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