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 <dwarf-regs.h>
  34
  35 #include <linux/bitops.h>
  36 #include "event.h"
  37 #include "debug.h"
  38 #include "intlist.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 /* Dwarf FL wrappers */
  47 static char *debuginfo_path;    /* Currently dummy */
  48
  49 static const Dwfl_Callbacks offline_callbacks = {
  50         .find_debuginfo = dwfl_standard_find_debuginfo,
  51         .debuginfo_path = &debuginfo_path,
  52
  53         .section_address = dwfl_offline_section_address,
  54
  55         /* We use this table for core files too.  */
  56         .find_elf = dwfl_build_id_find_elf,
  57 };
  58
  59 /* Get a Dwarf from offline image */
  60 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
  61                                          const char *path)
  62 {
  63         int fd;
  64
  65         fd = open(path, O_RDONLY);
  66         if (fd < 0)
  67                 return fd;
  68
  69         dbg->dwfl = dwfl_begin(&offline_callbacks);
  70         if (!dbg->dwfl)
  71                 goto error;
  72
  73         dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
  74         if (!dbg->mod)
  75                 goto error;
  76
  77         dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
  78         if (!dbg->dbg)
  79                 goto error;
  80
  81         return 0;
  82 error:
  83         if (dbg->dwfl)
  84                 dwfl_end(dbg->dwfl);
  85         else
  86                 close(fd);
  87         memset(dbg, 0, sizeof(*dbg));
  88
  89         return -ENOENT;
  90 }
  91
  92 struct debuginfo *debuginfo__new(const char *path)
  93 {
  94         struct debuginfo *dbg = zalloc(sizeof(*dbg));
  95         if (!dbg)
  96                 return NULL;
  97
  98         if (debuginfo__init_offline_dwarf(dbg, path) < 0)
  99                 zfree(&dbg);
 100
 101         return dbg;
 102 }
 103
 104 void debuginfo__delete(struct debuginfo *dbg)
 105 {
 106         if (dbg) {
 107                 if (dbg->dwfl)
 108                         dwfl_end(dbg->dwfl);
 109                 free(dbg);
 110         }
 111 }
 112
 113 /*
 114  * Probe finder related functions
 115  */
 116
 117 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 118 {
 119         struct probe_trace_arg_ref *ref;
 120         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 121         if (ref != NULL)
 122                 ref->offset = offs;
 123         return ref;
 124 }
 125
 126 /*
 127  * Convert a location into trace_arg.
 128  * If tvar == NULL, this just checks variable can be converted.
 129  * If fentry == true and vr_die is a parameter, do huristic search
 130  * for the location fuzzed by function entry mcount.
 131  */
 132 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 133                                      Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
 134                                      struct probe_trace_arg *tvar)
 135 {
 136         Dwarf_Attribute attr;
 137         Dwarf_Addr tmp = 0;
 138         Dwarf_Op *op;
 139         size_t nops;
 140         unsigned int regn;
 141         Dwarf_Word offs = 0;
 142         bool ref = false;
 143         const char *regs;
 144         int ret;
 145
 146         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 147                 goto static_var;
 148
 149         /* TODO: handle more than 1 exprs */
 150         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
 151                 return -EINVAL; /* Broken DIE ? */
 152         if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
 153                 ret = dwarf_entrypc(sp_die, &tmp);
 154                 if (ret || addr != tmp ||
 155                     dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
 156                     dwarf_highpc(sp_die, &tmp))
 157                         return -ENOENT;
 158                 /*
 159                  * This is fuzzed by fentry mcount. We try to find the
 160                  * parameter location at the earliest address.
 161                  */
 162                 for (addr += 1; addr <= tmp; addr++) {
 163                         if (dwarf_getlocation_addr(&attr, addr, &op,
 164                                                    &nops, 1) > 0)
 165                                 goto found;
 166                 }
 167                 return -ENOENT;
 168         }
 169 found:
 170         if (nops == 0)
 171                 /* TODO: Support const_value */
 172                 return -ENOENT;
 173
 174         if (op->atom == DW_OP_addr) {
 175 static_var:
 176                 if (!tvar)
 177                         return 0;
 178                 /* Static variables on memory (not stack), make @varname */
 179                 ret = strlen(dwarf_diename(vr_die));
 180                 tvar->value = zalloc(ret + 2);
 181                 if (tvar->value == NULL)
 182                         return -ENOMEM;
 183                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 184                 tvar->ref = alloc_trace_arg_ref((long)offs);
 185                 if (tvar->ref == NULL)
 186                         return -ENOMEM;
 187                 return 0;
 188         }
 189
 190         /* If this is based on frame buffer, set the offset */
 191         if (op->atom == DW_OP_fbreg) {
 192                 if (fb_ops == NULL)
 193                         return -ENOTSUP;
 194                 ref = true;
 195                 offs = op->number;
 196                 op = &fb_ops[0];
 197         }
 198
 199         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 200                 regn = op->atom - DW_OP_breg0;
 201                 offs += op->number;
 202                 ref = true;
 203         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 204                 regn = op->atom - DW_OP_reg0;
 205         } else if (op->atom == DW_OP_bregx) {
 206                 regn = op->number;
 207                 offs += op->number2;
 208                 ref = true;
 209         } else if (op->atom == DW_OP_regx) {
 210                 regn = op->number;
 211         } else {
 212                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 213                 return -ENOTSUP;
 214         }
 215
 216         if (!tvar)
 217                 return 0;
 218
 219         regs = get_arch_regstr(regn);
 220         if (!regs) {
 221                 /* This should be a bug in DWARF or this tool */
 222                 pr_warning("Mapping for the register number %u "
 223                            "missing on this architecture.\n", regn);
 224                 return -ERANGE;
 225         }
 226
 227         tvar->value = strdup(regs);
 228         if (tvar->value == NULL)
 229                 return -ENOMEM;
 230
 231         if (ref) {
 232                 tvar->ref = alloc_trace_arg_ref((long)offs);
 233                 if (tvar->ref == NULL)
 234                         return -ENOMEM;
 235         }
 236         return 0;
 237 }
 238
 239 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
 240
 241 static int convert_variable_type(Dwarf_Die *vr_die,
 242                                  struct probe_trace_arg *tvar,
 243                                  const char *cast)
 244 {
 245         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 246         Dwarf_Die type;
 247         char buf[16];
 248         int bsize, boffs, total;
 249         int ret;
 250
 251         /* TODO: check all types */
 252         if (cast && strcmp(cast, "string") != 0) {
 253                 /* Non string type is OK */
 254                 tvar->type = strdup(cast);
 255                 return (tvar->type == NULL) ? -ENOMEM : 0;
 256         }
 257
 258         bsize = dwarf_bitsize(vr_die);
 259         if (bsize > 0) {
 260                 /* This is a bitfield */
 261                 boffs = dwarf_bitoffset(vr_die);
 262                 total = dwarf_bytesize(vr_die);
 263                 if (boffs < 0 || total < 0)
 264                         return -ENOENT;
 265                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
 266                                 BYTES_TO_BITS(total));
 267                 goto formatted;
 268         }
 269
 270         if (die_get_real_type(vr_die, &type) == NULL) {
 271                 pr_warning("Failed to get a type information of %s.\n",
 272                            dwarf_diename(vr_die));
 273                 return -ENOENT;
 274         }
 275
 276         pr_debug("%s type is %s.\n",
 277                  dwarf_diename(vr_die), dwarf_diename(&type));
 278
 279         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 280                 ret = dwarf_tag(&type);
 281                 if (ret != DW_TAG_pointer_type &&
 282                     ret != DW_TAG_array_type) {
 283                         pr_warning("Failed to cast into string: "
 284                                    "%s(%s) is not a pointer nor array.\n",
 285                                    dwarf_diename(vr_die), dwarf_diename(&type));
 286                         return -EINVAL;
 287                 }
 288                 if (die_get_real_type(&type, &type) == NULL) {
 289                         pr_warning("Failed to get a type"
 290                                    " information.\n");
 291                         return -ENOENT;
 292                 }
 293                 if (ret == DW_TAG_pointer_type) {
 294                         while (*ref_ptr)
 295                                 ref_ptr = &(*ref_ptr)->next;
 296                         /* Add new reference with offset +0 */
 297                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 298                         if (*ref_ptr == NULL) {
 299                                 pr_warning("Out of memory error\n");
 300                                 return -ENOMEM;
 301                         }
 302                 }
 303                 if (!die_compare_name(&type, "char") &&
 304                     !die_compare_name(&type, "unsigned char")) {
 305                         pr_warning("Failed to cast into string: "
 306                                    "%s is not (unsigned) char *.\n",
 307                                    dwarf_diename(vr_die));
 308                         return -EINVAL;
 309                 }
 310                 tvar->type = strdup(cast);
 311                 return (tvar->type == NULL) ? -ENOMEM : 0;
 312         }
 313
 314         ret = dwarf_bytesize(&type);
 315         if (ret <= 0)
 316                 /* No size ... try to use default type */
 317                 return 0;
 318         ret = BYTES_TO_BITS(ret);
 319
 320         /* Check the bitwidth */
 321         if (ret > MAX_BASIC_TYPE_BITS) {
 322                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
 323                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 324                 ret = MAX_BASIC_TYPE_BITS;
 325         }
 326         ret = snprintf(buf, 16, "%c%d",
 327                        die_is_signed_type(&type) ? 's' : 'u', ret);
 328
 329 formatted:
 330         if (ret < 0 || ret >= 16) {
 331                 if (ret >= 16)
 332                         ret = -E2BIG;
 333                 pr_warning("Failed to convert variable type: %s\n",
 334                            strerror(-ret));
 335                 return ret;
 336         }
 337         tvar->type = strdup(buf);
 338         if (tvar->type == NULL)
 339                 return -ENOMEM;
 340         return 0;
 341 }
 342
 343 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 344                                     struct perf_probe_arg_field *field,
 345                                     struct probe_trace_arg_ref **ref_ptr,
 346                                     Dwarf_Die *die_mem)
 347 {
 348         struct probe_trace_arg_ref *ref = *ref_ptr;
 349         Dwarf_Die type;
 350         Dwarf_Word offs;
 351         int ret, tag;
 352
 353         pr_debug("converting %s in %s\n", field->name, varname);
 354         if (die_get_real_type(vr_die, &type) == NULL) {
 355                 pr_warning("Failed to get the type of %s.\n", varname);
 356                 return -ENOENT;
 357         }
 358         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 359         tag = dwarf_tag(&type);
 360
 361         if (field->name[0] == '[' &&
 362             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 363                 if (field->next)
 364                         /* Save original type for next field */
 365                         memcpy(die_mem, &type, sizeof(*die_mem));
 366                 /* Get the type of this array */
 367                 if (die_get_real_type(&type, &type) == NULL) {
 368                         pr_warning("Failed to get the type of %s.\n", varname);
 369                         return -ENOENT;
 370                 }
 371                 pr_debug2("Array real type: (%x)\n",
 372                          (unsigned)dwarf_dieoffset(&type));
 373                 if (tag == DW_TAG_pointer_type) {
 374                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 375                         if (ref == NULL)
 376                                 return -ENOMEM;
 377                         if (*ref_ptr)
 378                                 (*ref_ptr)->next = ref;
 379                         else
 380                                 *ref_ptr = ref;
 381                 }
 382                 ref->offset += dwarf_bytesize(&type) * field->index;
 383                 if (!field->next)
 384                         /* Save vr_die for converting types */
 385                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 386                 goto next;
 387         } else if (tag == DW_TAG_pointer_type) {
 388                 /* Check the pointer and dereference */
 389                 if (!field->ref) {
 390                         pr_err("Semantic error: %s must be referred by '->'\n",
 391                                field->name);
 392                         return -EINVAL;
 393                 }
 394                 /* Get the type pointed by this pointer */
 395                 if (die_get_real_type(&type, &type) == NULL) {
 396                         pr_warning("Failed to get the type of %s.\n", varname);
 397                         return -ENOENT;
 398                 }
 399                 /* Verify it is a data structure  */
 400                 tag = dwarf_tag(&type);
 401                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 402                         pr_warning("%s is not a data structure nor an union.\n",
 403                                    varname);
 404                         return -EINVAL;
 405                 }
 406
 407                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 408                 if (ref == NULL)
 409                         return -ENOMEM;
 410                 if (*ref_ptr)
 411                         (*ref_ptr)->next = ref;
 412                 else
 413                         *ref_ptr = ref;
 414         } else {
 415                 /* Verify it is a data structure  */
 416                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 417                         pr_warning("%s is not a data structure nor an union.\n",
 418                                    varname);
 419                         return -EINVAL;
 420                 }
 421                 if (field->name[0] == '[') {
 422                         pr_err("Semantic error: %s is not a pointor"
 423                                " nor array.\n", varname);
 424                         return -EINVAL;
 425                 }
 426                 if (field->ref) {
 427                         pr_err("Semantic error: %s must be referred by '.'\n",
 428                                field->name);
 429                         return -EINVAL;
 430                 }
 431                 if (!ref) {
 432                         pr_warning("Structure on a register is not "
 433                                    "supported yet.\n");
 434                         return -ENOTSUP;
 435                 }
 436         }
 437
 438         if (die_find_member(&type, field->name, die_mem) == NULL) {
 439                 pr_warning("%s(type:%s) has no member %s.\n", varname,
 440                            dwarf_diename(&type), field->name);
 441                 return -EINVAL;
 442         }
 443
 444         /* Get the offset of the field */
 445         if (tag == DW_TAG_union_type) {
 446                 offs = 0;
 447         } else {
 448                 ret = die_get_data_member_location(die_mem, &offs);
 449                 if (ret < 0) {
 450                         pr_warning("Failed to get the offset of %s.\n",
 451                                    field->name);
 452                         return ret;
 453                 }
 454         }
 455         ref->offset += (long)offs;
 456
 457 next:
 458         /* Converting next field */
 459         if (field->next)
 460                 return convert_variable_fields(die_mem, field->name,
 461                                         field->next, &ref, die_mem);
 462         else
 463                 return 0;
 464 }
 465
 466 /* Show a variables in kprobe event format */
 467 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 468 {
 469         Dwarf_Die die_mem;
 470         int ret;
 471
 472         pr_debug("Converting variable %s into trace event.\n",
 473                  dwarf_diename(vr_die));
 474
 475         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 476                                         &pf->sp_die, pf->tvar);
 477         if (ret == -ENOENT)
 478                 pr_err("Failed to find the location of %s at this address.\n"
 479                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 480         else if (ret == -ENOTSUP)
 481                 pr_err("Sorry, we don't support this variable location yet.\n");
 482         else if (pf->pvar->field) {
 483                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 484                                               pf->pvar->field, &pf->tvar->ref,
 485                                               &die_mem);
 486                 vr_die = &die_mem;
 487         }
 488         if (ret == 0)
 489                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 490         /* *expr will be cached in libdw. Don't free it. */
 491         return ret;
 492 }
 493
 494 /* Find a variable in a scope DIE */
 495 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 496 {
 497         Dwarf_Die vr_die;
 498         char buf[32], *ptr;
 499         int ret = 0;
 500
 501         if (!is_c_varname(pf->pvar->var)) {
 502                 /* Copy raw parameters */
 503                 pf->tvar->value = strdup(pf->pvar->var);
 504                 if (pf->tvar->value == NULL)
 505                         return -ENOMEM;
 506                 if (pf->pvar->type) {
 507                         pf->tvar->type = strdup(pf->pvar->type);
 508                         if (pf->tvar->type == NULL)
 509                                 return -ENOMEM;
 510                 }
 511                 if (pf->pvar->name) {
 512                         pf->tvar->name = strdup(pf->pvar->name);
 513                         if (pf->tvar->name == NULL)
 514                                 return -ENOMEM;
 515                 } else
 516                         pf->tvar->name = NULL;
 517                 return 0;
 518         }
 519
 520         if (pf->pvar->name)
 521                 pf->tvar->name = strdup(pf->pvar->name);
 522         else {
 523                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 524                 if (ret < 0)
 525                         return ret;
 526                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 527                 if (ptr)
 528                         *ptr = '_';
 529                 pf->tvar->name = strdup(buf);
 530         }
 531         if (pf->tvar->name == NULL)
 532                 return -ENOMEM;
 533
 534         pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
 535         /* Search child die for local variables and parameters. */
 536         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
 537                 /* Search again in global variables */
 538                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
 539                         ret = -ENOENT;
 540         }
 541         if (ret >= 0)
 542                 ret = convert_variable(&vr_die, pf);
 543
 544         if (ret < 0)
 545                 pr_warning("Failed to find '%s' in this function.\n",
 546                            pf->pvar->var);
 547         return ret;
 548 }
 549
 550 /* Convert subprogram DIE to trace point */
 551 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 552                                   Dwarf_Addr paddr, bool retprobe,
 553                                   struct probe_trace_point *tp)
 554 {
 555         Dwarf_Addr eaddr, highaddr;
 556         GElf_Sym sym;
 557         const char *symbol;
 558
 559         /* Verify the address is correct */
 560         if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 561                 pr_warning("Failed to get entry address of %s\n",
 562                            dwarf_diename(sp_die));
 563                 return -ENOENT;
 564         }
 565         if (dwarf_highpc(sp_die, &highaddr) != 0) {
 566                 pr_warning("Failed to get end address of %s\n",
 567                            dwarf_diename(sp_die));
 568                 return -ENOENT;
 569         }
 570         if (paddr > highaddr) {
 571                 pr_warning("Offset specified is greater than size of %s\n",
 572                            dwarf_diename(sp_die));
 573                 return -EINVAL;
 574         }
 575
 576         /* Get an appropriate symbol from symtab */
 577         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
 578         if (!symbol) {
 579                 pr_warning("Failed to find symbol at 0x%lx\n",
 580                            (unsigned long)paddr);
 581                 return -ENOENT;
 582         }
 583         tp->offset = (unsigned long)(paddr - sym.st_value);
 584         tp->address = (unsigned long)paddr;
 585         tp->symbol = strdup(symbol);
 586         if (!tp->symbol)
 587                 return -ENOMEM;
 588
 589         /* Return probe must be on the head of a subprogram */
 590         if (retprobe) {
 591                 if (eaddr != paddr) {
 592                         pr_warning("Return probe must be on the head of"
 593                                    " a real function.\n");
 594                         return -EINVAL;
 595                 }
 596                 tp->retprobe = true;
 597         }
 598
 599         return 0;
 600 }
 601
 602 /* Call probe_finder callback with scope DIE */
 603 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 604 {
 605         Dwarf_Attribute fb_attr;
 606         size_t nops;
 607         int ret;
 608
 609         if (!sc_die) {
 610                 pr_err("Caller must pass a scope DIE. Program error.\n");
 611                 return -EINVAL;
 612         }
 613
 614         /* If not a real subprogram, find a real one */
 615         if (!die_is_func_def(sc_die)) {
 616                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
 617                         pr_warning("Failed to find probe point in any "
 618                                    "functions.\n");
 619                         return -ENOENT;
 620                 }
 621         } else
 622                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 623
 624         /* Get the frame base attribute/ops from subprogram */
 625         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
 626         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 627         if (ret <= 0 || nops == 0) {
 628                 pf->fb_ops = NULL;
 629 #if _ELFUTILS_PREREQ(0, 142)
 630         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 631                    pf->cfi != NULL) {
 632                 Dwarf_Frame *frame;
 633                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 634                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 635                         pr_warning("Failed to get call frame on 0x%jx\n",
 636                                    (uintmax_t)pf->addr);
 637                         return -ENOENT;
 638                 }
 639 #endif
 640         }
 641
 642         /* Call finder's callback handler */
 643         ret = pf->callback(sc_die, pf);
 644
 645         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 646         pf->fb_ops = NULL;
 647
 648         return ret;
 649 }
 650
 651 struct find_scope_param {
 652         const char *function;
 653         const char *file;
 654         int line;
 655         int diff;
 656         Dwarf_Die *die_mem;
 657         bool found;
 658 };
 659
 660 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
 661 {
 662         struct find_scope_param *fsp = data;
 663         const char *file;
 664         int lno;
 665
 666         /* Skip if declared file name does not match */
 667         if (fsp->file) {
 668                 file = dwarf_decl_file(fn_die);
 669                 if (!file || strcmp(fsp->file, file) != 0)
 670                         return 0;
 671         }
 672         /* If the function name is given, that's what user expects */
 673         if (fsp->function) {
 674                 if (die_compare_name(fn_die, fsp->function)) {
 675                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 676                         fsp->found = true;
 677                         return 1;
 678                 }
 679         } else {
 680                 /* With the line number, find the nearest declared DIE */
 681                 dwarf_decl_line(fn_die, &lno);
 682                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
 683                         /* Keep a candidate and continue */
 684                         fsp->diff = fsp->line - lno;
 685                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 686                         fsp->found = true;
 687                 }
 688         }
 689         return 0;
 690 }
 691
 692 /* Find an appropriate scope fits to given conditions */
 693 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
 694 {
 695         struct find_scope_param fsp = {
 696                 .function = pf->pev->point.function,
 697                 .file = pf->fname,
 698                 .line = pf->lno,
 699                 .diff = INT_MAX,
 700                 .die_mem = die_mem,
 701                 .found = false,
 702         };
 703
 704         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
 705
 706         return fsp.found ? die_mem : NULL;
 707 }
 708
 709 static int probe_point_line_walker(const char *fname, int lineno,
 710                                    Dwarf_Addr addr, void *data)
 711 {
 712         struct probe_finder *pf = data;
 713         Dwarf_Die *sc_die, die_mem;
 714         int ret;
 715
 716         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 717                 return 0;
 718
 719         pf->addr = addr;
 720         sc_die = find_best_scope(pf, &die_mem);
 721         if (!sc_die) {
 722                 pr_warning("Failed to find scope of probe point.\n");
 723                 return -ENOENT;
 724         }
 725
 726         ret = call_probe_finder(sc_die, pf);
 727
 728         /* Continue if no error, because the line will be in inline function */
 729         return ret < 0 ? ret : 0;
 730 }
 731
 732 /* Find probe point from its line number */
 733 static int find_probe_point_by_line(struct probe_finder *pf)
 734 {
 735         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 736 }
 737
 738 /* Find lines which match lazy pattern */
 739 static int find_lazy_match_lines(struct intlist *list,
 740                                  const char *fname, const char *pat)
 741 {
 742         FILE *fp;
 743         char *line = NULL;
 744         size_t line_len;
 745         ssize_t len;
 746         int count = 0, linenum = 1;
 747
 748         fp = fopen(fname, "r");
 749         if (!fp) {
 750                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 751                 return -errno;
 752         }
 753
 754         while ((len = getline(&line, &line_len, fp)) > 0) {
 755
 756                 if (line[len - 1] == '\n')
 757                         line[len - 1] = '\0';
 758
 759                 if (strlazymatch(line, pat)) {
 760                         intlist__add(list, linenum);
 761                         count++;
 762                 }
 763                 linenum++;
 764         }
 765
 766         if (ferror(fp))
 767                 count = -errno;
 768         free(line);
 769         fclose(fp);
 770
 771         if (count == 0)
 772                 pr_debug("No matched lines found in %s.\n", fname);
 773         return count;
 774 }
 775
 776 static int probe_point_lazy_walker(const char *fname, int lineno,
 777                                    Dwarf_Addr addr, void *data)
 778 {
 779         struct probe_finder *pf = data;
 780         Dwarf_Die *sc_die, die_mem;
 781         int ret;
 782
 783         if (!intlist__has_entry(pf->lcache, lineno) ||
 784             strtailcmp(fname, pf->fname) != 0)
 785                 return 0;
 786
 787         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 788                  lineno, (unsigned long long)addr);
 789         pf->addr = addr;
 790         pf->lno = lineno;
 791         sc_die = find_best_scope(pf, &die_mem);
 792         if (!sc_die) {
 793                 pr_warning("Failed to find scope of probe point.\n");
 794                 return -ENOENT;
 795         }
 796
 797         ret = call_probe_finder(sc_die, pf);
 798
 799         /*
 800          * Continue if no error, because the lazy pattern will match
 801          * to other lines
 802          */
 803         return ret < 0 ? ret : 0;
 804 }
 805
 806 /* Find probe points from lazy pattern  */
 807 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 808 {
 809         int ret = 0;
 810
 811         if (intlist__empty(pf->lcache)) {
 812                 /* Matching lazy line pattern */
 813                 ret = find_lazy_match_lines(pf->lcache, pf->fname,
 814                                             pf->pev->point.lazy_line);
 815                 if (ret <= 0)
 816                         return ret;
 817         }
 818
 819         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 820 }
 821
 822 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 823 {
 824         struct probe_finder *pf = data;
 825         struct perf_probe_point *pp = &pf->pev->point;
 826         Dwarf_Addr addr;
 827         int ret;
 828
 829         if (pp->lazy_line)
 830                 ret = find_probe_point_lazy(in_die, pf);
 831         else {
 832                 /* Get probe address */
 833                 if (dwarf_entrypc(in_die, &addr) != 0) {
 834                         pr_warning("Failed to get entry address of %s.\n",
 835                                    dwarf_diename(in_die));
 836                         return -ENOENT;
 837                 }
 838                 pf->addr = addr;
 839                 pf->addr += pp->offset;
 840                 pr_debug("found inline addr: 0x%jx\n",
 841                          (uintmax_t)pf->addr);
 842
 843                 ret = call_probe_finder(in_die, pf);
 844         }
 845
 846         return ret;
 847 }
 848
 849 /* Callback parameter with return value for libdw */
 850 struct dwarf_callback_param {
 851         void *data;
 852         int retval;
 853 };
 854
 855 /* Search function from function name */
 856 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 857 {
 858         struct dwarf_callback_param *param = data;
 859         struct probe_finder *pf = param->data;
 860         struct perf_probe_point *pp = &pf->pev->point;
 861
 862         /* Check tag and diename */
 863         if (!die_is_func_def(sp_die) ||
 864             !die_compare_name(sp_die, pp->function))
 865                 return DWARF_CB_OK;
 866
 867         /* Check declared file */
 868         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 869                 return DWARF_CB_OK;
 870
 871         pf->fname = dwarf_decl_file(sp_die);
 872         if (pp->line) { /* Function relative line */
 873                 dwarf_decl_line(sp_die, &pf->lno);
 874                 pf->lno += pp->line;
 875                 param->retval = find_probe_point_by_line(pf);
 876         } else if (!dwarf_func_inline(sp_die)) {
 877                 /* Real function */
 878                 if (pp->lazy_line)
 879                         param->retval = find_probe_point_lazy(sp_die, pf);
 880                 else {
 881                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 882                                 pr_warning("Failed to get entry address of "
 883                                            "%s.\n", dwarf_diename(sp_die));
 884                                 param->retval = -ENOENT;
 885                                 return DWARF_CB_ABORT;
 886                         }
 887                         pf->addr += pp->offset;
 888                         /* TODO: Check the address in this function */
 889                         param->retval = call_probe_finder(sp_die, pf);
 890                 }
 891         } else
 892                 /* Inlined function: search instances */
 893                 param->retval = die_walk_instances(sp_die,
 894                                         probe_point_inline_cb, (void *)pf);
 895
 896         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 897 }
 898
 899 static int find_probe_point_by_func(struct probe_finder *pf)
 900 {
 901         struct dwarf_callback_param _param = {.data = (void *)pf,
 902                                               .retval = 0};
 903         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 904         return _param.retval;
 905 }
 906
 907 struct pubname_callback_param {
 908         char *function;
 909         char *file;
 910         Dwarf_Die *cu_die;
 911         Dwarf_Die *sp_die;
 912         int found;
 913 };
 914
 915 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
 916 {
 917         struct pubname_callback_param *param = data;
 918
 919         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
 920                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
 921                         return DWARF_CB_OK;
 922
 923                 if (die_compare_name(param->sp_die, param->function)) {
 924                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
 925                                 return DWARF_CB_OK;
 926
 927                         if (param->file &&
 928                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
 929                                 return DWARF_CB_OK;
 930
 931                         param->found = 1;
 932                         return DWARF_CB_ABORT;
 933                 }
 934         }
 935
 936         return DWARF_CB_OK;
 937 }
 938
 939 /* Find probe points from debuginfo */
 940 static int debuginfo__find_probes(struct debuginfo *dbg,
 941                                   struct probe_finder *pf)
 942 {
 943         struct perf_probe_point *pp = &pf->pev->point;
 944         Dwarf_Off off, noff;
 945         size_t cuhl;
 946         Dwarf_Die *diep;
 947         int ret = 0;
 948
 949 #if _ELFUTILS_PREREQ(0, 142)
 950         /* Get the call frame information from this dwarf */
 951         pf->cfi = dwarf_getcfi(dbg->dbg);
 952 #endif
 953
 954         off = 0;
 955         pf->lcache = intlist__new(NULL);
 956         if (!pf->lcache)
 957                 return -ENOMEM;
 958
 959         /* Fastpath: lookup by function name from .debug_pubnames section */
 960         if (pp->function) {
 961                 struct pubname_callback_param pubname_param = {
 962                         .function = pp->function,
 963                         .file     = pp->file,
 964                         .cu_die   = &pf->cu_die,
 965                         .sp_die   = &pf->sp_die,
 966                         .found    = 0,
 967                 };
 968                 struct dwarf_callback_param probe_param = {
 969                         .data = pf,
 970                 };
 971
 972                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
 973                                   &pubname_param, 0);
 974                 if (pubname_param.found) {
 975                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
 976                         if (ret)
 977                                 goto found;
 978                 }
 979         }
 980
 981         /* Loop on CUs (Compilation Unit) */
 982         while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
 983                 /* Get the DIE(Debugging Information Entry) of this CU */
 984                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
 985                 if (!diep)
 986                         continue;
 987
 988                 /* Check if target file is included. */
 989                 if (pp->file)
 990                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
 991                 else
 992                         pf->fname = NULL;
 993
 994                 if (!pp->file || pf->fname) {
 995                         if (pp->function)
 996                                 ret = find_probe_point_by_func(pf);
 997                         else if (pp->lazy_line)
 998                                 ret = find_probe_point_lazy(NULL, pf);
 999                         else {
1000                                 pf->lno = pp->line;
1001                                 ret = find_probe_point_by_line(pf);
1002                         }
1003                         if (ret < 0)
1004                                 break;
1005                 }
1006                 off = noff;
1007         }
1008
1009 found:
1010         intlist__delete(pf->lcache);
1011         pf->lcache = NULL;
1012
1013         return ret;
1014 }
1015
1016 struct local_vars_finder {
1017         struct probe_finder *pf;
1018         struct perf_probe_arg *args;
1019         int max_args;
1020         int nargs;
1021         int ret;
1022 };
1023
1024 /* Collect available variables in this scope */
1025 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1026 {
1027         struct local_vars_finder *vf = data;
1028         struct probe_finder *pf = vf->pf;
1029         int tag;
1030
1031         tag = dwarf_tag(die_mem);
1032         if (tag == DW_TAG_formal_parameter ||
1033             tag == DW_TAG_variable) {
1034                 if (convert_variable_location(die_mem, vf->pf->addr,
1035                                               vf->pf->fb_ops, &pf->sp_die,
1036                                               NULL) == 0) {
1037                         vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1038                         if (vf->args[vf->nargs].var == NULL) {
1039                                 vf->ret = -ENOMEM;
1040                                 return DIE_FIND_CB_END;
1041                         }
1042                         pr_debug(" %s", vf->args[vf->nargs].var);
1043                         vf->nargs++;
1044                 }
1045         }
1046
1047         if (dwarf_haspc(die_mem, vf->pf->addr))
1048                 return DIE_FIND_CB_CONTINUE;
1049         else
1050                 return DIE_FIND_CB_SIBLING;
1051 }
1052
1053 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1054                              struct perf_probe_arg *args)
1055 {
1056         Dwarf_Die die_mem;
1057         int i;
1058         int n = 0;
1059         struct local_vars_finder vf = {.pf = pf, .args = args,
1060                                 .max_args = MAX_PROBE_ARGS, .ret = 0};
1061
1062         for (i = 0; i < pf->pev->nargs; i++) {
1063                 /* var never be NULL */
1064                 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1065                         pr_debug("Expanding $vars into:");
1066                         vf.nargs = n;
1067                         /* Special local variables */
1068                         die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1069                                        &die_mem);
1070                         pr_debug(" (%d)\n", vf.nargs - n);
1071                         if (vf.ret < 0)
1072                                 return vf.ret;
1073                         n = vf.nargs;
1074                 } else {
1075                         /* Copy normal argument */
1076                         args[n] = pf->pev->args[i];
1077                         n++;
1078                 }
1079         }
1080         return n;
1081 }
1082
1083 /* Add a found probe point into trace event list */
1084 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1085 {
1086         struct trace_event_finder *tf =
1087                         container_of(pf, struct trace_event_finder, pf);
1088         struct probe_trace_event *tev;
1089         struct perf_probe_arg *args;
1090         int ret, i;
1091
1092         /* Check number of tevs */
1093         if (tf->ntevs == tf->max_tevs) {
1094                 pr_warning("Too many( > %d) probe point found.\n",
1095                            tf->max_tevs);
1096                 return -ERANGE;
1097         }
1098         tev = &tf->tevs[tf->ntevs++];
1099
1100         /* Trace point should be converted from subprogram DIE */
1101         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1102                                      pf->pev->point.retprobe, &tev->point);
1103         if (ret < 0)
1104                 return ret;
1105
1106         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1107                  tev->point.offset);
1108
1109         /* Expand special probe argument if exist */
1110         args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1111         if (args == NULL)
1112                 return -ENOMEM;
1113
1114         ret = expand_probe_args(sc_die, pf, args);
1115         if (ret < 0)
1116                 goto end;
1117
1118         tev->nargs = ret;
1119         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1120         if (tev->args == NULL) {
1121                 ret = -ENOMEM;
1122                 goto end;
1123         }
1124
1125         /* Find each argument */
1126         for (i = 0; i < tev->nargs; i++) {
1127                 pf->pvar = &args[i];
1128                 pf->tvar = &tev->args[i];
1129                 /* Variable should be found from scope DIE */
1130                 ret = find_variable(sc_die, pf);
1131                 if (ret != 0)
1132                         break;
1133         }
1134
1135 end:
1136         free(args);
1137         return ret;
1138 }
1139
1140 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1141 int debuginfo__find_trace_events(struct debuginfo *dbg,
1142                                  struct perf_probe_event *pev,
1143                                  struct probe_trace_event **tevs, int max_tevs)
1144 {
1145         struct trace_event_finder tf = {
1146                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1147                         .mod = dbg->mod, .max_tevs = max_tevs};
1148         int ret;
1149
1150         /* Allocate result tevs array */
1151         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1152         if (*tevs == NULL)
1153                 return -ENOMEM;
1154
1155         tf.tevs = *tevs;
1156         tf.ntevs = 0;
1157
1158         ret = debuginfo__find_probes(dbg, &tf.pf);
1159         if (ret < 0) {
1160                 zfree(tevs);
1161                 return ret;
1162         }
1163
1164         return (ret < 0) ? ret : tf.ntevs;
1165 }
1166
1167 #define MAX_VAR_LEN 64
1168
1169 /* Collect available variables in this scope */
1170 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1171 {
1172         struct available_var_finder *af = data;
1173         struct variable_list *vl;
1174         char buf[MAX_VAR_LEN];
1175         int tag, ret;
1176
1177         vl = &af->vls[af->nvls - 1];
1178
1179         tag = dwarf_tag(die_mem);
1180         if (tag == DW_TAG_formal_parameter ||
1181             tag == DW_TAG_variable) {
1182                 ret = convert_variable_location(die_mem, af->pf.addr,
1183                                                 af->pf.fb_ops, &af->pf.sp_die,
1184                                                 NULL);
1185                 if (ret == 0) {
1186                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1187                         pr_debug2("Add new var: %s\n", buf);
1188                         if (ret > 0)
1189                                 strlist__add(vl->vars, buf);
1190                 }
1191         }
1192
1193         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1194                 return DIE_FIND_CB_CONTINUE;
1195         else
1196                 return DIE_FIND_CB_SIBLING;
1197 }
1198
1199 /* Add a found vars into available variables list */
1200 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1201 {
1202         struct available_var_finder *af =
1203                         container_of(pf, struct available_var_finder, pf);
1204         struct variable_list *vl;
1205         Dwarf_Die die_mem;
1206         int ret;
1207
1208         /* Check number of tevs */
1209         if (af->nvls == af->max_vls) {
1210                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1211                 return -ERANGE;
1212         }
1213         vl = &af->vls[af->nvls++];
1214
1215         /* Trace point should be converted from subprogram DIE */
1216         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1217                                      pf->pev->point.retprobe, &vl->point);
1218         if (ret < 0)
1219                 return ret;
1220
1221         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1222                  vl->point.offset);
1223
1224         /* Find local variables */
1225         vl->vars = strlist__new(true, NULL);
1226         if (vl->vars == NULL)
1227                 return -ENOMEM;
1228         af->child = true;
1229         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1230
1231         /* Find external variables */
1232         if (!af->externs)
1233                 goto out;
1234         /* Don't need to search child DIE for externs. */
1235         af->child = false;
1236         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1237
1238 out:
1239         if (strlist__empty(vl->vars)) {
1240                 strlist__delete(vl->vars);
1241                 vl->vars = NULL;
1242         }
1243
1244         return ret;
1245 }
1246
1247 /* Find available variables at given probe point */
1248 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1249                                       struct perf_probe_event *pev,
1250                                       struct variable_list **vls,
1251                                       int max_vls, bool externs)
1252 {
1253         struct available_var_finder af = {
1254                         .pf = {.pev = pev, .callback = add_available_vars},
1255                         .mod = dbg->mod,
1256                         .max_vls = max_vls, .externs = externs};
1257         int ret;
1258
1259         /* Allocate result vls array */
1260         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1261         if (*vls == NULL)
1262                 return -ENOMEM;
1263
1264         af.vls = *vls;
1265         af.nvls = 0;
1266
1267         ret = debuginfo__find_probes(dbg, &af.pf);
1268         if (ret < 0) {
1269                 /* Free vlist for error */
1270                 while (af.nvls--) {
1271                         zfree(&af.vls[af.nvls].point.symbol);
1272                         strlist__delete(af.vls[af.nvls].vars);
1273                 }
1274                 zfree(vls);
1275                 return ret;
1276         }
1277
1278         return (ret < 0) ? ret : af.nvls;
1279 }
1280
1281 /* Reverse search */
1282 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1283                                 struct perf_probe_point *ppt)
1284 {
1285         Dwarf_Die cudie, spdie, indie;
1286         Dwarf_Addr _addr = 0, baseaddr = 0;
1287         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1288         int baseline = 0, lineno = 0, ret = 0;
1289
1290         /* Adjust address with bias */
1291         addr += dbg->bias;
1292
1293         /* Find cu die */
1294         if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1295                 pr_warning("Failed to find debug information for address %lx\n",
1296                            addr);
1297                 ret = -EINVAL;
1298                 goto end;
1299         }
1300
1301         /* Find a corresponding line (filename and lineno) */
1302         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1303         /* Don't care whether it failed or not */
1304
1305         /* Find a corresponding function (name, baseline and baseaddr) */
1306         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1307                 /* Get function entry information */
1308                 func = basefunc = dwarf_diename(&spdie);
1309                 if (!func ||
1310                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1311                     dwarf_decl_line(&spdie, &baseline) != 0) {
1312                         lineno = 0;
1313                         goto post;
1314                 }
1315
1316                 fname = dwarf_decl_file(&spdie);
1317                 if (addr == (unsigned long)baseaddr) {
1318                         /* Function entry - Relative line number is 0 */
1319                         lineno = baseline;
1320                         goto post;
1321                 }
1322
1323                 /* Track down the inline functions step by step */
1324                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1325                                                 &indie)) {
1326                         /* There is an inline function */
1327                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1328                             _addr == addr) {
1329                                 /*
1330                                  * addr is at an inline function entry.
1331                                  * In this case, lineno should be the call-site
1332                                  * line number. (overwrite lineinfo)
1333                                  */
1334                                 lineno = die_get_call_lineno(&indie);
1335                                 fname = die_get_call_file(&indie);
1336                                 break;
1337                         } else {
1338                                 /*
1339                                  * addr is in an inline function body.
1340                                  * Since lineno points one of the lines
1341                                  * of the inline function, baseline should
1342                                  * be the entry line of the inline function.
1343                                  */
1344                                 tmp = dwarf_diename(&indie);
1345                                 if (!tmp ||
1346                                     dwarf_decl_line(&indie, &baseline) != 0)
1347                                         break;
1348                                 func = tmp;
1349                                 spdie = indie;
1350                         }
1351                 }
1352                 /* Verify the lineno and baseline are in a same file */
1353                 tmp = dwarf_decl_file(&spdie);
1354                 if (!tmp || strcmp(tmp, fname) != 0)
1355                         lineno = 0;
1356         }
1357
1358 post:
1359         /* Make a relative line number or an offset */
1360         if (lineno)
1361                 ppt->line = lineno - baseline;
1362         else if (basefunc) {
1363                 ppt->offset = addr - (unsigned long)baseaddr;
1364                 func = basefunc;
1365         }
1366
1367         /* Duplicate strings */
1368         if (func) {
1369                 ppt->function = strdup(func);
1370                 if (ppt->function == NULL) {
1371                         ret = -ENOMEM;
1372                         goto end;
1373                 }
1374         }
1375         if (fname) {
1376                 ppt->file = strdup(fname);
1377                 if (ppt->file == NULL) {
1378                         zfree(&ppt->function);
1379                         ret = -ENOMEM;
1380                         goto end;
1381                 }
1382         }
1383 end:
1384         if (ret == 0 && (fname || func))
1385                 ret = 1;        /* Found a point */
1386         return ret;
1387 }
1388
1389 /* Add a line and store the src path */
1390 static int line_range_add_line(const char *src, unsigned int lineno,
1391                                struct line_range *lr)
1392 {
1393         /* Copy source path */
1394         if (!lr->path) {
1395                 lr->path = strdup(src);
1396                 if (lr->path == NULL)
1397                         return -ENOMEM;
1398         }
1399         return intlist__add(lr->line_list, lineno);
1400 }
1401
1402 static int line_range_walk_cb(const char *fname, int lineno,
1403                               Dwarf_Addr addr __maybe_unused,
1404                               void *data)
1405 {
1406         struct line_finder *lf = data;
1407
1408         if ((strtailcmp(fname, lf->fname) != 0) ||
1409             (lf->lno_s > lineno || lf->lno_e < lineno))
1410                 return 0;
1411
1412         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1413                 return -EINVAL;
1414
1415         return 0;
1416 }
1417
1418 /* Find line range from its line number */
1419 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1420 {
1421         int ret;
1422
1423         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1424
1425         /* Update status */
1426         if (ret >= 0)
1427                 if (!intlist__empty(lf->lr->line_list))
1428                         ret = lf->found = 1;
1429                 else
1430                         ret = 0;        /* Lines are not found */
1431         else {
1432                 zfree(&lf->lr->path);
1433         }
1434         return ret;
1435 }
1436
1437 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1438 {
1439         find_line_range_by_line(in_die, data);
1440
1441         /*
1442          * We have to check all instances of inlined function, because
1443          * some execution paths can be optimized out depends on the
1444          * function argument of instances
1445          */
1446         return 0;
1447 }
1448
1449 /* Search function definition from function name */
1450 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1451 {
1452         struct dwarf_callback_param *param = data;
1453         struct line_finder *lf = param->data;
1454         struct line_range *lr = lf->lr;
1455
1456         /* Check declared file */
1457         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1458                 return DWARF_CB_OK;
1459
1460         if (die_is_func_def(sp_die) &&
1461             die_compare_name(sp_die, lr->function)) {
1462                 lf->fname = dwarf_decl_file(sp_die);
1463                 dwarf_decl_line(sp_die, &lr->offset);
1464                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1465                 lf->lno_s = lr->offset + lr->start;
1466                 if (lf->lno_s < 0)      /* Overflow */
1467                         lf->lno_s = INT_MAX;
1468                 lf->lno_e = lr->offset + lr->end;
1469                 if (lf->lno_e < 0)      /* Overflow */
1470                         lf->lno_e = INT_MAX;
1471                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1472                 lr->start = lf->lno_s;
1473                 lr->end = lf->lno_e;
1474                 if (dwarf_func_inline(sp_die))
1475                         param->retval = die_walk_instances(sp_die,
1476                                                 line_range_inline_cb, lf);
1477                 else
1478                         param->retval = find_line_range_by_line(sp_die, lf);
1479                 return DWARF_CB_ABORT;
1480         }
1481         return DWARF_CB_OK;
1482 }
1483
1484 static int find_line_range_by_func(struct line_finder *lf)
1485 {
1486         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1487         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1488         return param.retval;
1489 }
1490
1491 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1492 {
1493         struct line_finder lf = {.lr = lr, .found = 0};
1494         int ret = 0;
1495         Dwarf_Off off = 0, noff;
1496         size_t cuhl;
1497         Dwarf_Die *diep;
1498         const char *comp_dir;
1499
1500         /* Fastpath: lookup by function name from .debug_pubnames section */
1501         if (lr->function) {
1502                 struct pubname_callback_param pubname_param = {
1503                         .function = lr->function, .file = lr->file,
1504                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1505                 struct dwarf_callback_param line_range_param = {
1506                         .data = (void *)&lf, .retval = 0};
1507
1508                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1509                                   &pubname_param, 0);
1510                 if (pubname_param.found) {
1511                         line_range_search_cb(&lf.sp_die, &line_range_param);
1512                         if (lf.found)
1513                                 goto found;
1514                 }
1515         }
1516
1517         /* Loop on CUs (Compilation Unit) */
1518         while (!lf.found && ret >= 0) {
1519                 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1520                                  NULL, NULL, NULL) != 0)
1521                         break;
1522
1523                 /* Get the DIE(Debugging Information Entry) of this CU */
1524                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1525                 if (!diep)
1526                         continue;
1527
1528                 /* Check if target file is included. */
1529                 if (lr->file)
1530                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1531                 else
1532                         lf.fname = 0;
1533
1534                 if (!lr->file || lf.fname) {
1535                         if (lr->function)
1536                                 ret = find_line_range_by_func(&lf);
1537                         else {
1538                                 lf.lno_s = lr->start;
1539                                 lf.lno_e = lr->end;
1540                                 ret = find_line_range_by_line(NULL, &lf);
1541                         }
1542                 }
1543                 off = noff;
1544         }
1545
1546 found:
1547         /* Store comp_dir */
1548         if (lf.found) {
1549                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1550                 if (comp_dir) {
1551                         lr->comp_dir = strdup(comp_dir);
1552                         if (!lr->comp_dir)
1553                                 ret = -ENOMEM;
1554                 }
1555         }
1556
1557         pr_debug("path: %s\n", lr->path);
1558         return (ret < 0) ? ret : lf.found;
1559 }
1560