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 "dso.h"
  38 #include "debug.h"
  39 #include "intlist.h"
  40 #include "util.h"
  41 #include "symbol.h"
  42 #include "probe-finder.h"
  43
  44 /* Kprobe tracer basic type is up to u64 */
  45 #define MAX_BASIC_TYPE_BITS     64
  46
  47 /* Dwarf FL wrappers */
  48 static char *debuginfo_path;    /* Currently dummy */
  49
  50 static const Dwfl_Callbacks offline_callbacks = {
  51         .find_debuginfo = dwfl_standard_find_debuginfo,
  52         .debuginfo_path = &debuginfo_path,
  53
  54         .section_address = dwfl_offline_section_address,
  55
  56         /* We use this table for core files too.  */
  57         .find_elf = dwfl_build_id_find_elf,
  58 };
  59
  60 /* Get a Dwarf from offline image */
  61 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
  62                                          const char *path)
  63 {
  64         int fd;
  65
  66         fd = open(path, O_RDONLY);
  67         if (fd < 0)
  68                 return fd;
  69
  70         dbg->dwfl = dwfl_begin(&offline_callbacks);
  71         if (!dbg->dwfl)
  72                 goto error;
  73
  74         dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
  75         if (!dbg->mod)
  76                 goto error;
  77
  78         dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
  79         if (!dbg->dbg)
  80                 goto error;
  81
  82         return 0;
  83 error:
  84         if (dbg->dwfl)
  85                 dwfl_end(dbg->dwfl);
  86         else
  87                 close(fd);
  88         memset(dbg, 0, sizeof(*dbg));
  89
  90         return -ENOENT;
  91 }
  92
  93 static struct debuginfo *__debuginfo__new(const char *path)
  94 {
  95         struct debuginfo *dbg = zalloc(sizeof(*dbg));
  96         if (!dbg)
  97                 return NULL;
  98
  99         if (debuginfo__init_offline_dwarf(dbg, path) < 0)
 100                 zfree(&dbg);
 101         if (dbg)
 102                 pr_debug("Open Debuginfo file: %s\n", path);
 103         return dbg;
 104 }
 105
 106 enum dso_binary_type distro_dwarf_types[] = {
 107         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
 108         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
 109         DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
 110         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
 111         DSO_BINARY_TYPE__NOT_FOUND,
 112 };
 113
 114 struct debuginfo *debuginfo__new(const char *path)
 115 {
 116         enum dso_binary_type *type;
 117         char buf[PATH_MAX], nil = '\0';
 118         struct dso *dso;
 119         struct debuginfo *dinfo = NULL;
 120
 121         /* Try to open distro debuginfo files */
 122         dso = dso__new(path);
 123         if (!dso)
 124                 goto out;
 125
 126         for (type = distro_dwarf_types;
 127              !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
 128              type++) {
 129                 if (dso__read_binary_type_filename(dso, *type, &nil,
 130                                                    buf, PATH_MAX) < 0)
 131                         continue;
 132                 dinfo = __debuginfo__new(buf);
 133         }
 134         dso__delete(dso);
 135
 136 out:
 137         /* if failed to open all distro debuginfo, open given binary */
 138         return dinfo ? : __debuginfo__new(path);
 139 }
 140
 141 void debuginfo__delete(struct debuginfo *dbg)
 142 {
 143         if (dbg) {
 144                 if (dbg->dwfl)
 145                         dwfl_end(dbg->dwfl);
 146                 free(dbg);
 147         }
 148 }
 149
 150 /*
 151  * Probe finder related functions
 152  */
 153
 154 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 155 {
 156         struct probe_trace_arg_ref *ref;
 157         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 158         if (ref != NULL)
 159                 ref->offset = offs;
 160         return ref;
 161 }
 162
 163 /*
 164  * Convert a location into trace_arg.
 165  * If tvar == NULL, this just checks variable can be converted.
 166  * If fentry == true and vr_die is a parameter, do huristic search
 167  * for the location fuzzed by function entry mcount.
 168  */
 169 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 170                                      Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
 171                                      struct probe_trace_arg *tvar)
 172 {
 173         Dwarf_Attribute attr;
 174         Dwarf_Addr tmp = 0;
 175         Dwarf_Op *op;
 176         size_t nops;
 177         unsigned int regn;
 178         Dwarf_Word offs = 0;
 179         bool ref = false;
 180         const char *regs;
 181         int ret;
 182
 183         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 184                 goto static_var;
 185
 186         /* TODO: handle more than 1 exprs */
 187         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
 188                 return -EINVAL; /* Broken DIE ? */
 189         if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
 190                 ret = dwarf_entrypc(sp_die, &tmp);
 191                 if (ret || addr != tmp ||
 192                     dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
 193                     dwarf_highpc(sp_die, &tmp))
 194                         return -ENOENT;
 195                 /*
 196                  * This is fuzzed by fentry mcount. We try to find the
 197                  * parameter location at the earliest address.
 198                  */
 199                 for (addr += 1; addr <= tmp; addr++) {
 200                         if (dwarf_getlocation_addr(&attr, addr, &op,
 201                                                    &nops, 1) > 0)
 202                                 goto found;
 203                 }
 204                 return -ENOENT;
 205         }
 206 found:
 207         if (nops == 0)
 208                 /* TODO: Support const_value */
 209                 return -ENOENT;
 210
 211         if (op->atom == DW_OP_addr) {
 212 static_var:
 213                 if (!tvar)
 214                         return 0;
 215                 /* Static variables on memory (not stack), make @varname */
 216                 ret = strlen(dwarf_diename(vr_die));
 217                 tvar->value = zalloc(ret + 2);
 218                 if (tvar->value == NULL)
 219                         return -ENOMEM;
 220                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 221                 tvar->ref = alloc_trace_arg_ref((long)offs);
 222                 if (tvar->ref == NULL)
 223                         return -ENOMEM;
 224                 return 0;
 225         }
 226
 227         /* If this is based on frame buffer, set the offset */
 228         if (op->atom == DW_OP_fbreg) {
 229                 if (fb_ops == NULL)
 230                         return -ENOTSUP;
 231                 ref = true;
 232                 offs = op->number;
 233                 op = &fb_ops[0];
 234         }
 235
 236         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 237                 regn = op->atom - DW_OP_breg0;
 238                 offs += op->number;
 239                 ref = true;
 240         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 241                 regn = op->atom - DW_OP_reg0;
 242         } else if (op->atom == DW_OP_bregx) {
 243                 regn = op->number;
 244                 offs += op->number2;
 245                 ref = true;
 246         } else if (op->atom == DW_OP_regx) {
 247                 regn = op->number;
 248         } else {
 249                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 250                 return -ENOTSUP;
 251         }
 252
 253         if (!tvar)
 254                 return 0;
 255
 256         regs = get_arch_regstr(regn);
 257         if (!regs) {
 258                 /* This should be a bug in DWARF or this tool */
 259                 pr_warning("Mapping for the register number %u "
 260                            "missing on this architecture.\n", regn);
 261                 return -ERANGE;
 262         }
 263
 264         tvar->value = strdup(regs);
 265         if (tvar->value == NULL)
 266                 return -ENOMEM;
 267
 268         if (ref) {
 269                 tvar->ref = alloc_trace_arg_ref((long)offs);
 270                 if (tvar->ref == NULL)
 271                         return -ENOMEM;
 272         }
 273         return 0;
 274 }
 275
 276 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
 277
 278 static int convert_variable_type(Dwarf_Die *vr_die,
 279                                  struct probe_trace_arg *tvar,
 280                                  const char *cast)
 281 {
 282         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 283         Dwarf_Die type;
 284         char buf[16];
 285         int bsize, boffs, total;
 286         int ret;
 287
 288         /* TODO: check all types */
 289         if (cast && strcmp(cast, "string") != 0) {
 290                 /* Non string type is OK */
 291                 tvar->type = strdup(cast);
 292                 return (tvar->type == NULL) ? -ENOMEM : 0;
 293         }
 294
 295         bsize = dwarf_bitsize(vr_die);
 296         if (bsize > 0) {
 297                 /* This is a bitfield */
 298                 boffs = dwarf_bitoffset(vr_die);
 299                 total = dwarf_bytesize(vr_die);
 300                 if (boffs < 0 || total < 0)
 301                         return -ENOENT;
 302                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
 303                                 BYTES_TO_BITS(total));
 304                 goto formatted;
 305         }
 306
 307         if (die_get_real_type(vr_die, &type) == NULL) {
 308                 pr_warning("Failed to get a type information of %s.\n",
 309                            dwarf_diename(vr_die));
 310                 return -ENOENT;
 311         }
 312
 313         pr_debug("%s type is %s.\n",
 314                  dwarf_diename(vr_die), dwarf_diename(&type));
 315
 316         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 317                 ret = dwarf_tag(&type);
 318                 if (ret != DW_TAG_pointer_type &&
 319                     ret != DW_TAG_array_type) {
 320                         pr_warning("Failed to cast into string: "
 321                                    "%s(%s) is not a pointer nor array.\n",
 322                                    dwarf_diename(vr_die), dwarf_diename(&type));
 323                         return -EINVAL;
 324                 }
 325                 if (die_get_real_type(&type, &type) == NULL) {
 326                         pr_warning("Failed to get a type"
 327                                    " information.\n");
 328                         return -ENOENT;
 329                 }
 330                 if (ret == DW_TAG_pointer_type) {
 331                         while (*ref_ptr)
 332                                 ref_ptr = &(*ref_ptr)->next;
 333                         /* Add new reference with offset +0 */
 334                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 335                         if (*ref_ptr == NULL) {
 336                                 pr_warning("Out of memory error\n");
 337                                 return -ENOMEM;
 338                         }
 339                 }
 340                 if (!die_compare_name(&type, "char") &&
 341                     !die_compare_name(&type, "unsigned char")) {
 342                         pr_warning("Failed to cast into string: "
 343                                    "%s is not (unsigned) char *.\n",
 344                                    dwarf_diename(vr_die));
 345                         return -EINVAL;
 346                 }
 347                 tvar->type = strdup(cast);
 348                 return (tvar->type == NULL) ? -ENOMEM : 0;
 349         }
 350
 351         ret = dwarf_bytesize(&type);
 352         if (ret <= 0)
 353                 /* No size ... try to use default type */
 354                 return 0;
 355         ret = BYTES_TO_BITS(ret);
 356
 357         /* Check the bitwidth */
 358         if (ret > MAX_BASIC_TYPE_BITS) {
 359                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
 360                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 361                 ret = MAX_BASIC_TYPE_BITS;
 362         }
 363         ret = snprintf(buf, 16, "%c%d",
 364                        die_is_signed_type(&type) ? 's' : 'u', ret);
 365
 366 formatted:
 367         if (ret < 0 || ret >= 16) {
 368                 if (ret >= 16)
 369                         ret = -E2BIG;
 370                 pr_warning("Failed to convert variable type: %s\n",
 371                            strerror(-ret));
 372                 return ret;
 373         }
 374         tvar->type = strdup(buf);
 375         if (tvar->type == NULL)
 376                 return -ENOMEM;
 377         return 0;
 378 }
 379
 380 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 381                                     struct perf_probe_arg_field *field,
 382                                     struct probe_trace_arg_ref **ref_ptr,
 383                                     Dwarf_Die *die_mem)
 384 {
 385         struct probe_trace_arg_ref *ref = *ref_ptr;
 386         Dwarf_Die type;
 387         Dwarf_Word offs;
 388         int ret, tag;
 389
 390         pr_debug("converting %s in %s\n", field->name, varname);
 391         if (die_get_real_type(vr_die, &type) == NULL) {
 392                 pr_warning("Failed to get the type of %s.\n", varname);
 393                 return -ENOENT;
 394         }
 395         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 396         tag = dwarf_tag(&type);
 397
 398         if (field->name[0] == '[' &&
 399             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 400                 if (field->next)
 401                         /* Save original type for next field */
 402                         memcpy(die_mem, &type, sizeof(*die_mem));
 403                 /* Get the type of this array */
 404                 if (die_get_real_type(&type, &type) == NULL) {
 405                         pr_warning("Failed to get the type of %s.\n", varname);
 406                         return -ENOENT;
 407                 }
 408                 pr_debug2("Array real type: (%x)\n",
 409                          (unsigned)dwarf_dieoffset(&type));
 410                 if (tag == DW_TAG_pointer_type) {
 411                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 412                         if (ref == NULL)
 413                                 return -ENOMEM;
 414                         if (*ref_ptr)
 415                                 (*ref_ptr)->next = ref;
 416                         else
 417                                 *ref_ptr = ref;
 418                 }
 419                 ref->offset += dwarf_bytesize(&type) * field->index;
 420                 if (!field->next)
 421                         /* Save vr_die for converting types */
 422                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 423                 goto next;
 424         } else if (tag == DW_TAG_pointer_type) {
 425                 /* Check the pointer and dereference */
 426                 if (!field->ref) {
 427                         pr_err("Semantic error: %s must be referred by '->'\n",
 428                                field->name);
 429                         return -EINVAL;
 430                 }
 431                 /* Get the type pointed by this pointer */
 432                 if (die_get_real_type(&type, &type) == NULL) {
 433                         pr_warning("Failed to get the type of %s.\n", varname);
 434                         return -ENOENT;
 435                 }
 436                 /* Verify it is a data structure  */
 437                 tag = dwarf_tag(&type);
 438                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 439                         pr_warning("%s is not a data structure nor an union.\n",
 440                                    varname);
 441                         return -EINVAL;
 442                 }
 443
 444                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 445                 if (ref == NULL)
 446                         return -ENOMEM;
 447                 if (*ref_ptr)
 448                         (*ref_ptr)->next = ref;
 449                 else
 450                         *ref_ptr = ref;
 451         } else {
 452                 /* Verify it is a data structure  */
 453                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 454                         pr_warning("%s is not a data structure nor an union.\n",
 455                                    varname);
 456                         return -EINVAL;
 457                 }
 458                 if (field->name[0] == '[') {
 459                         pr_err("Semantic error: %s is not a pointor"
 460                                " nor array.\n", varname);
 461                         return -EINVAL;
 462                 }
 463                 if (field->ref) {
 464                         pr_err("Semantic error: %s must be referred by '.'\n",
 465                                field->name);
 466                         return -EINVAL;
 467                 }
 468                 if (!ref) {
 469                         pr_warning("Structure on a register is not "
 470                                    "supported yet.\n");
 471                         return -ENOTSUP;
 472                 }
 473         }
 474
 475         if (die_find_member(&type, field->name, die_mem) == NULL) {
 476                 pr_warning("%s(type:%s) has no member %s.\n", varname,
 477                            dwarf_diename(&type), field->name);
 478                 return -EINVAL;
 479         }
 480
 481         /* Get the offset of the field */
 482         if (tag == DW_TAG_union_type) {
 483                 offs = 0;
 484         } else {
 485                 ret = die_get_data_member_location(die_mem, &offs);
 486                 if (ret < 0) {
 487                         pr_warning("Failed to get the offset of %s.\n",
 488                                    field->name);
 489                         return ret;
 490                 }
 491         }
 492         ref->offset += (long)offs;
 493
 494 next:
 495         /* Converting next field */
 496         if (field->next)
 497                 return convert_variable_fields(die_mem, field->name,
 498                                         field->next, &ref, die_mem);
 499         else
 500                 return 0;
 501 }
 502
 503 /* Show a variables in kprobe event format */
 504 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 505 {
 506         Dwarf_Die die_mem;
 507         int ret;
 508
 509         pr_debug("Converting variable %s into trace event.\n",
 510                  dwarf_diename(vr_die));
 511
 512         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 513                                         &pf->sp_die, pf->tvar);
 514         if (ret == -ENOENT || ret == -EINVAL)
 515                 pr_err("Failed to find the location of %s at this address.\n"
 516                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 517         else if (ret == -ENOTSUP)
 518                 pr_err("Sorry, we don't support this variable location yet.\n");
 519         else if (ret == 0 && pf->pvar->field) {
 520                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 521                                               pf->pvar->field, &pf->tvar->ref,
 522                                               &die_mem);
 523                 vr_die = &die_mem;
 524         }
 525         if (ret == 0)
 526                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 527         /* *expr will be cached in libdw. Don't free it. */
 528         return ret;
 529 }
 530
 531 /* Find a variable in a scope DIE */
 532 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 533 {
 534         Dwarf_Die vr_die;
 535         char buf[32], *ptr;
 536         int ret = 0;
 537
 538         if (!is_c_varname(pf->pvar->var)) {
 539                 /* Copy raw parameters */
 540                 pf->tvar->value = strdup(pf->pvar->var);
 541                 if (pf->tvar->value == NULL)
 542                         return -ENOMEM;
 543                 if (pf->pvar->type) {
 544                         pf->tvar->type = strdup(pf->pvar->type);
 545                         if (pf->tvar->type == NULL)
 546                                 return -ENOMEM;
 547                 }
 548                 if (pf->pvar->name) {
 549                         pf->tvar->name = strdup(pf->pvar->name);
 550                         if (pf->tvar->name == NULL)
 551                                 return -ENOMEM;
 552                 } else
 553                         pf->tvar->name = NULL;
 554                 return 0;
 555         }
 556
 557         if (pf->pvar->name)
 558                 pf->tvar->name = strdup(pf->pvar->name);
 559         else {
 560                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 561                 if (ret < 0)
 562                         return ret;
 563                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 564                 if (ptr)
 565                         *ptr = '_';
 566                 pf->tvar->name = strdup(buf);
 567         }
 568         if (pf->tvar->name == NULL)
 569                 return -ENOMEM;
 570
 571         pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
 572         /* Search child die for local variables and parameters. */
 573         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
 574                 /* Search again in global variables */
 575                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
 576                         pr_warning("Failed to find '%s' in this function.\n",
 577                                    pf->pvar->var);
 578                         ret = -ENOENT;
 579         }
 580         if (ret >= 0)
 581                 ret = convert_variable(&vr_die, pf);
 582
 583         return ret;
 584 }
 585
 586 /* Convert subprogram DIE to trace point */
 587 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 588                                   Dwarf_Addr paddr, bool retprobe,
 589                                   struct probe_trace_point *tp)
 590 {
 591         Dwarf_Addr eaddr, highaddr;
 592         GElf_Sym sym;
 593         const char *symbol;
 594
 595         /* Verify the address is correct */
 596         if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 597                 pr_warning("Failed to get entry address of %s\n",
 598                            dwarf_diename(sp_die));
 599                 return -ENOENT;
 600         }
 601         if (dwarf_highpc(sp_die, &highaddr) != 0) {
 602                 pr_warning("Failed to get end address of %s\n",
 603                            dwarf_diename(sp_die));
 604                 return -ENOENT;
 605         }
 606         if (paddr > highaddr) {
 607                 pr_warning("Offset specified is greater than size of %s\n",
 608                            dwarf_diename(sp_die));
 609                 return -EINVAL;
 610         }
 611
 612         /* Get an appropriate symbol from symtab */
 613         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
 614         if (!symbol) {
 615                 pr_warning("Failed to find symbol at 0x%lx\n",
 616                            (unsigned long)paddr);
 617                 return -ENOENT;
 618         }
 619         tp->offset = (unsigned long)(paddr - sym.st_value);
 620         tp->address = (unsigned long)paddr;
 621         tp->symbol = strdup(symbol);
 622         if (!tp->symbol)
 623                 return -ENOMEM;
 624
 625         /* Return probe must be on the head of a subprogram */
 626         if (retprobe) {
 627                 if (eaddr != paddr) {
 628                         pr_warning("Return probe must be on the head of"
 629                                    " a real function.\n");
 630                         return -EINVAL;
 631                 }
 632                 tp->retprobe = true;
 633         }
 634
 635         return 0;
 636 }
 637
 638 /* Call probe_finder callback with scope DIE */
 639 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 640 {
 641         Dwarf_Attribute fb_attr;
 642         size_t nops;
 643         int ret;
 644
 645         if (!sc_die) {
 646                 pr_err("Caller must pass a scope DIE. Program error.\n");
 647                 return -EINVAL;
 648         }
 649
 650         /* If not a real subprogram, find a real one */
 651         if (!die_is_func_def(sc_die)) {
 652                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
 653                         pr_warning("Failed to find probe point in any "
 654                                    "functions.\n");
 655                         return -ENOENT;
 656                 }
 657         } else
 658                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 659
 660         /* Get the frame base attribute/ops from subprogram */
 661         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
 662         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 663         if (ret <= 0 || nops == 0) {
 664                 pf->fb_ops = NULL;
 665 #if _ELFUTILS_PREREQ(0, 142)
 666         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 667                    pf->cfi != NULL) {
 668                 Dwarf_Frame *frame;
 669                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 670                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 671                         pr_warning("Failed to get call frame on 0x%jx\n",
 672                                    (uintmax_t)pf->addr);
 673                         return -ENOENT;
 674                 }
 675 #endif
 676         }
 677
 678         /* Call finder's callback handler */
 679         ret = pf->callback(sc_die, pf);
 680
 681         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 682         pf->fb_ops = NULL;
 683
 684         return ret;
 685 }
 686
 687 struct find_scope_param {
 688         const char *function;
 689         const char *file;
 690         int line;
 691         int diff;
 692         Dwarf_Die *die_mem;
 693         bool found;
 694 };
 695
 696 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
 697 {
 698         struct find_scope_param *fsp = data;
 699         const char *file;
 700         int lno;
 701
 702         /* Skip if declared file name does not match */
 703         if (fsp->file) {
 704                 file = dwarf_decl_file(fn_die);
 705                 if (!file || strcmp(fsp->file, file) != 0)
 706                         return 0;
 707         }
 708         /* If the function name is given, that's what user expects */
 709         if (fsp->function) {
 710                 if (die_compare_name(fn_die, fsp->function)) {
 711                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 712                         fsp->found = true;
 713                         return 1;
 714                 }
 715         } else {
 716                 /* With the line number, find the nearest declared DIE */
 717                 dwarf_decl_line(fn_die, &lno);
 718                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
 719                         /* Keep a candidate and continue */
 720                         fsp->diff = fsp->line - lno;
 721                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 722                         fsp->found = true;
 723                 }
 724         }
 725         return 0;
 726 }
 727
 728 /* Find an appropriate scope fits to given conditions */
 729 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
 730 {
 731         struct find_scope_param fsp = {
 732                 .function = pf->pev->point.function,
 733                 .file = pf->fname,
 734                 .line = pf->lno,
 735                 .diff = INT_MAX,
 736                 .die_mem = die_mem,
 737                 .found = false,
 738         };
 739
 740         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
 741
 742         return fsp.found ? die_mem : NULL;
 743 }
 744
 745 static int probe_point_line_walker(const char *fname, int lineno,
 746                                    Dwarf_Addr addr, void *data)
 747 {
 748         struct probe_finder *pf = data;
 749         Dwarf_Die *sc_die, die_mem;
 750         int ret;
 751
 752         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 753                 return 0;
 754
 755         pf->addr = addr;
 756         sc_die = find_best_scope(pf, &die_mem);
 757         if (!sc_die) {
 758                 pr_warning("Failed to find scope of probe point.\n");
 759                 return -ENOENT;
 760         }
 761
 762         ret = call_probe_finder(sc_die, pf);
 763
 764         /* Continue if no error, because the line will be in inline function */
 765         return ret < 0 ? ret : 0;
 766 }
 767
 768 /* Find probe point from its line number */
 769 static int find_probe_point_by_line(struct probe_finder *pf)
 770 {
 771         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 772 }
 773
 774 /* Find lines which match lazy pattern */
 775 static int find_lazy_match_lines(struct intlist *list,
 776                                  const char *fname, const char *pat)
 777 {
 778         FILE *fp;
 779         char *line = NULL;
 780         size_t line_len;
 781         ssize_t len;
 782         int count = 0, linenum = 1;
 783
 784         fp = fopen(fname, "r");
 785         if (!fp) {
 786                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 787                 return -errno;
 788         }
 789
 790         while ((len = getline(&line, &line_len, fp)) > 0) {
 791
 792                 if (line[len - 1] == '\n')
 793                         line[len - 1] = '\0';
 794
 795                 if (strlazymatch(line, pat)) {
 796                         intlist__add(list, linenum);
 797                         count++;
 798                 }
 799                 linenum++;
 800         }
 801
 802         if (ferror(fp))
 803                 count = -errno;
 804         free(line);
 805         fclose(fp);
 806
 807         if (count == 0)
 808                 pr_debug("No matched lines found in %s.\n", fname);
 809         return count;
 810 }
 811
 812 static int probe_point_lazy_walker(const char *fname, int lineno,
 813                                    Dwarf_Addr addr, void *data)
 814 {
 815         struct probe_finder *pf = data;
 816         Dwarf_Die *sc_die, die_mem;
 817         int ret;
 818
 819         if (!intlist__has_entry(pf->lcache, lineno) ||
 820             strtailcmp(fname, pf->fname) != 0)
 821                 return 0;
 822
 823         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 824                  lineno, (unsigned long long)addr);
 825         pf->addr = addr;
 826         pf->lno = lineno;
 827         sc_die = find_best_scope(pf, &die_mem);
 828         if (!sc_die) {
 829                 pr_warning("Failed to find scope of probe point.\n");
 830                 return -ENOENT;
 831         }
 832
 833         ret = call_probe_finder(sc_die, pf);
 834
 835         /*
 836          * Continue if no error, because the lazy pattern will match
 837          * to other lines
 838          */
 839         return ret < 0 ? ret : 0;
 840 }
 841
 842 /* Find probe points from lazy pattern  */
 843 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 844 {
 845         int ret = 0;
 846
 847         if (intlist__empty(pf->lcache)) {
 848                 /* Matching lazy line pattern */
 849                 ret = find_lazy_match_lines(pf->lcache, pf->fname,
 850                                             pf->pev->point.lazy_line);
 851                 if (ret <= 0)
 852                         return ret;
 853         }
 854
 855         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 856 }
 857
 858 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 859 {
 860         struct probe_finder *pf = data;
 861         struct perf_probe_point *pp = &pf->pev->point;
 862         Dwarf_Addr addr;
 863         int ret;
 864
 865         if (pp->lazy_line)
 866                 ret = find_probe_point_lazy(in_die, pf);
 867         else {
 868                 /* Get probe address */
 869                 if (dwarf_entrypc(in_die, &addr) != 0) {
 870                         pr_warning("Failed to get entry address of %s.\n",
 871                                    dwarf_diename(in_die));
 872                         return -ENOENT;
 873                 }
 874                 pf->addr = addr;
 875                 pf->addr += pp->offset;
 876                 pr_debug("found inline addr: 0x%jx\n",
 877                          (uintmax_t)pf->addr);
 878
 879                 ret = call_probe_finder(in_die, pf);
 880         }
 881
 882         return ret;
 883 }
 884
 885 /* Callback parameter with return value for libdw */
 886 struct dwarf_callback_param {
 887         void *data;
 888         int retval;
 889 };
 890
 891 /* Search function from function name */
 892 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 893 {
 894         struct dwarf_callback_param *param = data;
 895         struct probe_finder *pf = param->data;
 896         struct perf_probe_point *pp = &pf->pev->point;
 897
 898         /* Check tag and diename */
 899         if (!die_is_func_def(sp_die) ||
 900             !die_compare_name(sp_die, pp->function))
 901                 return DWARF_CB_OK;
 902
 903         /* Check declared file */
 904         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 905                 return DWARF_CB_OK;
 906
 907         pf->fname = dwarf_decl_file(sp_die);
 908         if (pp->line) { /* Function relative line */
 909                 dwarf_decl_line(sp_die, &pf->lno);
 910                 pf->lno += pp->line;
 911                 param->retval = find_probe_point_by_line(pf);
 912         } else if (!dwarf_func_inline(sp_die)) {
 913                 /* Real function */
 914                 if (pp->lazy_line)
 915                         param->retval = find_probe_point_lazy(sp_die, pf);
 916                 else {
 917                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 918                                 pr_warning("Failed to get entry address of "
 919                                            "%s.\n", dwarf_diename(sp_die));
 920                                 param->retval = -ENOENT;
 921                                 return DWARF_CB_ABORT;
 922                         }
 923                         pf->addr += pp->offset;
 924                         /* TODO: Check the address in this function */
 925                         param->retval = call_probe_finder(sp_die, pf);
 926                 }
 927         } else
 928                 /* Inlined function: search instances */
 929                 param->retval = die_walk_instances(sp_die,
 930                                         probe_point_inline_cb, (void *)pf);
 931
 932         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 933 }
 934
 935 static int find_probe_point_by_func(struct probe_finder *pf)
 936 {
 937         struct dwarf_callback_param _param = {.data = (void *)pf,
 938                                               .retval = 0};
 939         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 940         return _param.retval;
 941 }
 942
 943 struct pubname_callback_param {
 944         char *function;
 945         char *file;
 946         Dwarf_Die *cu_die;
 947         Dwarf_Die *sp_die;
 948         int found;
 949 };
 950
 951 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
 952 {
 953         struct pubname_callback_param *param = data;
 954
 955         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
 956                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
 957                         return DWARF_CB_OK;
 958
 959                 if (die_compare_name(param->sp_die, param->function)) {
 960                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
 961                                 return DWARF_CB_OK;
 962
 963                         if (param->file &&
 964                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
 965                                 return DWARF_CB_OK;
 966
 967                         param->found = 1;
 968                         return DWARF_CB_ABORT;
 969                 }
 970         }
 971
 972         return DWARF_CB_OK;
 973 }
 974
 975 /* Find probe points from debuginfo */
 976 static int debuginfo__find_probes(struct debuginfo *dbg,
 977                                   struct probe_finder *pf)
 978 {
 979         struct perf_probe_point *pp = &pf->pev->point;
 980         Dwarf_Off off, noff;
 981         size_t cuhl;
 982         Dwarf_Die *diep;
 983         int ret = 0;
 984
 985 #if _ELFUTILS_PREREQ(0, 142)
 986         /* Get the call frame information from this dwarf */
 987         pf->cfi = dwarf_getcfi_elf(dwarf_getelf(dbg->dbg));
 988 #endif
 989
 990         off = 0;
 991         pf->lcache = intlist__new(NULL);
 992         if (!pf->lcache)
 993                 return -ENOMEM;
 994
 995         /* Fastpath: lookup by function name from .debug_pubnames section */
 996         if (pp->function) {
 997                 struct pubname_callback_param pubname_param = {
 998                         .function = pp->function,
 999                         .file     = pp->file,
1000                         .cu_die   = &pf->cu_die,
1001                         .sp_die   = &pf->sp_die,
1002                         .found    = 0,
1003                 };
1004                 struct dwarf_callback_param probe_param = {
1005                         .data = pf,
1006                 };
1007
1008                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1009                                   &pubname_param, 0);
1010                 if (pubname_param.found) {
1011                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1012                         if (ret)
1013                                 goto found;
1014                 }
1015         }
1016
1017         /* Loop on CUs (Compilation Unit) */
1018         while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1019                 /* Get the DIE(Debugging Information Entry) of this CU */
1020                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1021                 if (!diep)
1022                         continue;
1023
1024                 /* Check if target file is included. */
1025                 if (pp->file)
1026                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1027                 else
1028                         pf->fname = NULL;
1029
1030                 if (!pp->file || pf->fname) {
1031                         if (pp->function)
1032                                 ret = find_probe_point_by_func(pf);
1033                         else if (pp->lazy_line)
1034                                 ret = find_probe_point_lazy(NULL, pf);
1035                         else {
1036                                 pf->lno = pp->line;
1037                                 ret = find_probe_point_by_line(pf);
1038                         }
1039                         if (ret < 0)
1040                                 break;
1041                 }
1042                 off = noff;
1043         }
1044
1045 found:
1046         intlist__delete(pf->lcache);
1047         pf->lcache = NULL;
1048
1049         return ret;
1050 }
1051
1052 struct local_vars_finder {
1053         struct probe_finder *pf;
1054         struct perf_probe_arg *args;
1055         int max_args;
1056         int nargs;
1057         int ret;
1058 };
1059
1060 /* Collect available variables in this scope */
1061 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1062 {
1063         struct local_vars_finder *vf = data;
1064         struct probe_finder *pf = vf->pf;
1065         int tag;
1066
1067         tag = dwarf_tag(die_mem);
1068         if (tag == DW_TAG_formal_parameter ||
1069             tag == DW_TAG_variable) {
1070                 if (convert_variable_location(die_mem, vf->pf->addr,
1071                                               vf->pf->fb_ops, &pf->sp_die,
1072                                               NULL) == 0) {
1073                         vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1074                         if (vf->args[vf->nargs].var == NULL) {
1075                                 vf->ret = -ENOMEM;
1076                                 return DIE_FIND_CB_END;
1077                         }
1078                         pr_debug(" %s", vf->args[vf->nargs].var);
1079                         vf->nargs++;
1080                 }
1081         }
1082
1083         if (dwarf_haspc(die_mem, vf->pf->addr))
1084                 return DIE_FIND_CB_CONTINUE;
1085         else
1086                 return DIE_FIND_CB_SIBLING;
1087 }
1088
1089 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1090                              struct perf_probe_arg *args)
1091 {
1092         Dwarf_Die die_mem;
1093         int i;
1094         int n = 0;
1095         struct local_vars_finder vf = {.pf = pf, .args = args,
1096                                 .max_args = MAX_PROBE_ARGS, .ret = 0};
1097
1098         for (i = 0; i < pf->pev->nargs; i++) {
1099                 /* var never be NULL */
1100                 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1101                         pr_debug("Expanding $vars into:");
1102                         vf.nargs = n;
1103                         /* Special local variables */
1104                         die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1105                                        &die_mem);
1106                         pr_debug(" (%d)\n", vf.nargs - n);
1107                         if (vf.ret < 0)
1108                                 return vf.ret;
1109                         n = vf.nargs;
1110                 } else {
1111                         /* Copy normal argument */
1112                         args[n] = pf->pev->args[i];
1113                         n++;
1114                 }
1115         }
1116         return n;
1117 }
1118
1119 /* Add a found probe point into trace event list */
1120 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1121 {
1122         struct trace_event_finder *tf =
1123                         container_of(pf, struct trace_event_finder, pf);
1124         struct probe_trace_event *tev;
1125         struct perf_probe_arg *args;
1126         int ret, i;
1127
1128         /* Check number of tevs */
1129         if (tf->ntevs == tf->max_tevs) {
1130                 pr_warning("Too many( > %d) probe point found.\n",
1131                            tf->max_tevs);
1132                 return -ERANGE;
1133         }
1134         tev = &tf->tevs[tf->ntevs++];
1135
1136         /* Trace point should be converted from subprogram DIE */
1137         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1138                                      pf->pev->point.retprobe, &tev->point);
1139         if (ret < 0)
1140                 return ret;
1141
1142         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1143                  tev->point.offset);
1144
1145         /* Expand special probe argument if exist */
1146         args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1147         if (args == NULL)
1148                 return -ENOMEM;
1149
1150         ret = expand_probe_args(sc_die, pf, args);
1151         if (ret < 0)
1152                 goto end;
1153
1154         tev->nargs = ret;
1155         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1156         if (tev->args == NULL) {
1157                 ret = -ENOMEM;
1158                 goto end;
1159         }
1160
1161         /* Find each argument */
1162         for (i = 0; i < tev->nargs; i++) {
1163                 pf->pvar = &args[i];
1164                 pf->tvar = &tev->args[i];
1165                 /* Variable should be found from scope DIE */
1166                 ret = find_variable(sc_die, pf);
1167                 if (ret != 0)
1168                         break;
1169         }
1170
1171 end:
1172         free(args);
1173         return ret;
1174 }
1175
1176 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1177 int debuginfo__find_trace_events(struct debuginfo *dbg,
1178                                  struct perf_probe_event *pev,
1179                                  struct probe_trace_event **tevs, int max_tevs)
1180 {
1181         struct trace_event_finder tf = {
1182                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1183                         .mod = dbg->mod, .max_tevs = max_tevs};
1184         int ret;
1185
1186         /* Allocate result tevs array */
1187         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1188         if (*tevs == NULL)
1189                 return -ENOMEM;
1190
1191         tf.tevs = *tevs;
1192         tf.ntevs = 0;
1193
1194         ret = debuginfo__find_probes(dbg, &tf.pf);
1195         if (ret < 0) {
1196                 zfree(tevs);
1197                 return ret;
1198         }
1199
1200         return (ret < 0) ? ret : tf.ntevs;
1201 }
1202
1203 #define MAX_VAR_LEN 64
1204
1205 /* Collect available variables in this scope */
1206 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1207 {
1208         struct available_var_finder *af = data;
1209         struct variable_list *vl;
1210         char buf[MAX_VAR_LEN];
1211         int tag, ret;
1212
1213         vl = &af->vls[af->nvls - 1];
1214
1215         tag = dwarf_tag(die_mem);
1216         if (tag == DW_TAG_formal_parameter ||
1217             tag == DW_TAG_variable) {
1218                 ret = convert_variable_location(die_mem, af->pf.addr,
1219                                                 af->pf.fb_ops, &af->pf.sp_die,
1220                                                 NULL);
1221                 if (ret == 0) {
1222                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1223                         pr_debug2("Add new var: %s\n", buf);
1224                         if (ret > 0)
1225                                 strlist__add(vl->vars, buf);
1226                 }
1227         }
1228
1229         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1230                 return DIE_FIND_CB_CONTINUE;
1231         else
1232                 return DIE_FIND_CB_SIBLING;
1233 }
1234
1235 /* Add a found vars into available variables list */
1236 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1237 {
1238         struct available_var_finder *af =
1239                         container_of(pf, struct available_var_finder, pf);
1240         struct variable_list *vl;
1241         Dwarf_Die die_mem;
1242         int ret;
1243
1244         /* Check number of tevs */
1245         if (af->nvls == af->max_vls) {
1246                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1247                 return -ERANGE;
1248         }
1249         vl = &af->vls[af->nvls++];
1250
1251         /* Trace point should be converted from subprogram DIE */
1252         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1253                                      pf->pev->point.retprobe, &vl->point);
1254         if (ret < 0)
1255                 return ret;
1256
1257         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1258                  vl->point.offset);
1259
1260         /* Find local variables */
1261         vl->vars = strlist__new(true, NULL);
1262         if (vl->vars == NULL)
1263                 return -ENOMEM;
1264         af->child = true;
1265         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1266
1267         /* Find external variables */
1268         if (!af->externs)
1269                 goto out;
1270         /* Don't need to search child DIE for externs. */
1271         af->child = false;
1272         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1273
1274 out:
1275         if (strlist__empty(vl->vars)) {
1276                 strlist__delete(vl->vars);
1277                 vl->vars = NULL;
1278         }
1279
1280         return ret;
1281 }
1282
1283 /*
1284  * Find available variables at given probe point
1285  * Return the number of found probe points. Return 0 if there is no
1286  * matched probe point. Return <0 if an error occurs.
1287  */
1288 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1289                                       struct perf_probe_event *pev,
1290                                       struct variable_list **vls,
1291                                       int max_vls, bool externs)
1292 {
1293         struct available_var_finder af = {
1294                         .pf = {.pev = pev, .callback = add_available_vars},
1295                         .mod = dbg->mod,
1296                         .max_vls = max_vls, .externs = externs};
1297         int ret;
1298
1299         /* Allocate result vls array */
1300         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1301         if (*vls == NULL)
1302                 return -ENOMEM;
1303
1304         af.vls = *vls;
1305         af.nvls = 0;
1306
1307         ret = debuginfo__find_probes(dbg, &af.pf);
1308         if (ret < 0) {
1309                 /* Free vlist for error */
1310                 while (af.nvls--) {
1311                         zfree(&af.vls[af.nvls].point.symbol);
1312                         strlist__delete(af.vls[af.nvls].vars);
1313                 }
1314                 zfree(vls);
1315                 return ret;
1316         }
1317
1318         return (ret < 0) ? ret : af.nvls;
1319 }
1320
1321 /* Reverse search */
1322 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1323                                 struct perf_probe_point *ppt)
1324 {
1325         Dwarf_Die cudie, spdie, indie;
1326         Dwarf_Addr _addr = 0, baseaddr = 0;
1327         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1328         int baseline = 0, lineno = 0, ret = 0;
1329
1330         /* Adjust address with bias */
1331         addr += dbg->bias;
1332
1333         /* Find cu die */
1334         if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1335                 pr_warning("Failed to find debug information for address %lx\n",
1336                            addr);
1337                 ret = -EINVAL;
1338                 goto end;
1339         }
1340
1341         /* Find a corresponding line (filename and lineno) */
1342         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1343         /* Don't care whether it failed or not */
1344
1345         /* Find a corresponding function (name, baseline and baseaddr) */
1346         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1347                 /* Get function entry information */
1348                 func = basefunc = dwarf_diename(&spdie);
1349                 if (!func ||
1350                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1351                     dwarf_decl_line(&spdie, &baseline) != 0) {
1352                         lineno = 0;
1353                         goto post;
1354                 }
1355
1356                 fname = dwarf_decl_file(&spdie);
1357                 if (addr == (unsigned long)baseaddr) {
1358                         /* Function entry - Relative line number is 0 */
1359                         lineno = baseline;
1360                         goto post;
1361                 }
1362
1363                 /* Track down the inline functions step by step */
1364                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1365                                                 &indie)) {
1366                         /* There is an inline function */
1367                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1368                             _addr == addr) {
1369                                 /*
1370                                  * addr is at an inline function entry.
1371                                  * In this case, lineno should be the call-site
1372                                  * line number. (overwrite lineinfo)
1373                                  */
1374                                 lineno = die_get_call_lineno(&indie);
1375                                 fname = die_get_call_file(&indie);
1376                                 break;
1377                         } else {
1378                                 /*
1379                                  * addr is in an inline function body.
1380                                  * Since lineno points one of the lines
1381                                  * of the inline function, baseline should
1382                                  * be the entry line of the inline function.
1383                                  */
1384                                 tmp = dwarf_diename(&indie);
1385                                 if (!tmp ||
1386                                     dwarf_decl_line(&indie, &baseline) != 0)
1387                                         break;
1388                                 func = tmp;
1389                                 spdie = indie;
1390                         }
1391                 }
1392                 /* Verify the lineno and baseline are in a same file */
1393                 tmp = dwarf_decl_file(&spdie);
1394                 if (!tmp || strcmp(tmp, fname) != 0)
1395                         lineno = 0;
1396         }
1397
1398 post:
1399         /* Make a relative line number or an offset */
1400         if (lineno)
1401                 ppt->line = lineno - baseline;
1402         else if (basefunc) {
1403                 ppt->offset = addr - (unsigned long)baseaddr;
1404                 func = basefunc;
1405         }
1406
1407         /* Duplicate strings */
1408         if (func) {
1409                 ppt->function = strdup(func);
1410                 if (ppt->function == NULL) {
1411                         ret = -ENOMEM;
1412                         goto end;
1413                 }
1414         }
1415         if (fname) {
1416                 ppt->file = strdup(fname);
1417                 if (ppt->file == NULL) {
1418                         zfree(&ppt->function);
1419                         ret = -ENOMEM;
1420                         goto end;
1421                 }
1422         }
1423 end:
1424         if (ret == 0 && (fname || func))
1425                 ret = 1;        /* Found a point */
1426         return ret;
1427 }
1428
1429 /* Add a line and store the src path */
1430 static int line_range_add_line(const char *src, unsigned int lineno,
1431                                struct line_range *lr)
1432 {
1433         /* Copy source path */
1434         if (!lr->path) {
1435                 lr->path = strdup(src);
1436                 if (lr->path == NULL)
1437                         return -ENOMEM;
1438         }
1439         return intlist__add(lr->line_list, lineno);
1440 }
1441
1442 static int line_range_walk_cb(const char *fname, int lineno,
1443                               Dwarf_Addr addr __maybe_unused,
1444                               void *data)
1445 {
1446         struct line_finder *lf = data;
1447         int err;
1448
1449         if ((strtailcmp(fname, lf->fname) != 0) ||
1450             (lf->lno_s > lineno || lf->lno_e < lineno))
1451                 return 0;
1452
1453         err = line_range_add_line(fname, lineno, lf->lr);
1454         if (err < 0 && err != -EEXIST)
1455                 return err;
1456
1457         return 0;
1458 }
1459
1460 /* Find line range from its line number */
1461 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1462 {
1463         int ret;
1464
1465         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1466
1467         /* Update status */
1468         if (ret >= 0)
1469                 if (!intlist__empty(lf->lr->line_list))
1470                         ret = lf->found = 1;
1471                 else
1472                         ret = 0;        /* Lines are not found */
1473         else {
1474                 zfree(&lf->lr->path);
1475         }
1476         return ret;
1477 }
1478
1479 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1480 {
1481         int ret = find_line_range_by_line(in_die, data);
1482
1483         /*
1484          * We have to check all instances of inlined function, because
1485          * some execution paths can be optimized out depends on the
1486          * function argument of instances. However, if an error occurs,
1487          * it should be handled by the caller.
1488          */
1489         return ret < 0 ? ret : 0;
1490 }
1491
1492 /* Search function definition from function name */
1493 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1494 {
1495         struct dwarf_callback_param *param = data;
1496         struct line_finder *lf = param->data;
1497         struct line_range *lr = lf->lr;
1498
1499         /* Check declared file */
1500         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1501                 return DWARF_CB_OK;
1502
1503         if (die_is_func_def(sp_die) &&
1504             die_compare_name(sp_die, lr->function)) {
1505                 lf->fname = dwarf_decl_file(sp_die);
1506                 dwarf_decl_line(sp_die, &lr->offset);
1507                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1508                 lf->lno_s = lr->offset + lr->start;
1509                 if (lf->lno_s < 0)      /* Overflow */
1510                         lf->lno_s = INT_MAX;
1511                 lf->lno_e = lr->offset + lr->end;
1512                 if (lf->lno_e < 0)      /* Overflow */
1513                         lf->lno_e = INT_MAX;
1514                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1515                 lr->start = lf->lno_s;
1516                 lr->end = lf->lno_e;
1517                 if (dwarf_func_inline(sp_die))
1518                         param->retval = die_walk_instances(sp_die,
1519                                                 line_range_inline_cb, lf);
1520                 else
1521                         param->retval = find_line_range_by_line(sp_die, lf);
1522                 return DWARF_CB_ABORT;
1523         }
1524         return DWARF_CB_OK;
1525 }
1526
1527 static int find_line_range_by_func(struct line_finder *lf)
1528 {
1529         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1530         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1531         return param.retval;
1532 }
1533
1534 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1535 {
1536         struct line_finder lf = {.lr = lr, .found = 0};
1537         int ret = 0;
1538         Dwarf_Off off = 0, noff;
1539         size_t cuhl;
1540         Dwarf_Die *diep;
1541         const char *comp_dir;
1542
1543         /* Fastpath: lookup by function name from .debug_pubnames section */
1544         if (lr->function) {
1545                 struct pubname_callback_param pubname_param = {
1546                         .function = lr->function, .file = lr->file,
1547                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1548                 struct dwarf_callback_param line_range_param = {
1549                         .data = (void *)&lf, .retval = 0};
1550
1551                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1552                                   &pubname_param, 0);
1553                 if (pubname_param.found) {
1554                         line_range_search_cb(&lf.sp_die, &line_range_param);
1555                         if (lf.found)
1556                                 goto found;
1557                 }
1558         }
1559
1560         /* Loop on CUs (Compilation Unit) */
1561         while (!lf.found && ret >= 0) {
1562                 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1563                                  NULL, NULL, NULL) != 0)
1564                         break;
1565
1566                 /* Get the DIE(Debugging Information Entry) of this CU */
1567                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1568                 if (!diep)
1569                         continue;
1570
1571                 /* Check if target file is included. */
1572                 if (lr->file)
1573                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1574                 else
1575                         lf.fname = 0;
1576
1577                 if (!lr->file || lf.fname) {
1578                         if (lr->function)
1579                                 ret = find_line_range_by_func(&lf);
1580                         else {
1581                                 lf.lno_s = lr->start;
1582                                 lf.lno_e = lr->end;
1583                                 ret = find_line_range_by_line(NULL, &lf);
1584                         }
1585                 }
1586                 off = noff;
1587         }
1588
1589 found:
1590         /* Store comp_dir */
1591         if (lf.found) {
1592                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1593                 if (comp_dir) {
1594                         lr->comp_dir = strdup(comp_dir);
1595                         if (!lr->comp_dir)
1596                                 ret = -ENOMEM;
1597                 }
1598         }
1599
1600         pr_debug("path: %s\n", lr->path);
1601         return (ret < 0) ? ret : lf.found;
1602 }
1603