tools/perf/util/probe-finder.c

   1 /*
   2  * probe-finder.c : C expression to kprobe event converter
   3  *
   4  * Written by Masami Hiramatsu <mhiramat@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  */
  21
  22 #include <sys/utsname.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include <unistd.h>
  29 #include <getopt.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdarg.h>
  33 #include <dwarf-regs.h>
  34
  35 #include <linux/bitops.h>
  36 #include "event.h"
  37 #include "debug.h"
  38 #include "util.h"
  39 #include "symbol.h"
  40 #include "probe-finder.h"
  41
  42 /* Kprobe tracer basic type is up to u64 */
  43 #define MAX_BASIC_TYPE_BITS     64
  44
  45 /* Line number list operations */
  46
  47 /* Add a line to line number list */
  48 static int line_list__add_line(struct list_head *head, int line)
  49 {
  50         struct line_node *ln;
  51         struct list_head *p;
  52
  53         /* Reverse search, because new line will be the last one */
  54         list_for_each_entry_reverse(ln, head, list) {
  55                 if (ln->line < line) {
  56                         p = &ln->list;
  57                         goto found;
  58                 } else if (ln->line == line)    /* Already exist */
  59                         return 1;
  60         }
  61         /* List is empty, or the smallest entry */
  62         p = head;
  63 found:
  64         pr_debug("line list: add a line %u\n", line);
  65         ln = zalloc(sizeof(struct line_node));
  66         if (ln == NULL)
  67                 return -ENOMEM;
  68         ln->line = line;
  69         INIT_LIST_HEAD(&ln->list);
  70         list_add(&ln->list, p);
  71         return 0;
  72 }
  73
  74 /* Check if the line in line number list */
  75 static int line_list__has_line(struct list_head *head, int line)
  76 {
  77         struct line_node *ln;
  78
  79         /* Reverse search, because new line will be the last one */
  80         list_for_each_entry(ln, head, list)
  81                 if (ln->line == line)
  82                         return 1;
  83
  84         return 0;
  85 }
  86
  87 /* Init line number list */
  88 static void line_list__init(struct list_head *head)
  89 {
  90         INIT_LIST_HEAD(head);
  91 }
  92
  93 /* Free line number list */
  94 static void line_list__free(struct list_head *head)
  95 {
  96         struct line_node *ln;
  97         while (!list_empty(head)) {
  98                 ln = list_first_entry(head, struct line_node, list);
  99                 list_del(&ln->list);
 100                 free(ln);
 101         }
 102 }
 103
 104 /* Dwarf FL wrappers */
 105 static char *debuginfo_path;    /* Currently dummy */
 106
 107 static const Dwfl_Callbacks offline_callbacks = {
 108         .find_debuginfo = dwfl_standard_find_debuginfo,
 109         .debuginfo_path = &debuginfo_path,
 110
 111         .section_address = dwfl_offline_section_address,
 112
 113         /* We use this table for core files too.  */
 114         .find_elf = dwfl_build_id_find_elf,
 115 };
 116
 117 /* Get a Dwarf from offline image */
 118 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
 119                                          const char *path)
 120 {
 121         int fd;
 122
 123         fd = open(path, O_RDONLY);
 124         if (fd < 0)
 125                 return fd;
 126
 127         self->dwfl = dwfl_begin(&offline_callbacks);
 128         if (!self->dwfl)
 129                 goto error;
 130
 131         self->mod = dwfl_report_offline(self->dwfl, "", "", fd);
 132         if (!self->mod)
 133                 goto error;
 134
 135         self->dbg = dwfl_module_getdwarf(self->mod, &self->bias);
 136         if (!self->dbg)
 137                 goto error;
 138
 139         return 0;
 140 error:
 141         if (self->dwfl)
 142                 dwfl_end(self->dwfl);
 143         else
 144                 close(fd);
 145         memset(self, 0, sizeof(*self));
 146
 147         return -ENOENT;
 148 }
 149
 150 #if _ELFUTILS_PREREQ(0, 148)
 151 /* This method is buggy if elfutils is older than 0.148 */
 152 static int __linux_kernel_find_elf(Dwfl_Module *mod,
 153                                    void **userdata,
 154                                    const char *module_name,
 155                                    Dwarf_Addr base,
 156                                    char **file_name, Elf **elfp)
 157 {
 158         int fd;
 159         const char *path = kernel_get_module_path(module_name);
 160
 161         pr_debug2("Use file %s for %s\n", path, module_name);
 162         if (path) {
 163                 fd = open(path, O_RDONLY);
 164                 if (fd >= 0) {
 165                         *file_name = strdup(path);
 166                         return fd;
 167                 }
 168         }
 169         /* If failed, try to call standard method */
 170         return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
 171                                           file_name, elfp);
 172 }
 173
 174 static const Dwfl_Callbacks kernel_callbacks = {
 175         .find_debuginfo = dwfl_standard_find_debuginfo,
 176         .debuginfo_path = &debuginfo_path,
 177
 178         .find_elf = __linux_kernel_find_elf,
 179         .section_address = dwfl_linux_kernel_module_section_address,
 180 };
 181
 182 /* Get a Dwarf from live kernel image */
 183 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
 184                                                Dwarf_Addr addr)
 185 {
 186         self->dwfl = dwfl_begin(&kernel_callbacks);
 187         if (!self->dwfl)
 188                 return -EINVAL;
 189
 190         /* Load the kernel dwarves: Don't care the result here */
 191         dwfl_linux_kernel_report_kernel(self->dwfl);
 192         dwfl_linux_kernel_report_modules(self->dwfl);
 193
 194         self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
 195         /* Here, check whether we could get a real dwarf */
 196         if (!self->dbg) {
 197                 pr_debug("Failed to find kernel dwarf at %lx\n",
 198                          (unsigned long)addr);
 199                 dwfl_end(self->dwfl);
 200                 memset(self, 0, sizeof(*self));
 201                 return -ENOENT;
 202         }
 203
 204         return 0;
 205 }
 206 #else
 207 /* With older elfutils, this just support kernel module... */
 208 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
 209                                                Dwarf_Addr addr __maybe_unused)
 210 {
 211         const char *path = kernel_get_module_path("kernel");
 212
 213         if (!path) {
 214                 pr_err("Failed to find vmlinux path\n");
 215                 return -ENOENT;
 216         }
 217
 218         pr_debug2("Use file %s for debuginfo\n", path);
 219         return debuginfo__init_offline_dwarf(self, path);
 220 }
 221 #endif
 222
 223 struct debuginfo *debuginfo__new(const char *path)
 224 {
 225         struct debuginfo *self = zalloc(sizeof(struct debuginfo));
 226         if (!self)
 227                 return NULL;
 228
 229         if (debuginfo__init_offline_dwarf(self, path) < 0) {
 230                 free(self);
 231                 self = NULL;
 232         }
 233
 234         return self;
 235 }
 236
 237 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
 238 {
 239         struct debuginfo *self = zalloc(sizeof(struct debuginfo));
 240         if (!self)
 241                 return NULL;
 242
 243         if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
 244                 free(self);
 245                 self = NULL;
 246         }
 247
 248         return self;
 249 }
 250
 251 void debuginfo__delete(struct debuginfo *self)
 252 {
 253         if (self) {
 254                 if (self->dwfl)
 255                         dwfl_end(self->dwfl);
 256                 free(self);
 257         }
 258 }
 259
 260 /*
 261  * Probe finder related functions
 262  */
 263
 264 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 265 {
 266         struct probe_trace_arg_ref *ref;
 267         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 268         if (ref != NULL)
 269                 ref->offset = offs;
 270         return ref;
 271 }
 272
 273 /*
 274  * Convert a location into trace_arg.
 275  * If tvar == NULL, this just checks variable can be converted.
 276  */
 277 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 278                                      Dwarf_Op *fb_ops,
 279                                      struct probe_trace_arg *tvar)
 280 {
 281         Dwarf_Attribute attr;
 282         Dwarf_Op *op;
 283         size_t nops;
 284         unsigned int regn;
 285         Dwarf_Word offs = 0;
 286         bool ref = false;
 287         const char *regs;
 288         int ret;
 289
 290         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 291                 goto static_var;
 292
 293         /* TODO: handle more than 1 exprs */
 294         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
 295             dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
 296             nops == 0) {
 297                 /* TODO: Support const_value */
 298                 return -ENOENT;
 299         }
 300
 301         if (op->atom == DW_OP_addr) {
 302 static_var:
 303                 if (!tvar)
 304                         return 0;
 305                 /* Static variables on memory (not stack), make @varname */
 306                 ret = strlen(dwarf_diename(vr_die));
 307                 tvar->value = zalloc(ret + 2);
 308                 if (tvar->value == NULL)
 309                         return -ENOMEM;
 310                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 311                 tvar->ref = alloc_trace_arg_ref((long)offs);
 312                 if (tvar->ref == NULL)
 313                         return -ENOMEM;
 314                 return 0;
 315         }
 316
 317         /* If this is based on frame buffer, set the offset */
 318         if (op->atom == DW_OP_fbreg) {
 319                 if (fb_ops == NULL)
 320                         return -ENOTSUP;
 321                 ref = true;
 322                 offs = op->number;
 323                 op = &fb_ops[0];
 324         }
 325
 326         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 327                 regn = op->atom - DW_OP_breg0;
 328                 offs += op->number;
 329                 ref = true;
 330         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 331                 regn = op->atom - DW_OP_reg0;
 332         } else if (op->atom == DW_OP_bregx) {
 333                 regn = op->number;
 334                 offs += op->number2;
 335                 ref = true;
 336         } else if (op->atom == DW_OP_regx) {
 337                 regn = op->number;
 338         } else {
 339                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 340                 return -ENOTSUP;
 341         }
 342
 343         if (!tvar)
 344                 return 0;
 345
 346         regs = get_arch_regstr(regn);
 347         if (!regs) {
 348                 /* This should be a bug in DWARF or this tool */
 349                 pr_warning("Mapping for the register number %u "
 350                            "missing on this architecture.\n", regn);
 351                 return -ERANGE;
 352         }
 353
 354         tvar->value = strdup(regs);
 355         if (tvar->value == NULL)
 356                 return -ENOMEM;
 357
 358         if (ref) {
 359                 tvar->ref = alloc_trace_arg_ref((long)offs);
 360                 if (tvar->ref == NULL)
 361                         return -ENOMEM;
 362         }
 363         return 0;
 364 }
 365
 366 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
 367
 368 static int convert_variable_type(Dwarf_Die *vr_die,
 369                                  struct probe_trace_arg *tvar,
 370                                  const char *cast)
 371 {
 372         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 373         Dwarf_Die type;
 374         char buf[16];
 375         int bsize, boffs, total;
 376         int ret;
 377
 378         /* TODO: check all types */
 379         if (cast && strcmp(cast, "string") != 0) {
 380                 /* Non string type is OK */
 381                 tvar->type = strdup(cast);
 382                 return (tvar->type == NULL) ? -ENOMEM : 0;
 383         }
 384
 385         bsize = dwarf_bitsize(vr_die);
 386         if (bsize > 0) {
 387                 /* This is a bitfield */
 388                 boffs = dwarf_bitoffset(vr_die);
 389                 total = dwarf_bytesize(vr_die);
 390                 if (boffs < 0 || total < 0)
 391                         return -ENOENT;
 392                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
 393                                 BYTES_TO_BITS(total));
 394                 goto formatted;
 395         }
 396
 397         if (die_get_real_type(vr_die, &type) == NULL) {
 398                 pr_warning("Failed to get a type information of %s.\n",
 399                            dwarf_diename(vr_die));
 400                 return -ENOENT;
 401         }
 402
 403         pr_debug("%s type is %s.\n",
 404                  dwarf_diename(vr_die), dwarf_diename(&type));
 405
 406         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 407                 ret = dwarf_tag(&type);
 408                 if (ret != DW_TAG_pointer_type &&
 409                     ret != DW_TAG_array_type) {
 410                         pr_warning("Failed to cast into string: "
 411                                    "%s(%s) is not a pointer nor array.\n",
 412                                    dwarf_diename(vr_die), dwarf_diename(&type));
 413                         return -EINVAL;
 414                 }
 415                 if (die_get_real_type(&type, &type) == NULL) {
 416                         pr_warning("Failed to get a type"
 417                                    " information.\n");
 418                         return -ENOENT;
 419                 }
 420                 if (ret == DW_TAG_pointer_type) {
 421                         while (*ref_ptr)
 422                                 ref_ptr = &(*ref_ptr)->next;
 423                         /* Add new reference with offset +0 */
 424                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 425                         if (*ref_ptr == NULL) {
 426                                 pr_warning("Out of memory error\n");
 427                                 return -ENOMEM;
 428                         }
 429                 }
 430                 if (!die_compare_name(&type, "char") &&
 431                     !die_compare_name(&type, "unsigned char")) {
 432                         pr_warning("Failed to cast into string: "
 433                                    "%s is not (unsigned) char *.\n",
 434                                    dwarf_diename(vr_die));
 435                         return -EINVAL;
 436                 }
 437                 tvar->type = strdup(cast);
 438                 return (tvar->type == NULL) ? -ENOMEM : 0;
 439         }
 440
 441         ret = dwarf_bytesize(&type);
 442         if (ret <= 0)
 443                 /* No size ... try to use default type */
 444                 return 0;
 445         ret = BYTES_TO_BITS(ret);
 446
 447         /* Check the bitwidth */
 448         if (ret > MAX_BASIC_TYPE_BITS) {
 449                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
 450                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 451                 ret = MAX_BASIC_TYPE_BITS;
 452         }
 453         ret = snprintf(buf, 16, "%c%d",
 454                        die_is_signed_type(&type) ? 's' : 'u', ret);
 455
 456 formatted:
 457         if (ret < 0 || ret >= 16) {
 458                 if (ret >= 16)
 459                         ret = -E2BIG;
 460                 pr_warning("Failed to convert variable type: %s\n",
 461                            strerror(-ret));
 462                 return ret;
 463         }
 464         tvar->type = strdup(buf);
 465         if (tvar->type == NULL)
 466                 return -ENOMEM;
 467         return 0;
 468 }
 469
 470 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 471                                     struct perf_probe_arg_field *field,
 472                                     struct probe_trace_arg_ref **ref_ptr,
 473                                     Dwarf_Die *die_mem)
 474 {
 475         struct probe_trace_arg_ref *ref = *ref_ptr;
 476         Dwarf_Die type;
 477         Dwarf_Word offs;
 478         int ret, tag;
 479
 480         pr_debug("converting %s in %s\n", field->name, varname);
 481         if (die_get_real_type(vr_die, &type) == NULL) {
 482                 pr_warning("Failed to get the type of %s.\n", varname);
 483                 return -ENOENT;
 484         }
 485         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 486         tag = dwarf_tag(&type);
 487
 488         if (field->name[0] == '[' &&
 489             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 490                 if (field->next)
 491                         /* Save original type for next field */
 492                         memcpy(die_mem, &type, sizeof(*die_mem));
 493                 /* Get the type of this array */
 494                 if (die_get_real_type(&type, &type) == NULL) {
 495                         pr_warning("Failed to get the type of %s.\n", varname);
 496                         return -ENOENT;
 497                 }
 498                 pr_debug2("Array real type: (%x)\n",
 499                          (unsigned)dwarf_dieoffset(&type));
 500                 if (tag == DW_TAG_pointer_type) {
 501                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 502                         if (ref == NULL)
 503                                 return -ENOMEM;
 504                         if (*ref_ptr)
 505                                 (*ref_ptr)->next = ref;
 506                         else
 507                                 *ref_ptr = ref;
 508                 }
 509                 ref->offset += dwarf_bytesize(&type) * field->index;
 510                 if (!field->next)
 511                         /* Save vr_die for converting types */
 512                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 513                 goto next;
 514         } else if (tag == DW_TAG_pointer_type) {
 515                 /* Check the pointer and dereference */
 516                 if (!field->ref) {
 517                         pr_err("Semantic error: %s must be referred by '->'\n",
 518                                field->name);
 519                         return -EINVAL;
 520                 }
 521                 /* Get the type pointed by this pointer */
 522                 if (die_get_real_type(&type, &type) == NULL) {
 523                         pr_warning("Failed to get the type of %s.\n", varname);
 524                         return -ENOENT;
 525                 }
 526                 /* Verify it is a data structure  */
 527                 tag = dwarf_tag(&type);
 528                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 529                         pr_warning("%s is not a data structure nor an union.\n",
 530                                    varname);
 531                         return -EINVAL;
 532                 }
 533
 534                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 535                 if (ref == NULL)
 536                         return -ENOMEM;
 537                 if (*ref_ptr)
 538                         (*ref_ptr)->next = ref;
 539                 else
 540                         *ref_ptr = ref;
 541         } else {
 542                 /* Verify it is a data structure  */
 543                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
 544                         pr_warning("%s is not a data structure nor an union.\n",
 545                                    varname);
 546                         return -EINVAL;
 547                 }
 548                 if (field->name[0] == '[') {
 549                         pr_err("Semantic error: %s is not a pointor"
 550                                " nor array.\n", varname);
 551                         return -EINVAL;
 552                 }
 553                 if (field->ref) {
 554                         pr_err("Semantic error: %s must be referred by '.'\n",
 555                                field->name);
 556                         return -EINVAL;
 557                 }
 558                 if (!ref) {
 559                         pr_warning("Structure on a register is not "
 560                                    "supported yet.\n");
 561                         return -ENOTSUP;
 562                 }
 563         }
 564
 565         if (die_find_member(&type, field->name, die_mem) == NULL) {
 566                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 567                            dwarf_diename(&type), field->name);
 568                 return -EINVAL;
 569         }
 570
 571         /* Get the offset of the field */
 572         if (tag == DW_TAG_union_type) {
 573                 offs = 0;
 574         } else {
 575                 ret = die_get_data_member_location(die_mem, &offs);
 576                 if (ret < 0) {
 577                         pr_warning("Failed to get the offset of %s.\n",
 578                                    field->name);
 579                         return ret;
 580                 }
 581         }
 582         ref->offset += (long)offs;
 583
 584 next:
 585         /* Converting next field */
 586         if (field->next)
 587                 return convert_variable_fields(die_mem, field->name,
 588                                         field->next, &ref, die_mem);
 589         else
 590                 return 0;
 591 }
 592
 593 /* Show a variables in kprobe event format */
 594 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 595 {
 596         Dwarf_Die die_mem;
 597         int ret;
 598
 599         pr_debug("Converting variable %s into trace event.\n",
 600                  dwarf_diename(vr_die));
 601
 602         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 603                                         pf->tvar);
 604         if (ret == -ENOENT)
 605                 pr_err("Failed to find the location of %s at this address.\n"
 606                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 607         else if (ret == -ENOTSUP)
 608                 pr_err("Sorry, we don't support this variable location yet.\n");
 609         else if (pf->pvar->field) {
 610                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 611                                               pf->pvar->field, &pf->tvar->ref,
 612                                               &die_mem);
 613                 vr_die = &die_mem;
 614         }
 615         if (ret == 0)
 616                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 617         /* *expr will be cached in libdw. Don't free it. */
 618         return ret;
 619 }
 620
 621 /* Find a variable in a scope DIE */
 622 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 623 {
 624         Dwarf_Die vr_die;
 625         char buf[32], *ptr;
 626         int ret = 0;
 627
 628         if (!is_c_varname(pf->pvar->var)) {
 629                 /* Copy raw parameters */
 630                 pf->tvar->value = strdup(pf->pvar->var);
 631                 if (pf->tvar->value == NULL)
 632                         return -ENOMEM;
 633                 if (pf->pvar->type) {
 634                         pf->tvar->type = strdup(pf->pvar->type);
 635                         if (pf->tvar->type == NULL)
 636                                 return -ENOMEM;
 637                 }
 638                 if (pf->pvar->name) {
 639                         pf->tvar->name = strdup(pf->pvar->name);
 640                         if (pf->tvar->name == NULL)
 641                                 return -ENOMEM;
 642                 } else
 643                         pf->tvar->name = NULL;
 644                 return 0;
 645         }
 646
 647         if (pf->pvar->name)
 648                 pf->tvar->name = strdup(pf->pvar->name);
 649         else {
 650                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 651                 if (ret < 0)
 652                         return ret;
 653                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 654                 if (ptr)
 655                         *ptr = '_';
 656                 pf->tvar->name = strdup(buf);
 657         }
 658         if (pf->tvar->name == NULL)
 659                 return -ENOMEM;
 660
 661         pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
 662         /* Search child die for local variables and parameters. */
 663         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
 664                 /* Search again in global variables */
 665                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
 666                         ret = -ENOENT;
 667         }
 668         if (ret >= 0)
 669                 ret = convert_variable(&vr_die, pf);
 670
 671         if (ret < 0)
 672                 pr_warning("Failed to find '%s' in this function.\n",
 673                            pf->pvar->var);
 674         return ret;
 675 }
 676
 677 /* Convert subprogram DIE to trace point */
 678 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
 679                                   Dwarf_Addr paddr, bool retprobe,
 680                                   struct probe_trace_point *tp)
 681 {
 682         Dwarf_Addr eaddr, highaddr;
 683         GElf_Sym sym;
 684         const char *symbol;
 685
 686         /* Verify the address is correct */
 687         if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 688                 pr_warning("Failed to get entry address of %s\n",
 689                            dwarf_diename(sp_die));
 690                 return -ENOENT;
 691         }
 692         if (dwarf_highpc(sp_die, &highaddr) != 0) {
 693                 pr_warning("Failed to get end address of %s\n",
 694                            dwarf_diename(sp_die));
 695                 return -ENOENT;
 696         }
 697         if (paddr > highaddr) {
 698                 pr_warning("Offset specified is greater than size of %s\n",
 699                            dwarf_diename(sp_die));
 700                 return -EINVAL;
 701         }
 702
 703         /* Get an appropriate symbol from symtab */
 704         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
 705         if (!symbol) {
 706                 pr_warning("Failed to find symbol at 0x%lx\n",
 707                            (unsigned long)paddr);
 708                 return -ENOENT;
 709         }
 710         tp->offset = (unsigned long)(paddr - sym.st_value);
 711         tp->symbol = strdup(symbol);
 712         if (!tp->symbol)
 713                 return -ENOMEM;
 714
 715         /* Return probe must be on the head of a subprogram */
 716         if (retprobe) {
 717                 if (eaddr != paddr) {
 718                         pr_warning("Return probe must be on the head of"
 719                                    " a real function.\n");
 720                         return -EINVAL;
 721                 }
 722                 tp->retprobe = true;
 723         }
 724
 725         return 0;
 726 }
 727
 728 /* Call probe_finder callback with scope DIE */
 729 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 730 {
 731         Dwarf_Attribute fb_attr;
 732         size_t nops;
 733         int ret;
 734
 735         if (!sc_die) {
 736                 pr_err("Caller must pass a scope DIE. Program error.\n");
 737                 return -EINVAL;
 738         }
 739
 740         /* If not a real subprogram, find a real one */
 741         if (!die_is_func_def(sc_die)) {
 742                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
 743                         pr_warning("Failed to find probe point in any "
 744                                    "functions.\n");
 745                         return -ENOENT;
 746                 }
 747         } else
 748                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 749
 750         /* Get the frame base attribute/ops from subprogram */
 751         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
 752         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 753         if (ret <= 0 || nops == 0) {
 754                 pf->fb_ops = NULL;
 755 #if _ELFUTILS_PREREQ(0, 142)
 756         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 757                    pf->cfi != NULL) {
 758                 Dwarf_Frame *frame;
 759                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 760                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 761                         pr_warning("Failed to get call frame on 0x%jx\n",
 762                                    (uintmax_t)pf->addr);
 763                         return -ENOENT;
 764                 }
 765 #endif
 766         }
 767
 768         /* Call finder's callback handler */
 769         ret = pf->callback(sc_die, pf);
 770
 771         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 772         pf->fb_ops = NULL;
 773
 774         return ret;
 775 }
 776
 777 struct find_scope_param {
 778         const char *function;
 779         const char *file;
 780         int line;
 781         int diff;
 782         Dwarf_Die *die_mem;
 783         bool found;
 784 };
 785
 786 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
 787 {
 788         struct find_scope_param *fsp = data;
 789         const char *file;
 790         int lno;
 791
 792         /* Skip if declared file name does not match */
 793         if (fsp->file) {
 794                 file = dwarf_decl_file(fn_die);
 795                 if (!file || strcmp(fsp->file, file) != 0)
 796                         return 0;
 797         }
 798         /* If the function name is given, that's what user expects */
 799         if (fsp->function) {
 800                 if (die_compare_name(fn_die, fsp->function)) {
 801                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 802                         fsp->found = true;
 803                         return 1;
 804                 }
 805         } else {
 806                 /* With the line number, find the nearest declared DIE */
 807                 dwarf_decl_line(fn_die, &lno);
 808                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
 809                         /* Keep a candidate and continue */
 810                         fsp->diff = fsp->line - lno;
 811                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
 812                         fsp->found = true;
 813                 }
 814         }
 815         return 0;
 816 }
 817
 818 /* Find an appropriate scope fits to given conditions */
 819 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
 820 {
 821         struct find_scope_param fsp = {
 822                 .function = pf->pev->point.function,
 823                 .file = pf->fname,
 824                 .line = pf->lno,
 825                 .diff = INT_MAX,
 826                 .die_mem = die_mem,
 827                 .found = false,
 828         };
 829
 830         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
 831
 832         return fsp.found ? die_mem : NULL;
 833 }
 834
 835 static int probe_point_line_walker(const char *fname, int lineno,
 836                                    Dwarf_Addr addr, void *data)
 837 {
 838         struct probe_finder *pf = data;
 839         Dwarf_Die *sc_die, die_mem;
 840         int ret;
 841
 842         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 843                 return 0;
 844
 845         pf->addr = addr;
 846         sc_die = find_best_scope(pf, &die_mem);
 847         if (!sc_die) {
 848                 pr_warning("Failed to find scope of probe point.\n");
 849                 return -ENOENT;
 850         }
 851
 852         ret = call_probe_finder(sc_die, pf);
 853
 854         /* Continue if no error, because the line will be in inline function */
 855         return ret < 0 ? ret : 0;
 856 }
 857
 858 /* Find probe point from its line number */
 859 static int find_probe_point_by_line(struct probe_finder *pf)
 860 {
 861         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 862 }
 863
 864 /* Find lines which match lazy pattern */
 865 static int find_lazy_match_lines(struct list_head *head,
 866                                  const char *fname, const char *pat)
 867 {
 868         FILE *fp;
 869         char *line = NULL;
 870         size_t line_len;
 871         ssize_t len;
 872         int count = 0, linenum = 1;
 873
 874         fp = fopen(fname, "r");
 875         if (!fp) {
 876                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 877                 return -errno;
 878         }
 879
 880         while ((len = getline(&line, &line_len, fp)) > 0) {
 881
 882                 if (line[len - 1] == '\n')
 883                         line[len - 1] = '\0';
 884
 885                 if (strlazymatch(line, pat)) {
 886                         line_list__add_line(head, linenum);
 887                         count++;
 888                 }
 889                 linenum++;
 890         }
 891
 892         if (ferror(fp))
 893                 count = -errno;
 894         free(line);
 895         fclose(fp);
 896
 897         if (count == 0)
 898                 pr_debug("No matched lines found in %s.\n", fname);
 899         return count;
 900 }
 901
 902 static int probe_point_lazy_walker(const char *fname, int lineno,
 903                                    Dwarf_Addr addr, void *data)
 904 {
 905         struct probe_finder *pf = data;
 906         Dwarf_Die *sc_die, die_mem;
 907         int ret;
 908
 909         if (!line_list__has_line(&pf->lcache, lineno) ||
 910             strtailcmp(fname, pf->fname) != 0)
 911                 return 0;
 912
 913         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 914                  lineno, (unsigned long long)addr);
 915         pf->addr = addr;
 916         pf->lno = lineno;
 917         sc_die = find_best_scope(pf, &die_mem);
 918         if (!sc_die) {
 919                 pr_warning("Failed to find scope of probe point.\n");
 920                 return -ENOENT;
 921         }
 922
 923         ret = call_probe_finder(sc_die, pf);
 924
 925         /*
 926          * Continue if no error, because the lazy pattern will match
 927          * to other lines
 928          */
 929         return ret < 0 ? ret : 0;
 930 }
 931
 932 /* Find probe points from lazy pattern  */
 933 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 934 {
 935         int ret = 0;
 936
 937         if (list_empty(&pf->lcache)) {
 938                 /* Matching lazy line pattern */
 939                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
 940                                             pf->pev->point.lazy_line);
 941                 if (ret <= 0)
 942                         return ret;
 943         }
 944
 945         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 946 }
 947
 948 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 949 {
 950         struct probe_finder *pf = data;
 951         struct perf_probe_point *pp = &pf->pev->point;
 952         Dwarf_Addr addr;
 953         int ret;
 954
 955         if (pp->lazy_line)
 956                 ret = find_probe_point_lazy(in_die, pf);
 957         else {
 958                 /* Get probe address */
 959                 if (dwarf_entrypc(in_die, &addr) != 0) {
 960                         pr_warning("Failed to get entry address of %s.\n",
 961                                    dwarf_diename(in_die));
 962                         return -ENOENT;
 963                 }
 964                 pf->addr = addr;
 965                 pf->addr += pp->offset;
 966                 pr_debug("found inline addr: 0x%jx\n",
 967                          (uintmax_t)pf->addr);
 968
 969                 ret = call_probe_finder(in_die, pf);
 970         }
 971
 972         return ret;
 973 }
 974
 975 /* Callback parameter with return value for libdw */
 976 struct dwarf_callback_param {
 977         void *data;
 978         int retval;
 979 };
 980
 981 /* Search function from function name */
 982 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 983 {
 984         struct dwarf_callback_param *param = data;
 985         struct probe_finder *pf = param->data;
 986         struct perf_probe_point *pp = &pf->pev->point;
 987
 988         /* Check tag and diename */
 989         if (!die_is_func_def(sp_die) ||
 990             !die_compare_name(sp_die, pp->function))
 991                 return DWARF_CB_OK;
 992
 993         /* Check declared file */
 994         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 995                 return DWARF_CB_OK;
 996
 997         pf->fname = dwarf_decl_file(sp_die);
 998         if (pp->line) { /* Function relative line */
 999                 dwarf_decl_line(sp_die, &pf->lno);
1000                 pf->lno += pp->line;
1001                 param->retval = find_probe_point_by_line(pf);
1002         } else if (!dwarf_func_inline(sp_die)) {
1003                 /* Real function */
1004                 if (pp->lazy_line)
1005                         param->retval = find_probe_point_lazy(sp_die, pf);
1006                 else {
1007                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1008                                 pr_warning("Failed to get entry address of "
1009                                            "%s.\n", dwarf_diename(sp_die));
1010                                 param->retval = -ENOENT;
1011                                 return DWARF_CB_ABORT;
1012                         }
1013                         pf->addr += pp->offset;
1014                         /* TODO: Check the address in this function */
1015                         param->retval = call_probe_finder(sp_die, pf);
1016                 }
1017         } else
1018                 /* Inlined function: search instances */
1019                 param->retval = die_walk_instances(sp_die,
1020                                         probe_point_inline_cb, (void *)pf);
1021
1022         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1023 }
1024
1025 static int find_probe_point_by_func(struct probe_finder *pf)
1026 {
1027         struct dwarf_callback_param _param = {.data = (void *)pf,
1028                                               .retval = 0};
1029         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1030         return _param.retval;
1031 }
1032
1033 struct pubname_callback_param {
1034         char *function;
1035         char *file;
1036         Dwarf_Die *cu_die;
1037         Dwarf_Die *sp_die;
1038         int found;
1039 };
1040
1041 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1042 {
1043         struct pubname_callback_param *param = data;
1044
1045         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1046                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1047                         return DWARF_CB_OK;
1048
1049                 if (die_compare_name(param->sp_die, param->function)) {
1050                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1051                                 return DWARF_CB_OK;
1052
1053                         if (param->file &&
1054                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1055                                 return DWARF_CB_OK;
1056
1057                         param->found = 1;
1058                         return DWARF_CB_ABORT;
1059                 }
1060         }
1061
1062         return DWARF_CB_OK;
1063 }
1064
1065 /* Find probe points from debuginfo */
1066 static int debuginfo__find_probes(struct debuginfo *self,
1067                                   struct probe_finder *pf)
1068 {
1069         struct perf_probe_point *pp = &pf->pev->point;
1070         Dwarf_Off off, noff;
1071         size_t cuhl;
1072         Dwarf_Die *diep;
1073         int ret = 0;
1074
1075 #if _ELFUTILS_PREREQ(0, 142)
1076         /* Get the call frame information from this dwarf */
1077         pf->cfi = dwarf_getcfi(self->dbg);
1078 #endif
1079
1080         off = 0;
1081         line_list__init(&pf->lcache);
1082
1083         /* Fastpath: lookup by function name from .debug_pubnames section */
1084         if (pp->function) {
1085                 struct pubname_callback_param pubname_param = {
1086                         .function = pp->function,
1087                         .file     = pp->file,
1088                         .cu_die   = &pf->cu_die,
1089                         .sp_die   = &pf->sp_die,
1090                         .found    = 0,
1091                 };
1092                 struct dwarf_callback_param probe_param = {
1093                         .data = pf,
1094                 };
1095
1096                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1097                                   &pubname_param, 0);
1098                 if (pubname_param.found) {
1099                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1100                         if (ret)
1101                                 goto found;
1102                 }
1103         }
1104
1105         /* Loop on CUs (Compilation Unit) */
1106         while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1107                 /* Get the DIE(Debugging Information Entry) of this CU */
1108                 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1109                 if (!diep)
1110                         continue;
1111
1112                 /* Check if target file is included. */
1113                 if (pp->file)
1114                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1115                 else
1116                         pf->fname = NULL;
1117
1118                 if (!pp->file || pf->fname) {
1119                         if (pp->function)
1120                                 ret = find_probe_point_by_func(pf);
1121                         else if (pp->lazy_line)
1122                                 ret = find_probe_point_lazy(NULL, pf);
1123                         else {
1124                                 pf->lno = pp->line;
1125                                 ret = find_probe_point_by_line(pf);
1126                         }
1127                         if (ret < 0)
1128                                 break;
1129                 }
1130                 off = noff;
1131         }
1132
1133 found:
1134         line_list__free(&pf->lcache);
1135
1136         return ret;
1137 }
1138
1139 /* Add a found probe point into trace event list */
1140 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1141 {
1142         struct trace_event_finder *tf =
1143                         container_of(pf, struct trace_event_finder, pf);
1144         struct probe_trace_event *tev;
1145         int ret, i;
1146
1147         /* Check number of tevs */
1148         if (tf->ntevs == tf->max_tevs) {
1149                 pr_warning("Too many( > %d) probe point found.\n",
1150                            tf->max_tevs);
1151                 return -ERANGE;
1152         }
1153         tev = &tf->tevs[tf->ntevs++];
1154
1155         /* Trace point should be converted from subprogram DIE */
1156         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1157                                      pf->pev->point.retprobe, &tev->point);
1158         if (ret < 0)
1159                 return ret;
1160
1161         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1162                  tev->point.offset);
1163
1164         /* Find each argument */
1165         tev->nargs = pf->pev->nargs;
1166         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1167         if (tev->args == NULL)
1168                 return -ENOMEM;
1169         for (i = 0; i < pf->pev->nargs; i++) {
1170                 pf->pvar = &pf->pev->args[i];
1171                 pf->tvar = &tev->args[i];
1172                 /* Variable should be found from scope DIE */
1173                 ret = find_variable(sc_die, pf);
1174                 if (ret != 0)
1175                         return ret;
1176         }
1177
1178         return 0;
1179 }
1180
1181 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1182 int debuginfo__find_trace_events(struct debuginfo *self,
1183                                  struct perf_probe_event *pev,
1184                                  struct probe_trace_event **tevs, int max_tevs)
1185 {
1186         struct trace_event_finder tf = {
1187                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1188                         .mod = self->mod, .max_tevs = max_tevs};
1189         int ret;
1190
1191         /* Allocate result tevs array */
1192         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1193         if (*tevs == NULL)
1194                 return -ENOMEM;
1195
1196         tf.tevs = *tevs;
1197         tf.ntevs = 0;
1198
1199         ret = debuginfo__find_probes(self, &tf.pf);
1200         if (ret < 0) {
1201                 free(*tevs);
1202                 *tevs = NULL;
1203                 return ret;
1204         }
1205
1206         return (ret < 0) ? ret : tf.ntevs;
1207 }
1208
1209 #define MAX_VAR_LEN 64
1210
1211 /* Collect available variables in this scope */
1212 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1213 {
1214         struct available_var_finder *af = data;
1215         struct variable_list *vl;
1216         char buf[MAX_VAR_LEN];
1217         int tag, ret;
1218
1219         vl = &af->vls[af->nvls - 1];
1220
1221         tag = dwarf_tag(die_mem);
1222         if (tag == DW_TAG_formal_parameter ||
1223             tag == DW_TAG_variable) {
1224                 ret = convert_variable_location(die_mem, af->pf.addr,
1225                                                 af->pf.fb_ops, NULL);
1226                 if (ret == 0) {
1227                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1228                         pr_debug2("Add new var: %s\n", buf);
1229                         if (ret > 0)
1230                                 strlist__add(vl->vars, buf);
1231                 }
1232         }
1233
1234         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1235                 return DIE_FIND_CB_CONTINUE;
1236         else
1237                 return DIE_FIND_CB_SIBLING;
1238 }
1239
1240 /* Add a found vars into available variables list */
1241 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1242 {
1243         struct available_var_finder *af =
1244                         container_of(pf, struct available_var_finder, pf);
1245         struct variable_list *vl;
1246         Dwarf_Die die_mem;
1247         int ret;
1248
1249         /* Check number of tevs */
1250         if (af->nvls == af->max_vls) {
1251                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1252                 return -ERANGE;
1253         }
1254         vl = &af->vls[af->nvls++];
1255
1256         /* Trace point should be converted from subprogram DIE */
1257         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1258                                      pf->pev->point.retprobe, &vl->point);
1259         if (ret < 0)
1260                 return ret;
1261
1262         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1263                  vl->point.offset);
1264
1265         /* Find local variables */
1266         vl->vars = strlist__new(true, NULL);
1267         if (vl->vars == NULL)
1268                 return -ENOMEM;
1269         af->child = true;
1270         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1271
1272         /* Find external variables */
1273         if (!af->externs)
1274                 goto out;
1275         /* Don't need to search child DIE for externs. */
1276         af->child = false;
1277         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1278
1279 out:
1280         if (strlist__empty(vl->vars)) {
1281                 strlist__delete(vl->vars);
1282                 vl->vars = NULL;
1283         }
1284
1285         return ret;
1286 }
1287
1288 /* Find available variables at given probe point */
1289 int debuginfo__find_available_vars_at(struct debuginfo *self,
1290                                       struct perf_probe_event *pev,
1291                                       struct variable_list **vls,
1292                                       int max_vls, bool externs)
1293 {
1294         struct available_var_finder af = {
1295                         .pf = {.pev = pev, .callback = add_available_vars},
1296                         .mod = self->mod,
1297                         .max_vls = max_vls, .externs = externs};
1298         int ret;
1299
1300         /* Allocate result vls array */
1301         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1302         if (*vls == NULL)
1303                 return -ENOMEM;
1304
1305         af.vls = *vls;
1306         af.nvls = 0;
1307
1308         ret = debuginfo__find_probes(self, &af.pf);
1309         if (ret < 0) {
1310                 /* Free vlist for error */
1311                 while (af.nvls--) {
1312                         if (af.vls[af.nvls].point.symbol)
1313                                 free(af.vls[af.nvls].point.symbol);
1314                         if (af.vls[af.nvls].vars)
1315                                 strlist__delete(af.vls[af.nvls].vars);
1316                 }
1317                 free(af.vls);
1318                 *vls = NULL;
1319                 return ret;
1320         }
1321
1322         return (ret < 0) ? ret : af.nvls;
1323 }
1324
1325 /* Reverse search */
1326 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1327                                 struct perf_probe_point *ppt)
1328 {
1329         Dwarf_Die cudie, spdie, indie;
1330         Dwarf_Addr _addr = 0, baseaddr = 0;
1331         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1332         int baseline = 0, lineno = 0, ret = 0;
1333
1334         /* Adjust address with bias */
1335         addr += self->bias;
1336
1337         /* Find cu die */
1338         if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1339                 pr_warning("Failed to find debug information for address %lx\n",
1340                            addr);
1341                 ret = -EINVAL;
1342                 goto end;
1343         }
1344
1345         /* Find a corresponding line (filename and lineno) */
1346         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1347         /* Don't care whether it failed or not */
1348
1349         /* Find a corresponding function (name, baseline and baseaddr) */
1350         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1351                 /* Get function entry information */
1352                 func = basefunc = dwarf_diename(&spdie);
1353                 if (!func ||
1354                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1355                     dwarf_decl_line(&spdie, &baseline) != 0) {
1356                         lineno = 0;
1357                         goto post;
1358                 }
1359
1360                 fname = dwarf_decl_file(&spdie);
1361                 if (addr == (unsigned long)baseaddr) {
1362                         /* Function entry - Relative line number is 0 */
1363                         lineno = baseline;
1364                         goto post;
1365                 }
1366
1367                 /* Track down the inline functions step by step */
1368                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1369                                                 &indie)) {
1370                         /* There is an inline function */
1371                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1372                             _addr == addr) {
1373                                 /*
1374                                  * addr is at an inline function entry.
1375                                  * In this case, lineno should be the call-site
1376                                  * line number. (overwrite lineinfo)
1377                                  */
1378                                 lineno = die_get_call_lineno(&indie);
1379                                 fname = die_get_call_file(&indie);
1380                                 break;
1381                         } else {
1382                                 /*
1383                                  * addr is in an inline function body.
1384                                  * Since lineno points one of the lines
1385                                  * of the inline function, baseline should
1386                                  * be the entry line of the inline function.
1387                                  */
1388                                 tmp = dwarf_diename(&indie);
1389                                 if (!tmp ||
1390                                     dwarf_decl_line(&indie, &baseline) != 0)
1391                                         break;
1392                                 func = tmp;
1393                                 spdie = indie;
1394                         }
1395                 }
1396                 /* Verify the lineno and baseline are in a same file */
1397                 tmp = dwarf_decl_file(&spdie);
1398                 if (!tmp || strcmp(tmp, fname) != 0)
1399                         lineno = 0;
1400         }
1401
1402 post:
1403         /* Make a relative line number or an offset */
1404         if (lineno)
1405                 ppt->line = lineno - baseline;
1406         else if (basefunc) {
1407                 ppt->offset = addr - (unsigned long)baseaddr;
1408                 func = basefunc;
1409         }
1410
1411         /* Duplicate strings */
1412         if (func) {
1413                 ppt->function = strdup(func);
1414                 if (ppt->function == NULL) {
1415                         ret = -ENOMEM;
1416                         goto end;
1417                 }
1418         }
1419         if (fname) {
1420                 ppt->file = strdup(fname);
1421                 if (ppt->file == NULL) {
1422                         if (ppt->function) {
1423                                 free(ppt->function);
1424                                 ppt->function = NULL;
1425                         }
1426                         ret = -ENOMEM;
1427                         goto end;
1428                 }
1429         }
1430 end:
1431         if (ret == 0 && (fname || func))
1432                 ret = 1;        /* Found a point */
1433         return ret;
1434 }
1435
1436 /* Add a line and store the src path */
1437 static int line_range_add_line(const char *src, unsigned int lineno,
1438                                struct line_range *lr)
1439 {
1440         /* Copy source path */
1441         if (!lr->path) {
1442                 lr->path = strdup(src);
1443                 if (lr->path == NULL)
1444                         return -ENOMEM;
1445         }
1446         return line_list__add_line(&lr->line_list, lineno);
1447 }
1448
1449 static int line_range_walk_cb(const char *fname, int lineno,
1450                               Dwarf_Addr addr __maybe_unused,
1451                               void *data)
1452 {
1453         struct line_finder *lf = data;
1454
1455         if ((strtailcmp(fname, lf->fname) != 0) ||
1456             (lf->lno_s > lineno || lf->lno_e < lineno))
1457                 return 0;
1458
1459         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1460                 return -EINVAL;
1461
1462         return 0;
1463 }
1464
1465 /* Find line range from its line number */
1466 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1467 {
1468         int ret;
1469
1470         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1471
1472         /* Update status */
1473         if (ret >= 0)
1474                 if (!list_empty(&lf->lr->line_list))
1475                         ret = lf->found = 1;
1476                 else
1477                         ret = 0;        /* Lines are not found */
1478         else {
1479                 free(lf->lr->path);
1480                 lf->lr->path = NULL;
1481         }
1482         return ret;
1483 }
1484
1485 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1486 {
1487         find_line_range_by_line(in_die, data);
1488
1489         /*
1490          * We have to check all instances of inlined function, because
1491          * some execution paths can be optimized out depends on the
1492          * function argument of instances
1493          */
1494         return 0;
1495 }
1496
1497 /* Search function definition from function name */
1498 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1499 {
1500         struct dwarf_callback_param *param = data;
1501         struct line_finder *lf = param->data;
1502         struct line_range *lr = lf->lr;
1503
1504         /* Check declared file */
1505         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1506                 return DWARF_CB_OK;
1507
1508         if (die_is_func_def(sp_die) &&
1509             die_compare_name(sp_die, lr->function)) {
1510                 lf->fname = dwarf_decl_file(sp_die);
1511                 dwarf_decl_line(sp_die, &lr->offset);
1512                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1513                 lf->lno_s = lr->offset + lr->start;
1514                 if (lf->lno_s < 0)      /* Overflow */
1515                         lf->lno_s = INT_MAX;
1516                 lf->lno_e = lr->offset + lr->end;
1517                 if (lf->lno_e < 0)      /* Overflow */
1518                         lf->lno_e = INT_MAX;
1519                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1520                 lr->start = lf->lno_s;
1521                 lr->end = lf->lno_e;
1522                 if (dwarf_func_inline(sp_die))
1523                         param->retval = die_walk_instances(sp_die,
1524                                                 line_range_inline_cb, lf);
1525                 else
1526                         param->retval = find_line_range_by_line(sp_die, lf);
1527                 return DWARF_CB_ABORT;
1528         }
1529         return DWARF_CB_OK;
1530 }
1531
1532 static int find_line_range_by_func(struct line_finder *lf)
1533 {
1534         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1535         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1536         return param.retval;
1537 }
1538
1539 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1540 {
1541         struct line_finder lf = {.lr = lr, .found = 0};
1542         int ret = 0;
1543         Dwarf_Off off = 0, noff;
1544         size_t cuhl;
1545         Dwarf_Die *diep;
1546         const char *comp_dir;
1547
1548         /* Fastpath: lookup by function name from .debug_pubnames section */
1549         if (lr->function) {
1550                 struct pubname_callback_param pubname_param = {
1551                         .function = lr->function, .file = lr->file,
1552                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1553                 struct dwarf_callback_param line_range_param = {
1554                         .data = (void *)&lf, .retval = 0};
1555
1556                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1557                                   &pubname_param, 0);
1558                 if (pubname_param.found) {
1559                         line_range_search_cb(&lf.sp_die, &line_range_param);
1560                         if (lf.found)
1561                                 goto found;
1562                 }
1563         }
1564
1565         /* Loop on CUs (Compilation Unit) */
1566         while (!lf.found && ret >= 0) {
1567                 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1568                                  NULL, NULL, NULL) != 0)
1569                         break;
1570
1571                 /* Get the DIE(Debugging Information Entry) of this CU */
1572                 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1573                 if (!diep)
1574                         continue;
1575
1576                 /* Check if target file is included. */
1577                 if (lr->file)
1578                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1579                 else
1580                         lf.fname = 0;
1581
1582                 if (!lr->file || lf.fname) {
1583                         if (lr->function)
1584                                 ret = find_line_range_by_func(&lf);
1585                         else {
1586                                 lf.lno_s = lr->start;
1587                                 lf.lno_e = lr->end;
1588                                 ret = find_line_range_by_line(NULL, &lf);
1589                         }
1590                 }
1591                 off = noff;
1592         }
1593
1594 found:
1595         /* Store comp_dir */
1596         if (lf.found) {
1597                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1598                 if (comp_dir) {
1599                         lr->comp_dir = strdup(comp_dir);
1600                         if (!lr->comp_dir)
1601                                 ret = -ENOMEM;
1602                 }
1603         }
1604
1605         pr_debug("path: %s\n", lr->path);
1606         return (ret < 0) ? ret : lf.found;
1607 }
1608