unknown_type)"); 955 } 956 957 strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); 958 959 return 0; 960} 961 962/** 963 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE 964 * @sp_die: a subprogram DIE 965 * @vr_die: a variable DIE 966 * @buf: a strbuf for variable byte offset range 967 * 968 * Get the innermost scope range of @vr_die and stores it in @buf as 969 * "@<function_name+[NN-NN,NN-NN]>". 970 */ 971static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die, 972 struct strbuf *buf) 973{ 974 Dwarf_Die *scopes; 975 int count; 976 size_t offset = 0; 977 Dwarf_Addr base; 978 Dwarf_Addr start, end; 979 Dwarf_Addr entry; 980 int ret; 981 bool first = true; 982 const char *name; 983 984 ret = dwarf_entrypc(sp_die, &entry); 985 if (ret) 986 return ret; 987 988 name = dwarf_diename(sp_die); 989 if (!name) 990 return -ENOENT; 991 992 count = dwarf_getscopes_die(vr_die, &scopes); 993 994 /* (*SCOPES)[1] is the DIE for the scope containing that scope */ 995 if (count <= 1) { 996 ret = -EINVAL; 997 goto out; 998 } 999 1000 while ((offset = dwarf_ranges(&scopes[1], offset, &base, 1001 &start, &end)) > 0) { 1002 start -= entry; 1003 end -= entry; 1004 1005 if (first) { 1006 strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64, 1007 name, start, end); 1008 first = false; 1009 } else { 1010 strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64, 1011 start, end); 1012 } 1013 } 1014 1015 if (!first) 1016 strbuf_addf(buf, "]>"); 1017 1018out: 1019 free(scopes); 1020 return ret; 1021} 1022 1023/** 1024 * die_get_var_range - Get byte offset range of given variable DIE 1025 * @sp_die: a subprogram DIE 1026 * @vr_die: a variable DIE 1027 * @buf: a strbuf for type and variable name and byte offset range 1028 * 1029 * Get the byte offset range of @vr_die and stores it in @buf as 1030 * "@<function_name+[NN-NN,NN-NN]>". 1031 */ 1032int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf) 1033{ 1034 int ret = 0; 1035 Dwarf_Addr base; 1036 Dwarf_Addr start, end; 1037 Dwarf_Addr entry; 1038 Dwarf_Op *op; 1039 size_t nops; 1040 size_t offset = 0; 1041 Dwarf_Attribute attr; 1042 bool first = true; 1043 const char *name; 1044 1045 ret = dwarf_entrypc(sp_die, &entry); 1046 if (ret) 1047 return ret; 1048 1049 name = dwarf_diename(sp_die); 1050 if (!name) 1051 return -ENOENT; 1052 1053 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) 1054 return -EINVAL; 1055 1056 while ((offset = dwarf_getlocations( 1057 &attr, offset, &base, 1058 &start, &end, &op, &nops)) > 0) { 1059 if (start == 0) { 1060 /* Single Location Descriptions */ 1061 ret = die_get_var_innermost_scope(sp_die, vr_die, buf); 1062 return ret; 1063 } 1064 1065 /* Location Lists */ 1066 start -= entry; 1067 end -= entry; 1068 if (first) { 1069 strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64, 1070 name, start, end); 1071 first = false; 1072 } else { 1073 strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64, 1074 start, end); 1075 } 1076 } 1077 1078 if (!first) 1079 strbuf_addf(buf, "]>"); 1080 1081 return ret; 1082} 1083