tools/perf/util/probe-finder.c

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