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                         ret = -ENOENT;
 577         }
 578         if (ret >= 0)
 579                 ret = convert_variable(&vr_die, pf);
 580
 581         if (ret < 0)
 582                 pr_warning("Failed to find '%s' in this function.\n",
 583                            pf->pvar->var);
 584         return ret;
 585 }
 586
 587 /* Convert subprogram DIE to trace point */
 588 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 589                                   Dwarf_Addr paddr, bool retprobe,
 590                                   struct probe_trace_point *tp)
 591 {
 592         Dwarf_Addr eaddr, highaddr;
 593         GElf_Sym sym;
 594         const char *symbol;
 595
 596         /* Verify the address is correct */
 597         if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 598                 pr_warning("Failed to get entry address of %s\n",
 599                            dwarf_diename(sp_die));
 600                 return -ENOENT;
 601         }
 602         if (dwarf_highpc(sp_die, &highaddr) != 0) {
 603                 pr_warning("Failed to get end address of %s\n",
 604                            dwarf_diename(sp_die));
 605                 return -ENOENT;
 606         }
 607         if (paddr > highaddr) {
 608                 pr_warning("Offset specified is greater than size of %s\n",
 609                            dwarf_diename(sp_die));
 610                 return -EINVAL;
 611         }
 612
 613         /* Get an appropriate symbol from symtab */
 614         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
 615         if (!symbol) {
 616                 pr_warning("Failed to find symbol at 0x%lx\n",
 617                            (unsigned long)paddr);
 618                 return -ENOENT;
 619         }
 620         tp->offset = (unsigned long)(paddr - sym.st_value);
 621         tp->address = (unsigned long)paddr;
 622         tp->symbol = strdup(symbol);
 623         if (!tp->symbol)
 624                 return -ENOMEM;
 625
 626         /* Return probe must be on the head of a subprogram */
 627         if (retprobe) {
 628                 if (eaddr != paddr) {
 629                         pr_warning("Return probe must be on the head of"
 630                                    " a real function.\n");
 631                         return -EINVAL;
 632                 }
 633                 tp->retprobe = true;
 634         }
 635
 636         return 0;
 637 }
 638
 639 /* Call probe_finder callback with scope DIE */
 640 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 641 {
 642         Dwarf_Attribute fb_attr;
 643         size_t nops;
 644         int ret;
 645
 646         if (!sc_die) {
 647                 pr_err("Caller must pass a scope DIE. Program error.\n");
 648                 return -EINVAL;
 649         }
 650
 651         /* If not a real subprogram, find a real one */
 652         if (!die_is_func_def(sc_die)) {
 653                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
 654                         pr_warning("Failed to find probe point in any "
 655                                    "functions.\n");
 656                         return -ENOENT;
 657                 }
 658         } else
 659                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 660
 661         /* Get the frame base attribute/ops from subprogram */
 662         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
 663         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 664         if (ret <= 0 || nops == 0) {
 665                 pf->fb_ops = NULL;
 666 #if _ELFUTILS_PREREQ(0, 142)
 667         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 668                    pf->cfi != NULL) {
 669                 Dwarf_Frame *frame;
 670                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 671                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 672                         pr_warning("Failed to get call frame on 0x%jx\n",
 673                                    (uintmax_t)pf->addr);
 674                         return -ENOENT;
 675                 }
 676 #endif
 677         }
 678
 679         /* Call finder's callback handler */
 680         ret = pf->callback(sc_die, pf);
 681
 682         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 683         pf->fb_ops = NULL;
 684
 685         return ret;
 686 }
 687
 688 struct find_scope_param {
 689         const char *function;
 690         const char *file;
 691         int line;
 692         int diff;
 693         Dwarf_Die *die_mem;
 694         bool found;
 695 };
 696
 697 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
 698 {
 699         struct find_scope_param *fsp = data;
 700         const char *file;
 701         int lno;
 702
 703         /* Skip if declared file name does not match */
 704         if (fsp->file) {
 705                 file = dwarf_decl_file(fn_die);
 706                 if (!file || strcmp(fsp->file, file) != 0)
 707                         return 0;
 708         }
 709         /* If the function name is given, that's what user expects */
 710         if (fsp->function) {
 711                 if (die_compare_name(fn_die, fsp->function)) {
 712                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 713                         fsp->found = true;
 714                         return 1;
 715                 }
 716         } else {
 717                 /* With the line number, find the nearest declared DIE */
 718                 dwarf_decl_line(fn_die, &lno);
 719                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
 720                         /* Keep a candidate and continue */
 721                         fsp->diff = fsp->line - lno;
 722                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 723                         fsp->found = true;
 724                 }
 725         }
 726         return 0;
 727 }
 728
 729 /* Find an appropriate scope fits to given conditions */
 730 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
 731 {
 732         struct find_scope_param fsp = {
 733                 .function = pf->pev->point.function,
 734                 .file = pf->fname,
 735                 .line = pf->lno,
 736                 .diff = INT_MAX,
 737                 .die_mem = die_mem,
 738                 .found = false,
 739         };
 740
 741         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
 742
 743         return fsp.found ? die_mem : NULL;
 744 }
 745
 746 static int probe_point_line_walker(const char *fname, int lineno,
 747                                    Dwarf_Addr addr, void *data)
 748 {
 749         struct probe_finder *pf = data;
 750         Dwarf_Die *sc_die, die_mem;
 751         int ret;
 752
 753         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 754                 return 0;
 755
 756         pf->addr = addr;
 757         sc_die = find_best_scope(pf, &die_mem);
 758         if (!sc_die) {
 759                 pr_warning("Failed to find scope of probe point.\n");
 760                 return -ENOENT;
 761         }
 762
 763         ret = call_probe_finder(sc_die, pf);
 764
 765         /* Continue if no error, because the line will be in inline function */
 766         return ret < 0 ? ret : 0;
 767 }
 768
 769 /* Find probe point from its line number */
 770 static int find_probe_point_by_line(struct probe_finder *pf)
 771 {
 772         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 773 }
 774
 775 /* Find lines which match lazy pattern */
 776 static int find_lazy_match_lines(struct intlist *list,
 777                                  const char *fname, const char *pat)
 778 {
 779         FILE *fp;
 780         char *line = NULL;
 781         size_t line_len;
 782         ssize_t len;
 783         int count = 0, linenum = 1;
 784
 785         fp = fopen(fname, "r");
 786         if (!fp) {
 787                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 788                 return -errno;
 789         }
 790
 791         while ((len = getline(&line, &line_len, fp)) > 0) {
 792
 793                 if (line[len - 1] == '\n')
 794                         line[len - 1] = '\0';
 795
 796                 if (strlazymatch(line, pat)) {
 797                         intlist__add(list, linenum);
 798                         count++;
 799                 }
 800                 linenum++;
 801         }
 802
 803         if (ferror(fp))
 804                 count = -errno;
 805         free(line);
 806         fclose(fp);
 807
 808         if (count == 0)
 809                 pr_debug("No matched lines found in %s.\n", fname);
 810         return count;
 811 }
 812
 813 static int probe_point_lazy_walker(const char *fname, int lineno,
 814                                    Dwarf_Addr addr, void *data)
 815 {
 816         struct probe_finder *pf = data;
 817         Dwarf_Die *sc_die, die_mem;
 818         int ret;
 819
 820         if (!intlist__has_entry(pf->lcache, lineno) ||
 821             strtailcmp(fname, pf->fname) != 0)
 822                 return 0;
 823
 824         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 825                  lineno, (unsigned long long)addr);
 826         pf->addr = addr;
 827         pf->lno = lineno;
 828         sc_die = find_best_scope(pf, &die_mem);
 829         if (!sc_die) {
 830                 pr_warning("Failed to find scope of probe point.\n");
 831                 return -ENOENT;
 832         }
 833
 834         ret = call_probe_finder(sc_die, pf);
 835
 836         /*
 837          * Continue if no error, because the lazy pattern will match
 838          * to other lines
 839          */
 840         return ret < 0 ? ret : 0;
 841 }
 842
 843 /* Find probe points from lazy pattern  */
 844 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 845 {
 846         int ret = 0;
 847
 848         if (intlist__empty(pf->lcache)) {
 849                 /* Matching lazy line pattern */
 850                 ret = find_lazy_match_lines(pf->lcache, pf->fname,
 851                                             pf->pev->point.lazy_line);
 852                 if (ret <= 0)
 853                         return ret;
 854         }
 855
 856         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 857 }
 858
 859 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 860 {
 861         struct probe_finder *pf = data;
 862         struct perf_probe_point *pp = &pf->pev->point;
 863         Dwarf_Addr addr;
 864         int ret;
 865
 866         if (pp->lazy_line)
 867                 ret = find_probe_point_lazy(in_die, pf);
 868         else {
 869                 /* Get probe address */
 870                 if (dwarf_entrypc(in_die, &addr) != 0) {
 871                         pr_warning("Failed to get entry address of %s.\n",
 872                                    dwarf_diename(in_die));
 873                         return -ENOENT;
 874                 }
 875                 pf->addr = addr;
 876                 pf->addr += pp->offset;
 877                 pr_debug("found inline addr: 0x%jx\n",
 878                          (uintmax_t)pf->addr);
 879
 880                 ret = call_probe_finder(in_die, pf);
 881         }
 882
 883         return ret;
 884 }
 885
 886 /* Callback parameter with return value for libdw */
 887 struct dwarf_callback_param {
 888         void *data;
 889         int retval;
 890 };
 891
 892 /* Search function from function name */
 893 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 894 {
 895         struct dwarf_callback_param *param = data;
 896         struct probe_finder *pf = param->data;
 897         struct perf_probe_point *pp = &pf->pev->point;
 898
 899         /* Check tag and diename */
 900         if (!die_is_func_def(sp_die) ||
 901             !die_compare_name(sp_die, pp->function))
 902                 return DWARF_CB_OK;
 903
 904         /* Check declared file */
 905         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 906                 return DWARF_CB_OK;
 907
 908         pf->fname = dwarf_decl_file(sp_die);
 909         if (pp->line) { /* Function relative line */
 910                 dwarf_decl_line(sp_die, &pf->lno);
 911                 pf->lno += pp->line;
 912                 param->retval = find_probe_point_by_line(pf);
 913         } else if (!dwarf_func_inline(sp_die)) {
 914                 /* Real function */
 915                 if (pp->lazy_line)
 916                         param->retval = find_probe_point_lazy(sp_die, pf);
 917                 else {
 918                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 919                                 pr_warning("Failed to get entry address of "
 920                                            "%s.\n", dwarf_diename(sp_die));
 921                                 param->retval = -ENOENT;
 922                                 return DWARF_CB_ABORT;
 923                         }
 924                         pf->addr += pp->offset;
 925                         /* TODO: Check the address in this function */
 926                         param->retval = call_probe_finder(sp_die, pf);
 927                 }
 928         } else
 929                 /* Inlined function: search instances */
 930                 param->retval = die_walk_instances(sp_die,
 931                                         probe_point_inline_cb, (void *)pf);
 932
 933         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 934 }
 935
 936 static int find_probe_point_by_func(struct probe_finder *pf)
 937 {
 938         struct dwarf_callback_param _param = {.data = (void *)pf,
 939                                               .retval = 0};
 940         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 941         return _param.retval;
 942 }
 943
 944 struct pubname_callback_param {
 945         char *function;
 946         char *file;
 947         Dwarf_Die *cu_die;
 948         Dwarf_Die *sp_die;
 949         int found;
 950 };
 951
 952 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
 953 {
 954         struct pubname_callback_param *param = data;
 955
 956         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
 957                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
 958                         return DWARF_CB_OK;
 959
 960                 if (die_compare_name(param->sp_die, param->function)) {
 961                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
 962                                 return DWARF_CB_OK;
 963
 964                         if (param->file &&
 965                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
 966                                 return DWARF_CB_OK;
 967
 968                         param->found = 1;
 969                         return DWARF_CB_ABORT;
 970                 }
 971         }
 972
 973         return DWARF_CB_OK;
 974 }
 975
 976 /* Find probe points from debuginfo */
 977 static int debuginfo__find_probes(struct debuginfo *dbg,
 978                                   struct probe_finder *pf)
 979 {
 980         struct perf_probe_point *pp = &pf->pev->point;
 981         Dwarf_Off off, noff;
 982         size_t cuhl;
 983         Dwarf_Die *diep;
 984         int ret = 0;
 985
 986 #if _ELFUTILS_PREREQ(0, 142)
 987         /* Get the call frame information from this dwarf */
 988         pf->cfi = dwarf_getcfi_elf(dwarf_getelf(dbg->dbg));
 989 #endif
 990
 991         off = 0;
 992         pf->lcache = intlist__new(NULL);
 993         if (!pf->lcache)
 994                 return -ENOMEM;
 995
 996         /* Fastpath: lookup by function name from .debug_pubnames section */
 997         if (pp->function) {
 998                 struct pubname_callback_param pubname_param = {
 999                         .function = pp->function,
1000                         .file     = pp->file,
1001                         .cu_die   = &pf->cu_die,
1002                         .sp_die   = &pf->sp_die,
1003                         .found    = 0,
1004                 };
1005                 struct dwarf_callback_param probe_param = {
1006                         .data = pf,
1007                 };
1008
1009                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1010                                   &pubname_param, 0);
1011                 if (pubname_param.found) {
1012                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1013                         if (ret)
1014                                 goto found;
1015                 }
1016         }
1017
1018         /* Loop on CUs (Compilation Unit) */
1019         while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1020                 /* Get the DIE(Debugging Information Entry) of this CU */
1021                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1022                 if (!diep)
1023                         continue;
1024
1025                 /* Check if target file is included. */
1026                 if (pp->file)
1027                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1028                 else
1029                         pf->fname = NULL;
1030
1031                 if (!pp->file || pf->fname) {
1032                         if (pp->function)
1033                                 ret = find_probe_point_by_func(pf);
1034                         else if (pp->lazy_line)
1035                                 ret = find_probe_point_lazy(NULL, pf);
1036                         else {
1037                                 pf->lno = pp->line;
1038                                 ret = find_probe_point_by_line(pf);
1039                         }
1040                         if (ret < 0)
1041                                 break;
1042                 }
1043                 off = noff;
1044         }
1045
1046 found:
1047         intlist__delete(pf->lcache);
1048         pf->lcache = NULL;
1049
1050         return ret;
1051 }
1052
1053 struct local_vars_finder {
1054         struct probe_finder *pf;
1055         struct perf_probe_arg *args;
1056         int max_args;
1057         int nargs;
1058         int ret;
1059 };
1060
1061 /* Collect available variables in this scope */
1062 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1063 {
1064         struct local_vars_finder *vf = data;
1065         struct probe_finder *pf = vf->pf;
1066         int tag;
1067
1068         tag = dwarf_tag(die_mem);
1069         if (tag == DW_TAG_formal_parameter ||
1070             tag == DW_TAG_variable) {
1071                 if (convert_variable_location(die_mem, vf->pf->addr,
1072                                               vf->pf->fb_ops, &pf->sp_die,
1073                                               NULL) == 0) {
1074                         vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1075                         if (vf->args[vf->nargs].var == NULL) {
1076                                 vf->ret = -ENOMEM;
1077                                 return DIE_FIND_CB_END;
1078                         }
1079                         pr_debug(" %s", vf->args[vf->nargs].var);
1080                         vf->nargs++;
1081                 }
1082         }
1083
1084         if (dwarf_haspc(die_mem, vf->pf->addr))
1085                 return DIE_FIND_CB_CONTINUE;
1086         else
1087                 return DIE_FIND_CB_SIBLING;
1088 }
1089
1090 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1091                              struct perf_probe_arg *args)
1092 {
1093         Dwarf_Die die_mem;
1094         int i;
1095         int n = 0;
1096         struct local_vars_finder vf = {.pf = pf, .args = args,
1097                                 .max_args = MAX_PROBE_ARGS, .ret = 0};
1098
1099         for (i = 0; i < pf->pev->nargs; i++) {
1100                 /* var never be NULL */
1101                 if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
1102                         pr_debug("Expanding $vars into:");
1103                         vf.nargs = n;
1104                         /* Special local variables */
1105                         die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1106                                        &die_mem);
1107                         pr_debug(" (%d)\n", vf.nargs - n);
1108                         if (vf.ret < 0)
1109                                 return vf.ret;
1110                         n = vf.nargs;
1111                 } else {
1112                         /* Copy normal argument */
1113                         args[n] = pf->pev->args[i];
1114                         n++;
1115                 }
1116         }
1117         return n;
1118 }
1119
1120 /* Add a found probe point into trace event list */
1121 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1122 {
1123         struct trace_event_finder *tf =
1124                         container_of(pf, struct trace_event_finder, pf);
1125         struct probe_trace_event *tev;
1126         struct perf_probe_arg *args;
1127         int ret, i;
1128
1129         /* Check number of tevs */
1130         if (tf->ntevs == tf->max_tevs) {
1131                 pr_warning("Too many( > %d) probe point found.\n",
1132                            tf->max_tevs);
1133                 return -ERANGE;
1134         }
1135         tev = &tf->tevs[tf->ntevs++];
1136
1137         /* Trace point should be converted from subprogram DIE */
1138         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1139                                      pf->pev->point.retprobe, &tev->point);
1140         if (ret < 0)
1141                 return ret;
1142
1143         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1144                  tev->point.offset);
1145
1146         /* Expand special probe argument if exist */
1147         args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1148         if (args == NULL)
1149                 return -ENOMEM;
1150
1151         ret = expand_probe_args(sc_die, pf, args);
1152         if (ret < 0)
1153                 goto end;
1154
1155         tev->nargs = ret;
1156         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1157         if (tev->args == NULL) {
1158                 ret = -ENOMEM;
1159                 goto end;
1160         }
1161
1162         /* Find each argument */
1163         for (i = 0; i < tev->nargs; i++) {
1164                 pf->pvar = &args[i];
1165                 pf->tvar = &tev->args[i];
1166                 /* Variable should be found from scope DIE */
1167                 ret = find_variable(sc_die, pf);
1168                 if (ret != 0)
1169                         break;
1170         }
1171
1172 end:
1173         free(args);
1174         return ret;
1175 }
1176
1177 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1178 int debuginfo__find_trace_events(struct debuginfo *dbg,
1179                                  struct perf_probe_event *pev,
1180                                  struct probe_trace_event **tevs, int max_tevs)
1181 {
1182         struct trace_event_finder tf = {
1183                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1184                         .mod = dbg->mod, .max_tevs = max_tevs};
1185         int ret;
1186
1187         /* Allocate result tevs array */
1188         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1189         if (*tevs == NULL)
1190                 return -ENOMEM;
1191
1192         tf.tevs = *tevs;
1193         tf.ntevs = 0;
1194
1195         ret = debuginfo__find_probes(dbg, &tf.pf);
1196         if (ret < 0) {
1197                 zfree(tevs);
1198                 return ret;
1199         }
1200
1201         return (ret < 0) ? ret : tf.ntevs;
1202 }
1203
1204 #define MAX_VAR_LEN 64
1205
1206 /* Collect available variables in this scope */
1207 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1208 {
1209         struct available_var_finder *af = data;
1210         struct variable_list *vl;
1211         char buf[MAX_VAR_LEN];
1212         int tag, ret;
1213
1214         vl = &af->vls[af->nvls - 1];
1215
1216         tag = dwarf_tag(die_mem);
1217         if (tag == DW_TAG_formal_parameter ||
1218             tag == DW_TAG_variable) {
1219                 ret = convert_variable_location(die_mem, af->pf.addr,
1220                                                 af->pf.fb_ops, &af->pf.sp_die,
1221                                                 NULL);
1222                 if (ret == 0) {
1223                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1224                         pr_debug2("Add new var: %s\n", buf);
1225                         if (ret > 0)
1226                                 strlist__add(vl->vars, buf);
1227                 }
1228         }
1229
1230         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1231                 return DIE_FIND_CB_CONTINUE;
1232         else
1233                 return DIE_FIND_CB_SIBLING;
1234 }
1235
1236 /* Add a found vars into available variables list */
1237 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1238 {
1239         struct available_var_finder *af =
1240                         container_of(pf, struct available_var_finder, pf);
1241         struct variable_list *vl;
1242         Dwarf_Die die_mem;
1243         int ret;
1244
1245         /* Check number of tevs */
1246         if (af->nvls == af->max_vls) {
1247                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1248                 return -ERANGE;
1249         }
1250         vl = &af->vls[af->nvls++];
1251
1252         /* Trace point should be converted from subprogram DIE */
1253         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1254                                      pf->pev->point.retprobe, &vl->point);
1255         if (ret < 0)
1256                 return ret;
1257
1258         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1259                  vl->point.offset);
1260
1261         /* Find local variables */
1262         vl->vars = strlist__new(true, NULL);
1263         if (vl->vars == NULL)
1264                 return -ENOMEM;
1265         af->child = true;
1266         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1267
1268         /* Find external variables */
1269         if (!af->externs)
1270                 goto out;
1271         /* Don't need to search child DIE for externs. */
1272         af->child = false;
1273         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1274
1275 out:
1276         if (strlist__empty(vl->vars)) {
1277                 strlist__delete(vl->vars);
1278                 vl->vars = NULL;
1279         }
1280
1281         return ret;
1282 }
1283
1284 /* Find available variables at given probe point */
1285 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1286                                       struct perf_probe_event *pev,
1287                                       struct variable_list **vls,
1288                                       int max_vls, bool externs)
1289 {
1290         struct available_var_finder af = {
1291                         .pf = {.pev = pev, .callback = add_available_vars},
1292                         .mod = dbg->mod,
1293                         .max_vls = max_vls, .externs = externs};
1294         int ret;
1295
1296         /* Allocate result vls array */
1297         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1298         if (*vls == NULL)
1299                 return -ENOMEM;
1300
1301         af.vls = *vls;
1302         af.nvls = 0;
1303
1304         ret = debuginfo__find_probes(dbg, &af.pf);
1305         if (ret < 0) {
1306                 /* Free vlist for error */
1307                 while (af.nvls--) {
1308                         zfree(&af.vls[af.nvls].point.symbol);
1309                         strlist__delete(af.vls[af.nvls].vars);
1310                 }
1311                 zfree(vls);
1312                 return ret;
1313         }
1314
1315         return (ret < 0) ? ret : af.nvls;
1316 }
1317
1318 /* Reverse search */
1319 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1320                                 struct perf_probe_point *ppt)
1321 {
1322         Dwarf_Die cudie, spdie, indie;
1323         Dwarf_Addr _addr = 0, baseaddr = 0;
1324         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1325         int baseline = 0, lineno = 0, ret = 0;
1326
1327         /* Adjust address with bias */
1328         addr += dbg->bias;
1329
1330         /* Find cu die */
1331         if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
1332                 pr_warning("Failed to find debug information for address %lx\n",
1333                            addr);
1334                 ret = -EINVAL;
1335                 goto end;
1336         }
1337
1338         /* Find a corresponding line (filename and lineno) */
1339         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1340         /* Don't care whether it failed or not */
1341
1342         /* Find a corresponding function (name, baseline and baseaddr) */
1343         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1344                 /* Get function entry information */
1345                 func = basefunc = dwarf_diename(&spdie);
1346                 if (!func ||
1347                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1348                     dwarf_decl_line(&spdie, &baseline) != 0) {
1349                         lineno = 0;
1350                         goto post;
1351                 }
1352
1353                 fname = dwarf_decl_file(&spdie);
1354                 if (addr == (unsigned long)baseaddr) {
1355                         /* Function entry - Relative line number is 0 */
1356                         lineno = baseline;
1357                         goto post;
1358                 }
1359
1360                 /* Track down the inline functions step by step */
1361                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1362                                                 &indie)) {
1363                         /* There is an inline function */
1364                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1365                             _addr == addr) {
1366                                 /*
1367                                  * addr is at an inline function entry.
1368                                  * In this case, lineno should be the call-site
1369                                  * line number. (overwrite lineinfo)
1370                                  */
1371                                 lineno = die_get_call_lineno(&indie);
1372                                 fname = die_get_call_file(&indie);
1373                                 break;
1374                         } else {
1375                                 /*
1376                                  * addr is in an inline function body.
1377                                  * Since lineno points one of the lines
1378                                  * of the inline function, baseline should
1379                                  * be the entry line of the inline function.
1380                                  */
1381                                 tmp = dwarf_diename(&indie);
1382                                 if (!tmp ||
1383                                     dwarf_decl_line(&indie, &baseline) != 0)
1384                                         break;
1385                                 func = tmp;
1386                                 spdie = indie;
1387                         }
1388                 }
1389                 /* Verify the lineno and baseline are in a same file */
1390                 tmp = dwarf_decl_file(&spdie);
1391                 if (!tmp || strcmp(tmp, fname) != 0)
1392                         lineno = 0;
1393         }
1394
1395 post:
1396         /* Make a relative line number or an offset */
1397         if (lineno)
1398                 ppt->line = lineno - baseline;
1399         else if (basefunc) {
1400                 ppt->offset = addr - (unsigned long)baseaddr;
1401                 func = basefunc;
1402         }
1403
1404         /* Duplicate strings */
1405         if (func) {
1406                 ppt->function = strdup(func);
1407                 if (ppt->function == NULL) {
1408                         ret = -ENOMEM;
1409                         goto end;
1410                 }
1411         }
1412         if (fname) {
1413                 ppt->file = strdup(fname);
1414                 if (ppt->file == NULL) {
1415                         zfree(&ppt->function);
1416                         ret = -ENOMEM;
1417                         goto end;
1418                 }
1419         }
1420 end:
1421         if (ret == 0 && (fname || func))
1422                 ret = 1;        /* Found a point */
1423         return ret;
1424 }
1425
1426 /* Add a line and store the src path */
1427 static int line_range_add_line(const char *src, unsigned int lineno,
1428                                struct line_range *lr)
1429 {
1430         /* Copy source path */
1431         if (!lr->path) {
1432                 lr->path = strdup(src);
1433                 if (lr->path == NULL)
1434                         return -ENOMEM;
1435         }
1436         return intlist__add(lr->line_list, lineno);
1437 }
1438
1439 static int line_range_walk_cb(const char *fname, int lineno,
1440                               Dwarf_Addr addr __maybe_unused,
1441                               void *data)
1442 {
1443         struct line_finder *lf = data;
1444         int err;
1445
1446         if ((strtailcmp(fname, lf->fname) != 0) ||
1447             (lf->lno_s > lineno || lf->lno_e < lineno))
1448                 return 0;
1449
1450         err = line_range_add_line(fname, lineno, lf->lr);
1451         if (err < 0 && err != -EEXIST)
1452                 return err;
1453
1454         return 0;
1455 }
1456
1457 /* Find line range from its line number */
1458 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1459 {
1460         int ret;
1461
1462         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1463
1464         /* Update status */
1465         if (ret >= 0)
1466                 if (!intlist__empty(lf->lr->line_list))
1467                         ret = lf->found = 1;
1468                 else
1469                         ret = 0;        /* Lines are not found */
1470         else {
1471                 zfree(&lf->lr->path);
1472         }
1473         return ret;
1474 }
1475
1476 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1477 {
1478         int ret = find_line_range_by_line(in_die, data);
1479
1480         /*
1481          * We have to check all instances of inlined function, because
1482          * some execution paths can be optimized out depends on the
1483          * function argument of instances. However, if an error occurs,
1484          * it should be handled by the caller.
1485          */
1486         return ret < 0 ? ret : 0;
1487 }
1488
1489 /* Search function definition from function name */
1490 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1491 {
1492         struct dwarf_callback_param *param = data;
1493         struct line_finder *lf = param->data;
1494         struct line_range *lr = lf->lr;
1495
1496         /* Check declared file */
1497         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1498                 return DWARF_CB_OK;
1499
1500         if (die_is_func_def(sp_die) &&
1501             die_compare_name(sp_die, lr->function)) {
1502                 lf->fname = dwarf_decl_file(sp_die);
1503                 dwarf_decl_line(sp_die, &lr->offset);
1504                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1505                 lf->lno_s = lr->offset + lr->start;
1506                 if (lf->lno_s < 0)      /* Overflow */
1507                         lf->lno_s = INT_MAX;
1508                 lf->lno_e = lr->offset + lr->end;
1509                 if (lf->lno_e < 0)      /* Overflow */
1510                         lf->lno_e = INT_MAX;
1511                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1512                 lr->start = lf->lno_s;
1513                 lr->end = lf->lno_e;
1514                 if (dwarf_func_inline(sp_die))
1515                         param->retval = die_walk_instances(sp_die,
1516                                                 line_range_inline_cb, lf);
1517                 else
1518                         param->retval = find_line_range_by_line(sp_die, lf);
1519                 return DWARF_CB_ABORT;
1520         }
1521         return DWARF_CB_OK;
1522 }
1523
1524 static int find_line_range_by_func(struct line_finder *lf)
1525 {
1526         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1527         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1528         return param.retval;
1529 }
1530
1531 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1532 {
1533         struct line_finder lf = {.lr = lr, .found = 0};
1534         int ret = 0;
1535         Dwarf_Off off = 0, noff;
1536         size_t cuhl;
1537         Dwarf_Die *diep;
1538         const char *comp_dir;
1539
1540         /* Fastpath: lookup by function name from .debug_pubnames section */
1541         if (lr->function) {
1542                 struct pubname_callback_param pubname_param = {
1543                         .function = lr->function, .file = lr->file,
1544                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1545                 struct dwarf_callback_param line_range_param = {
1546                         .data = (void *)&lf, .retval = 0};
1547
1548                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1549                                   &pubname_param, 0);
1550                 if (pubname_param.found) {
1551                         line_range_search_cb(&lf.sp_die, &line_range_param);
1552                         if (lf.found)
1553                                 goto found;
1554                 }
1555         }
1556
1557         /* Loop on CUs (Compilation Unit) */
1558         while (!lf.found && ret >= 0) {
1559                 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1560                                  NULL, NULL, NULL) != 0)
1561                         break;
1562
1563                 /* Get the DIE(Debugging Information Entry) of this CU */
1564                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1565                 if (!diep)
1566                         continue;
1567
1568                 /* Check if target file is included. */
1569                 if (lr->file)
1570                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1571                 else
1572                         lf.fname = 0;
1573
1574                 if (!lr->file || lf.fname) {
1575                         if (lr->function)
1576                                 ret = find_line_range_by_func(&lf);
1577                         else {
1578                                 lf.lno_s = lr->start;
1579                                 lf.lno_e = lr->end;
1580                                 ret = find_line_range_by_line(NULL, &lf);
1581                         }
1582                 }
1583                 off = noff;
1584         }
1585
1586 found:
1587         /* Store comp_dir */
1588         if (lf.found) {
1589                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1590                 if (comp_dir) {
1591                         lr->comp_dir = strdup(comp_dir);
1592                         if (!lr->comp_dir)
1593                                 ret = -ENOMEM;
1594                 }
1595         }
1596
1597         pr_debug("path: %s\n", lr->path);
1598         return (ret < 0) ? ret : lf.found;
1599 }
1600