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 name = dwarf_diename(dw_die); 143 return name ? (strcmp(tname, name) == 0) : false; 144} 145 146/** 147 * die_get_call_lineno - Get callsite line number of inline-function instance 148 * @in_die: a DIE of an inlined function instance 149 * 150 * Get call-site line number of @in_die. This means from where the inline 151 * function is called. 152 */ 153int die_get_call_lineno(Dwarf_Die *in_die) 154{ 155 Dwarf_Attribute attr; 156 Dwarf_Word ret; 157 158 if (!dwarf_attr(in_die, DW_AT_call_line, &attr)) 159 return -ENOENT; 160 161 dwarf_formudata(&attr, &ret); 162 return (int)ret; 163} 164 165/** 166 * die_get_type - Get type DIE 167 * @vr_die: a DIE of a variable 168 * @die_mem: where to store a type DIE 169 * 170 * Get a DIE of the type of given variable (@vr_die), and store 171 * it to die_mem. Return NULL if fails to get a type DIE. 172 */ 173Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 174{ 175 Dwarf_Attribute attr; 176 177 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) && 178 dwarf_formref_die(&attr, die_mem)) 179 return die_mem; 180 else 181 return NULL; 182} 183 184/* Get a type die, but skip qualifiers */ 185static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 186{ 187 int tag; 188 189 do { 190 vr_die = die_get_type(vr_die, die_mem); 191 if (!vr_die) 192 break; 193 tag = dwarf_tag(vr_die); 194 } while (tag == DW_TAG_const_type || 195 tag == DW_TAG_restrict_type || 196 tag == DW_TAG_volatile_type || 197 tag == DW_TAG_shared_type); 198 199 return vr_die; 200} 201 202/** 203 * die_get_real_type - Get a type die, but skip qualifiers and typedef 204 * @vr_die: a DIE of a variable 205 * @die_mem: where to store a type DIE 206 * 207 * Get a DIE of the type of given variable (@vr_die), and store 208 * it to die_mem. Return NULL if fails to get a type DIE. 209 * If the type is qualifiers (e.g. const) or typedef, this skips it 210 * and tries to find real type (structure or basic types, e.g. int). 211 */ 212Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem) 213{ 214 do { 215 vr_die = __die_get_real_type(vr_die, die_mem); 216 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef); 217 218 return vr_die; 219} 220 221/* Get attribute and translate it as a udata */ 222static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name, 223 Dwarf_Word *result) 224{ 225 Dwarf_Attribute attr; 226 227 if (dwarf_attr(tp_die, attr_name, &attr) == NULL || 228 dwarf_formudata(&attr, result) != 0) 229 return -ENOENT; 230 231 return 0; 232} 233 234/* Get attribute and translate it as a sdata */ 235static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name, 236 Dwarf_Sword *result) 237{ 238 Dwarf_Attribute attr; 239 240 if (dwarf_attr(tp_die, attr_name, &attr) == NULL || 241 dwarf_formsdata(&attr, result) != 0) 242 return -ENOENT; 243 244 return 0; 245} 246 247/** 248 * die_is_signed_type - Check whether a type DIE is signed or not 249 * @tp_die: a DIE of a type 250 * 251 * Get the encoding of @tp_die and return true if the encoding 252 * is signed. 253 */ 254bool die_is_signed_type(Dwarf_Die *tp_die) 255{ 256 Dwarf_Word ret; 257 258 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret)) 259 return false; 260 261 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed || 262 ret == DW_ATE_signed_fixed); 263} 264 265/** 266 * die_is_func_def - Ensure that this DIE is a subprogram and definition 267 * @dw_die: a DIE 268 * 269 * Ensure that this DIE is a subprogram and NOT a declaration. This 270 * returns true if @dw_die is a function definition. 271 **/ 272bool die_is_func_def(Dwarf_Die *dw_die) 273{ 274 Dwarf_Attribute attr; 275 276 return (dwarf_tag(dw_die) == DW_TAG_subprogram && 277 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL); 278} 279 280/** 281 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram 282 * @dw_die: a DIE 283 * 284 * Ensure that this DIE is an instance (which has an entry address). 285 * This returns true if @dw_die is a function instance. If not, you need to 286 * call die_walk_instances() to find actual instances. 287 **/ 288bool die_is_func_instance(Dwarf_Die *dw_die) 289{ 290 Dwarf_Addr tmp; 291 292 /* Actually gcc optimizes non-inline as like as inlined */ 293 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0; 294} 295/** 296 * die_get_data_member_location - Get the data-member offset 297 * @mb_die: a DIE of a member of a data structure 298 * @offs: The offset of the member in the data structure 299 * 300 * Get the offset of @mb_die in the data structure including @mb_die, and 301 * stores result offset to @offs. If any error occurs this returns errno. 302 */ 303int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) 304{ 305 Dwarf_Attribute attr; 306 Dwarf_Op *expr; 307 size_t nexpr; 308 int ret; 309 310 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) 311 return -ENOENT; 312 313 if (dwarf_formudata(&attr, offs) != 0) { 314 /* DW_AT_data_member_location should be DW_OP_plus_uconst */ 315 ret = dwarf_getlocation(&attr, &expr, &nexpr); 316 if (ret < 0 || nexpr == 0) 317 return -ENOENT; 318 319 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) { 320 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n", 321 expr[0].atom, nexpr); 322 return -ENOTSUP; 323 } 324 *offs = (Dwarf_Word)expr[0].number; 325 } 326 return 0; 327} 328 329/* Get the call file index number in CU DIE */ 330static int die_get_call_fileno(Dwarf_Die *in_die) 331{ 332 Dwarf_Sword idx; 333 334 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0) 335 return (int)idx; 336 else 337 return -ENOENT; 338} 339 340/* Get the declared file index number in CU DIE */ 341static int die_get_decl_fileno(Dwarf_Die *pdie) 342{ 343 Dwarf_Sword idx; 344 345 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) 346 return (int)idx; 347 else 348 return -ENOENT; 349} 350 351/** 352 * die_get_call_file - Get callsite file name of inlined function instance 353 * @in_die: a DIE of an inlined function instance 354 * 355 * Get call-site file name of @in_die. This means from which file the inline 356 * function is called. 357 */ 358const char *die_get_call_file(Dwarf_Die *in_die) 359{ 360 Dwarf_Die cu_die; 361 Dwarf_Files *files; 362 int idx; 363 364 idx = die_get_call_fileno(in_die); 365 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) || 366 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0) 367 return NULL; 368 369 return dwarf_filesrc(files, idx, NULL, NULL); 370} 371 372 373/** 374 * die_find_child - Generic DIE search function in DIE tree 375 * @rt_die: a root DIE 376 * @callback: a callback function 377 * @data: a user data passed to the callback function 378 * @die_mem: a buffer for result DIE 379 * 380 * Trace DIE tree from @rt_die and call @callback for each child DIE. 381 * If @callback returns DIE_FIND_CB_END, this stores the DIE into 382 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE, 383 * this continues to trace the tree. Optionally, @callback can return 384 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only 385 * the children and trace only the siblings respectively. 386 * Returns NULL if @callback can't find any appropriate DIE. 387 */ 388Dwarf_Die *die_find_child(Dwarf_Die *rt_die, 389 int (*callback)(Dwarf_Die *, void *), 390 void *data, Dwarf_Die *die_mem) 391{ 392 Dwarf_Die child_die; 393 int ret; 394 395 ret = dwarf_child(rt_die, die_mem); 396 if (ret != 0) 397 return NULL; 398 399 do { 400 ret = callback(die_mem, data); 401 if (ret == DIE_FIND_CB_END) 402 return die_mem; 403 404 if ((ret & DIE_FIND_CB_CHILD) && 405 die_find_child(die_mem, callback, data, &child_die)) { 406 memcpy(die_mem, &child_die, sizeof(Dwarf_Die)); 407 return die_mem; 408 } 409 } while ((ret & DIE_FIND_CB_SIBLING) && 410 dwarf_siblingof(die_mem, die_mem) == 0); 411 412 return NULL; 413} 414 415struct __addr_die_search_param { 416 Dwarf_Addr addr; 417 Dwarf_Die *die_mem; 418}; 419 420/* die_find callback for non-inlined function search */ 421static int __die_search_func_cb(Dwarf_Die *fn_die, void *data) 422{ 423 struct __addr_die_search_param *ad = data; 424 425 /* 426 * Since a declaration entry doesn't has given pc, this always returns 427 * function definition entry. 428 */ 429 if (dwarf_tag(fn_die) == DW_TAG_subprogram && 430 dwarf_haspc(fn_die, ad->addr)) { 431 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); 432 return DWARF_CB_ABORT; 433 } 434 return DWARF_CB_OK; 435} 436 437/** 438 * die_find_realfunc - Search a non-inlined function at given address 439 * @cu_die: a CU DIE which including @addr 440 * @addr: target address 441 * @die_mem: a buffer for result DIE 442 * 443 * Search a non-inlined function DIE which includes @addr. Stores the 444 * DIE to @die_mem and returns it if found. Returns NULL if failed. 445 */ 446Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, 447 Dwarf_Die *die_mem) 448{ 449 struct __addr_die_search_param ad; 450 ad.addr = addr; 451 ad.die_mem = die_mem; 452 /* dwarf_getscopes can't find subprogram. */ 453 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0)) 454 return NULL; 455 else 456 return die_mem; 457} 458 459/* die_find callback for inline function search */ 460static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data) 461{ 462 Dwarf_Addr *addr = data; 463 464 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine && 465 dwarf_haspc(die_mem, *addr)) 466 return DIE_FIND_CB_END; 467 468 return DIE_FIND_CB_CONTINUE; 469} 470 471/** 472 * die_find_top_inlinefunc - Search the top inlined function at given address 473 * @sp_die: a subprogram DIE which including @addr 474 * @addr: target address 475 * @die_mem: a buffer for result DIE 476 * 477 * Search an inlined function DIE which includes @addr. Stores the 478 * DIE to @die_mem and returns it if found. Returns NULL if failed. 479 * Even if several inlined functions are expanded recursively, this 480 * doesn't trace it down, and returns the topmost one. 481 */ 482Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 483 Dwarf_Die *die_mem) 484{ 485 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); 486} 487 488/** 489 * die_find_inlinefunc - Search an inlined function at given address 490 * @sp_die: a subprogram DIE which including @addr 491 * @addr: target address 492 * @die_mem: a buffer for result DIE 493 * 494 * Search an inlined function DIE which includes @addr. Stores the 495 * DIE to @die_mem and returns it if found. Returns NULL if failed. 496 * If several inlined functions are expanded recursively, this trace 497 * it down and returns deepest one. 498 */ 499Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 500 Dwarf_Die *die_mem) 501{ 502 Dwarf_Die tmp_die; 503 504 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die); 505 if (!sp_die) 506 return NULL; 507 508 /* Inlined function could be recursive. Trace it until fail */ 509 while (sp_die) { 510 memcpy(die_mem, sp_die, sizeof(Dwarf_Die)); 511 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, 512 &tmp_die); 513 } 514 515 return die_mem; 516} 517 518struct __instance_walk_param { 519 void *addr; 520 int (*callback)(Dwarf_Die *, void *); 521 void *data; 522 int retval; 523}; 524 525static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) 526{ 527 struct __instance_walk_param *iwp = data; 528 Dwarf_Attribute attr_mem; 529 Dwarf_Die origin_mem; 530 Dwarf_Attribute *attr; 531 Dwarf_Die *origin; 532 int tmp; 533 534 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); 535 if (attr == NULL) 536 return DIE_FIND_CB_CONTINUE; 537 538 origin = dwarf_formref_die(attr, &origin_mem); 539 if (origin == NULL || origin->addr != iwp->addr) 540 return DIE_FIND_CB_CONTINUE; 541 542 /* Ignore redundant instances */ 543 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { 544 dwarf_decl_line(origin, &tmp); 545 if (die_get_call_lineno(inst) == tmp) { 546 tmp = die_get_decl_fileno(origin); 547 if (die_get_call_fileno(inst) == tmp) 548 return DIE_FIND_CB_CONTINUE; 549 } 550 } 551 552 iwp->retval = iwp->callback(inst, iwp->data); 553 554 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; 555} 556 557/** 558 * die_walk_instances - Walk on instances of given DIE 559 * @or_die: an abstract original DIE 560 * @callback: a callback function which is called with instance DIE 561 * @data: user data 562 * 563 * Walk on the instances of give @in_die. @in_die must be an inlined function 564 * declartion. This returns the return value of @callback if it returns 565 * non-zero value, or -ENOENT if there is no instance. 566 */ 567int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *), 568 void *data) 569{ 570 Dwarf_Die cu_die; 571 Dwarf_Die die_mem; 572 struct __instance_walk_param iwp = { 573 .addr = or_die->addr, 574 .callback = callback, 575 .data = data, 576 .retval = -ENOENT, 577 }; 578 579 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL) 580 return -ENOENT; 581 582 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem); 583 584 return iwp.retval; 585} 586 587/* Line walker internal parameters */ 588struct __line_walk_param { 589 bool recursive; 590 line_walk_callback_t callback; 591 void *data; 592 int retval; 593}; 594 595static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data) 596{ 597 struct __line_walk_param *lw = data; 598 Dwarf_Addr addr = 0; 599 const char *fname; 600 int lineno; 601 602 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) { 603 fname = die_get_call_file(in_die); 604 lineno = die_get_call_lineno(in_die); 605 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) { 606 lw->retval = lw->callback(fname, lineno, addr, lw->data); 607 if (lw->retval != 0) 608 return DIE_FIND_CB_END; 609 } 610 } 611 if (!lw->recursive) 612 /* Don't need to search recursively */ 613 return DIE_FIND_CB_SIBLING; 614 615 if (addr) { 616 fname = dwarf_decl_file(in_die); 617 if (fname && dwarf_decl_line(in_die, &lineno) == 0) { 618 lw->retval = lw->callback(fname, lineno, addr, lw->data); 619 if (lw->retval != 0) 620 return DIE_FIND_CB_END; 621 } 622 } 623 624 /* Continue to search nested inlined function call-sites */ 625 return DIE_FIND_CB_CONTINUE; 626} 627 628/* Walk on lines of blocks included in given DIE */ 629static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive, 630 line_walk_callback_t callback, void *data) 631{ 632 struct __line_walk_param lw = { 633 .recursive = recursive, 634 .callback = callback, 635 .data = data, 636 .retval = 0, 637 }; 638 Dwarf_Die die_mem; 639 Dwarf_Addr addr; 640 const char *fname; 641 int lineno; 642 643 /* Handle function declaration line */ 644 fname = dwarf_decl_file(sp_die); 645 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 && 646 dwarf_entrypc(sp_die, &addr) == 0) { 647 lw.retval = callback(fname, lineno, addr, data); 648 if (lw.retval != 0) 649 goto done; 650 } 651 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem); 652done: 653 return lw.retval; 654} 655 656static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data) 657{ 658 struct __line_walk_param *lw = data; 659 660 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data); 661 if (lw->retval != 0) 662 return DWARF_CB_ABORT; 663 664 return DWARF_CB_OK; 665} 666 667/** 668 * die_walk_lines - Walk on lines inside given DIE 669 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine) 670 * @callback: callback routine 671 * @data: user data 672 * 673 * Walk on all lines inside given @rt_die and call @callback on each line. 674 * If the @rt_die is a function, walk only on the lines inside the function, 675 * otherwise @rt_die must be a CU DIE. 676 * Note that this walks not only dwarf line list, but also function entries 677 * and inline call-site. 678 */ 679int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) 680{ 681 Dwarf_Lines *lines; 682 Dwarf_Line *line; 683 Dwarf_Addr addr; 684 const char *fname; 685 int lineno, ret = 0; 686 Dwarf_Die die_mem, *cu_die; 687 size_t nlines, i; 688 689 /* Get the CU die */ 690 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) 691 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL); 692 else 693 cu_die = rt_die; 694 if (!cu_die) { 695 pr_debug2("Failed to get CU from given DIE.\n"); 696 return -EINVAL; 697 } 698 699 /* Get lines list in the CU */ 700 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) { 701 pr_debug2("Failed to get source lines on this CU.\n"); 702 return -ENOENT; 703 } 704 pr_debug2("Get %zd lines from this CU\n", nlines); 705 706 /* Walk on the lines on lines list */ 707 for (i = 0; i < nlines; i++) { 708 line = dwarf_onesrcline(lines, i); 709 if (line == NULL || 710 dwarf_lineno(line, &lineno) != 0 || 711 dwarf_lineaddr(line, &addr) != 0) { 712 pr_debug2("Failed to get line info. " 713 "Possible error in debuginfo.\n"); 714 continue; 715 } 716 /* Filter lines based on address */ 717 if (rt_die != cu_die) 718 /* 719 * Address filtering 720 * The line is included in given function, and 721 * no inline block includes it. 722 */ 723 if (!dwarf_haspc(rt_die, addr) || 724 die_find_inlinefunc(rt_die, addr, &die_mem)) 725 continue; 726 /* Get source line */ 727 fname = dwarf_linesrc(line, NULL, NULL); 728 729 ret = callback(fname, lineno, addr, data); 730 if (ret != 0) 731 return ret; 732 } 733 734 /* 735 * Dwarf lines doesn't include function declarations and inlined 736 * subroutines. We have to check functions list or given function. 737 */ 738 if (rt_die != cu_die) 739 /* 740 * Don't need walk functions recursively, because nested 741 * inlined functions don't have lines of the specified DIE. 742 */ 743 ret = __die_walk_funclines(rt_die, false, callback, data); 744 else { 745 struct __line_walk_param param = { 746 .callback = callback, 747 .data = data, 748 .retval = 0, 749 }; 750 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0); 751 ret = param.retval; 752 } 753 754 return ret; 755} 756 757struct __find_variable_param { 758 const char *name; 759 Dwarf_Addr addr; 760}; 761 762static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data) 763{ 764 struct __find_variable_param *fvp = data; 765 Dwarf_Attribute attr; 766 int tag; 767 768 tag = dwarf_tag(die_mem); 769 if ((tag == DW_TAG_formal_parameter || 770 tag == DW_TAG_variable) && 771 die_compare_name(die_mem, fvp->name) && 772 /* Does the DIE have location information or external instance? */ 773 (dwarf_attr(die_mem, DW_AT_external, &attr) || 774 dwarf_attr(die_mem, DW_AT_location, &attr))) 775 return DIE_FIND_CB_END; 776 if (dwarf_haspc(die_mem, fvp->addr)) 777 return DIE_FIND_CB_CONTINUE; 778 else 779 return DIE_FIND_CB_SIBLING; 780} 781 782/** 783 * die_find_variable_at - Find a given name variable at given address 784 * @sp_die: a function DIE 785 * @name: variable name 786 * @addr: address 787 * @die_mem: a buffer for result DIE 788 * 789 * Find a variable DIE called @name at @addr in @sp_die. 790 */ 791Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name, 792 Dwarf_Addr addr, Dwarf_Die *die_mem) 793{ 794 struct __find_variable_param fvp = { .name = name, .addr = addr}; 795 796 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp, 797 die_mem); 798} 799 800static int __die_find_member_cb(Dwarf_Die *die_mem, void *data) 801{ 802 const char *name = data; 803 804 if (dwarf_tag(die_mem) == DW_TAG_member) { 805 if (die_compare_name(die_mem, name)) 806 return DIE_FIND_CB_END; 807 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */ 808 Dwarf_Die type_die, tmp_die; 809 if (die_get_type(die_mem, &type_die) && 810 die_find_member(&type_die, name, &tmp_die)) 811 return DIE_FIND_CB_END; 812 } 813 } 814 return DIE_FIND_CB_SIBLING; 815} 816 817/** 818 * die_find_member - Find a given name member in a data structure 819 * @st_die: a data structure type DIE 820 * @name: member name 821 * @die_mem: a buffer for result DIE 822 * 823 * Find a member DIE called @name in @st_die. 824 */ 825Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, 826 Dwarf_Die *die_mem) 827{ 828 return die_find_child(st_die, __die_find_member_cb, (void *)name, 829 die_mem); 830} 831 832/** 833 * die_get_typename - Get the name of given variable DIE 834 * @vr_die: a variable DIE 835 * @buf: a buffer for result type name 836 * @len: a max-length of @buf 837 * 838 * Get the name of @vr_die and stores it to @buf. Return the actual length 839 * of type name if succeeded. Return -E2BIG if @len is not enough long, and 840 * Return -ENOENT if failed to find type name. 841 * Note that the result will stores typedef name if possible, and stores 842 * "*(function_type)" if the type is a function pointer. 843 */ 844int die_get_typename(Dwarf_Die *vr_die, char *buf, int len) 845{ 846 Dwarf_Die type; 847 int tag, ret, ret2; 848 const char *tmp = ""; 849 850 if (__die_get_real_type(vr_die, &type) == NULL) 851 return -ENOENT; 852 853 tag = dwarf_tag(&type); 854 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type) 855 tmp = "*"; 856 else if (tag == DW_TAG_subroutine_type) { 857 /* Function pointer */ 858 ret = snprintf(buf, len, "(function_type)"); 859 return (ret >= len) ? -E2BIG : ret; 860 } else { 861 if (!dwarf_diename(&type)) 862 return -ENOENT; 863 if (tag == DW_TAG_union_type) 864 tmp = "union "; 865 else if (tag == DW_TAG_structure_type) 866 tmp = "struct "; 867 else if (tag == DW_TAG_enumeration_type) 868 tmp = "enum "; 869 /* Write a base name */ 870 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type)); 871 return (ret >= len) ? -E2BIG : ret; 872 } 873 ret = die_get_typename(&type, buf, len); 874 if (ret > 0) { 875 ret2 = snprintf(buf + ret, len - ret, "%s", tmp); 876 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; 877 } 878 return ret; 879} 880 881/** 882 * die_get_varname - Get the name and type of given variable DIE 883 * @vr_die: a variable DIE 884 * @buf: a buffer for type and variable name 885 * @len: the max-length of @buf 886 * 887 * Get the name and type of @vr_die and stores it in @buf as "type\tname". 888 */ 889int die_get_varname(Dwarf_Die *vr_die, char *buf, int len) 890{ 891 int ret, ret2; 892 893 ret = die_get_typename(vr_die, buf, len); 894 if (ret < 0) { 895 pr_debug("Failed to get type, make it unknown.\n"); 896 ret = snprintf(buf, len, "(unknown_type)"); 897 } 898 if (ret > 0) { 899 ret2 = snprintf(buf + ret, len - ret, "\t%s", 900 dwarf_diename(vr_die)); 901 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; 902 } 903 return ret; 904} 905 906