tools/perf/util/probe-finder.c

   1 /*
   2  * probe-finder.c : C expression to kprobe event converter
   3  *
   4  * Written by Masami Hiramatsu <mhiramat@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  */
  21
  22 #include <sys/utsname.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include <unistd.h>
  29 #include <getopt.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdarg.h>
  33 #include <ctype.h>
  34 #include <dwarf-regs.h>
  35
  36 #include "string.h"
  37 #include "event.h"
  38 #include "debug.h"
  39 #include "util.h"
  40 #include "symbol.h"
  41 #include "probe-finder.h"
  42
  43 /* Kprobe tracer basic type is up to u64 */
  44 #define MAX_BASIC_TYPE_BITS     64
  45
  46 /*
  47  * Compare the tail of two strings.
  48  * Return 0 if whole of either string is same as another's tail part.
  49  */
  50 static int strtailcmp(const char *s1, const char *s2)
  51 {
  52         int i1 = strlen(s1);
  53         int i2 = strlen(s2);
  54         while (--i1 >= 0 && --i2 >= 0) {
  55                 if (s1[i1] != s2[i2])
  56                         return s1[i1] - s2[i2];
  57         }
  58         return 0;
  59 }
  60
  61 /* Line number list operations */
  62
  63 /* Add a line to line number list */
  64 static int line_list__add_line(struct list_head *head, int line)
  65 {
  66         struct line_node *ln;
  67         struct list_head *p;
  68
  69         /* Reverse search, because new line will be the last one */
  70         list_for_each_entry_reverse(ln, head, list) {
  71                 if (ln->line < line) {
  72                         p = &ln->list;
  73                         goto found;
  74                 } else if (ln->line == line)    /* Already exist */
  75                         return 1;
  76         }
  77         /* List is empty, or the smallest entry */
  78         p = head;
  79 found:
  80         pr_debug("line list: add a line %u\n", line);
  81         ln = zalloc(sizeof(struct line_node));
  82         if (ln == NULL)
  83                 return -ENOMEM;
  84         ln->line = line;
  85         INIT_LIST_HEAD(&ln->list);
  86         list_add(&ln->list, p);
  87         return 0;
  88 }
  89
  90 /* Check if the line in line number list */
  91 static int line_list__has_line(struct list_head *head, int line)
  92 {
  93         struct line_node *ln;
  94
  95         /* Reverse search, because new line will be the last one */
  96         list_for_each_entry(ln, head, list)
  97                 if (ln->line == line)
  98                         return 1;
  99
 100         return 0;
 101 }
 102
 103 /* Init line number list */
 104 static void line_list__init(struct list_head *head)
 105 {
 106         INIT_LIST_HEAD(head);
 107 }
 108
 109 /* Free line number list */
 110 static void line_list__free(struct list_head *head)
 111 {
 112         struct line_node *ln;
 113         while (!list_empty(head)) {
 114                 ln = list_first_entry(head, struct line_node, list);
 115                 list_del(&ln->list);
 116                 free(ln);
 117         }
 118 }
 119
 120 /* Dwarf wrappers */
 121
 122 /* Find the realpath of the target file. */
 123 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
 124 {
 125         Dwarf_Files *files;
 126         size_t nfiles, i;
 127         const char *src = NULL;
 128         int ret;
 129
 130         if (!fname)
 131                 return NULL;
 132
 133         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
 134         if (ret != 0)
 135                 return NULL;
 136
 137         for (i = 0; i < nfiles; i++) {
 138                 src = dwarf_filesrc(files, i, NULL, NULL);
 139                 if (strtailcmp(src, fname) == 0)
 140                         break;
 141         }
 142         if (i == nfiles)
 143                 return NULL;
 144         return src;
 145 }
 146
 147 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
 148 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
 149 {
 150         Dwarf_Attribute attr;
 151         if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
 152                 return NULL;
 153         return dwarf_formstring(&attr);
 154 }
 155
 156 /* Compare diename and tname */
 157 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 158 {
 159         const char *name;
 160         name = dwarf_diename(dw_die);
 161         return name ? (strcmp(tname, name) == 0) : false;
 162 }
 163
 164 /* Get type die, but skip qualifiers and typedef */
 165 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 166 {
 167         Dwarf_Attribute attr;
 168         int tag;
 169
 170         do {
 171                 if (dwarf_attr(vr_die, DW_AT_type, &attr) == NULL ||
 172                     dwarf_formref_die(&attr, die_mem) == NULL)
 173                         return NULL;
 174
 175                 tag = dwarf_tag(die_mem);
 176                 vr_die = die_mem;
 177         } while (tag == DW_TAG_const_type ||
 178                  tag == DW_TAG_restrict_type ||
 179                  tag == DW_TAG_volatile_type ||
 180                  tag == DW_TAG_shared_type ||
 181                  tag == DW_TAG_typedef);
 182
 183         return die_mem;
 184 }
 185
 186 static bool die_is_signed_type(Dwarf_Die *tp_die)
 187 {
 188         Dwarf_Attribute attr;
 189         Dwarf_Word ret;
 190
 191         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
 192             dwarf_formudata(&attr, &ret) != 0)
 193                 return false;
 194
 195         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
 196                 ret == DW_ATE_signed_fixed);
 197 }
 198
 199 static int die_get_byte_size(Dwarf_Die *tp_die)
 200 {
 201         Dwarf_Attribute attr;
 202         Dwarf_Word ret;
 203
 204         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
 205             dwarf_formudata(&attr, &ret) != 0)
 206                 return 0;
 207
 208         return (int)ret;
 209 }
 210
 211 /* Get data_member_location offset */
 212 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
 213 {
 214         Dwarf_Attribute attr;
 215         Dwarf_Op *expr;
 216         size_t nexpr;
 217         int ret;
 218
 219         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
 220                 return -ENOENT;
 221
 222         if (dwarf_formudata(&attr, offs) != 0) {
 223                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
 224                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
 225                 if (ret < 0 || nexpr == 0)
 226                         return -ENOENT;
 227
 228                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
 229                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
 230                                  expr[0].atom, nexpr);
 231                         return -ENOTSUP;
 232                 }
 233                 *offs = (Dwarf_Word)expr[0].number;
 234         }
 235         return 0;
 236 }
 237
 238 /* Return values for die_find callbacks */
 239 enum {
 240         DIE_FIND_CB_FOUND = 0,          /* End of Search */
 241         DIE_FIND_CB_CHILD = 1,          /* Search only children */
 242         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
 243         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
 244 };
 245
 246 /* Search a child die */
 247 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
 248                                  int (*callback)(Dwarf_Die *, void *),
 249                                  void *data, Dwarf_Die *die_mem)
 250 {
 251         Dwarf_Die child_die;
 252         int ret;
 253
 254         ret = dwarf_child(rt_die, die_mem);
 255         if (ret != 0)
 256                 return NULL;
 257
 258         do {
 259                 ret = callback(die_mem, data);
 260                 if (ret == DIE_FIND_CB_FOUND)
 261                         return die_mem;
 262
 263                 if ((ret & DIE_FIND_CB_CHILD) &&
 264                     die_find_child(die_mem, callback, data, &child_die)) {
 265                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
 266                         return die_mem;
 267                 }
 268         } while ((ret & DIE_FIND_CB_SIBLING) &&
 269                  dwarf_siblingof(die_mem, die_mem) == 0);
 270
 271         return NULL;
 272 }
 273
 274 struct __addr_die_search_param {
 275         Dwarf_Addr      addr;
 276         Dwarf_Die       *die_mem;
 277 };
 278
 279 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 280 {
 281         struct __addr_die_search_param *ad = data;
 282
 283         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
 284             dwarf_haspc(fn_die, ad->addr)) {
 285                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
 286                 return DWARF_CB_ABORT;
 287         }
 288         return DWARF_CB_OK;
 289 }
 290
 291 /* Search a real subprogram including this line, */
 292 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
 293                                            Dwarf_Die *die_mem)
 294 {
 295         struct __addr_die_search_param ad;
 296         ad.addr = addr;
 297         ad.die_mem = die_mem;
 298         /* dwarf_getscopes can't find subprogram. */
 299         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
 300                 return NULL;
 301         else
 302                 return die_mem;
 303 }
 304
 305 /* die_find callback for inline function search */
 306 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 307 {
 308         Dwarf_Addr *addr = data;
 309
 310         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
 311             dwarf_haspc(die_mem, *addr))
 312                 return DIE_FIND_CB_FOUND;
 313
 314         return DIE_FIND_CB_CONTINUE;
 315 }
 316
 317 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
 318 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 319                                       Dwarf_Die *die_mem)
 320 {
 321         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 322 }
 323
 324 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 325 {
 326         const char *name = data;
 327         int tag;
 328
 329         tag = dwarf_tag(die_mem);
 330         if ((tag == DW_TAG_formal_parameter ||
 331              tag == DW_TAG_variable) &&
 332             die_compare_name(die_mem, name))
 333                 return DIE_FIND_CB_FOUND;
 334
 335         return DIE_FIND_CB_CONTINUE;
 336 }
 337
 338 /* Find a variable called 'name' */
 339 static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
 340                                     Dwarf_Die *die_mem)
 341 {
 342         return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
 343                               die_mem);
 344 }
 345
 346 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
 347 {
 348         const char *name = data;
 349
 350         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
 351             die_compare_name(die_mem, name))
 352                 return DIE_FIND_CB_FOUND;
 353
 354         return DIE_FIND_CB_SIBLING;
 355 }
 356
 357 /* Find a member called 'name' */
 358 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
 359                                   Dwarf_Die *die_mem)
 360 {
 361         return die_find_child(st_die, __die_find_member_cb, (void *)name,
 362                               die_mem);
 363 }
 364
 365 /*
 366  * Probe finder related functions
 367  */
 368
 369 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 370 {
 371         struct probe_trace_arg_ref *ref;
 372         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 373         if (ref != NULL)
 374                 ref->offset = offs;
 375         return ref;
 376 }
 377
 378 /* Show a location */
 379 static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
 380 {
 381         Dwarf_Attribute attr;
 382         Dwarf_Op *op;
 383         size_t nops;
 384         unsigned int regn;
 385         Dwarf_Word offs = 0;
 386         bool ref = false;
 387         const char *regs;
 388         struct probe_trace_arg *tvar = pf->tvar;
 389         int ret;
 390
 391         /* TODO: handle more than 1 exprs */
 392         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
 393             dwarf_getlocation_addr(&attr, pf->addr, &op, &nops, 1) <= 0 ||
 394             nops == 0) {
 395                 /* TODO: Support const_value */
 396                 pr_err("Failed to find the location of %s at this address.\n"
 397                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 398                 return -ENOENT;
 399         }
 400
 401         if (op->atom == DW_OP_addr) {
 402                 /* Static variables on memory (not stack), make @varname */
 403                 ret = strlen(dwarf_diename(vr_die));
 404                 tvar->value = zalloc(ret + 2);
 405                 if (tvar->value == NULL)
 406                         return -ENOMEM;
 407                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 408                 tvar->ref = alloc_trace_arg_ref((long)offs);
 409                 if (tvar->ref == NULL)
 410                         return -ENOMEM;
 411                 return 0;
 412         }
 413
 414         /* If this is based on frame buffer, set the offset */
 415         if (op->atom == DW_OP_fbreg) {
 416                 if (pf->fb_ops == NULL) {
 417                         pr_warning("The attribute of frame base is not "
 418                                    "supported.\n");
 419                         return -ENOTSUP;
 420                 }
 421                 ref = true;
 422                 offs = op->number;
 423                 op = &pf->fb_ops[0];
 424         }
 425
 426         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 427                 regn = op->atom - DW_OP_breg0;
 428                 offs += op->number;
 429                 ref = true;
 430         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 431                 regn = op->atom - DW_OP_reg0;
 432         } else if (op->atom == DW_OP_bregx) {
 433                 regn = op->number;
 434                 offs += op->number2;
 435                 ref = true;
 436         } else if (op->atom == DW_OP_regx) {
 437                 regn = op->number;
 438         } else {
 439                 pr_warning("DW_OP %x is not supported.\n", op->atom);
 440                 return -ENOTSUP;
 441         }
 442
 443         regs = get_arch_regstr(regn);
 444         if (!regs) {
 445                 pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
 446                 return -ERANGE;
 447         }
 448
 449         tvar->value = strdup(regs);
 450         if (tvar->value == NULL)
 451                 return -ENOMEM;
 452
 453         if (ref) {
 454                 tvar->ref = alloc_trace_arg_ref((long)offs);
 455                 if (tvar->ref == NULL)
 456                         return -ENOMEM;
 457         }
 458         return 0;
 459 }
 460
 461 static int convert_variable_type(Dwarf_Die *vr_die,
 462                                  struct probe_trace_arg *tvar,
 463                                  const char *cast)
 464 {
 465         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 466         Dwarf_Die type;
 467         char buf[16];
 468         int ret;
 469
 470         /* TODO: check all types */
 471         if (cast && strcmp(cast, "string") != 0) {
 472                 /* Non string type is OK */
 473                 tvar->type = strdup(cast);
 474                 return (tvar->type == NULL) ? -ENOMEM : 0;
 475         }
 476
 477         if (die_get_real_type(vr_die, &type) == NULL) {
 478                 pr_warning("Failed to get a type information of %s.\n",
 479                            dwarf_diename(vr_die));
 480                 return -ENOENT;
 481         }
 482
 483         pr_debug("%s type is %s.\n",
 484                  dwarf_diename(vr_die), dwarf_diename(&type));
 485
 486         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 487                 ret = dwarf_tag(&type);
 488                 if (ret != DW_TAG_pointer_type &&
 489                     ret != DW_TAG_array_type) {
 490                         pr_warning("Failed to cast into string: "
 491                                    "%s(%s) is not a pointer nor array.",
 492                                    dwarf_diename(vr_die), dwarf_diename(&type));
 493                         return -EINVAL;
 494                 }
 495                 if (ret == DW_TAG_pointer_type) {
 496                         if (die_get_real_type(&type, &type) == NULL) {
 497                                 pr_warning("Failed to get a type information.");
 498                                 return -ENOENT;
 499                         }
 500                         while (*ref_ptr)
 501                                 ref_ptr = &(*ref_ptr)->next;
 502                         /* Add new reference with offset +0 */
 503                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 504                         if (*ref_ptr == NULL) {
 505                                 pr_warning("Out of memory error\n");
 506                                 return -ENOMEM;
 507                         }
 508                 }
 509                 if (!die_compare_name(&type, "char") &&
 510                     !die_compare_name(&type, "unsigned char")) {
 511                         pr_warning("Failed to cast into string: "
 512                                    "%s is not (unsigned) char *.",
 513                                    dwarf_diename(vr_die));
 514                         return -EINVAL;
 515                 }
 516                 tvar->type = strdup(cast);
 517                 return (tvar->type == NULL) ? -ENOMEM : 0;
 518         }
 519
 520         ret = die_get_byte_size(&type) * 8;
 521         if (ret) {
 522                 /* Check the bitwidth */
 523                 if (ret > MAX_BASIC_TYPE_BITS) {
 524                         pr_info("%s exceeds max-bitwidth."
 525                                 " Cut down to %d bits.\n",
 526                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 527                         ret = MAX_BASIC_TYPE_BITS;
 528                 }
 529
 530                 ret = snprintf(buf, 16, "%c%d",
 531                                die_is_signed_type(&type) ? 's' : 'u', ret);
 532                 if (ret < 0 || ret >= 16) {
 533                         if (ret >= 16)
 534                                 ret = -E2BIG;
 535                         pr_warning("Failed to convert variable type: %s\n",
 536                                    strerror(-ret));
 537                         return ret;
 538                 }
 539                 tvar->type = strdup(buf);
 540                 if (tvar->type == NULL)
 541                         return -ENOMEM;
 542         }
 543         return 0;
 544 }
 545
 546 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 547                                     struct perf_probe_arg_field *field,
 548                                     struct probe_trace_arg_ref **ref_ptr,
 549                                     Dwarf_Die *die_mem)
 550 {
 551         struct probe_trace_arg_ref *ref = *ref_ptr;
 552         Dwarf_Die type;
 553         Dwarf_Word offs;
 554         int ret, tag;
 555
 556         pr_debug("converting %s in %s\n", field->name, varname);
 557         if (die_get_real_type(vr_die, &type) == NULL) {
 558                 pr_warning("Failed to get the type of %s.\n", varname);
 559                 return -ENOENT;
 560         }
 561         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 562         tag = dwarf_tag(&type);
 563
 564         if (field->name[0] == '[' &&
 565             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 566                 if (field->next)
 567                         /* Save original type for next field */
 568                         memcpy(die_mem, &type, sizeof(*die_mem));
 569                 /* Get the type of this array */
 570                 if (die_get_real_type(&type, &type) == NULL) {
 571                         pr_warning("Failed to get the type of %s.\n", varname);
 572                         return -ENOENT;
 573                 }
 574                 pr_debug2("Array real type: (%x)\n",
 575                          (unsigned)dwarf_dieoffset(&type));
 576                 if (tag == DW_TAG_pointer_type) {
 577                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 578                         if (ref == NULL)
 579                                 return -ENOMEM;
 580                         if (*ref_ptr)
 581                                 (*ref_ptr)->next = ref;
 582                         else
 583                                 *ref_ptr = ref;
 584                 }
 585                 ref->offset += die_get_byte_size(&type) * field->index;
 586                 if (!field->next)
 587                         /* Save vr_die for converting types */
 588                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 589                 goto next;
 590         } else if (tag == DW_TAG_pointer_type) {
 591                 /* Check the pointer and dereference */
 592                 if (!field->ref) {
 593                         pr_err("Semantic error: %s must be referred by '->'\n",
 594                                field->name);
 595                         return -EINVAL;
 596                 }
 597                 /* Get the type pointed by this pointer */
 598                 if (die_get_real_type(&type, &type) == NULL) {
 599                         pr_warning("Failed to get the type of %s.\n", varname);
 600                         return -ENOENT;
 601                 }
 602                 /* Verify it is a data structure  */
 603                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 604                         pr_warning("%s is not a data structure.\n", varname);
 605                         return -EINVAL;
 606                 }
 607
 608                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 609                 if (ref == NULL)
 610                         return -ENOMEM;
 611                 if (*ref_ptr)
 612                         (*ref_ptr)->next = ref;
 613                 else
 614                         *ref_ptr = ref;
 615         } else {
 616                 /* Verify it is a data structure  */
 617                 if (tag != DW_TAG_structure_type) {
 618                         pr_warning("%s is not a data structure.\n", varname);
 619                         return -EINVAL;
 620                 }
 621                 if (field->name[0] == '[') {
 622                         pr_err("Semantic error: %s is not a pointor nor array.",
 623                                varname);
 624                         return -EINVAL;
 625                 }
 626                 if (field->ref) {
 627                         pr_err("Semantic error: %s must be referred by '.'\n",
 628                                field->name);
 629                         return -EINVAL;
 630                 }
 631                 if (!ref) {
 632                         pr_warning("Structure on a register is not "
 633                                    "supported yet.\n");
 634                         return -ENOTSUP;
 635                 }
 636         }
 637
 638         if (die_find_member(&type, field->name, die_mem) == NULL) {
 639                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 640                            dwarf_diename(&type), field->name);
 641                 return -EINVAL;
 642         }
 643
 644         /* Get the offset of the field */
 645         ret = die_get_data_member_location(die_mem, &offs);
 646         if (ret < 0) {
 647                 pr_warning("Failed to get the offset of %s.\n", field->name);
 648                 return ret;
 649         }
 650         ref->offset += (long)offs;
 651
 652 next:
 653         /* Converting next field */
 654         if (field->next)
 655                 return convert_variable_fields(die_mem, field->name,
 656                                         field->next, &ref, die_mem);
 657         else
 658                 return 0;
 659 }
 660
 661 /* Show a variables in kprobe event format */
 662 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 663 {
 664         Dwarf_Die die_mem;
 665         int ret;
 666
 667         pr_debug("Converting variable %s into trace event.\n",
 668                  dwarf_diename(vr_die));
 669
 670         ret = convert_variable_location(vr_die, pf);
 671         if (ret == 0 && pf->pvar->field) {
 672                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 673                                               pf->pvar->field, &pf->tvar->ref,
 674                                               &die_mem);
 675                 vr_die = &die_mem;
 676         }
 677         if (ret == 0)
 678                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 679         /* *expr will be cached in libdw. Don't free it. */
 680         return ret;
 681 }
 682
 683 /* Find a variable in a subprogram die */
 684 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 685 {
 686         Dwarf_Die vr_die, *scopes;
 687         char buf[32], *ptr;
 688         int ret, nscopes;
 689
 690         if (pf->pvar->name)
 691                 pf->tvar->name = strdup(pf->pvar->name);
 692         else {
 693                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 694                 if (ret < 0)
 695                         return ret;
 696                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 697                 if (ptr)
 698                         *ptr = '_';
 699                 pf->tvar->name = strdup(buf);
 700         }
 701         if (pf->tvar->name == NULL)
 702                 return -ENOMEM;
 703
 704         if (!is_c_varname(pf->pvar->var)) {
 705                 /* Copy raw parameters */
 706                 pf->tvar->value = strdup(pf->pvar->var);
 707                 if (pf->tvar->value == NULL)
 708                         return -ENOMEM;
 709                 else
 710                         return 0;
 711         }
 712
 713         pr_debug("Searching '%s' variable in context.\n",
 714                  pf->pvar->var);
 715         /* Search child die for local variables and parameters. */
 716         if (die_find_variable(sp_die, pf->pvar->var, &vr_die))
 717                 ret = convert_variable(&vr_die, pf);
 718         else {
 719                 /* Search upper class */
 720                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 721                 if (nscopes > 0) {
 722                         ret = dwarf_getscopevar(scopes, nscopes, pf->pvar->var,
 723                                                 0, NULL, 0, 0, &vr_die);
 724                         if (ret >= 0)
 725                                 ret = convert_variable(&vr_die, pf);
 726                         else
 727                                 ret = -ENOENT;
 728                         free(scopes);
 729                 } else
 730                         ret = -ENOENT;
 731         }
 732         if (ret < 0)
 733                 pr_warning("Failed to find '%s' in this function.\n",
 734                            pf->pvar->var);
 735         return ret;
 736 }
 737
 738 /* Show a probe point to output buffer */
 739 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 740 {
 741         struct probe_trace_event *tev;
 742         Dwarf_Addr eaddr;
 743         Dwarf_Die die_mem;
 744         const char *name;
 745         int ret, i;
 746         Dwarf_Attribute fb_attr;
 747         size_t nops;
 748
 749         if (pf->ntevs == pf->max_tevs) {
 750                 pr_warning("Too many( > %d) probe point found.\n",
 751                            pf->max_tevs);
 752                 return -ERANGE;
 753         }
 754         tev = &pf->tevs[pf->ntevs++];
 755
 756         /* If no real subprogram, find a real one */
 757         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
 758                 sp_die = die_find_real_subprogram(&pf->cu_die,
 759                                                  pf->addr, &die_mem);
 760                 if (!sp_die) {
 761                         pr_warning("Failed to find probe point in any "
 762                                    "functions.\n");
 763                         return -ENOENT;
 764                 }
 765         }
 766
 767         /* Copy the name of probe point */
 768         name = dwarf_diename(sp_die);
 769         if (name) {
 770                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 771                         pr_warning("Failed to get entry pc of %s\n",
 772                                    dwarf_diename(sp_die));
 773                         return -ENOENT;
 774                 }
 775                 tev->point.symbol = strdup(name);
 776                 if (tev->point.symbol == NULL)
 777                         return -ENOMEM;
 778                 tev->point.offset = (unsigned long)(pf->addr - eaddr);
 779         } else
 780                 /* This function has no name. */
 781                 tev->point.offset = (unsigned long)pf->addr;
 782
 783         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
 784                  tev->point.offset);
 785
 786         /* Get the frame base attribute/ops */
 787         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
 788         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 789         if (ret <= 0 || nops == 0) {
 790                 pf->fb_ops = NULL;
 791 #if _ELFUTILS_PREREQ(0, 142)
 792         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 793                    pf->cfi != NULL) {
 794                 Dwarf_Frame *frame;
 795                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 796                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 797                         pr_warning("Failed to get CFA on 0x%jx\n",
 798                                    (uintmax_t)pf->addr);
 799                         return -ENOENT;
 800                 }
 801 #endif
 802         }
 803
 804         /* Find each argument */
 805         tev->nargs = pf->pev->nargs;
 806         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
 807         if (tev->args == NULL)
 808                 return -ENOMEM;
 809         for (i = 0; i < pf->pev->nargs; i++) {
 810                 pf->pvar = &pf->pev->args[i];
 811                 pf->tvar = &tev->args[i];
 812                 ret = find_variable(sp_die, pf);
 813                 if (ret != 0)
 814                         return ret;
 815         }
 816
 817         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 818         pf->fb_ops = NULL;
 819         return 0;
 820 }
 821
 822 /* Find probe point from its line number */
 823 static int find_probe_point_by_line(struct probe_finder *pf)
 824 {
 825         Dwarf_Lines *lines;
 826         Dwarf_Line *line;
 827         size_t nlines, i;
 828         Dwarf_Addr addr;
 829         int lineno;
 830         int ret = 0;
 831
 832         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
 833                 pr_warning("No source lines found in this CU.\n");
 834                 return -ENOENT;
 835         }
 836
 837         for (i = 0; i < nlines && ret == 0; i++) {
 838                 line = dwarf_onesrcline(lines, i);
 839                 if (dwarf_lineno(line, &lineno) != 0 ||
 840                     lineno != pf->lno)
 841                         continue;
 842
 843                 /* TODO: Get fileno from line, but how? */
 844                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
 845                         continue;
 846
 847                 if (dwarf_lineaddr(line, &addr) != 0) {
 848                         pr_warning("Failed to get the address of the line.\n");
 849                         return -ENOENT;
 850                 }
 851                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
 852                          (int)i, lineno, (uintmax_t)addr);
 853                 pf->addr = addr;
 854
 855                 ret = convert_probe_point(NULL, pf);
 856                 /* Continuing, because target line might be inlined. */
 857         }
 858         return ret;
 859 }
 860
 861 /* Find lines which match lazy pattern */
 862 static int find_lazy_match_lines(struct list_head *head,
 863                                  const char *fname, const char *pat)
 864 {
 865         char *fbuf, *p1, *p2;
 866         int fd, line, nlines = -1;
 867         struct stat st;
 868
 869         fd = open(fname, O_RDONLY);
 870         if (fd < 0) {
 871                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
 872                 return -errno;
 873         }
 874
 875         if (fstat(fd, &st) < 0) {
 876                 pr_warning("Failed to get the size of %s: %s\n",
 877                            fname, strerror(errno));
 878                 nlines = -errno;
 879                 goto out_close;
 880         }
 881
 882         nlines = -ENOMEM;
 883         fbuf = malloc(st.st_size + 2);
 884         if (fbuf == NULL)
 885                 goto out_close;
 886         if (read(fd, fbuf, st.st_size) < 0) {
 887                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
 888                 nlines = -errno;
 889                 goto out_free_fbuf;
 890         }
 891         fbuf[st.st_size] = '\n';        /* Dummy line */
 892         fbuf[st.st_size + 1] = '\0';
 893         p1 = fbuf;
 894         line = 1;
 895         nlines = 0;
 896         while ((p2 = strchr(p1, '\n')) != NULL) {
 897                 *p2 = '\0';
 898                 if (strlazymatch(p1, pat)) {
 899                         line_list__add_line(head, line);
 900                         nlines++;
 901                 }
 902                 line++;
 903                 p1 = p2 + 1;
 904         }
 905 out_free_fbuf:
 906         free(fbuf);
 907 out_close:
 908         close(fd);
 909         return nlines;
 910 }
 911
 912 /* Find probe points from lazy pattern  */
 913 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 914 {
 915         Dwarf_Lines *lines;
 916         Dwarf_Line *line;
 917         size_t nlines, i;
 918         Dwarf_Addr addr;
 919         Dwarf_Die die_mem;
 920         int lineno;
 921         int ret = 0;
 922
 923         if (list_empty(&pf->lcache)) {
 924                 /* Matching lazy line pattern */
 925                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
 926                                             pf->pev->point.lazy_line);
 927                 if (ret == 0) {
 928                         pr_debug("No matched lines found in %s.\n", pf->fname);
 929                         return 0;
 930                 } else if (ret < 0)
 931                         return ret;
 932         }
 933
 934         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
 935                 pr_warning("No source lines found in this CU.\n");
 936                 return -ENOENT;
 937         }
 938
 939         for (i = 0; i < nlines && ret >= 0; i++) {
 940                 line = dwarf_onesrcline(lines, i);
 941
 942                 if (dwarf_lineno(line, &lineno) != 0 ||
 943                     !line_list__has_line(&pf->lcache, lineno))
 944                         continue;
 945
 946                 /* TODO: Get fileno from line, but how? */
 947                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
 948                         continue;
 949
 950                 if (dwarf_lineaddr(line, &addr) != 0) {
 951                         pr_debug("Failed to get the address of line %d.\n",
 952                                  lineno);
 953                         continue;
 954                 }
 955                 if (sp_die) {
 956                         /* Address filtering 1: does sp_die include addr? */
 957                         if (!dwarf_haspc(sp_die, addr))
 958                                 continue;
 959                         /* Address filtering 2: No child include addr? */
 960                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
 961                                 continue;
 962                 }
 963
 964                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
 965                          (int)i, lineno, (unsigned long long)addr);
 966                 pf->addr = addr;
 967
 968                 ret = convert_probe_point(sp_die, pf);
 969                 /* Continuing, because target line might be inlined. */
 970         }
 971         /* TODO: deallocate lines, but how? */
 972         return ret;
 973 }
 974
 975 /* Callback parameter with return value */
 976 struct dwarf_callback_param {
 977         void *data;
 978         int retval;
 979 };
 980
 981 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 982 {
 983         struct dwarf_callback_param *param = data;
 984         struct probe_finder *pf = param->data;
 985         struct perf_probe_point *pp = &pf->pev->point;
 986         Dwarf_Addr addr;
 987
 988         if (pp->lazy_line)
 989                 param->retval = find_probe_point_lazy(in_die, pf);
 990         else {
 991                 /* Get probe address */
 992                 if (dwarf_entrypc(in_die, &addr) != 0) {
 993                         pr_warning("Failed to get entry pc of %s.\n",
 994                                    dwarf_diename(in_die));
 995                         param->retval = -ENOENT;
 996                         return DWARF_CB_ABORT;
 997                 }
 998                 pf->addr = addr;
 999                 pf->addr += pp->offset;
1000                 pr_debug("found inline addr: 0x%jx\n",
1001                          (uintmax_t)pf->addr);
1002
1003                 param->retval = convert_probe_point(in_die, pf);
1004                 if (param->retval < 0)
1005                         return DWARF_CB_ABORT;
1006         }
1007
1008         return DWARF_CB_OK;
1009 }
1010
1011 /* Search function from function name */
1012 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1013 {
1014         struct dwarf_callback_param *param = data;
1015         struct probe_finder *pf = param->data;
1016         struct perf_probe_point *pp = &pf->pev->point;
1017
1018         /* Check tag and diename */
1019         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1020             !die_compare_name(sp_die, pp->function))
1021                 return DWARF_CB_OK;
1022
1023         pf->fname = dwarf_decl_file(sp_die);
1024         if (pp->line) { /* Function relative line */
1025                 dwarf_decl_line(sp_die, &pf->lno);
1026                 pf->lno += pp->line;
1027                 param->retval = find_probe_point_by_line(pf);
1028         } else if (!dwarf_func_inline(sp_die)) {
1029                 /* Real function */
1030                 if (pp->lazy_line)
1031                         param->retval = find_probe_point_lazy(sp_die, pf);
1032                 else {
1033                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1034                                 pr_warning("Failed to get entry pc of %s.\n",
1035                                            dwarf_diename(sp_die));
1036                                 param->retval = -ENOENT;
1037                                 return DWARF_CB_ABORT;
1038                         }
1039                         pf->addr += pp->offset;
1040                         /* TODO: Check the address in this function */
1041                         param->retval = convert_probe_point(sp_die, pf);
1042                 }
1043         } else {
1044                 struct dwarf_callback_param _param = {.data = (void *)pf,
1045                                                       .retval = 0};
1046                 /* Inlined function: search instances */
1047                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1048                                             &_param);
1049                 param->retval = _param.retval;
1050         }
1051
1052         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1053 }
1054
1055 static int find_probe_point_by_func(struct probe_finder *pf)
1056 {
1057         struct dwarf_callback_param _param = {.data = (void *)pf,
1058                                               .retval = 0};
1059         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1060         return _param.retval;
1061 }
1062
1063 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1064 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1065                              struct probe_trace_event **tevs, int max_tevs)
1066 {
1067         struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};
1068         struct perf_probe_point *pp = &pev->point;
1069         Dwarf_Off off, noff;
1070         size_t cuhl;
1071         Dwarf_Die *diep;
1072         Dwarf *dbg;
1073         int ret = 0;
1074
1075         pf.tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1076         if (pf.tevs == NULL)
1077                 return -ENOMEM;
1078         *tevs = pf.tevs;
1079         pf.ntevs = 0;
1080
1081         dbg = dwarf_begin(fd, DWARF_C_READ);
1082         if (!dbg) {
1083                 pr_warning("No dwarf info found in the vmlinux - "
1084                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1085                 free(pf.tevs);
1086                 *tevs = NULL;
1087                 return -EBADF;
1088         }
1089
1090 #if _ELFUTILS_PREREQ(0, 142)
1091         /* Get the call frame information from this dwarf */
1092         pf.cfi = dwarf_getcfi(dbg);
1093 #endif
1094
1095         off = 0;
1096         line_list__init(&pf.lcache);
1097         /* Loop on CUs (Compilation Unit) */
1098         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1099                ret >= 0) {
1100                 /* Get the DIE(Debugging Information Entry) of this CU */
1101                 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
1102                 if (!diep)
1103                         continue;
1104
1105                 /* Check if target file is included. */
1106                 if (pp->file)
1107                         pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
1108                 else
1109                         pf.fname = NULL;
1110
1111                 if (!pp->file || pf.fname) {
1112                         if (pp->function)
1113                                 ret = find_probe_point_by_func(&pf);
1114                         else if (pp->lazy_line)
1115                                 ret = find_probe_point_lazy(NULL, &pf);
1116                         else {
1117                                 pf.lno = pp->line;
1118                                 ret = find_probe_point_by_line(&pf);
1119                         }
1120                 }
1121                 off = noff;
1122         }
1123         line_list__free(&pf.lcache);
1124         dwarf_end(dbg);
1125
1126         return (ret < 0) ? ret : pf.ntevs;
1127 }
1128
1129 /* Reverse search */
1130 int find_perf_probe_point(int fd, unsigned long addr,
1131                           struct perf_probe_point *ppt)
1132 {
1133         Dwarf_Die cudie, spdie, indie;
1134         Dwarf *dbg;
1135         Dwarf_Line *line;
1136         Dwarf_Addr laddr, eaddr;
1137         const char *tmp;
1138         int lineno, ret = 0;
1139         bool found = false;
1140
1141         dbg = dwarf_begin(fd, DWARF_C_READ);
1142         if (!dbg)
1143                 return -EBADF;
1144
1145         /* Find cu die */
1146         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1147                 ret = -EINVAL;
1148                 goto end;
1149         }
1150
1151         /* Find a corresponding line */
1152         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1153         if (line) {
1154                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1155                     (Dwarf_Addr)addr == laddr &&
1156                     dwarf_lineno(line, &lineno) == 0) {
1157                         tmp = dwarf_linesrc(line, NULL, NULL);
1158                         if (tmp) {
1159                                 ppt->line = lineno;
1160                                 ppt->file = strdup(tmp);
1161                                 if (ppt->file == NULL) {
1162                                         ret = -ENOMEM;
1163                                         goto end;
1164                                 }
1165                                 found = true;
1166                         }
1167                 }
1168         }
1169
1170         /* Find a corresponding function */
1171         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1172                 tmp = dwarf_diename(&spdie);
1173                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1174                         goto end;
1175
1176                 if (ppt->line) {
1177                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1178                                                 &indie)) {
1179                                 /* addr in an inline function */
1180                                 tmp = dwarf_diename(&indie);
1181                                 if (!tmp)
1182                                         goto end;
1183                                 ret = dwarf_decl_line(&indie, &lineno);
1184                         } else {
1185                                 if (eaddr == addr) {    /* Function entry */
1186                                         lineno = ppt->line;
1187                                         ret = 0;
1188                                 } else
1189                                         ret = dwarf_decl_line(&spdie, &lineno);
1190                         }
1191                         if (ret == 0) {
1192                                 /* Make a relative line number */
1193                                 ppt->line -= lineno;
1194                                 goto found;
1195                         }
1196                 }
1197                 /* We don't have a line number, let's use offset */
1198                 ppt->offset = addr - (unsigned long)eaddr;
1199 found:
1200                 ppt->function = strdup(tmp);
1201                 if (ppt->function == NULL) {
1202                         ret = -ENOMEM;
1203                         goto end;
1204                 }
1205                 found = true;
1206         }
1207
1208 end:
1209         dwarf_end(dbg);
1210         if (ret >= 0)
1211                 ret = found ? 1 : 0;
1212         return ret;
1213 }
1214
1215 /* Add a line and store the src path */
1216 static int line_range_add_line(const char *src, unsigned int lineno,
1217                                struct line_range *lr)
1218 {
1219         /* Copy source path */
1220         if (!lr->path) {
1221                 lr->path = strdup(src);
1222                 if (lr->path == NULL)
1223                         return -ENOMEM;
1224         }
1225         return line_list__add_line(&lr->line_list, lineno);
1226 }
1227
1228 /* Search function declaration lines */
1229 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1230 {
1231         struct dwarf_callback_param *param = data;
1232         struct line_finder *lf = param->data;
1233         const char *src;
1234         int lineno;
1235
1236         src = dwarf_decl_file(sp_die);
1237         if (src && strtailcmp(src, lf->fname) != 0)
1238                 return DWARF_CB_OK;
1239
1240         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1241             (lf->lno_s > lineno || lf->lno_e < lineno))
1242                 return DWARF_CB_OK;
1243
1244         param->retval = line_range_add_line(src, lineno, lf->lr);
1245         if (param->retval < 0)
1246                 return DWARF_CB_ABORT;
1247         return DWARF_CB_OK;
1248 }
1249
1250 static int find_line_range_func_decl_lines(struct line_finder *lf)
1251 {
1252         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1253         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1254         return param.retval;
1255 }
1256
1257 /* Find line range from its line number */
1258 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1259 {
1260         Dwarf_Lines *lines;
1261         Dwarf_Line *line;
1262         size_t nlines, i;
1263         Dwarf_Addr addr;
1264         int lineno, ret = 0;
1265         const char *src;
1266         Dwarf_Die die_mem;
1267
1268         line_list__init(&lf->lr->line_list);
1269         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1270                 pr_warning("No source lines found in this CU.\n");
1271                 return -ENOENT;
1272         }
1273
1274         /* Search probable lines on lines list */
1275         for (i = 0; i < nlines; i++) {
1276                 line = dwarf_onesrcline(lines, i);
1277                 if (dwarf_lineno(line, &lineno) != 0 ||
1278                     (lf->lno_s > lineno || lf->lno_e < lineno))
1279                         continue;
1280
1281                 if (sp_die) {
1282                         /* Address filtering 1: does sp_die include addr? */
1283                         if (dwarf_lineaddr(line, &addr) != 0 ||
1284                             !dwarf_haspc(sp_die, addr))
1285                                 continue;
1286
1287                         /* Address filtering 2: No child include addr? */
1288                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1289                                 continue;
1290                 }
1291
1292                 /* TODO: Get fileno from line, but how? */
1293                 src = dwarf_linesrc(line, NULL, NULL);
1294                 if (strtailcmp(src, lf->fname) != 0)
1295                         continue;
1296
1297                 ret = line_range_add_line(src, lineno, lf->lr);
1298                 if (ret < 0)
1299                         return ret;
1300         }
1301
1302         /*
1303          * Dwarf lines doesn't include function declarations. We have to
1304          * check functions list or given function.
1305          */
1306         if (sp_die) {
1307                 src = dwarf_decl_file(sp_die);
1308                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1309                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1310                         ret = line_range_add_line(src, lineno, lf->lr);
1311         } else
1312                 ret = find_line_range_func_decl_lines(lf);
1313
1314         /* Update status */
1315         if (ret >= 0)
1316                 if (!list_empty(&lf->lr->line_list))
1317                         ret = lf->found = 1;
1318                 else
1319                         ret = 0;        /* Lines are not found */
1320         else {
1321                 free(lf->lr->path);
1322                 lf->lr->path = NULL;
1323         }
1324         return ret;
1325 }
1326
1327 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1328 {
1329         struct dwarf_callback_param *param = data;
1330
1331         param->retval = find_line_range_by_line(in_die, param->data);
1332         return DWARF_CB_ABORT;  /* No need to find other instances */
1333 }
1334
1335 /* Search function from function name */
1336 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1337 {
1338         struct dwarf_callback_param *param = data;
1339         struct line_finder *lf = param->data;
1340         struct line_range *lr = lf->lr;
1341
1342         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1343             die_compare_name(sp_die, lr->function)) {
1344                 lf->fname = dwarf_decl_file(sp_die);
1345                 dwarf_decl_line(sp_die, &lr->offset);
1346                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1347                 lf->lno_s = lr->offset + lr->start;
1348                 if (lf->lno_s < 0)      /* Overflow */
1349                         lf->lno_s = INT_MAX;
1350                 lf->lno_e = lr->offset + lr->end;
1351                 if (lf->lno_e < 0)      /* Overflow */
1352                         lf->lno_e = INT_MAX;
1353                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1354                 lr->start = lf->lno_s;
1355                 lr->end = lf->lno_e;
1356                 if (dwarf_func_inline(sp_die)) {
1357                         struct dwarf_callback_param _param;
1358                         _param.data = (void *)lf;
1359                         _param.retval = 0;
1360                         dwarf_func_inline_instances(sp_die,
1361                                                     line_range_inline_cb,
1362                                                     &_param);
1363                         param->retval = _param.retval;
1364                 } else
1365                         param->retval = find_line_range_by_line(sp_die, lf);
1366                 return DWARF_CB_ABORT;
1367         }
1368         return DWARF_CB_OK;
1369 }
1370
1371 static int find_line_range_by_func(struct line_finder *lf)
1372 {
1373         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1374         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1375         return param.retval;
1376 }
1377
1378 int find_line_range(int fd, struct line_range *lr)
1379 {
1380         struct line_finder lf = {.lr = lr, .found = 0};
1381         int ret = 0;
1382         Dwarf_Off off = 0, noff;
1383         size_t cuhl;
1384         Dwarf_Die *diep;
1385         Dwarf *dbg;
1386         const char *comp_dir;
1387
1388         dbg = dwarf_begin(fd, DWARF_C_READ);
1389         if (!dbg) {
1390                 pr_warning("No dwarf info found in the vmlinux - "
1391                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1392                 return -EBADF;
1393         }
1394
1395         /* Loop on CUs (Compilation Unit) */
1396         while (!lf.found && ret >= 0) {
1397                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1398                         break;
1399
1400                 /* Get the DIE(Debugging Information Entry) of this CU */
1401                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1402                 if (!diep)
1403                         continue;
1404
1405                 /* Check if target file is included. */
1406                 if (lr->file)
1407                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1408                 else
1409                         lf.fname = 0;
1410
1411                 if (!lr->file || lf.fname) {
1412                         if (lr->function)
1413                                 ret = find_line_range_by_func(&lf);
1414                         else {
1415                                 lf.lno_s = lr->start;
1416                                 lf.lno_e = lr->end;
1417                                 ret = find_line_range_by_line(NULL, &lf);
1418                         }
1419                 }
1420                 off = noff;
1421         }
1422
1423         /* Store comp_dir */
1424         if (lf.found) {
1425                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1426                 if (comp_dir) {
1427                         lr->comp_dir = strdup(comp_dir);
1428                         if (!lr->comp_dir)
1429                                 ret = -ENOMEM;
1430                 }
1431         }
1432
1433         pr_debug("path: %s\n", lr->path);
1434         dwarf_end(dbg);
1435
1436         return (ret < 0) ? ret : lf.found;
1437 }
1438