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 <stdlib.h>
  30 #include <string.h>
  31 #include <stdarg.h>
  32 #include <dwarf-regs.h>
  33
  34 #include <linux/bitops.h>
  35 #include "event.h"
  36 #include "dso.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 static 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         if (dbg)
 101                 pr_debug("Open Debuginfo file: %s\n", path);
 102         return dbg;
 103 }
 104
 105 enum dso_binary_type distro_dwarf_types[] = {
 106         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
 107         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
 108         DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
 109         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
 110         DSO_BINARY_TYPE__NOT_FOUND,
 111 };
 112
 113 struct debuginfo *debuginfo__new(const char *path)
 114 {
 115         enum dso_binary_type *type;
 116         char buf[PATH_MAX], nil = '\0';
 117         struct dso *dso;
 118         struct debuginfo *dinfo = NULL;
 119
 120         /* Try to open distro debuginfo files */
 121         dso = dso__new(path);
 122         if (!dso)
 123                 goto out;
 124
 125         for (type = distro_dwarf_types;
 126              !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
 127              type++) {
 128                 if (dso__read_binary_type_filename(dso, *type, &nil,
 129                                                    buf, PATH_MAX) < 0)
 130                         continue;
 131                 dinfo = __debuginfo__new(buf);
 132         }
 133         dso__delete(dso);
 134
 135 out:
 136         /* if failed to open all distro debuginfo, open given binary */
 137         return dinfo ? : __debuginfo__new(path);
 138 }
 139
 140 void debuginfo__delete(struct debuginfo *dbg)
 141 {
 142         if (dbg) {
 143                 if (dbg->dwfl)
 144                         dwfl_end(dbg->dwfl);
 145                 free(dbg);
 146         }
 147 }
 148
 149 /*
 150  * Probe finder related functions
 151  */
 152
 153 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 154 {
 155         struct probe_trace_arg_ref *ref;
 156         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 157         if (ref != NULL)
 158                 ref->offset = offs;
 159         return ref;
 160 }
 161
 162 /*
 163  * Convert a location into trace_arg.
 164  * If tvar == NULL, this just checks variable can be converted.
 165  * If fentry == true and vr_die is a parameter, do huristic search
 166  * for the location fuzzed by function entry mcount.
 167  */
 168 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 169                                      Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
 170                                      struct probe_trace_arg *tvar)
 171 {
 172         Dwarf_Attribute attr;
 173         Dwarf_Addr tmp = 0;
 174         Dwarf_Op *op;
 175         size_t nops;
 176         unsigned int regn;
 177         Dwarf_Word offs = 0;
 178         bool ref = false;
 179         const char *regs;
 180         int ret;
 181
 182         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 183                 goto static_var;
 184
 185         /* TODO: handle more than 1 exprs */
 186         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
 187                 return -EINVAL; /* Broken DIE ? */
 188         if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
 189                 ret = dwarf_entrypc(sp_die, &tmp);
 190                 if (ret || addr != tmp ||
 191                     dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
 192                     dwarf_highpc(sp_die, &tmp))
 193                         return -ENOENT;
 194                 /*
 195                  * This is fuzzed by fentry mcount. We try to find the
 196                  * parameter location at the earliest address.
 197                  */
 198                 for (addr += 1; addr <= tmp; addr++) {
 199                         if (dwarf_getlocation_addr(&attr, addr, &op,
 200                                                    &nops, 1) > 0)
 201                                 goto found;
 202                 }
 203                 return -ENOENT;
 204         }
 205 found:
 206         if (nops == 0)
 207                 /* TODO: Support const_value */
 208                 return -ENOENT;
 209
 210         if (op->atom == DW_OP_addr) {
 211 static_var:
 212                 if (!tvar)
 213                         return 0;
 214                 /* Static variables on memory (not stack), make @varname */
 215                 ret = strlen(dwarf_diename(vr_die));
 216                 tvar->value = zalloc(ret + 2);
 217                 if (tvar->value == NULL)
 218                         return -ENOMEM;
 219                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 220                 tvar->ref = alloc_trace_arg_ref((long)offs);
 221                 if (tvar->ref == NULL)
 222                         return -ENOMEM;
 223                 return 0;
 224         }
 225
 226         /* If this is based on frame buffer, set the offset */
 227         if (op->atom == DW_OP_fbreg) {
 228                 if (fb_ops == NULL)
 229                         return -ENOTSUP;
 230                 ref = true;
 231                 offs = op->number;
 232                 op = &fb_ops[0];
 233         }
 234
 235         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 236                 regn = op->atom - DW_OP_breg0;
 237                 offs += op->number;
 238                 ref = true;
 239         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 240                 regn = op->atom - DW_OP_reg0;
 241         } else if (op->atom == DW_OP_bregx) {
 242                 regn = op->number;
 243                 offs += op->number2;
 244                 ref = true;
 245         } else if (op->atom == DW_OP_regx) {
 246                 regn = op->number;
 247         } else {
 248                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 249                 return -ENOTSUP;
 250         }
 251
 252         if (!tvar)
 253                 return 0;
 254
 255         regs = get_arch_regstr(regn);
 256         if (!regs) {
 257                 /* This should be a bug in DWARF or this tool */
 258                 pr_warning("Mapping for the register number %u "
 259                            "missing on this architecture.\n", regn);
 260                 return -ERANGE;
 261         }
 262
 263         tvar->value = strdup(regs);
 264         if (tvar->value == NULL)
 265                 return -ENOMEM;
 266
 267         if (ref) {
 268                 tvar->ref = alloc_trace_arg_ref((long)offs);
 269                 if (tvar->ref == NULL)
 270                         return -ENOMEM;
 271         }
 272         return 0;
 273 }
 274
 275 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
 276
 277 static int convert_variable_type(Dwarf_Die *vr_die,
 278                                  struct probe_trace_arg *tvar,
 279                                  const char *cast)
 280 {
 281         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 282         Dwarf_Die type;
 283         char buf[16];
 284         int bsize, boffs, total;
 285         int ret;
 286
 287         /* TODO: check all types */
 288         if (cast && strcmp(cast, "string") != 0) {
 289                 /* Non string type is OK */
 290                 tvar->type = strdup(cast);
 291                 return (tvar->type == NULL) ? -ENOMEM : 0;
 292         }
 293
 294         bsize = dwarf_bitsize(vr_die);
 295         if (bsize > 0) {
 296                 /* This is a bitfield */
 297                 boffs = dwarf_bitoffset(vr_die);
 298                 total = dwarf_bytesize(vr_die);
 299                 if (boffs < 0 || total < 0)
 300                         return -ENOENT;
 301                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
 302                                 BYTES_TO_BITS(total));
 303                 goto formatted;
 304         }
 305
 306         if (die_get_real_type(vr_die, &type) == NULL) {
 307                 pr_warning("Failed to get a type information of %s.\n",
 308                            dwarf_diename(vr_die));
 309                 return -ENOENT;
 310         }
 311
 312         pr_debug("%s type is %s.\n",
 313                  dwarf_diename(vr_die), dwarf_diename(&type));
 314
 315         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 316                 ret = dwarf_tag(&type);
 317                 if (ret != DW_TAG_pointer_type &&
 318                     ret != DW_TAG_array_type) {
 319                         pr_warning("Failed to cast into string: "
 320                                    "%s(%s) is not a pointer nor array.\n",
 321                                    dwarf_diename(vr_die), dwarf_diename(&type));
 322                         return -EINVAL;
 323                 }
 324                 if (die_get_real_type(&type, &type) == NULL) {
 325                         pr_warning("Failed to get a type"
 326                                    " information.\n");
 327                         return -ENOENT;
 328                 }
 329                 if (ret == DW_TAG_pointer_type) {
 330                         while (*ref_ptr)
 331                                 ref_ptr = &(*ref_ptr)->next;
 332                         /* Add new reference with offset +0 */
 333                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 334                         if (*ref_ptr == NULL) {
 335                                 pr_warning("Out of memory error\n");
 336                                 return -ENOMEM;
 337                         }
 338                 }
 339                 if (!die_compare_name(&type, "char") &&
 340                     !die_compare_name(&type, "unsigned char")) {
 341                         pr_warning("Failed to cast into string: "
 342                                    "%s is not (unsigned) char *.\n",
 343                                    dwarf_diename(vr_die));
 344                         return -EINVAL;
 345                 }
 346                 tvar->type = strdup(cast);
 347                 return (tvar->type == NULL) ? -ENOMEM : 0;
 348         }
 349
 350         ret = dwarf_bytesize(&type);
 351         if (ret <= 0)
 352                 /* No size ... try to use default type */
 353                 return 0;
 354         ret = BYTES_TO_BITS(ret);
 355
 356         /* Check the bitwidth */
 357         if (ret > MAX_BASIC_TYPE_BITS) {
 358                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
 359                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 360                 ret = MAX_BASIC_TYPE_BITS;
 361         }
 362         ret = snprintf(buf, 16, "%c%d",
 363                        die_is_signed_type(&type) ? 's' : 'u', ret);
 364
 365 formatted:
 366         if (ret < 0 || ret >= 16) {
 367                 if (ret >= 16)
 368                         ret = -E2BIG;
 369                 pr_warning("Failed to convert variable type: %s\n",
 370                            strerror(-ret));
 371                 return ret;
 372         }
 373         tvar->type = strdup(buf);
 374         if (tvar->type == NULL)
 375                 return -ENOMEM;
 376         return 0;
 377 }
 378
 379 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 380                                     struct perf_probe_arg_field *field,
 381                                     struct probe_trace_arg_ref **ref_ptr,
 382                                     Dwarf_Die *die_mem)
 383 {
 384         struct probe_trace_arg_ref *ref = *ref_ptr;
 385         Dwarf_Die type;
 386         Dwarf_Word offs;
 387         int ret, tag;
 388
 389         pr_debug("converting %s in %s\n", field->name, varname);
 390         if (die_get_real_type(vr_die, &type) == NULL) {
 391                 pr_warning("Failed to get the type of %s.\n", varname);
 392                 return -ENOENT;
 393         }
 394         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 395         tag = dwarf_tag(&type);
 396
 397         if (field->name[0] == '[' &&
 398             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 399                 if (field->next)
 400                         /* Save original type for next field */
 401                         memcpy(die_mem, &type, sizeof(*die_mem));
 402                 /* Get the type of this array */
 403                 if (die_get_real_type(&type, &type) == NULL) {
 404                         pr_warning("Failed to get the type of %s.\n", varname);
 405                         return -ENOENT;
 406                 }
 407                 pr_debug2("Array real type: (%x)\n",
 408                          (unsigned)dwarf_dieoffset(&type));
 409                 if (tag == DW_TAG_pointer_type) {
 410                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 411                         if (ref == NULL)
 412                                 return -ENOMEM;
 413                         if (*ref_ptr)
 414                                 (*ref_ptr)->next = ref;
 415                         else
 416                                 *ref_ptr = ref;
 417                 }
 418                 ref->offset += dwarf_bytesize(&type) * field->index;
 419                 if (!field->next)
 420                         /* Save vr_die for converting types */
 421                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 422                 goto next;
 423         } else if (tag == DW_TAG_pointer_type) {
 424                 /* Check the pointer and dereference */
 425                 if (!field->ref) {
 426                         pr_err("Semantic error: %s must be referred by '->'\n",
 427                                field->name);
 428                         return -EINVAL;
 429                 }
 430                 /* Get the type pointed by this pointer */
 431                 if (die_get_real_type(&type, &type) == NULL) {
 432                         pr_warning("Failed to get the type of %s.\n", varname);
 433                         return -ENOENT;
 434                 }
 435                 /* Verify it is a data structure  */
 436                 tag = dwarf_tag(&type);
 437                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 438                         pr_warning("%s is not a data structure nor an union.\n",
 439                                    varname);
 440                         return -EINVAL;
 441                 }
 442
 443                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 444                 if (ref == NULL)
 445                         return -ENOMEM;
 446                 if (*ref_ptr)
 447                         (*ref_ptr)->next = ref;
 448                 else
 449                         *ref_ptr = ref;
 450         } else {
 451                 /* Verify it is a data structure  */
 452                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 453                         pr_warning("%s is not a data structure nor an union.\n",
 454                                    varname);
 455                         return -EINVAL;
 456                 }
 457                 if (field->name[0] == '[') {
 458                         pr_err("Semantic error: %s is not a pointor"
 459                                " nor array.\n", varname);
 460                         return -EINVAL;
 461                 }
 462                 if (field->ref) {
 463                         pr_err("Semantic error: %s must be referred by '.'\n",
 464                                field->name);
 465                         return -EINVAL;
 466                 }
 467                 if (!ref) {
 468                         pr_warning("Structure on a register is not "
 469                                    "supported yet.\n");
 470                         return -ENOTSUP;
 471                 }
 472         }
 473
 474         if (die_find_member(&type, field->name, die_mem) == NULL) {
 475                 pr_warning("%s(type:%s) has no member %s.\n", varname,
 476                            dwarf_diename(&type), field->name);
 477                 return -EINVAL;
 478         }
 479
 480         /* Get the offset of the field */
 481         if (tag == DW_TAG_union_type) {
 482                 offs = 0;
 483         } else {
 484                 ret = die_get_data_member_location(die_mem, &offs);
 485                 if (ret < 0) {
 486                         pr_warning("Failed to get the offset of %s.\n",
 487                                    field->name);
 488                         return ret;
 489                 }
 490         }
 491         ref->offset += (long)offs;
 492
 493 next:
 494         /* Converting next field */
 495         if (field->next)
 496                 return convert_variable_fields(die_mem, field->name,
 497                                         field->next, &ref, die_mem);
 498         else
 499                 return 0;
 500 }
 501
 502 /* Show a variables in kprobe event format */
 503 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 504 {
 505         Dwarf_Die die_mem;
 506         int ret;
 507
 508         pr_debug("Converting variable %s into trace event.\n",
 509                  dwarf_diename(vr_die));
 510
 511         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 512                                         &pf->sp_die, pf->tvar);
 513         if (ret == -ENOENT || ret == -EINVAL)
 514                 pr_err("Failed to find the location of %s at this address.\n"
 515                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 516         else if (ret == -ENOTSUP)
 517                 pr_err("Sorry, we don't support this variable location yet.\n");
 518         else if (ret == 0 && pf->pvar->field) {
 519                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 520                                               pf->pvar->field, &pf->tvar->ref,
 521                                               &die_mem);
 522                 vr_die = &die_mem;
 523         }
 524         if (ret == 0)
 525                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 526         /* *expr will be cached in libdw. Don't free it. */
 527         return ret;
 528 }
 529
 530 /* Find a variable in a scope DIE */
 531 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 532 {
 533         Dwarf_Die vr_die;
 534         char buf[32], *ptr;
 535         int ret = 0;
 536
 537         if (!is_c_varname(pf->pvar->var)) {
 538                 /* Copy raw parameters */
 539                 pf->tvar->value = strdup(pf->pvar->var);
 540                 if (pf->tvar->value == NULL)
 541                         return -ENOMEM;
 542                 if (pf->pvar->type) {
 543                         pf->tvar->type = strdup(pf->pvar->type);
 544                         if (pf->tvar->type == NULL)
 545                                 return -ENOMEM;
 546                 }
 547                 if (pf->pvar->name) {
 548                         pf->tvar->name = strdup(pf->pvar->name);
 549                         if (pf->tvar->name == NULL)
 550                                 return -ENOMEM;
 551                 } else
 552                         pf->tvar->name = NULL;
 553                 return 0;
 554         }
 555
 556         if (pf->pvar->name)
 557                 pf->tvar->name = strdup(pf->pvar->name);
 558         else {
 559                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 560                 if (ret < 0)
 561                         return ret;
 562                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 563                 if (ptr)
 564                         *ptr = '_';
 565                 pf->tvar->name = strdup(buf);
 566         }
 567         if (pf->tvar->name == NULL)
 568                 return -ENOMEM;
 569
 570         pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
 571         /* Search child die for local variables and parameters. */
 572         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
 573                 /* Search again in global variables */
 574                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
 575                         pr_warning("Failed to find '%s' in this function.\n",
 576                                    pf->pvar->var);
 577                         ret = -ENOENT;
 578         }
 579         if (ret >= 0)
 580                 ret = convert_variable(&vr_die, pf);
 581
 582         return ret;
 583 }
 584
 585 /* Convert subprogram DIE to trace point */
 586 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 587                                   Dwarf_Addr paddr, bool retprobe,
 588                                   struct probe_trace_point *tp)
 589 {
 590         Dwarf_Addr eaddr, highaddr;
 591         GElf_Sym sym;
 592         const char *symbol;
 593
 594         /* Verify the address is correct */
 595         if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 596                 pr_warning("Failed to get entry address of %s\n",
 597                            dwarf_diename(sp_die));
 598                 return -ENOENT;
 599         }
 600         if (dwarf_highpc(sp_die, &highaddr) != 0) {
 601                 pr_warning("Failed to get end address of %s\n",
 602                            dwarf_diename(sp_die));
 603                 return -ENOENT;
 604         }
 605         if (paddr > highaddr) {
 606                 pr_warning("Offset specified is greater than size of %s\n",
 607                            dwarf_diename(sp_die));
 608                 return -EINVAL;
 609         }
 610
 611         /* Get an appropriate symbol from symtab */
 612         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
 613         if (!symbol) {
 614                 pr_warning("Failed to find symbol at 0x%lx\n",
 615                            (unsigned long)paddr);
 616                 return -ENOENT;
 617         }
 618         tp->offset = (unsigned long)(paddr - sym.st_value);
 619         tp->address = (unsigned long)paddr;
 620         tp->symbol = strdup(symbol);
 621         if (!tp->symbol)
 622                 return -ENOMEM;
 623
 624         /* Return probe must be on the head of a subprogram */
 625         if (retprobe) {
 626                 if (eaddr != paddr) {
 627                         pr_warning("Return probe must be on the head of"
 628                                    " a real function.\n");
 629                         return -EINVAL;
 630                 }
 631                 tp->retprobe = true;
 632         }
 633
 634         return 0;
 635 }
 636
 637 /* Call probe_finder callback with scope DIE */
 638 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 639 {
 640         Dwarf_Attribute fb_attr;
 641         size_t nops;
 642         int ret;
 643
 644         if (!sc_die) {
 645                 pr_err("Caller must pass a scope DIE. Program error.\n");
 646                 return -EINVAL;
 647         }
 648
 649         /* If not a real subprogram, find a real one */
 650         if (!die_is_func_def(sc_die)) {
 651                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
 652                         pr_warning("Failed to find probe point in any "
 653                                    "functions.\n");
 654                         return -ENOENT;
 655                 }
 656         } else
 657                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 658
 659         /* Get the frame base attribute/ops from subprogram */
 660         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
 661         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 662         if (ret <= 0 || nops == 0) {
 663                 pf->fb_ops = NULL;
 664 #if _ELFUTILS_PREREQ(0, 142)
 665         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 666                    pf->cfi != NULL) {
 667                 Dwarf_Frame *frame;
 668                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 669                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 670                         pr_warning("Failed to get call frame on 0x%jx\n",
 671                                    (uintmax_t)pf->addr);
 672                         return -ENOENT;
 673                 }
 674 #endif
 675         }
 676
 677         /* Call finder's callback handler */
 678         ret = pf->callback(sc_die, pf);
 679
 680         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 681         pf->fb_ops = NULL;
 682
 683         return ret;
 684 }
 685
 686 struct find_scope_param {
 687         const char *function;
 688         const char *file;
 689         int line;
 690         int diff;
 691         Dwarf_Die *die_mem;
 692         bool found;
 693 };
 694
 695 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
 696 {
 697         struct find_scope_param *fsp = data;
 698         const char *file;
 699         int lno;
 700
 701         /* Skip if declared file name does not match */
 702         if (fsp->file) {
 703                 file = dwarf_decl_file(fn_die);
 704                 if (!file || strcmp(fsp->file, file) != 0)
 705                         return 0;
 706         }
 707         /* If the function name is given, that's what user expects */
 708         if (fsp->function) {
 709                 if (die_compare_name(fn_die, fsp->function)) {
 710                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 711                         fsp->found = true;
 712                         return 1;
 713                 }
 714         } else {
 715                 /* With the line number, find the nearest declared DIE */
 716                 dwarf_decl_line(fn_die, &lno);
 717                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
 718                         /* Keep a candidate and continue */
 719                         fsp->diff = fsp->line - lno;
 720                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 721                         fsp->found = true;
 722                 }
 723         }
 724         return 0;
 725 }
 726
 727 /* Find an appropriate scope fits to given conditions */
 728 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
 729 {
 730         struct find_scope_param fsp = {
 731                 .function = pf->pev->point.function,
 732                 .file = pf->fname,
 733                 .line = pf->lno,
 734                 .diff = INT_MAX,
 735                 .die_mem = die_mem,
 736                 .found = false,
 737         };
 738
 739         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
 740
 741         return fsp.found ? die_mem : NULL;
 742 }
 743
 744 static int probe_point_line_walker(const char *fname, int lineno,
 745                                    Dwarf_Addr addr, void *data)
 746 {
 747         struct probe_finder *pf = data;
 748         Dwarf_Die *sc_die, die_mem;
 749         int ret;
 750
 751         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 752                 return 0;
 753
 754         pf->addr = addr;
 755         sc_die = find_best_scope(pf, &die_mem);
 756         if (!sc_die) {
 757                 pr_warning("Failed to find scope of probe point.\n");
 758                 return -ENOENT;
 759         }
 760
 761         ret = call_probe_finder(sc_die, pf);
 762
 763         /* Continue if no error, because the line will be in inline function */
 764         return ret < 0 ? ret : 0;
 765 }
 766
 767 /* Find probe point from its line number */
 768 static int find_probe_point_by_line(struct probe_finder *pf)
 769 {
 770         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 771 }
 772
 773 /* Find lines which match lazy pattern */
 774 static int find_lazy_match_lines(struct intlist *list,
 775                                  const char *fname, const char *pat)
 776 {
 777         FILE *fp;
 778         char *line = NULL;
 779         size_t line_len;
 780         ssize_t len;
 781         int count = 0, linenum = 1;
 782
 783         fp = fopen(fname, "r");
 784         if (!fp) {
 785                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 786                 return -errno;
 787         }
 788
 789         while ((len = getline(&line, &line_len, fp)) > 0) {
 790
 791                 if (line[len - 1] == '\n')
 792                         line[len - 1] = '\0';
 793
 794                 if (strlazymatch(line, pat)) {
 795                         intlist__add(list, linenum);
 796                         count++;
 797                 }
 798                 linenum++;
 799         }
 800
 801         if (ferror(fp))
 802                 count = -errno;
 803         free(line);
 804         fclose(fp);
 805
 806         if (count == 0)
 807                 pr_debug("No matched lines found in %s.\n", fname);
 808         return count;
 809 }
 810
 811 static int probe_point_lazy_walker(const char *fname, int lineno,
 812                                    Dwarf_Addr addr, void *data)
 813 {
 814         struct probe_finder *pf = data;
 815         Dwarf_Die *sc_die, die_mem;
 816         int ret;
 817
 818         if (!intlist__has_entry(pf->lcache, lineno) ||
 819             strtailcmp(fname, pf->fname) != 0)
 820                 return 0;
 821
 822         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 823                  lineno, (unsigned long long)addr);
 824         pf->addr = addr;
 825         pf->lno = lineno;
 826         sc_die = find_best_scope(pf, &die_mem);
 827         if (!sc_die) {
 828                 pr_warning("Failed to find scope of probe point.\n");
 829                 return -ENOENT;
 830         }
 831
 832         ret = call_probe_finder(sc_die, pf);
 833
 834         /*
 835          * Continue if no error, because the lazy pattern will match
 836          * to other lines
 837          */
 838         return ret < 0 ? ret : 0;
 839 }
 840
 841 /* Find probe points from lazy pattern  */
 842 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 843 {
 844         int ret = 0;
 845
 846         if (intlist__empty(pf->lcache)) {
 847                 /* Matching lazy line pattern */
 848                 ret = find_lazy_match_lines(pf->lcache, pf->fname,
 849                                             pf->pev->point.lazy_line);
 850                 if (ret <= 0)
 851                         return ret;
 852         }
 853
 854         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 855 }
 856
 857 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 858 {
 859         struct probe_finder *pf = data;
 860         struct perf_probe_point *pp = &pf->pev->point;
 861         Dwarf_Addr addr;
 862         int ret;
 863
 864         if (pp->lazy_line)
 865                 ret = find_probe_point_lazy(in_die, pf);
 866         else {
 867                 /* Get probe address */
 868                 if (dwarf_entrypc(in_die, &addr) != 0) {
 869                         pr_warning("Failed to get entry address of %s.\n",
 870                                    dwarf_diename(in_die));
 871                         return -ENOENT;
 872                 }
 873                 pf->addr = addr;
 874                 pf->addr += pp->offset;
 875                 pr_debug("found inline addr: 0x%jx\n",
 876                          (uintmax_t)pf->addr);
 877
 878                 ret = call_probe_finder(in_die, pf);
 879         }
 880
 881         return ret;
 882 }
 883
 884 /* Callback parameter with return value for libdw */
 885 struct dwarf_callback_param {
 886         void *data;
 887         int retval;
 888 };
 889
 890 /* Search function from function name */
 891 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 892 {
 893         struct dwarf_callback_param *param = data;
 894         struct probe_finder *pf = param->data;
 895         struct perf_probe_point *pp = &pf->pev->point;
 896
 897         /* Check tag and diename */
 898         if (!die_is_func_def(sp_die) ||
 899             !die_compare_name(sp_die, pp->function))
 900                 return DWARF_CB_OK;
 901
 902         /* Check declared file */
 903         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 904                 return DWARF_CB_OK;
 905
 906         pf->fname = dwarf_decl_file(sp_die);
 907         if (pp->line) { /* Function relative line */
 908                 dwarf_decl_line(sp_die, &pf->lno);
 909                 pf->lno += pp->line;
 910                 param->retval = find_probe_point_by_line(pf);
 911         } else if (!dwarf_func_inline(sp_die)) {
 912                 /* Real function */
 913                 if (pp->lazy_line)
 914                         param->retval = find_probe_point_lazy(sp_die, pf);
 915                 else {
 916                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 917                                 pr_warning("Failed to get entry address of "
 918                                            "%s.\n", dwarf_diename(sp_die));
 919                                 param->retval = -ENOENT;
 920                                 return DWARF_CB_ABORT;
 921                         }
 922                         pf->addr += pp->offset;
 923                         /* TODO: Check the address in this function */
 924                         param->retval = call_probe_finder(sp_die, pf);
 925                 }
 926         } else
 927                 /* Inlined function: search instances */
 928                 param->retval = die_walk_instances(sp_die,
 929                                         probe_point_inline_cb, (void *)pf);
 930
 931         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 932 }
 933
 934 static int find_probe_point_by_func(struct probe_finder *pf)
 935 {
 936         struct dwarf_callback_param _param = {.data = (void *)pf,
 937                                               .retval = 0};
 938         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 939         return _param.retval;
 940 }
 941
 942 struct pubname_callback_param {
 943         char *function;
 944         char *file;
 945         Dwarf_Die *cu_die;
 946         Dwarf_Die *sp_die;
 947         int found;
 948 };
 949
 950 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
 951 {
 952         struct pubname_callback_param *param = data;
 953
 954         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
 955                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
 956                         return DWARF_CB_OK;
 957
 958                 if (die_compare_name(param->sp_die, param->function)) {
 959                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
 960                                 return DWARF_CB_OK;
 961
 962                         if (param->file &&
 963                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
 964                                 return DWARF_CB_OK;
 965
 966                         param->found = 1;
 967                         return DWARF_CB_ABORT;
 968                 }
 969         }
 970
 971         return DWARF_CB_OK;
 972 }
 973
 974 /* Find probe points from debuginfo */
 975 static int debuginfo__find_probes(struct debuginfo *dbg,
 976                                   struct probe_finder *pf)
 977 {
 978         struct perf_probe_point *pp = &pf->pev->point;
 979         Dwarf_Off off, noff;
 980         size_t cuhl;
 981         Dwarf_Die *diep;
 982         int ret = 0;
 983
 984 #if _ELFUTILS_PREREQ(0, 142)
 985         /* Get the call frame information from this dwarf */
 986         pf->cfi = dwarf_getcfi_elf(dwarf_getelf(dbg->dbg));
 987 #endif
 988
 989         off = 0;
 990         pf->lcache = intlist__new(NULL);
 991         if (!pf->lcache)
 992                 return -ENOMEM;
 993
 994         /* Fastpath: lookup by function name from .debug_pubnames section */
 995         if (pp->function) {
 996                 struct pubname_callback_param pubname_param = {
 997                         .function = pp->function,
 998                         .file     = pp->file,
 999                         .cu_die   = &pf->cu_die,
1000                         .sp_die   = &pf->sp_die,
1001                         .found    = 0,
1002                 };
1003                 struct dwarf_callback_param probe_param = {
1004                         .data = pf,
1005                 };
1006
1007                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1008                                   &pubname_param, 0);
1009                 if (pubname_param.found) {
1010                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1011                         if (ret)
1012                                 goto found;
1013                 }
1014         }
1015
1016         /* Loop on CUs (Compilation Unit) */
1017         while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1018                 /* Get the DIE(Debugging Information Entry) of this CU */
1019                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1020                 if (!diep)
1021                         continue;
1022
1023                 /* Check if target file is included. */
1024                 if (pp->file)
1025                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1026                 else
1027                         pf->fname = NULL;
1028
1029                 if (!pp->file || pf->fname) {
1030                         if (pp->function)
1031                                 ret = find_probe_point_by_func(pf);
1032                         else if (pp->lazy_line)
1033                                 ret = find_probe_point_lazy(NULL, pf);
1034                         else {
1035                                 pf->lno = pp->line;
1036                                 ret = find_probe_point_by_line(pf);
1037                         }
1038                         if (ret < 0)
1039                                 break;
1040                 }
1041                 off = noff;
1042         }
1043
1044 found:
1045         intlist__delete(pf->lcache);
1046         pf->lcache = NULL;
1047
1048         return ret;
1049 }
1050
1051 struct local_vars_finder {
1052         struct probe_finder *pf;
1053         struct perf_probe_arg *args;
1054         int max_args;
1055         int nargs;
1056         int ret;
1057 };
1058
1059 /* Collect available variables in this scope */
1060 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1061 {
1062         struct local_vars_finder *vf = data;
1063         struct probe_finder *pf = vf->pf;
1064         int tag;
1065
1066         tag = dwarf_tag(die_mem);
1067         if (tag == DW_TAG_formal_parameter ||
1068             tag == DW_TAG_variable) {
1069                 if (convert_variable_location(die_mem, vf->pf->addr,
1070                                               vf->pf->fb_ops, &pf->sp_die,
1071                                               NULL) == 0) {
1072                         vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1073                         if (vf->args[vf->nargs].var == NULL) {
1074                                 vf->ret = -ENOMEM;
1075                                 return DIE_FIND_CB_END;
1076                         }
1077                         pr_debug(" %s", vf->args[vf->nargs].var);
1078                         vf->nargs++;
1079                 }
1080         }
1081
1082         if (dwarf_haspc(die_mem, vf->pf->addr))
1083                 return DIE_FIND_CB_CONTINUE;
1084         else
1085                 return DIE_FIND_CB_SIBLING;
1086 }
1087
1088 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1089                              struct perf_probe_arg *args)
1090 {
1091         Dwarf_Die die_mem;
1092         int i;
1093         int n = 0;
1094         struct local_vars_finder vf = {.pf = pf, .args = args,
1095                                 .max_args = MAX_PROBE_ARGS, .ret = 0};
1096
1097         for (i = 0; i < pf->pev->nargs; i++) {
1098                 /* var never be NULL */
1099                 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1100                         pr_debug("Expanding $vars into:");
1101                         vf.nargs = n;
1102                         /* Special local variables */
1103                         die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1104                                        &die_mem);
1105                         pr_debug(" (%d)\n", vf.nargs - n);
1106                         if (vf.ret < 0)
1107                                 return vf.ret;
1108                         n = vf.nargs;
1109                 } else {
1110                         /* Copy normal argument */
1111                         args[n] = pf->pev->args[i];
1112                         n++;
1113                 }
1114         }
1115         return n;
1116 }
1117
1118 /* Add a found probe point into trace event list */
1119 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1120 {
1121         struct trace_event_finder *tf =
1122                         container_of(pf, struct trace_event_finder, pf);
1123         struct probe_trace_event *tev;
1124         struct perf_probe_arg *args;
1125         int ret, i;
1126
1127         /* Check number of tevs */
1128         if (tf->ntevs == tf->max_tevs) {
1129                 pr_warning("Too many( > %d) probe point found.\n",
1130                            tf->max_tevs);
1131                 return -ERANGE;
1132         }
1133         tev = &tf->tevs[tf->ntevs++];
1134
1135         /* Trace point should be converted from subprogram DIE */
1136         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1137                                      pf->pev->point.retprobe, &tev->point);
1138         if (ret < 0)
1139                 return ret;
1140
1141         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1142                  tev->point.offset);
1143
1144         /* Expand special probe argument if exist */
1145         args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1146         if (args == NULL)
1147                 return -ENOMEM;
1148
1149         ret = expand_probe_args(sc_die, pf, args);
1150         if (ret < 0)
1151                 goto end;
1152
1153         tev->nargs = ret;
1154         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1155         if (tev->args == NULL) {
1156                 ret = -ENOMEM;
1157                 goto end;
1158         }
1159
1160         /* Find each argument */
1161         for (i = 0; i < tev->nargs; i++) {
1162                 pf->pvar = &args[i];
1163                 pf->tvar = &tev->args[i];
1164                 /* Variable should be found from scope DIE */
1165                 ret = find_variable(sc_die, pf);
1166                 if (ret != 0)
1167                         break;
1168         }
1169
1170 end:
1171         free(args);
1172         return ret;
1173 }
1174
1175 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1176 int debuginfo__find_trace_events(struct debuginfo *dbg,
1177                                  struct perf_probe_event *pev,
1178                                  struct probe_trace_event **tevs, int max_tevs)
1179 {
1180         struct trace_event_finder tf = {
1181                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1182                         .mod = dbg->mod, .max_tevs = max_tevs};
1183         int ret;
1184
1185         /* Allocate result tevs array */
1186         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1187         if (*tevs == NULL)
1188                 return -ENOMEM;
1189
1190         tf.tevs = *tevs;
1191         tf.ntevs = 0;
1192
1193         ret = debuginfo__find_probes(dbg, &tf.pf);
1194         if (ret < 0) {
1195                 zfree(tevs);
1196                 return ret;
1197         }
1198
1199         return (ret < 0) ? ret : tf.ntevs;
1200 }
1201
1202 #define MAX_VAR_LEN 64
1203
1204 /* Collect available variables in this scope */
1205 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1206 {
1207         struct available_var_finder *af = data;
1208         struct variable_list *vl;
1209         char buf[MAX_VAR_LEN];
1210         int tag, ret;
1211
1212         vl = &af->vls[af->nvls - 1];
1213
1214         tag = dwarf_tag(die_mem);
1215         if (tag == DW_TAG_formal_parameter ||
1216             tag == DW_TAG_variable) {
1217                 ret = convert_variable_location(die_mem, af->pf.addr,
1218                                                 af->pf.fb_ops, &af->pf.sp_die,
1219                                                 NULL);
1220                 if (ret == 0) {
1221                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1222                         pr_debug2("Add new var: %s\n", buf);
1223                         if (ret > 0)
1224                                 strlist__add(vl->vars, buf);
1225                 }
1226         }
1227
1228         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1229                 return DIE_FIND_CB_CONTINUE;
1230         else
1231                 return DIE_FIND_CB_SIBLING;
1232 }
1233
1234 /* Add a found vars into available variables list */
1235 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1236 {
1237         struct available_var_finder *af =
1238                         container_of(pf, struct available_var_finder, pf);
1239         struct variable_list *vl;
1240         Dwarf_Die die_mem;
1241         int ret;
1242
1243         /* Check number of tevs */
1244         if (af->nvls == af->max_vls) {
1245                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1246                 return -ERANGE;
1247         }
1248         vl = &af->vls[af->nvls++];
1249
1250         /* Trace point should be converted from subprogram DIE */
1251         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1252                                      pf->pev->point.retprobe, &vl->point);
1253         if (ret < 0)
1254                 return ret;
1255
1256         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1257                  vl->point.offset);
1258
1259         /* Find local variables */
1260         vl->vars = strlist__new(true, NULL);
1261         if (vl->vars == NULL)
1262                 return -ENOMEM;
1263         af->child = true;
1264         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1265
1266         /* Find external variables */
1267         if (!af->externs)
1268                 goto out;
1269         /* Don't need to search child DIE for externs. */
1270         af->child = false;
1271         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1272
1273 out:
1274         if (strlist__empty(vl->vars)) {
1275                 strlist__delete(vl->vars);
1276                 vl->vars = NULL;
1277         }
1278
1279         return ret;
1280 }
1281
1282 /*
1283  * Find available variables at given probe point
1284  * Return the number of found probe points. Return 0 if there is no
1285  * matched probe point. Return <0 if an error occurs.
1286  */
1287 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1288                                       struct perf_probe_event *pev,
1289                                       struct variable_list **vls,
1290                                       int max_vls, bool externs)
1291 {
1292         struct available_var_finder af = {
1293                         .pf = {.pev = pev, .callback = add_available_vars},
1294                         .mod = dbg->mod,
1295                         .max_vls = max_vls, .externs = externs};
1296         int ret;
1297
1298         /* Allocate result vls array */
1299         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1300         if (*vls == NULL)
1301                 return -ENOMEM;
1302
1303         af.vls = *vls;
1304         af.nvls = 0;
1305
1306         ret = debuginfo__find_probes(dbg, &af.pf);
1307         if (ret < 0) {
1308                 /* Free vlist for error */
1309                 while (af.nvls--) {
1310                         zfree(&af.vls[af.nvls].point.symbol);
1311                         strlist__delete(af.vls[af.nvls].vars);
1312                 }
1313                 zfree(vls);
1314                 return ret;
1315         }
1316
1317         return (ret < 0) ? ret : af.nvls;
1318 }
1319
1320 /* Reverse search */
1321 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1322                                 struct perf_probe_point *ppt)
1323 {
1324         Dwarf_Die cudie, spdie, indie;
1325         Dwarf_Addr _addr = 0, baseaddr = 0;
1326         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1327         int baseline = 0, lineno = 0, ret = 0;
1328
1329         /* Adjust address with bias */
1330         addr += dbg->bias;
1331
1332         /* Find cu die */
1333         if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1334                 pr_warning("Failed to find debug information for address %lx\n",
1335                            addr);
1336                 ret = -EINVAL;
1337                 goto end;
1338         }
1339
1340         /* Find a corresponding line (filename and lineno) */
1341         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1342         /* Don't care whether it failed or not */
1343
1344         /* Find a corresponding function (name, baseline and baseaddr) */
1345         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1346                 /* Get function entry information */
1347                 func = basefunc = dwarf_diename(&spdie);
1348                 if (!func ||
1349                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1350                     dwarf_decl_line(&spdie, &baseline) != 0) {
1351                         lineno = 0;
1352                         goto post;
1353                 }
1354
1355                 fname = dwarf_decl_file(&spdie);
1356                 if (addr == (unsigned long)baseaddr) {
1357                         /* Function entry - Relative line number is 0 */
1358                         lineno = baseline;
1359                         goto post;
1360                 }
1361
1362                 /* Track down the inline functions step by step */
1363                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1364                                                 &indie)) {
1365                         /* There is an inline function */
1366                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1367                             _addr == addr) {
1368                                 /*
1369                                  * addr is at an inline function entry.
1370                                  * In this case, lineno should be the call-site
1371                                  * line number. (overwrite lineinfo)
1372                                  */
1373                                 lineno = die_get_call_lineno(&indie);
1374                                 fname = die_get_call_file(&indie);
1375                                 break;
1376                         } else {
1377                                 /*
1378                                  * addr is in an inline function body.
1379                                  * Since lineno points one of the lines
1380                                  * of the inline function, baseline should
1381                                  * be the entry line of the inline function.
1382                                  */
1383                                 tmp = dwarf_diename(&indie);
1384                                 if (!tmp ||
1385                                     dwarf_decl_line(&indie, &baseline) != 0)
1386                                         break;
1387                                 func = tmp;
1388                                 spdie = indie;
1389                         }
1390                 }
1391                 /* Verify the lineno and baseline are in a same file */
1392                 tmp = dwarf_decl_file(&spdie);
1393                 if (!tmp || strcmp(tmp, fname) != 0)
1394                         lineno = 0;
1395         }
1396
1397 post:
1398         /* Make a relative line number or an offset */
1399         if (lineno)
1400                 ppt->line = lineno - baseline;
1401         else if (basefunc) {
1402                 ppt->offset = addr - (unsigned long)baseaddr;
1403                 func = basefunc;
1404         }
1405
1406         /* Duplicate strings */
1407         if (func) {
1408                 ppt->function = strdup(func);
1409                 if (ppt->function == NULL) {
1410                         ret = -ENOMEM;
1411                         goto end;
1412                 }
1413         }
1414         if (fname) {
1415                 ppt->file = strdup(fname);
1416                 if (ppt->file == NULL) {
1417                         zfree(&ppt->function);
1418                         ret = -ENOMEM;
1419                         goto end;
1420                 }
1421         }
1422 end:
1423         if (ret == 0 && (fname || func))
1424                 ret = 1;        /* Found a point */
1425         return ret;
1426 }
1427
1428 /* Add a line and store the src path */
1429 static int line_range_add_line(const char *src, unsigned int lineno,
1430                                struct line_range *lr)
1431 {
1432         /* Copy source path */
1433         if (!lr->path) {
1434                 lr->path = strdup(src);
1435                 if (lr->path == NULL)
1436                         return -ENOMEM;
1437         }
1438         return intlist__add(lr->line_list, lineno);
1439 }
1440
1441 static int line_range_walk_cb(const char *fname, int lineno,
1442                               Dwarf_Addr addr __maybe_unused,
1443                               void *data)
1444 {
1445         struct line_finder *lf = data;
1446         int err;
1447
1448         if ((strtailcmp(fname, lf->fname) != 0) ||
1449             (lf->lno_s > lineno || lf->lno_e < lineno))
1450                 return 0;
1451
1452         err = line_range_add_line(fname, lineno, lf->lr);
1453         if (err < 0 && err != -EEXIST)
1454                 return err;
1455
1456         return 0;
1457 }
1458
1459 /* Find line range from its line number */
1460 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1461 {
1462         int ret;
1463
1464         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1465
1466         /* Update status */
1467         if (ret >= 0)
1468                 if (!intlist__empty(lf->lr->line_list))
1469                         ret = lf->found = 1;
1470                 else
1471                         ret = 0;        /* Lines are not found */
1472         else {
1473                 zfree(&lf->lr->path);
1474         }
1475         return ret;
1476 }
1477
1478 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1479 {
1480         int ret = find_line_range_by_line(in_die, data);
1481
1482         /*
1483          * We have to check all instances of inlined function, because
1484          * some execution paths can be optimized out depends on the
1485          * function argument of instances. However, if an error occurs,
1486          * it should be handled by the caller.
1487          */
1488         return ret < 0 ? ret : 0;
1489 }
1490
1491 /* Search function definition from function name */
1492 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1493 {
1494         struct dwarf_callback_param *param = data;
1495         struct line_finder *lf = param->data;
1496         struct line_range *lr = lf->lr;
1497
1498         /* Check declared file */
1499         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1500                 return DWARF_CB_OK;
1501
1502         if (die_is_func_def(sp_die) &&
1503             die_compare_name(sp_die, lr->function)) {
1504                 lf->fname = dwarf_decl_file(sp_die);
1505                 dwarf_decl_line(sp_die, &lr->offset);
1506                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1507                 lf->lno_s = lr->offset + lr->start;
1508                 if (lf->lno_s < 0)      /* Overflow */
1509                         lf->lno_s = INT_MAX;
1510                 lf->lno_e = lr->offset + lr->end;
1511                 if (lf->lno_e < 0)      /* Overflow */
1512                         lf->lno_e = INT_MAX;
1513                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1514                 lr->start = lf->lno_s;
1515                 lr->end = lf->lno_e;
1516                 if (dwarf_func_inline(sp_die))
1517                         param->retval = die_walk_instances(sp_die,
1518                                                 line_range_inline_cb, lf);
1519                 else
1520                         param->retval = find_line_range_by_line(sp_die, lf);
1521                 return DWARF_CB_ABORT;
1522         }
1523         return DWARF_CB_OK;
1524 }
1525
1526 static int find_line_range_by_func(struct line_finder *lf)
1527 {
1528         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1529         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1530         return param.retval;
1531 }
1532
1533 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1534 {
1535         struct line_finder lf = {.lr = lr, .found = 0};
1536         int ret = 0;
1537         Dwarf_Off off = 0, noff;
1538         size_t cuhl;
1539         Dwarf_Die *diep;
1540         const char *comp_dir;
1541
1542         /* Fastpath: lookup by function name from .debug_pubnames section */
1543         if (lr->function) {
1544                 struct pubname_callback_param pubname_param = {
1545                         .function = lr->function, .file = lr->file,
1546                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1547                 struct dwarf_callback_param line_range_param = {
1548                         .data = (void *)&lf, .retval = 0};
1549
1550                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1551                                   &pubname_param, 0);
1552                 if (pubname_param.found) {
1553                         line_range_search_cb(&lf.sp_die, &line_range_param);
1554                         if (lf.found)
1555                                 goto found;
1556                 }
1557         }
1558
1559         /* Loop on CUs (Compilation Unit) */
1560         while (!lf.found && ret >= 0) {
1561                 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1562                                  NULL, NULL, NULL) != 0)
1563                         break;
1564
1565                 /* Get the DIE(Debugging Information Entry) of this CU */
1566                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1567                 if (!diep)
1568                         continue;
1569
1570                 /* Check if target file is included. */
1571                 if (lr->file)
1572                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1573                 else
1574                         lf.fname = 0;
1575
1576                 if (!lr->file || lf.fname) {
1577                         if (lr->function)
1578                                 ret = find_line_range_by_func(&lf);
1579                         else {
1580                                 lf.lno_s = lr->start;
1581                                 lf.lno_e = lr->end;
1582                                 ret = find_line_range_by_line(NULL, &lf);
1583                         }
1584                 }
1585                 off = noff;
1586         }
1587
1588 found:
1589         /* Store comp_dir */
1590         if (lf.found) {
1591                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1592                 if (comp_dir) {
1593                         lr->comp_dir = strdup(comp_dir);
1594                         if (!lr->comp_dir)
1595                                 ret = -ENOMEM;
1596                 }
1597         }
1598
1599         pr_debug("path: %s\n", lr->path);
1600         return (ret < 0) ? ret : lf.found;
1601 }
1602