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