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 */ 32 const 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 */ 64 const 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 */ 81 int 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 99 static 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 */ 111 int 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 */ 139 bool 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 */ 153 int 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 */ 173 Dwarf_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 */ 185 static 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 */ 212 Dwarf_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 */ 222 static 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 */ 235 static 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 */ 254 bool 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 **/ 272 bool 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_get_data_member_location - Get the data-member offset 282 * @mb_die: a DIE of a member of a data structure 283 * @offs: The offset of the member in the data structure 284 * 285 * Get the offset of @mb_die in the data structure including @mb_die, and 286 * stores result offset to @offs. If any error occurs this returns errno. 287 */ 288 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) 289 { 290 Dwarf_Attribute attr; 291 Dwarf_Op *expr; 292 size_t nexpr; 293 int ret; 294 295 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) 296 return -ENOENT; 297 298 if (dwarf_formudata(&attr, offs) != 0) { 299 /* DW_AT_data_member_location should be DW_OP_plus_uconst */ 300 ret = dwarf_getlocation(&attr, &expr, &nexpr); 301 if (ret < 0 || nexpr == 0) 302 return -ENOENT; 303 304 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) { 305 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n", 306 expr[0].atom, nexpr); 307 return -ENOTSUP; 308 } 309 *offs = (Dwarf_Word)expr[0].number; 310 } 311 return 0; 312 } 313 314 /* Get the call file index number in CU DIE */ 315 static int die_get_call_fileno(Dwarf_Die *in_die) 316 { 317 Dwarf_Sword idx; 318 319 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0) 320 return (int)idx; 321 else 322 return -ENOENT; 323 } 324 325 /* Get the declared file index number in CU DIE */ 326 static int die_get_decl_fileno(Dwarf_Die *pdie) 327 { 328 Dwarf_Sword idx; 329 330 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) 331 return (int)idx; 332 else 333 return -ENOENT; 334 } 335 336 /** 337 * die_get_call_file - Get callsite file name of inlined function instance 338 * @in_die: a DIE of an inlined function instance 339 * 340 * Get call-site file name of @in_die. This means from which file the inline 341 * function is called. 342 */ 343 const char *die_get_call_file(Dwarf_Die *in_die) 344 { 345 Dwarf_Die cu_die; 346 Dwarf_Files *files; 347 int idx; 348 349 idx = die_get_call_fileno(in_die); 350 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) || 351 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0) 352 return NULL; 353 354 return dwarf_filesrc(files, idx, NULL, NULL); 355 } 356 357 358 /** 359 * die_find_child - Generic DIE search function in DIE tree 360 * @rt_die: a root DIE 361 * @callback: a callback function 362 * @data: a user data passed to the callback function 363 * @die_mem: a buffer for result DIE 364 * 365 * Trace DIE tree from @rt_die and call @callback for each child DIE. 366 * If @callback returns DIE_FIND_CB_END, this stores the DIE into 367 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE, 368 * this continues to trace the tree. Optionally, @callback can return 369 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only 370 * the children and trace only the siblings respectively. 371 * Returns NULL if @callback can't find any appropriate DIE. 372 */ 373 Dwarf_Die *die_find_child(Dwarf_Die *rt_die, 374 int (*callback)(Dwarf_Die *, void *), 375 void *data, Dwarf_Die *die_mem) 376 { 377 Dwarf_Die child_die; 378 int ret; 379 380 ret = dwarf_child(rt_die, die_mem); 381 if (ret != 0) 382 return NULL; 383 384 do { 385 ret = callback(die_mem, data); 386 if (ret == DIE_FIND_CB_END) 387 return die_mem; 388 389 if ((ret & DIE_FIND_CB_CHILD) && 390 die_find_child(die_mem, callback, data, &child_die)) { 391 memcpy(die_mem, &child_die, sizeof(Dwarf_Die)); 392 return die_mem; 393 } 394 } while ((ret & DIE_FIND_CB_SIBLING) && 395 dwarf_siblingof(die_mem, die_mem) == 0); 396 397 return NULL; 398 } 399 400 struct __addr_die_search_param { 401 Dwarf_Addr addr; 402 Dwarf_Die *die_mem; 403 }; 404 405 /* die_find callback for non-inlined function search */ 406 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data) 407 { 408 struct __addr_die_search_param *ad = data; 409 410 /* 411 * Since a declaration entry doesn't has given pc, this always returns 412 * function definition entry. 413 */ 414 if (dwarf_tag(fn_die) == DW_TAG_subprogram && 415 dwarf_haspc(fn_die, ad->addr)) { 416 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die)); 417 return DWARF_CB_ABORT; 418 } 419 return DWARF_CB_OK; 420 } 421 422 /** 423 * die_find_realfunc - Search a non-inlined function at given address 424 * @cu_die: a CU DIE which including @addr 425 * @addr: target address 426 * @die_mem: a buffer for result DIE 427 * 428 * Search a non-inlined function DIE which includes @addr. Stores the 429 * DIE to @die_mem and returns it if found. Returns NULL if failed. 430 */ 431 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, 432 Dwarf_Die *die_mem) 433 { 434 struct __addr_die_search_param ad; 435 ad.addr = addr; 436 ad.die_mem = die_mem; 437 /* dwarf_getscopes can't find subprogram. */ 438 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0)) 439 return NULL; 440 else 441 return die_mem; 442 } 443 444 /* die_find callback for inline function search */ 445 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data) 446 { 447 Dwarf_Addr *addr = data; 448 449 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine && 450 dwarf_haspc(die_mem, *addr)) 451 return DIE_FIND_CB_END; 452 453 return DIE_FIND_CB_CONTINUE; 454 } 455 456 /** 457 * die_find_top_inlinefunc - Search the top inlined function at given address 458 * @sp_die: a subprogram DIE which including @addr 459 * @addr: target address 460 * @die_mem: a buffer for result DIE 461 * 462 * Search an inlined function DIE which includes @addr. Stores the 463 * DIE to @die_mem and returns it if found. Returns NULL if failed. 464 * Even if several inlined functions are expanded recursively, this 465 * doesn't trace it down, and returns the topmost one. 466 */ 467 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 468 Dwarf_Die *die_mem) 469 { 470 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); 471 } 472 473 /** 474 * die_find_inlinefunc - Search an inlined function at given address 475 * @sp_die: a subprogram DIE which including @addr 476 * @addr: target address 477 * @die_mem: a buffer for result DIE 478 * 479 * Search an inlined function DIE which includes @addr. Stores the 480 * DIE to @die_mem and returns it if found. Returns NULL if failed. 481 * If several inlined functions are expanded recursively, this trace 482 * it down and returns deepest one. 483 */ 484 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, 485 Dwarf_Die *die_mem) 486 { 487 Dwarf_Die tmp_die; 488 489 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die); 490 if (!sp_die) 491 return NULL; 492 493 /* Inlined function could be recursive. Trace it until fail */ 494 while (sp_die) { 495 memcpy(die_mem, sp_die, sizeof(Dwarf_Die)); 496 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, 497 &tmp_die); 498 } 499 500 return die_mem; 501 } 502 503 struct __instance_walk_param { 504 void *addr; 505 int (*callback)(Dwarf_Die *, void *); 506 void *data; 507 int retval; 508 }; 509 510 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) 511 { 512 struct __instance_walk_param *iwp = data; 513 Dwarf_Attribute attr_mem; 514 Dwarf_Die origin_mem; 515 Dwarf_Attribute *attr; 516 Dwarf_Die *origin; 517 int tmp; 518 519 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); 520 if (attr == NULL) 521 return DIE_FIND_CB_CONTINUE; 522 523 origin = dwarf_formref_die(attr, &origin_mem); 524 if (origin == NULL || origin->addr != iwp->addr) 525 return DIE_FIND_CB_CONTINUE; 526 527 /* Ignore redundant instances */ 528 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { 529 dwarf_decl_line(origin, &tmp); 530 if (die_get_call_lineno(inst) == tmp) { 531 tmp = die_get_decl_fileno(origin); 532 if (die_get_call_fileno(inst) == tmp) 533 return DIE_FIND_CB_CONTINUE; 534 } 535 } 536 537 iwp->retval = iwp->callback(inst, iwp->data); 538 539 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; 540 } 541 542 /** 543 * die_walk_instances - Walk on instances of given DIE 544 * @or_die: an abstract original DIE 545 * @callback: a callback function which is called with instance DIE 546 * @data: user data 547 * 548 * Walk on the instances of give @in_die. @in_die must be an inlined function 549 * declartion. This returns the return value of @callback if it returns 550 * non-zero value, or -ENOENT if there is no instance. 551 */ 552 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *), 553 void *data) 554 { 555 Dwarf_Die cu_die; 556 Dwarf_Die die_mem; 557 struct __instance_walk_param iwp = { 558 .addr = or_die->addr, 559 .callback = callback, 560 .data = data, 561 .retval = -ENOENT, 562 }; 563 564 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL) 565 return -ENOENT; 566 567 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem); 568 569 return iwp.retval; 570 } 571 572 /* Line walker internal parameters */ 573 struct __line_walk_param { 574 bool recursive; 575 line_walk_callback_t callback; 576 void *data; 577 int retval; 578 }; 579 580 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data) 581 { 582 struct __line_walk_param *lw = data; 583 Dwarf_Addr addr = 0; 584 const char *fname; 585 int lineno; 586 587 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) { 588 fname = die_get_call_file(in_die); 589 lineno = die_get_call_lineno(in_die); 590 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) { 591 lw->retval = lw->callback(fname, lineno, addr, lw->data); 592 if (lw->retval != 0) 593 return DIE_FIND_CB_END; 594 } 595 } 596 if (!lw->recursive) 597 /* Don't need to search recursively */ 598 return DIE_FIND_CB_SIBLING; 599 600 if (addr) { 601 fname = dwarf_decl_file(in_die); 602 if (fname && dwarf_decl_line(in_die, &lineno) == 0) { 603 lw->retval = lw->callback(fname, lineno, addr, lw->data); 604 if (lw->retval != 0) 605 return DIE_FIND_CB_END; 606 } 607 } 608 609 /* Continue to search nested inlined function call-sites */ 610 return DIE_FIND_CB_CONTINUE; 611 } 612 613 /* Walk on lines of blocks included in given DIE */ 614 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive, 615 line_walk_callback_t callback, void *data) 616 { 617 struct __line_walk_param lw = { 618 .recursive = recursive, 619 .callback = callback, 620 .data = data, 621 .retval = 0, 622 }; 623 Dwarf_Die die_mem; 624 Dwarf_Addr addr; 625 const char *fname; 626 int lineno; 627 628 /* Handle function declaration line */ 629 fname = dwarf_decl_file(sp_die); 630 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 && 631 dwarf_entrypc(sp_die, &addr) == 0) { 632 lw.retval = callback(fname, lineno, addr, data); 633 if (lw.retval != 0) 634 goto done; 635 } 636 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem); 637 done: 638 return lw.retval; 639 } 640 641 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data) 642 { 643 struct __line_walk_param *lw = data; 644 645 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data); 646 if (lw->retval != 0) 647 return DWARF_CB_ABORT; 648 649 return DWARF_CB_OK; 650 } 651 652 /** 653 * die_walk_lines - Walk on lines inside given DIE 654 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine) 655 * @callback: callback routine 656 * @data: user data 657 * 658 * Walk on all lines inside given @rt_die and call @callback on each line. 659 * If the @rt_die is a function, walk only on the lines inside the function, 660 * otherwise @rt_die must be a CU DIE. 661 * Note that this walks not only dwarf line list, but also function entries 662 * and inline call-site. 663 */ 664 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) 665 { 666 Dwarf_Lines *lines; 667 Dwarf_Line *line; 668 Dwarf_Addr addr; 669 const char *fname; 670 int lineno, ret = 0; 671 Dwarf_Die die_mem, *cu_die; 672 size_t nlines, i; 673 674 /* Get the CU die */ 675 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) 676 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL); 677 else 678 cu_die = rt_die; 679 if (!cu_die) { 680 pr_debug2("Failed to get CU from given DIE.\n"); 681 return -EINVAL; 682 } 683 684 /* Get lines list in the CU */ 685 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) { 686 pr_debug2("Failed to get source lines on this CU.\n"); 687 return -ENOENT; 688 } 689 pr_debug2("Get %zd lines from this CU\n", nlines); 690 691 /* Walk on the lines on lines list */ 692 for (i = 0; i < nlines; i++) { 693 line = dwarf_onesrcline(lines, i); 694 if (line == NULL || 695 dwarf_lineno(line, &lineno) != 0 || 696 dwarf_lineaddr(line, &addr) != 0) { 697 pr_debug2("Failed to get line info. " 698 "Possible error in debuginfo.\n"); 699 continue; 700 } 701 /* Filter lines based on address */ 702 if (rt_die != cu_die) 703 /* 704 * Address filtering 705 * The line is included in given function, and 706 * no inline block includes it. 707 */ 708 if (!dwarf_haspc(rt_die, addr) || 709 die_find_inlinefunc(rt_die, addr, &die_mem)) 710 continue; 711 /* Get source line */ 712 fname = dwarf_linesrc(line, NULL, NULL); 713 714 ret = callback(fname, lineno, addr, data); 715 if (ret != 0) 716 return ret; 717 } 718 719 /* 720 * Dwarf lines doesn't include function declarations and inlined 721 * subroutines. We have to check functions list or given function. 722 */ 723 if (rt_die != cu_die) 724 /* 725 * Don't need walk functions recursively, because nested 726 * inlined functions don't have lines of the specified DIE. 727 */ 728 ret = __die_walk_funclines(rt_die, false, callback, data); 729 else { 730 struct __line_walk_param param = { 731 .callback = callback, 732 .data = data, 733 .retval = 0, 734 }; 735 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0); 736 ret = param.retval; 737 } 738 739 return ret; 740 } 741 742 struct __find_variable_param { 743 const char *name; 744 Dwarf_Addr addr; 745 }; 746 747 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data) 748 { 749 struct __find_variable_param *fvp = data; 750 int tag; 751 752 tag = dwarf_tag(die_mem); 753 if ((tag == DW_TAG_formal_parameter || 754 tag == DW_TAG_variable) && 755 die_compare_name(die_mem, fvp->name)) 756 return DIE_FIND_CB_END; 757 758 if (dwarf_haspc(die_mem, fvp->addr)) 759 return DIE_FIND_CB_CONTINUE; 760 else 761 return DIE_FIND_CB_SIBLING; 762 } 763 764 /** 765 * die_find_variable_at - Find a given name variable at given address 766 * @sp_die: a function DIE 767 * @name: variable name 768 * @addr: address 769 * @die_mem: a buffer for result DIE 770 * 771 * Find a variable DIE called @name at @addr in @sp_die. 772 */ 773 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name, 774 Dwarf_Addr addr, Dwarf_Die *die_mem) 775 { 776 struct __find_variable_param fvp = { .name = name, .addr = addr}; 777 778 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp, 779 die_mem); 780 } 781 782 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data) 783 { 784 const char *name = data; 785 786 if ((dwarf_tag(die_mem) == DW_TAG_member) && 787 die_compare_name(die_mem, name)) 788 return DIE_FIND_CB_END; 789 790 return DIE_FIND_CB_SIBLING; 791 } 792 793 /** 794 * die_find_member - Find a given name member in a data structure 795 * @st_die: a data structure type DIE 796 * @name: member name 797 * @die_mem: a buffer for result DIE 798 * 799 * Find a member DIE called @name in @st_die. 800 */ 801 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, 802 Dwarf_Die *die_mem) 803 { 804 return die_find_child(st_die, __die_find_member_cb, (void *)name, 805 die_mem); 806 } 807 808 /** 809 * die_get_typename - Get the name of given variable DIE 810 * @vr_die: a variable DIE 811 * @buf: a buffer for result type name 812 * @len: a max-length of @buf 813 * 814 * Get the name of @vr_die and stores it to @buf. Return the actual length 815 * of type name if succeeded. Return -E2BIG if @len is not enough long, and 816 * Return -ENOENT if failed to find type name. 817 * Note that the result will stores typedef name if possible, and stores 818 * "*(function_type)" if the type is a function pointer. 819 */ 820 int die_get_typename(Dwarf_Die *vr_die, char *buf, int len) 821 { 822 Dwarf_Die type; 823 int tag, ret, ret2; 824 const char *tmp = ""; 825 826 if (__die_get_real_type(vr_die, &type) == NULL) 827 return -ENOENT; 828 829 tag = dwarf_tag(&type); 830 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type) 831 tmp = "*"; 832 else if (tag == DW_TAG_subroutine_type) { 833 /* Function pointer */ 834 ret = snprintf(buf, len, "(function_type)"); 835 return (ret >= len) ? -E2BIG : ret; 836 } else { 837 if (!dwarf_diename(&type)) 838 return -ENOENT; 839 if (tag == DW_TAG_union_type) 840 tmp = "union "; 841 else if (tag == DW_TAG_structure_type) 842 tmp = "struct "; 843 else if (tag == DW_TAG_enumeration_type) 844 tmp = "enum "; 845 /* Write a base name */ 846 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type)); 847 return (ret >= len) ? -E2BIG : ret; 848 } 849 ret = die_get_typename(&type, buf, len); 850 if (ret > 0) { 851 ret2 = snprintf(buf + ret, len - ret, "%s", tmp); 852 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; 853 } 854 return ret; 855 } 856 857 /** 858 * die_get_varname - Get the name and type of given variable DIE 859 * @vr_die: a variable DIE 860 * @buf: a buffer for type and variable name 861 * @len: the max-length of @buf 862 * 863 * Get the name and type of @vr_die and stores it in @buf as "type\tname". 864 */ 865 int die_get_varname(Dwarf_Die *vr_die, char *buf, int len) 866 { 867 int ret, ret2; 868 869 ret = die_get_typename(vr_die, buf, len); 870 if (ret < 0) { 871 pr_debug("Failed to get type, make it unknown.\n"); 872 ret = snprintf(buf, len, "(unknown_type)"); 873 } 874 if (ret > 0) { 875 ret2 = snprintf(buf + ret, len - ret, "\t%s", 876 dwarf_diename(vr_die)); 877 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; 878 } 879 return ret; 880 } 881 882
