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 subprogram die */
 616 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 617 {
 618         Dwarf_Die vr_die, *scopes;
 619         char buf[32], *ptr;
 620         int ret, nscopes;
 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",
 656                  pf->pvar->var);
 657         /* Search child die for local variables and parameters. */
 658         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
 659                 ret = convert_variable(&vr_die, pf);
 660         else {
 661                 /* Search upper class */
 662                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 663                 while (nscopes-- > 1) {
 664                         pr_debug("Searching variables in %s\n",
 665                                  dwarf_diename(&scopes[nscopes]));
 666                         /* We should check this scope, so give dummy address */
 667                         if (die_find_variable_at(&scopes[nscopes],
 668                                                  pf->pvar->var, 0,
 669                                                  &vr_die)) {
 670                                 ret = convert_variable(&vr_die, pf);
 671                                 goto found;
 672                         }
 673                 }
 674                 if (scopes)
 675                         free(scopes);
 676                 ret = -ENOENT;
 677         }
 678 found:
 679         if (ret < 0)
 680                 pr_warning("Failed to find '%s' in this function.\n",
 681                            pf->pvar->var);
 682         return ret;
 683 }
 684
 685 /* Convert subprogram DIE to trace point */
 686 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
 687                                   bool retprobe, struct probe_trace_point *tp)
 688 {
 689         Dwarf_Addr eaddr;
 690         const char *name;
 691
 692         /* Copy the name of probe point */
 693         name = dwarf_diename(sp_die);
 694         if (name) {
 695                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 696                         pr_warning("Failed to get entry address of %s\n",
 697                                    dwarf_diename(sp_die));
 698                         return -ENOENT;
 699                 }
 700                 tp->symbol = strdup(name);
 701                 if (tp->symbol == NULL)
 702                         return -ENOMEM;
 703                 tp->offset = (unsigned long)(paddr - eaddr);
 704         } else
 705                 /* This function has no name. */
 706                 tp->offset = (unsigned long)paddr;
 707
 708         /* Return probe must be on the head of a subprogram */
 709         if (retprobe) {
 710                 if (eaddr != paddr) {
 711                         pr_warning("Return probe must be on the head of"
 712                                    " a real function.\n");
 713                         return -EINVAL;
 714                 }
 715                 tp->retprobe = true;
 716         }
 717
 718         return 0;
 719 }
 720
 721 /* Call probe_finder callback with real subprogram DIE */
 722 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
 723 {
 724         Dwarf_Die die_mem;
 725         Dwarf_Attribute fb_attr;
 726         size_t nops;
 727         int ret;
 728
 729         /* If no real subprogram, find a real one */
 730         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
 731                 sp_die = die_find_realfunc(&pf->cu_die, pf->addr, &die_mem);
 732                 if (!sp_die) {
 733                         pr_warning("Failed to find probe point in any "
 734                                    "functions.\n");
 735                         return -ENOENT;
 736                 }
 737         }
 738
 739         /* Get the frame base attribute/ops */
 740         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
 741         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 742         if (ret <= 0 || nops == 0) {
 743                 pf->fb_ops = NULL;
 744 #if _ELFUTILS_PREREQ(0, 142)
 745         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 746                    pf->cfi != NULL) {
 747                 Dwarf_Frame *frame;
 748                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 749                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 750                         pr_warning("Failed to get call frame on 0x%jx\n",
 751                                    (uintmax_t)pf->addr);
 752                         return -ENOENT;
 753                 }
 754 #endif
 755         }
 756
 757         /* Call finder's callback handler */
 758         ret = pf->callback(sp_die, pf);
 759
 760         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 761         pf->fb_ops = NULL;
 762
 763         return ret;
 764 }
 765
 766 static int probe_point_line_walker(const char *fname, int lineno,
 767                                    Dwarf_Addr addr, void *data)
 768 {
 769         struct probe_finder *pf = data;
 770         int ret;
 771
 772         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
 773                 return 0;
 774
 775         pf->addr = addr;
 776         ret = call_probe_finder(NULL, pf);
 777
 778         /* Continue if no error, because the line will be in inline function */
 779         return ret < 0 ? ret : 0;
 780 }
 781
 782 /* Find probe point from its line number */
 783 static int find_probe_point_by_line(struct probe_finder *pf)
 784 {
 785         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 786 }
 787
 788 /* Find lines which match lazy pattern */
 789 static int find_lazy_match_lines(struct list_head *head,
 790                                  const char *fname, const char *pat)
 791 {
 792         FILE *fp;
 793         char *line = NULL;
 794         size_t line_len;
 795         ssize_t len;
 796         int count = 0, linenum = 1;
 797
 798         fp = fopen(fname, "r");
 799         if (!fp) {
 800                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
 801                 return -errno;
 802         }
 803
 804         while ((len = getline(&line, &line_len, fp)) > 0) {
 805
 806                 if (line[len - 1] == '\n')
 807                         line[len - 1] = '\0';
 808
 809                 if (strlazymatch(line, pat)) {
 810                         line_list__add_line(head, linenum);
 811                         count++;
 812                 }
 813                 linenum++;
 814         }
 815
 816         if (ferror(fp))
 817                 count = -errno;
 818         free(line);
 819         fclose(fp);
 820
 821         if (count == 0)
 822                 pr_debug("No matched lines found in %s.\n", fname);
 823         return count;
 824 }
 825
 826 static int probe_point_lazy_walker(const char *fname, int lineno,
 827                                    Dwarf_Addr addr, void *data)
 828 {
 829         struct probe_finder *pf = data;
 830         int ret;
 831
 832         if (!line_list__has_line(&pf->lcache, lineno) ||
 833             strtailcmp(fname, pf->fname) != 0)
 834                 return 0;
 835
 836         pr_debug("Probe line found: line:%d addr:0x%llx\n",
 837                  lineno, (unsigned long long)addr);
 838         pf->addr = addr;
 839         ret = call_probe_finder(NULL, pf);
 840
 841         /*
 842          * Continue if no error, because the lazy pattern will match
 843          * to other lines
 844          */
 845         return ret < 0 ? ret : 0;
 846 }
 847
 848 /* Find probe points from lazy pattern  */
 849 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 850 {
 851         int ret = 0;
 852
 853         if (list_empty(&pf->lcache)) {
 854                 /* Matching lazy line pattern */
 855                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
 856                                             pf->pev->point.lazy_line);
 857                 if (ret <= 0)
 858                         return ret;
 859         }
 860
 861         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 862 }
 863
 864 /* Callback parameter with return value */
 865 struct dwarf_callback_param {
 866         void *data;
 867         int retval;
 868 };
 869
 870 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 871 {
 872         struct dwarf_callback_param *param = data;
 873         struct probe_finder *pf = param->data;
 874         struct perf_probe_point *pp = &pf->pev->point;
 875         Dwarf_Addr addr;
 876
 877         if (pp->lazy_line)
 878                 param->retval = find_probe_point_lazy(in_die, pf);
 879         else {
 880                 /* Get probe address */
 881                 if (dwarf_entrypc(in_die, &addr) != 0) {
 882                         pr_warning("Failed to get entry address of %s.\n",
 883                                    dwarf_diename(in_die));
 884                         param->retval = -ENOENT;
 885                         return DWARF_CB_ABORT;
 886                 }
 887                 pf->addr = addr;
 888                 pf->addr += pp->offset;
 889                 pr_debug("found inline addr: 0x%jx\n",
 890                          (uintmax_t)pf->addr);
 891
 892                 param->retval = call_probe_finder(in_die, pf);
 893                 if (param->retval < 0)
 894                         return DWARF_CB_ABORT;
 895         }
 896
 897         return DWARF_CB_OK;
 898 }
 899
 900 /* Search function from function name */
 901 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 902 {
 903         struct dwarf_callback_param *param = data;
 904         struct probe_finder *pf = param->data;
 905         struct perf_probe_point *pp = &pf->pev->point;
 906
 907         /* Check tag and diename */
 908         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
 909             !die_compare_name(sp_die, pp->function))
 910                 return DWARF_CB_OK;
 911
 912         /* Check declared file */
 913         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
 914                 return DWARF_CB_OK;
 915
 916         pf->fname = dwarf_decl_file(sp_die);
 917         if (pp->line) { /* Function relative line */
 918                 dwarf_decl_line(sp_die, &pf->lno);
 919                 pf->lno += pp->line;
 920                 param->retval = find_probe_point_by_line(pf);
 921         } else if (!dwarf_func_inline(sp_die)) {
 922                 /* Real function */
 923                 if (pp->lazy_line)
 924                         param->retval = find_probe_point_lazy(sp_die, pf);
 925                 else {
 926                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 927                                 pr_warning("Failed to get entry address of "
 928                                            "%s.\n", dwarf_diename(sp_die));
 929                                 param->retval = -ENOENT;
 930                                 return DWARF_CB_ABORT;
 931                         }
 932                         pf->addr += pp->offset;
 933                         /* TODO: Check the address in this function */
 934                         param->retval = call_probe_finder(sp_die, pf);
 935                 }
 936         } else {
 937                 struct dwarf_callback_param _param = {.data = (void *)pf,
 938                                                       .retval = 0};
 939                 /* Inlined function: search instances */
 940                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
 941                                             &_param);
 942                 param->retval = _param.retval;
 943         }
 944
 945         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 946 }
 947
 948 static int find_probe_point_by_func(struct probe_finder *pf)
 949 {
 950         struct dwarf_callback_param _param = {.data = (void *)pf,
 951                                               .retval = 0};
 952         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 953         return _param.retval;
 954 }
 955
 956 struct pubname_callback_param {
 957         char *function;
 958         char *file;
 959         Dwarf_Die *cu_die;
 960         Dwarf_Die *sp_die;
 961         int found;
 962 };
 963
 964 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
 965 {
 966         struct pubname_callback_param *param = data;
 967
 968         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
 969                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
 970                         return DWARF_CB_OK;
 971
 972                 if (die_compare_name(param->sp_die, param->function)) {
 973                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
 974                                 return DWARF_CB_OK;
 975
 976                         if (param->file &&
 977                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
 978                                 return DWARF_CB_OK;
 979
 980                         param->found = 1;
 981                         return DWARF_CB_ABORT;
 982                 }
 983         }
 984
 985         return DWARF_CB_OK;
 986 }
 987
 988 /* Find probe points from debuginfo */
 989 static int debuginfo__find_probes(struct debuginfo *self,
 990                                   struct probe_finder *pf)
 991 {
 992         struct perf_probe_point *pp = &pf->pev->point;
 993         Dwarf_Off off, noff;
 994         size_t cuhl;
 995         Dwarf_Die *diep;
 996         int ret = 0;
 997
 998 #if _ELFUTILS_PREREQ(0, 142)
 999         /* Get the call frame information from this dwarf */
1000         pf->cfi = dwarf_getcfi(self->dbg);
1001 #endif
1002
1003         off = 0;
1004         line_list__init(&pf->lcache);
1005
1006         /* Fastpath: lookup by function name from .debug_pubnames section */
1007         if (pp->function) {
1008                 struct pubname_callback_param pubname_param = {
1009                         .function = pp->function,
1010                         .file     = pp->file,
1011                         .cu_die   = &pf->cu_die,
1012                         .sp_die   = &pf->sp_die,
1013                         .found    = 0,
1014                 };
1015                 struct dwarf_callback_param probe_param = {
1016                         .data = pf,
1017                 };
1018
1019                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1020                                   &pubname_param, 0);
1021                 if (pubname_param.found) {
1022                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1023                         if (ret)
1024                                 goto found;
1025                 }
1026         }
1027
1028         /* Loop on CUs (Compilation Unit) */
1029         while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1030                 /* Get the DIE(Debugging Information Entry) of this CU */
1031                 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1032                 if (!diep)
1033                         continue;
1034
1035                 /* Check if target file is included. */
1036                 if (pp->file)
1037                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1038                 else
1039                         pf->fname = NULL;
1040
1041                 if (!pp->file || pf->fname) {
1042                         if (pp->function)
1043                                 ret = find_probe_point_by_func(pf);
1044                         else if (pp->lazy_line)
1045                                 ret = find_probe_point_lazy(NULL, pf);
1046                         else {
1047                                 pf->lno = pp->line;
1048                                 ret = find_probe_point_by_line(pf);
1049                         }
1050                         if (ret < 0)
1051                                 break;
1052                 }
1053                 off = noff;
1054         }
1055
1056 found:
1057         line_list__free(&pf->lcache);
1058
1059         return ret;
1060 }
1061
1062 /* Add a found probe point into trace event list */
1063 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1064 {
1065         struct trace_event_finder *tf =
1066                         container_of(pf, struct trace_event_finder, pf);
1067         struct probe_trace_event *tev;
1068         int ret, i;
1069
1070         /* Check number of tevs */
1071         if (tf->ntevs == tf->max_tevs) {
1072                 pr_warning("Too many( > %d) probe point found.\n",
1073                            tf->max_tevs);
1074                 return -ERANGE;
1075         }
1076         tev = &tf->tevs[tf->ntevs++];
1077
1078         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1079                                      &tev->point);
1080         if (ret < 0)
1081                 return ret;
1082
1083         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1084                  tev->point.offset);
1085
1086         /* Find each argument */
1087         tev->nargs = pf->pev->nargs;
1088         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1089         if (tev->args == NULL)
1090                 return -ENOMEM;
1091         for (i = 0; i < pf->pev->nargs; i++) {
1092                 pf->pvar = &pf->pev->args[i];
1093                 pf->tvar = &tev->args[i];
1094                 ret = find_variable(sp_die, pf);
1095                 if (ret != 0)
1096                         return ret;
1097         }
1098
1099         return 0;
1100 }
1101
1102 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1103 int debuginfo__find_trace_events(struct debuginfo *self,
1104                                  struct perf_probe_event *pev,
1105                                  struct probe_trace_event **tevs, int max_tevs)
1106 {
1107         struct trace_event_finder tf = {
1108                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1109                         .max_tevs = max_tevs};
1110         int ret;
1111
1112         /* Allocate result tevs array */
1113         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1114         if (*tevs == NULL)
1115                 return -ENOMEM;
1116
1117         tf.tevs = *tevs;
1118         tf.ntevs = 0;
1119
1120         ret = debuginfo__find_probes(self, &tf.pf);
1121         if (ret < 0) {
1122                 free(*tevs);
1123                 *tevs = NULL;
1124                 return ret;
1125         }
1126
1127         return (ret < 0) ? ret : tf.ntevs;
1128 }
1129
1130 #define MAX_VAR_LEN 64
1131
1132 /* Collect available variables in this scope */
1133 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1134 {
1135         struct available_var_finder *af = data;
1136         struct variable_list *vl;
1137         char buf[MAX_VAR_LEN];
1138         int tag, ret;
1139
1140         vl = &af->vls[af->nvls - 1];
1141
1142         tag = dwarf_tag(die_mem);
1143         if (tag == DW_TAG_formal_parameter ||
1144             tag == DW_TAG_variable) {
1145                 ret = convert_variable_location(die_mem, af->pf.addr,
1146                                                 af->pf.fb_ops, NULL);
1147                 if (ret == 0) {
1148                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1149                         pr_debug2("Add new var: %s\n", buf);
1150                         if (ret > 0)
1151                                 strlist__add(vl->vars, buf);
1152                 }
1153         }
1154
1155         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1156                 return DIE_FIND_CB_CONTINUE;
1157         else
1158                 return DIE_FIND_CB_SIBLING;
1159 }
1160
1161 /* Add a found vars into available variables list */
1162 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1163 {
1164         struct available_var_finder *af =
1165                         container_of(pf, struct available_var_finder, pf);
1166         struct variable_list *vl;
1167         Dwarf_Die die_mem, *scopes = NULL;
1168         int ret, nscopes;
1169
1170         /* Check number of tevs */
1171         if (af->nvls == af->max_vls) {
1172                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1173                 return -ERANGE;
1174         }
1175         vl = &af->vls[af->nvls++];
1176
1177         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1178                                      &vl->point);
1179         if (ret < 0)
1180                 return ret;
1181
1182         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1183                  vl->point.offset);
1184
1185         /* Find local variables */
1186         vl->vars = strlist__new(true, NULL);
1187         if (vl->vars == NULL)
1188                 return -ENOMEM;
1189         af->child = true;
1190         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1191
1192         /* Find external variables */
1193         if (!af->externs)
1194                 goto out;
1195         /* Don't need to search child DIE for externs. */
1196         af->child = false;
1197         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1198         while (nscopes-- > 1)
1199                 die_find_child(&scopes[nscopes], collect_variables_cb,
1200                                (void *)af, &die_mem);
1201         if (scopes)
1202                 free(scopes);
1203
1204 out:
1205         if (strlist__empty(vl->vars)) {
1206                 strlist__delete(vl->vars);
1207                 vl->vars = NULL;
1208         }
1209
1210         return ret;
1211 }
1212
1213 /* Find available variables at given probe point */
1214 int debuginfo__find_available_vars_at(struct debuginfo *self,
1215                                       struct perf_probe_event *pev,
1216                                       struct variable_list **vls,
1217                                       int max_vls, bool externs)
1218 {
1219         struct available_var_finder af = {
1220                         .pf = {.pev = pev, .callback = add_available_vars},
1221                         .max_vls = max_vls, .externs = externs};
1222         int ret;
1223
1224         /* Allocate result vls array */
1225         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1226         if (*vls == NULL)
1227                 return -ENOMEM;
1228
1229         af.vls = *vls;
1230         af.nvls = 0;
1231
1232         ret = debuginfo__find_probes(self, &af.pf);
1233         if (ret < 0) {
1234                 /* Free vlist for error */
1235                 while (af.nvls--) {
1236                         if (af.vls[af.nvls].point.symbol)
1237                                 free(af.vls[af.nvls].point.symbol);
1238                         if (af.vls[af.nvls].vars)
1239                                 strlist__delete(af.vls[af.nvls].vars);
1240                 }
1241                 free(af.vls);
1242                 *vls = NULL;
1243                 return ret;
1244         }
1245
1246         return (ret < 0) ? ret : af.nvls;
1247 }
1248
1249 /* Reverse search */
1250 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1251                                 struct perf_probe_point *ppt)
1252 {
1253         Dwarf_Die cudie, spdie, indie;
1254         Dwarf_Addr _addr, baseaddr;
1255         const char *fname = NULL, *func = NULL, *tmp;
1256         int baseline = 0, lineno = 0, ret = 0;
1257
1258         /* Adjust address with bias */
1259         addr += self->bias;
1260
1261         /* Find cu die */
1262         if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1263                 pr_warning("Failed to find debug information for address %lx\n",
1264                            addr);
1265                 ret = -EINVAL;
1266                 goto end;
1267         }
1268
1269         /* Find a corresponding line (filename and lineno) */
1270         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1271         /* Don't care whether it failed or not */
1272
1273         /* Find a corresponding function (name, baseline and baseaddr) */
1274         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1275                 /* Get function entry information */
1276                 tmp = dwarf_diename(&spdie);
1277                 if (!tmp ||
1278                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1279                     dwarf_decl_line(&spdie, &baseline) != 0)
1280                         goto post;
1281                 func = tmp;
1282
1283                 if (addr == (unsigned long)baseaddr)
1284                         /* Function entry - Relative line number is 0 */
1285                         lineno = baseline;
1286                 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1287                                              &indie)) {
1288                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1289                             _addr == addr)
1290                                 /*
1291                                  * addr is at an inline function entry.
1292                                  * In this case, lineno should be the call-site
1293                                  * line number.
1294                                  */
1295                                 lineno = die_get_call_lineno(&indie);
1296                         else {
1297                                 /*
1298                                  * addr is in an inline function body.
1299                                  * Since lineno points one of the lines
1300                                  * of the inline function, baseline should
1301                                  * be the entry line of the inline function.
1302                                  */
1303                                 tmp = dwarf_diename(&indie);
1304                                 if (tmp &&
1305                                     dwarf_decl_line(&spdie, &baseline) == 0)
1306                                         func = tmp;
1307                         }
1308                 }
1309         }
1310
1311 post:
1312         /* Make a relative line number or an offset */
1313         if (lineno)
1314                 ppt->line = lineno - baseline;
1315         else if (func)
1316                 ppt->offset = addr - (unsigned long)baseaddr;
1317
1318         /* Duplicate strings */
1319         if (func) {
1320                 ppt->function = strdup(func);
1321                 if (ppt->function == NULL) {
1322                         ret = -ENOMEM;
1323                         goto end;
1324                 }
1325         }
1326         if (fname) {
1327                 ppt->file = strdup(fname);
1328                 if (ppt->file == NULL) {
1329                         if (ppt->function) {
1330                                 free(ppt->function);
1331                                 ppt->function = NULL;
1332                         }
1333                         ret = -ENOMEM;
1334                         goto end;
1335                 }
1336         }
1337 end:
1338         if (ret == 0 && (fname || func))
1339                 ret = 1;        /* Found a point */
1340         return ret;
1341 }
1342
1343 /* Add a line and store the src path */
1344 static int line_range_add_line(const char *src, unsigned int lineno,
1345                                struct line_range *lr)
1346 {
1347         /* Copy source path */
1348         if (!lr->path) {
1349                 lr->path = strdup(src);
1350                 if (lr->path == NULL)
1351                         return -ENOMEM;
1352         }
1353         return line_list__add_line(&lr->line_list, lineno);
1354 }
1355
1356 static int line_range_walk_cb(const char *fname, int lineno,
1357                               Dwarf_Addr addr __used,
1358                               void *data)
1359 {
1360         struct line_finder *lf = data;
1361
1362         if ((strtailcmp(fname, lf->fname) != 0) ||
1363             (lf->lno_s > lineno || lf->lno_e < lineno))
1364                 return 0;
1365
1366         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1367                 return -EINVAL;
1368
1369         return 0;
1370 }
1371
1372 /* Find line range from its line number */
1373 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1374 {
1375         int ret;
1376
1377         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1378
1379         /* Update status */
1380         if (ret >= 0)
1381                 if (!list_empty(&lf->lr->line_list))
1382                         ret = lf->found = 1;
1383                 else
1384                         ret = 0;        /* Lines are not found */
1385         else {
1386                 free(lf->lr->path);
1387                 lf->lr->path = NULL;
1388         }
1389         return ret;
1390 }
1391
1392 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1393 {
1394         struct dwarf_callback_param *param = data;
1395
1396         param->retval = find_line_range_by_line(in_die, param->data);
1397         return DWARF_CB_ABORT;  /* No need to find other instances */
1398 }
1399
1400 /* Search function from function name */
1401 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1402 {
1403         struct dwarf_callback_param *param = data;
1404         struct line_finder *lf = param->data;
1405         struct line_range *lr = lf->lr;
1406
1407         /* Check declared file */
1408         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1409                 return DWARF_CB_OK;
1410
1411         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1412             die_compare_name(sp_die, lr->function)) {
1413                 lf->fname = dwarf_decl_file(sp_die);
1414                 dwarf_decl_line(sp_die, &lr->offset);
1415                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1416                 lf->lno_s = lr->offset + lr->start;
1417                 if (lf->lno_s < 0)      /* Overflow */
1418                         lf->lno_s = INT_MAX;
1419                 lf->lno_e = lr->offset + lr->end;
1420                 if (lf->lno_e < 0)      /* Overflow */
1421                         lf->lno_e = INT_MAX;
1422                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1423                 lr->start = lf->lno_s;
1424                 lr->end = lf->lno_e;
1425                 if (dwarf_func_inline(sp_die)) {
1426                         struct dwarf_callback_param _param;
1427                         _param.data = (void *)lf;
1428                         _param.retval = 0;
1429                         dwarf_func_inline_instances(sp_die,
1430                                                     line_range_inline_cb,
1431                                                     &_param);
1432                         param->retval = _param.retval;
1433                 } else
1434                         param->retval = find_line_range_by_line(sp_die, lf);
1435                 return DWARF_CB_ABORT;
1436         }
1437         return DWARF_CB_OK;
1438 }
1439
1440 static int find_line_range_by_func(struct line_finder *lf)
1441 {
1442         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1443         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1444         return param.retval;
1445 }
1446
1447 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1448 {
1449         struct line_finder lf = {.lr = lr, .found = 0};
1450         int ret = 0;
1451         Dwarf_Off off = 0, noff;
1452         size_t cuhl;
1453         Dwarf_Die *diep;
1454         const char *comp_dir;
1455
1456         /* Fastpath: lookup by function name from .debug_pubnames section */
1457         if (lr->function) {
1458                 struct pubname_callback_param pubname_param = {
1459                         .function = lr->function, .file = lr->file,
1460                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1461                 struct dwarf_callback_param line_range_param = {
1462                         .data = (void *)&lf, .retval = 0};
1463
1464                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1465                                   &pubname_param, 0);
1466                 if (pubname_param.found) {
1467                         line_range_search_cb(&lf.sp_die, &line_range_param);
1468                         if (lf.found)
1469                                 goto found;
1470                 }
1471         }
1472
1473         /* Loop on CUs (Compilation Unit) */
1474         while (!lf.found && ret >= 0) {
1475                 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1476                                  NULL, NULL, NULL) != 0)
1477                         break;
1478
1479                 /* Get the DIE(Debugging Information Entry) of this CU */
1480                 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1481                 if (!diep)
1482                         continue;
1483
1484                 /* Check if target file is included. */
1485                 if (lr->file)
1486                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1487                 else
1488                         lf.fname = 0;
1489
1490                 if (!lr->file || lf.fname) {
1491                         if (lr->function)
1492                                 ret = find_line_range_by_func(&lf);
1493                         else {
1494                                 lf.lno_s = lr->start;
1495                                 lf.lno_e = lr->end;
1496                                 ret = find_line_range_by_line(NULL, &lf);
1497                         }
1498                 }
1499                 off = noff;
1500         }
1501
1502 found:
1503         /* Store comp_dir */
1504         if (lf.found) {
1505                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1506                 if (comp_dir) {
1507                         lr->comp_dir = strdup(comp_dir);
1508                         if (!lr->comp_dir)
1509                                 ret = -ENOMEM;
1510                 }
1511         }
1512
1513         pr_debug("path: %s\n", lr->path);
1514         return (ret < 0) ? ret : lf.found;
1515 }
1516