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 "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 /*
  46  * Compare the tail of two strings.
  47  * Return 0 if whole of either string is same as another's tail part.
  48  */
  49 static int strtailcmp(const char *s1, const char *s2)
  50 {
  51         int i1 = strlen(s1);
  52         int i2 = strlen(s2);
  53         while (--i1 >= 0 && --i2 >= 0) {
  54                 if (s1[i1] != s2[i2])
  55                         return s1[i1] - s2[i2];
  56         }
  57         return 0;
  58 }
  59
  60 /* Line number list operations */
  61
  62 /* Add a line to line number list */
  63 static int line_list__add_line(struct list_head *head, int line)
  64 {
  65         struct line_node *ln;
  66         struct list_head *p;
  67
  68         /* Reverse search, because new line will be the last one */
  69         list_for_each_entry_reverse(ln, head, list) {
  70                 if (ln->line < line) {
  71                         p = &ln->list;
  72                         goto found;
  73                 } else if (ln->line == line)    /* Already exist */
  74                         return 1;
  75         }
  76         /* List is empty, or the smallest entry */
  77         p = head;
  78 found:
  79         pr_debug("line list: add a line %u\n", line);
  80         ln = zalloc(sizeof(struct line_node));
  81         if (ln == NULL)
  82                 return -ENOMEM;
  83         ln->line = line;
  84         INIT_LIST_HEAD(&ln->list);
  85         list_add(&ln->list, p);
  86         return 0;
  87 }
  88
  89 /* Check if the line in line number list */
  90 static int line_list__has_line(struct list_head *head, int line)
  91 {
  92         struct line_node *ln;
  93
  94         /* Reverse search, because new line will be the last one */
  95         list_for_each_entry(ln, head, list)
  96                 if (ln->line == line)
  97                         return 1;
  98
  99         return 0;
 100 }
 101
 102 /* Init line number list */
 103 static void line_list__init(struct list_head *head)
 104 {
 105         INIT_LIST_HEAD(head);
 106 }
 107
 108 /* Free line number list */
 109 static void line_list__free(struct list_head *head)
 110 {
 111         struct line_node *ln;
 112         while (!list_empty(head)) {
 113                 ln = list_first_entry(head, struct line_node, list);
 114                 list_del(&ln->list);
 115                 free(ln);
 116         }
 117 }
 118
 119 /* Dwarf FL wrappers */
 120
 121 static int __linux_kernel_find_elf(Dwfl_Module *mod,
 122                                    void **userdata,
 123                                    const char *module_name,
 124                                    Dwarf_Addr base,
 125                                    char **file_name, Elf **elfp)
 126 {
 127         int fd;
 128         const char *path = kernel_get_module_path(module_name);
 129
 130         if (path) {
 131                 fd = open(path, O_RDONLY);
 132                 if (fd >= 0) {
 133                         *file_name = strdup(path);
 134                         return fd;
 135                 }
 136         }
 137         /* If failed, try to call standard method */
 138         return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
 139                                           file_name, elfp);
 140 }
 141
 142 static char *debuginfo_path;    /* Currently dummy */
 143
 144 static const Dwfl_Callbacks offline_callbacks = {
 145         .find_debuginfo = dwfl_standard_find_debuginfo,
 146         .debuginfo_path = &debuginfo_path,
 147
 148         .section_address = dwfl_offline_section_address,
 149
 150         /* We use this table for core files too.  */
 151         .find_elf = dwfl_build_id_find_elf,
 152 };
 153
 154 static const Dwfl_Callbacks kernel_callbacks = {
 155         .find_debuginfo = dwfl_standard_find_debuginfo,
 156         .debuginfo_path = &debuginfo_path,
 157
 158         .find_elf = __linux_kernel_find_elf,
 159         .section_address = dwfl_linux_kernel_module_section_address,
 160 };
 161
 162 /* Get a Dwarf from offline image */
 163 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
 164 {
 165         Dwfl_Module *mod;
 166         Dwarf *dbg = NULL;
 167
 168         if (!dwflp)
 169                 return NULL;
 170
 171         *dwflp = dwfl_begin(&offline_callbacks);
 172         if (!*dwflp)
 173                 return NULL;
 174
 175         mod = dwfl_report_offline(*dwflp, "", "", fd);
 176         if (!mod)
 177                 goto error;
 178
 179         dbg = dwfl_module_getdwarf(mod, bias);
 180         if (!dbg) {
 181 error:
 182                 dwfl_end(*dwflp);
 183                 *dwflp = NULL;
 184         }
 185         return dbg;
 186 }
 187
 188 /* Get a Dwarf from live kernel image */
 189 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
 190                                           Dwarf_Addr *bias)
 191 {
 192         Dwarf *dbg;
 193
 194         if (!dwflp)
 195                 return NULL;
 196
 197         *dwflp = dwfl_begin(&kernel_callbacks);
 198         if (!*dwflp)
 199                 return NULL;
 200
 201         /* Load the kernel dwarves: Don't care the result here */
 202         dwfl_linux_kernel_report_kernel(*dwflp);
 203         dwfl_linux_kernel_report_modules(*dwflp);
 204
 205         dbg = dwfl_addrdwarf(*dwflp, addr, bias);
 206         /* Here, check whether we could get a real dwarf */
 207         if (!dbg) {
 208                 dwfl_end(*dwflp);
 209                 *dwflp = NULL;
 210         }
 211         return dbg;
 212 }
 213
 214 /* Dwarf wrappers */
 215
 216 /* Find the realpath of the target file. */
 217 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
 218 {
 219         Dwarf_Files *files;
 220         size_t nfiles, i;
 221         const char *src = NULL;
 222         int ret;
 223
 224         if (!fname)
 225                 return NULL;
 226
 227         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
 228         if (ret != 0)
 229                 return NULL;
 230
 231         for (i = 0; i < nfiles; i++) {
 232                 src = dwarf_filesrc(files, i, NULL, NULL);
 233                 if (strtailcmp(src, fname) == 0)
 234                         break;
 235         }
 236         if (i == nfiles)
 237                 return NULL;
 238         return src;
 239 }
 240
 241 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
 242 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
 243 {
 244         Dwarf_Attribute attr;
 245         if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
 246                 return NULL;
 247         return dwarf_formstring(&attr);
 248 }
 249
 250 /* Compare diename and tname */
 251 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 252 {
 253         const char *name;
 254         name = dwarf_diename(dw_die);
 255         return name ? (strcmp(tname, name) == 0) : false;
 256 }
 257
 258 /* Get type die */
 259 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 260 {
 261         Dwarf_Attribute attr;
 262
 263         if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
 264             dwarf_formref_die(&attr, die_mem))
 265                 return die_mem;
 266         else
 267                 return NULL;
 268 }
 269
 270 /* Get a type die, but skip qualifiers */
 271 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 272 {
 273         int tag;
 274
 275         do {
 276                 vr_die = die_get_type(vr_die, die_mem);
 277                 if (!vr_die)
 278                         break;
 279                 tag = dwarf_tag(vr_die);
 280         } while (tag == DW_TAG_const_type ||
 281                  tag == DW_TAG_restrict_type ||
 282                  tag == DW_TAG_volatile_type ||
 283                  tag == DW_TAG_shared_type);
 284
 285         return vr_die;
 286 }
 287
 288 /* Get a type die, but skip qualifiers and typedef */
 289 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 290 {
 291         do {
 292                 vr_die = __die_get_real_type(vr_die, die_mem);
 293         } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
 294
 295         return vr_die;
 296 }
 297
 298 static bool die_is_signed_type(Dwarf_Die *tp_die)
 299 {
 300         Dwarf_Attribute attr;
 301         Dwarf_Word ret;
 302
 303         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
 304             dwarf_formudata(&attr, &ret) != 0)
 305                 return false;
 306
 307         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
 308                 ret == DW_ATE_signed_fixed);
 309 }
 310
 311 static int die_get_byte_size(Dwarf_Die *tp_die)
 312 {
 313         Dwarf_Attribute attr;
 314         Dwarf_Word ret;
 315
 316         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
 317             dwarf_formudata(&attr, &ret) != 0)
 318                 return 0;
 319
 320         return (int)ret;
 321 }
 322
 323 /* Get data_member_location offset */
 324 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
 325 {
 326         Dwarf_Attribute attr;
 327         Dwarf_Op *expr;
 328         size_t nexpr;
 329         int ret;
 330
 331         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
 332                 return -ENOENT;
 333
 334         if (dwarf_formudata(&attr, offs) != 0) {
 335                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
 336                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
 337                 if (ret < 0 || nexpr == 0)
 338                         return -ENOENT;
 339
 340                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
 341                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
 342                                  expr[0].atom, nexpr);
 343                         return -ENOTSUP;
 344                 }
 345                 *offs = (Dwarf_Word)expr[0].number;
 346         }
 347         return 0;
 348 }
 349
 350 /* Return values for die_find callbacks */
 351 enum {
 352         DIE_FIND_CB_FOUND = 0,          /* End of Search */
 353         DIE_FIND_CB_CHILD = 1,          /* Search only children */
 354         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
 355         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
 356 };
 357
 358 /* Search a child die */
 359 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
 360                                  int (*callback)(Dwarf_Die *, void *),
 361                                  void *data, Dwarf_Die *die_mem)
 362 {
 363         Dwarf_Die child_die;
 364         int ret;
 365
 366         ret = dwarf_child(rt_die, die_mem);
 367         if (ret != 0)
 368                 return NULL;
 369
 370         do {
 371                 ret = callback(die_mem, data);
 372                 if (ret == DIE_FIND_CB_FOUND)
 373                         return die_mem;
 374
 375                 if ((ret & DIE_FIND_CB_CHILD) &&
 376                     die_find_child(die_mem, callback, data, &child_die)) {
 377                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
 378                         return die_mem;
 379                 }
 380         } while ((ret & DIE_FIND_CB_SIBLING) &&
 381                  dwarf_siblingof(die_mem, die_mem) == 0);
 382
 383         return NULL;
 384 }
 385
 386 struct __addr_die_search_param {
 387         Dwarf_Addr      addr;
 388         Dwarf_Die       *die_mem;
 389 };
 390
 391 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 392 {
 393         struct __addr_die_search_param *ad = data;
 394
 395         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
 396             dwarf_haspc(fn_die, ad->addr)) {
 397                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
 398                 return DWARF_CB_ABORT;
 399         }
 400         return DWARF_CB_OK;
 401 }
 402
 403 /* Search a real subprogram including this line, */
 404 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
 405                                            Dwarf_Die *die_mem)
 406 {
 407         struct __addr_die_search_param ad;
 408         ad.addr = addr;
 409         ad.die_mem = die_mem;
 410         /* dwarf_getscopes can't find subprogram. */
 411         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
 412                 return NULL;
 413         else
 414                 return die_mem;
 415 }
 416
 417 /* die_find callback for inline function search */
 418 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 419 {
 420         Dwarf_Addr *addr = data;
 421
 422         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
 423             dwarf_haspc(die_mem, *addr))
 424                 return DIE_FIND_CB_FOUND;
 425
 426         return DIE_FIND_CB_CONTINUE;
 427 }
 428
 429 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
 430 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 431                                       Dwarf_Die *die_mem)
 432 {
 433         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 434 }
 435
 436 struct __find_variable_param {
 437         const char *name;
 438         Dwarf_Addr addr;
 439 };
 440
 441 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 442 {
 443         struct __find_variable_param *fvp = data;
 444         int tag;
 445
 446         tag = dwarf_tag(die_mem);
 447         if ((tag == DW_TAG_formal_parameter ||
 448              tag == DW_TAG_variable) &&
 449             die_compare_name(die_mem, fvp->name))
 450                 return DIE_FIND_CB_FOUND;
 451
 452         if (dwarf_haspc(die_mem, fvp->addr))
 453                 return DIE_FIND_CB_CONTINUE;
 454         else
 455                 return DIE_FIND_CB_SIBLING;
 456 }
 457
 458 /* Find a variable called 'name' at given address */
 459 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
 460                                        Dwarf_Addr addr, Dwarf_Die *die_mem)
 461 {
 462         struct __find_variable_param fvp = { .name = name, .addr = addr};
 463
 464         return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
 465                               die_mem);
 466 }
 467
 468 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
 469 {
 470         const char *name = data;
 471
 472         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
 473             die_compare_name(die_mem, name))
 474                 return DIE_FIND_CB_FOUND;
 475
 476         return DIE_FIND_CB_SIBLING;
 477 }
 478
 479 /* Find a member called 'name' */
 480 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
 481                                   Dwarf_Die *die_mem)
 482 {
 483         return die_find_child(st_die, __die_find_member_cb, (void *)name,
 484                               die_mem);
 485 }
 486
 487 /* Get the name of given variable DIE */
 488 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
 489 {
 490         Dwarf_Die type;
 491         int tag, ret, ret2;
 492         const char *tmp = "";
 493
 494         if (__die_get_real_type(vr_die, &type) == NULL)
 495                 return -ENOENT;
 496
 497         tag = dwarf_tag(&type);
 498         if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
 499                 tmp = "*";
 500         else if (tag == DW_TAG_subroutine_type) {
 501                 /* Function pointer */
 502                 ret = snprintf(buf, len, "(function_type)");
 503                 return (ret >= len) ? -E2BIG : ret;
 504         } else {
 505                 if (!dwarf_diename(&type))
 506                         return -ENOENT;
 507                 if (tag == DW_TAG_union_type)
 508                         tmp = "union ";
 509                 else if (tag == DW_TAG_structure_type)
 510                         tmp = "struct ";
 511                 /* Write a base name */
 512                 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
 513                 return (ret >= len) ? -E2BIG : ret;
 514         }
 515         ret = die_get_typename(&type, buf, len);
 516         if (ret > 0) {
 517                 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
 518                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 519         }
 520         return ret;
 521 }
 522
 523 /* Get the name and type of given variable DIE, stored as "type\tname" */
 524 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
 525 {
 526         int ret, ret2;
 527
 528         ret = die_get_typename(vr_die, buf, len);
 529         if (ret < 0) {
 530                 pr_debug("Failed to get type, make it unknown.\n");
 531                 ret = snprintf(buf, len, "(unknown_type)");
 532         }
 533         if (ret > 0) {
 534                 ret2 = snprintf(buf + ret, len - ret, "\t%s",
 535                                 dwarf_diename(vr_die));
 536                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 537         }
 538         return ret;
 539 }
 540
 541 /*
 542  * Probe finder related functions
 543  */
 544
 545 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 546 {
 547         struct probe_trace_arg_ref *ref;
 548         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 549         if (ref != NULL)
 550                 ref->offset = offs;
 551         return ref;
 552 }
 553
 554 /*
 555  * Convert a location into trace_arg.
 556  * If tvar == NULL, this just checks variable can be converted.
 557  */
 558 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 559                                      Dwarf_Op *fb_ops,
 560                                      struct probe_trace_arg *tvar)
 561 {
 562         Dwarf_Attribute attr;
 563         Dwarf_Op *op;
 564         size_t nops;
 565         unsigned int regn;
 566         Dwarf_Word offs = 0;
 567         bool ref = false;
 568         const char *regs;
 569         int ret;
 570
 571         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 572                 goto static_var;
 573
 574         /* TODO: handle more than 1 exprs */
 575         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
 576             dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
 577             nops == 0) {
 578                 /* TODO: Support const_value */
 579                 return -ENOENT;
 580         }
 581
 582         if (op->atom == DW_OP_addr) {
 583 static_var:
 584                 if (!tvar)
 585                         return 0;
 586                 /* Static variables on memory (not stack), make @varname */
 587                 ret = strlen(dwarf_diename(vr_die));
 588                 tvar->value = zalloc(ret + 2);
 589                 if (tvar->value == NULL)
 590                         return -ENOMEM;
 591                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 592                 tvar->ref = alloc_trace_arg_ref((long)offs);
 593                 if (tvar->ref == NULL)
 594                         return -ENOMEM;
 595                 return 0;
 596         }
 597
 598         /* If this is based on frame buffer, set the offset */
 599         if (op->atom == DW_OP_fbreg) {
 600                 if (fb_ops == NULL)
 601                         return -ENOTSUP;
 602                 ref = true;
 603                 offs = op->number;
 604                 op = &fb_ops[0];
 605         }
 606
 607         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 608                 regn = op->atom - DW_OP_breg0;
 609                 offs += op->number;
 610                 ref = true;
 611         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 612                 regn = op->atom - DW_OP_reg0;
 613         } else if (op->atom == DW_OP_bregx) {
 614                 regn = op->number;
 615                 offs += op->number2;
 616                 ref = true;
 617         } else if (op->atom == DW_OP_regx) {
 618                 regn = op->number;
 619         } else {
 620                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 621                 return -ENOTSUP;
 622         }
 623
 624         if (!tvar)
 625                 return 0;
 626
 627         regs = get_arch_regstr(regn);
 628         if (!regs) {
 629                 /* This should be a bug in DWARF or this tool */
 630                 pr_warning("Mapping for the register number %u "
 631                            "missing on this architecture.\n", regn);
 632                 return -ERANGE;
 633         }
 634
 635         tvar->value = strdup(regs);
 636         if (tvar->value == NULL)
 637                 return -ENOMEM;
 638
 639         if (ref) {
 640                 tvar->ref = alloc_trace_arg_ref((long)offs);
 641                 if (tvar->ref == NULL)
 642                         return -ENOMEM;
 643         }
 644         return 0;
 645 }
 646
 647 static int convert_variable_type(Dwarf_Die *vr_die,
 648                                  struct probe_trace_arg *tvar,
 649                                  const char *cast)
 650 {
 651         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 652         Dwarf_Die type;
 653         char buf[16];
 654         int ret;
 655
 656         /* TODO: check all types */
 657         if (cast && strcmp(cast, "string") != 0) {
 658                 /* Non string type is OK */
 659                 tvar->type = strdup(cast);
 660                 return (tvar->type == NULL) ? -ENOMEM : 0;
 661         }
 662
 663         if (die_get_real_type(vr_die, &type) == NULL) {
 664                 pr_warning("Failed to get a type information of %s.\n",
 665                            dwarf_diename(vr_die));
 666                 return -ENOENT;
 667         }
 668
 669         pr_debug("%s type is %s.\n",
 670                  dwarf_diename(vr_die), dwarf_diename(&type));
 671
 672         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 673                 ret = dwarf_tag(&type);
 674                 if (ret != DW_TAG_pointer_type &&
 675                     ret != DW_TAG_array_type) {
 676                         pr_warning("Failed to cast into string: "
 677                                    "%s(%s) is not a pointer nor array.\n",
 678                                    dwarf_diename(vr_die), dwarf_diename(&type));
 679                         return -EINVAL;
 680                 }
 681                 if (ret == DW_TAG_pointer_type) {
 682                         if (die_get_real_type(&type, &type) == NULL) {
 683                                 pr_warning("Failed to get a type"
 684                                            " information.\n");
 685                                 return -ENOENT;
 686                         }
 687                         while (*ref_ptr)
 688                                 ref_ptr = &(*ref_ptr)->next;
 689                         /* Add new reference with offset +0 */
 690                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 691                         if (*ref_ptr == NULL) {
 692                                 pr_warning("Out of memory error\n");
 693                                 return -ENOMEM;
 694                         }
 695                 }
 696                 if (!die_compare_name(&type, "char") &&
 697                     !die_compare_name(&type, "unsigned char")) {
 698                         pr_warning("Failed to cast into string: "
 699                                    "%s is not (unsigned) char *.\n",
 700                                    dwarf_diename(vr_die));
 701                         return -EINVAL;
 702                 }
 703                 tvar->type = strdup(cast);
 704                 return (tvar->type == NULL) ? -ENOMEM : 0;
 705         }
 706
 707         ret = die_get_byte_size(&type) * 8;
 708         if (ret) {
 709                 /* Check the bitwidth */
 710                 if (ret > MAX_BASIC_TYPE_BITS) {
 711                         pr_info("%s exceeds max-bitwidth."
 712                                 " Cut down to %d bits.\n",
 713                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 714                         ret = MAX_BASIC_TYPE_BITS;
 715                 }
 716
 717                 ret = snprintf(buf, 16, "%c%d",
 718                                die_is_signed_type(&type) ? 's' : 'u', ret);
 719                 if (ret < 0 || ret >= 16) {
 720                         if (ret >= 16)
 721                                 ret = -E2BIG;
 722                         pr_warning("Failed to convert variable type: %s\n",
 723                                    strerror(-ret));
 724                         return ret;
 725                 }
 726                 tvar->type = strdup(buf);
 727                 if (tvar->type == NULL)
 728                         return -ENOMEM;
 729         }
 730         return 0;
 731 }
 732
 733 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 734                                     struct perf_probe_arg_field *field,
 735                                     struct probe_trace_arg_ref **ref_ptr,
 736                                     Dwarf_Die *die_mem)
 737 {
 738         struct probe_trace_arg_ref *ref = *ref_ptr;
 739         Dwarf_Die type;
 740         Dwarf_Word offs;
 741         int ret, tag;
 742
 743         pr_debug("converting %s in %s\n", field->name, varname);
 744         if (die_get_real_type(vr_die, &type) == NULL) {
 745                 pr_warning("Failed to get the type of %s.\n", varname);
 746                 return -ENOENT;
 747         }
 748         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 749         tag = dwarf_tag(&type);
 750
 751         if (field->name[0] == '[' &&
 752             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 753                 if (field->next)
 754                         /* Save original type for next field */
 755                         memcpy(die_mem, &type, sizeof(*die_mem));
 756                 /* Get the type of this array */
 757                 if (die_get_real_type(&type, &type) == NULL) {
 758                         pr_warning("Failed to get the type of %s.\n", varname);
 759                         return -ENOENT;
 760                 }
 761                 pr_debug2("Array real type: (%x)\n",
 762                          (unsigned)dwarf_dieoffset(&type));
 763                 if (tag == DW_TAG_pointer_type) {
 764                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 765                         if (ref == NULL)
 766                                 return -ENOMEM;
 767                         if (*ref_ptr)
 768                                 (*ref_ptr)->next = ref;
 769                         else
 770                                 *ref_ptr = ref;
 771                 }
 772                 ref->offset += die_get_byte_size(&type) * field->index;
 773                 if (!field->next)
 774                         /* Save vr_die for converting types */
 775                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 776                 goto next;
 777         } else if (tag == DW_TAG_pointer_type) {
 778                 /* Check the pointer and dereference */
 779                 if (!field->ref) {
 780                         pr_err("Semantic error: %s must be referred by '->'\n",
 781                                field->name);
 782                         return -EINVAL;
 783                 }
 784                 /* Get the type pointed by this pointer */
 785                 if (die_get_real_type(&type, &type) == NULL) {
 786                         pr_warning("Failed to get the type of %s.\n", varname);
 787                         return -ENOENT;
 788                 }
 789                 /* Verify it is a data structure  */
 790                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 791                         pr_warning("%s is not a data structure.\n", varname);
 792                         return -EINVAL;
 793                 }
 794
 795                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 796                 if (ref == NULL)
 797                         return -ENOMEM;
 798                 if (*ref_ptr)
 799                         (*ref_ptr)->next = ref;
 800                 else
 801                         *ref_ptr = ref;
 802         } else {
 803                 /* Verify it is a data structure  */
 804                 if (tag != DW_TAG_structure_type) {
 805                         pr_warning("%s is not a data structure.\n", varname);
 806                         return -EINVAL;
 807                 }
 808                 if (field->name[0] == '[') {
 809                         pr_err("Semantic error: %s is not a pointor"
 810                                " nor array.\n", varname);
 811                         return -EINVAL;
 812                 }
 813                 if (field->ref) {
 814                         pr_err("Semantic error: %s must be referred by '.'\n",
 815                                field->name);
 816                         return -EINVAL;
 817                 }
 818                 if (!ref) {
 819                         pr_warning("Structure on a register is not "
 820                                    "supported yet.\n");
 821                         return -ENOTSUP;
 822                 }
 823         }
 824
 825         if (die_find_member(&type, field->name, die_mem) == NULL) {
 826                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 827                            dwarf_diename(&type), field->name);
 828                 return -EINVAL;
 829         }
 830
 831         /* Get the offset of the field */
 832         ret = die_get_data_member_location(die_mem, &offs);
 833         if (ret < 0) {
 834                 pr_warning("Failed to get the offset of %s.\n", field->name);
 835                 return ret;
 836         }
 837         ref->offset += (long)offs;
 838
 839 next:
 840         /* Converting next field */
 841         if (field->next)
 842                 return convert_variable_fields(die_mem, field->name,
 843                                         field->next, &ref, die_mem);
 844         else
 845                 return 0;
 846 }
 847
 848 /* Show a variables in kprobe event format */
 849 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 850 {
 851         Dwarf_Die die_mem;
 852         int ret;
 853
 854         pr_debug("Converting variable %s into trace event.\n",
 855                  dwarf_diename(vr_die));
 856
 857         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 858                                         pf->tvar);
 859         if (ret == -ENOENT)
 860                 pr_err("Failed to find the location of %s at this address.\n"
 861                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 862         else if (ret == -ENOTSUP)
 863                 pr_err("Sorry, we don't support this variable location yet.\n");
 864         else if (pf->pvar->field) {
 865                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 866                                               pf->pvar->field, &pf->tvar->ref,
 867                                               &die_mem);
 868                 vr_die = &die_mem;
 869         }
 870         if (ret == 0)
 871                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 872         /* *expr will be cached in libdw. Don't free it. */
 873         return ret;
 874 }
 875
 876 /* Find a variable in a subprogram die */
 877 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 878 {
 879         Dwarf_Die vr_die, *scopes;
 880         char buf[32], *ptr;
 881         int ret, nscopes;
 882
 883         if (!is_c_varname(pf->pvar->var)) {
 884                 /* Copy raw parameters */
 885                 pf->tvar->value = strdup(pf->pvar->var);
 886                 if (pf->tvar->value == NULL)
 887                         return -ENOMEM;
 888                 if (pf->pvar->type) {
 889                         pf->tvar->type = strdup(pf->pvar->type);
 890                         if (pf->tvar->type == NULL)
 891                                 return -ENOMEM;
 892                 }
 893                 if (pf->pvar->name) {
 894                         pf->tvar->name = strdup(pf->pvar->name);
 895                         if (pf->tvar->name == NULL)
 896                                 return -ENOMEM;
 897                 } else
 898                         pf->tvar->name = NULL;
 899                 return 0;
 900         }
 901
 902         if (pf->pvar->name)
 903                 pf->tvar->name = strdup(pf->pvar->name);
 904         else {
 905                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 906                 if (ret < 0)
 907                         return ret;
 908                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 909                 if (ptr)
 910                         *ptr = '_';
 911                 pf->tvar->name = strdup(buf);
 912         }
 913         if (pf->tvar->name == NULL)
 914                 return -ENOMEM;
 915
 916         pr_debug("Searching '%s' variable in context.\n",
 917                  pf->pvar->var);
 918         /* Search child die for local variables and parameters. */
 919         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
 920                 ret = convert_variable(&vr_die, pf);
 921         else {
 922                 /* Search upper class */
 923                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 924                 while (nscopes-- > 1) {
 925                         pr_debug("Searching variables in %s\n",
 926                                  dwarf_diename(&scopes[nscopes]));
 927                         /* We should check this scope, so give dummy address */
 928                         if (die_find_variable_at(&scopes[nscopes],
 929                                                  pf->pvar->var, 0,
 930                                                  &vr_die)) {
 931                                 ret = convert_variable(&vr_die, pf);
 932                                 goto found;
 933                         }
 934                 }
 935                 if (scopes)
 936                         free(scopes);
 937                 ret = -ENOENT;
 938         }
 939 found:
 940         if (ret < 0)
 941                 pr_warning("Failed to find '%s' in this function.\n",
 942                            pf->pvar->var);
 943         return ret;
 944 }
 945
 946 /* Convert subprogram DIE to trace point */
 947 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
 948                                   bool retprobe, struct probe_trace_point *tp)
 949 {
 950         Dwarf_Addr eaddr;
 951         const char *name;
 952
 953         /* Copy the name of probe point */
 954         name = dwarf_diename(sp_die);
 955         if (name) {
 956                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 957                         pr_warning("Failed to get entry address of %s\n",
 958                                    dwarf_diename(sp_die));
 959                         return -ENOENT;
 960                 }
 961                 tp->symbol = strdup(name);
 962                 if (tp->symbol == NULL)
 963                         return -ENOMEM;
 964                 tp->offset = (unsigned long)(paddr - eaddr);
 965         } else
 966                 /* This function has no name. */
 967                 tp->offset = (unsigned long)paddr;
 968
 969         /* Return probe must be on the head of a subprogram */
 970         if (retprobe) {
 971                 if (eaddr != paddr) {
 972                         pr_warning("Return probe must be on the head of"
 973                                    " a real function.\n");
 974                         return -EINVAL;
 975                 }
 976                 tp->retprobe = true;
 977         }
 978
 979         return 0;
 980 }
 981
 982 /* Call probe_finder callback with real subprogram DIE */
 983 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
 984 {
 985         Dwarf_Die die_mem;
 986         Dwarf_Attribute fb_attr;
 987         size_t nops;
 988         int ret;
 989
 990         /* If no real subprogram, find a real one */
 991         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
 992                 sp_die = die_find_real_subprogram(&pf->cu_die,
 993                                                   pf->addr, &die_mem);
 994                 if (!sp_die) {
 995                         pr_warning("Failed to find probe point in any "
 996                                    "functions.\n");
 997                         return -ENOENT;
 998                 }
 999         }
1000
1001         /* Get the frame base attribute/ops */
1002         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1003         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1004         if (ret <= 0 || nops == 0) {
1005                 pf->fb_ops = NULL;
1006 #if _ELFUTILS_PREREQ(0, 142)
1007         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1008                    pf->cfi != NULL) {
1009                 Dwarf_Frame *frame;
1010                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1011                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1012                         pr_warning("Failed to get call frame on 0x%jx\n",
1013                                    (uintmax_t)pf->addr);
1014                         return -ENOENT;
1015                 }
1016 #endif
1017         }
1018
1019         /* Call finder's callback handler */
1020         ret = pf->callback(sp_die, pf);
1021
1022         /* *pf->fb_ops will be cached in libdw. Don't free it. */
1023         pf->fb_ops = NULL;
1024
1025         return ret;
1026 }
1027
1028 /* Find probe point from its line number */
1029 static int find_probe_point_by_line(struct probe_finder *pf)
1030 {
1031         Dwarf_Lines *lines;
1032         Dwarf_Line *line;
1033         size_t nlines, i;
1034         Dwarf_Addr addr;
1035         int lineno;
1036         int ret = 0;
1037
1038         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1039                 pr_warning("No source lines found.\n");
1040                 return -ENOENT;
1041         }
1042
1043         for (i = 0; i < nlines && ret == 0; i++) {
1044                 line = dwarf_onesrcline(lines, i);
1045                 if (dwarf_lineno(line, &lineno) != 0 ||
1046                     lineno != pf->lno)
1047                         continue;
1048
1049                 /* TODO: Get fileno from line, but how? */
1050                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1051                         continue;
1052
1053                 if (dwarf_lineaddr(line, &addr) != 0) {
1054                         pr_warning("Failed to get the address of the line.\n");
1055                         return -ENOENT;
1056                 }
1057                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1058                          (int)i, lineno, (uintmax_t)addr);
1059                 pf->addr = addr;
1060
1061                 ret = call_probe_finder(NULL, pf);
1062                 /* Continuing, because target line might be inlined. */
1063         }
1064         return ret;
1065 }
1066
1067 /* Find lines which match lazy pattern */
1068 static int find_lazy_match_lines(struct list_head *head,
1069                                  const char *fname, const char *pat)
1070 {
1071         char *fbuf, *p1, *p2;
1072         int fd, line, nlines = -1;
1073         struct stat st;
1074
1075         fd = open(fname, O_RDONLY);
1076         if (fd < 0) {
1077                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1078                 return -errno;
1079         }
1080
1081         if (fstat(fd, &st) < 0) {
1082                 pr_warning("Failed to get the size of %s: %s\n",
1083                            fname, strerror(errno));
1084                 nlines = -errno;
1085                 goto out_close;
1086         }
1087
1088         nlines = -ENOMEM;
1089         fbuf = malloc(st.st_size + 2);
1090         if (fbuf == NULL)
1091                 goto out_close;
1092         if (read(fd, fbuf, st.st_size) < 0) {
1093                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1094                 nlines = -errno;
1095                 goto out_free_fbuf;
1096         }
1097         fbuf[st.st_size] = '\n';        /* Dummy line */
1098         fbuf[st.st_size + 1] = '\0';
1099         p1 = fbuf;
1100         line = 1;
1101         nlines = 0;
1102         while ((p2 = strchr(p1, '\n')) != NULL) {
1103                 *p2 = '\0';
1104                 if (strlazymatch(p1, pat)) {
1105                         line_list__add_line(head, line);
1106                         nlines++;
1107                 }
1108                 line++;
1109                 p1 = p2 + 1;
1110         }
1111 out_free_fbuf:
1112         free(fbuf);
1113 out_close:
1114         close(fd);
1115         return nlines;
1116 }
1117
1118 /* Find probe points from lazy pattern  */
1119 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1120 {
1121         Dwarf_Lines *lines;
1122         Dwarf_Line *line;
1123         size_t nlines, i;
1124         Dwarf_Addr addr;
1125         Dwarf_Die die_mem;
1126         int lineno;
1127         int ret = 0;
1128
1129         if (list_empty(&pf->lcache)) {
1130                 /* Matching lazy line pattern */
1131                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1132                                             pf->pev->point.lazy_line);
1133                 if (ret == 0) {
1134                         pr_debug("No matched lines found in %s.\n", pf->fname);
1135                         return 0;
1136                 } else if (ret < 0)
1137                         return ret;
1138         }
1139
1140         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1141                 pr_warning("No source lines found.\n");
1142                 return -ENOENT;
1143         }
1144
1145         for (i = 0; i < nlines && ret >= 0; i++) {
1146                 line = dwarf_onesrcline(lines, i);
1147
1148                 if (dwarf_lineno(line, &lineno) != 0 ||
1149                     !line_list__has_line(&pf->lcache, lineno))
1150                         continue;
1151
1152                 /* TODO: Get fileno from line, but how? */
1153                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1154                         continue;
1155
1156                 if (dwarf_lineaddr(line, &addr) != 0) {
1157                         pr_debug("Failed to get the address of line %d.\n",
1158                                  lineno);
1159                         continue;
1160                 }
1161                 if (sp_die) {
1162                         /* Address filtering 1: does sp_die include addr? */
1163                         if (!dwarf_haspc(sp_die, addr))
1164                                 continue;
1165                         /* Address filtering 2: No child include addr? */
1166                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1167                                 continue;
1168                 }
1169
1170                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1171                          (int)i, lineno, (unsigned long long)addr);
1172                 pf->addr = addr;
1173
1174                 ret = call_probe_finder(sp_die, pf);
1175                 /* Continuing, because target line might be inlined. */
1176         }
1177         /* TODO: deallocate lines, but how? */
1178         return ret;
1179 }
1180
1181 /* Callback parameter with return value */
1182 struct dwarf_callback_param {
1183         void *data;
1184         int retval;
1185 };
1186
1187 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1188 {
1189         struct dwarf_callback_param *param = data;
1190         struct probe_finder *pf = param->data;
1191         struct perf_probe_point *pp = &pf->pev->point;
1192         Dwarf_Addr addr;
1193
1194         if (pp->lazy_line)
1195                 param->retval = find_probe_point_lazy(in_die, pf);
1196         else {
1197                 /* Get probe address */
1198                 if (dwarf_entrypc(in_die, &addr) != 0) {
1199                         pr_warning("Failed to get entry address of %s.\n",
1200                                    dwarf_diename(in_die));
1201                         param->retval = -ENOENT;
1202                         return DWARF_CB_ABORT;
1203                 }
1204                 pf->addr = addr;
1205                 pf->addr += pp->offset;
1206                 pr_debug("found inline addr: 0x%jx\n",
1207                          (uintmax_t)pf->addr);
1208
1209                 param->retval = call_probe_finder(in_die, pf);
1210                 if (param->retval < 0)
1211                         return DWARF_CB_ABORT;
1212         }
1213
1214         return DWARF_CB_OK;
1215 }
1216
1217 /* Search function from function name */
1218 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1219 {
1220         struct dwarf_callback_param *param = data;
1221         struct probe_finder *pf = param->data;
1222         struct perf_probe_point *pp = &pf->pev->point;
1223
1224         /* Check tag and diename */
1225         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1226             !die_compare_name(sp_die, pp->function))
1227                 return DWARF_CB_OK;
1228
1229         pf->fname = dwarf_decl_file(sp_die);
1230         if (pp->line) { /* Function relative line */
1231                 dwarf_decl_line(sp_die, &pf->lno);
1232                 pf->lno += pp->line;
1233                 param->retval = find_probe_point_by_line(pf);
1234         } else if (!dwarf_func_inline(sp_die)) {
1235                 /* Real function */
1236                 if (pp->lazy_line)
1237                         param->retval = find_probe_point_lazy(sp_die, pf);
1238                 else {
1239                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1240                                 pr_warning("Failed to get entry address of "
1241                                            "%s.\n", dwarf_diename(sp_die));
1242                                 param->retval = -ENOENT;
1243                                 return DWARF_CB_ABORT;
1244                         }
1245                         pf->addr += pp->offset;
1246                         /* TODO: Check the address in this function */
1247                         param->retval = call_probe_finder(sp_die, pf);
1248                 }
1249         } else {
1250                 struct dwarf_callback_param _param = {.data = (void *)pf,
1251                                                       .retval = 0};
1252                 /* Inlined function: search instances */
1253                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1254                                             &_param);
1255                 param->retval = _param.retval;
1256         }
1257
1258         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1259 }
1260
1261 static int find_probe_point_by_func(struct probe_finder *pf)
1262 {
1263         struct dwarf_callback_param _param = {.data = (void *)pf,
1264                                               .retval = 0};
1265         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1266         return _param.retval;
1267 }
1268
1269 /* Find probe points from debuginfo */
1270 static int find_probes(int fd, struct probe_finder *pf)
1271 {
1272         struct perf_probe_point *pp = &pf->pev->point;
1273         Dwarf_Off off, noff;
1274         size_t cuhl;
1275         Dwarf_Die *diep;
1276         Dwarf *dbg = NULL;
1277         Dwfl *dwfl;
1278         Dwarf_Addr bias;        /* Currently ignored */
1279         int ret = 0;
1280
1281         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1282         if (!dbg) {
1283                 pr_warning("No debug information found in the vmlinux - "
1284                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1285                 return -EBADF;
1286         }
1287
1288 #if _ELFUTILS_PREREQ(0, 142)
1289         /* Get the call frame information from this dwarf */
1290         pf->cfi = dwarf_getcfi(dbg);
1291 #endif
1292
1293         off = 0;
1294         line_list__init(&pf->lcache);
1295         /* Loop on CUs (Compilation Unit) */
1296         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1297                ret >= 0) {
1298                 /* Get the DIE(Debugging Information Entry) of this CU */
1299                 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1300                 if (!diep)
1301                         continue;
1302
1303                 /* Check if target file is included. */
1304                 if (pp->file)
1305                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1306                 else
1307                         pf->fname = NULL;
1308
1309                 if (!pp->file || pf->fname) {
1310                         if (pp->function)
1311                                 ret = find_probe_point_by_func(pf);
1312                         else if (pp->lazy_line)
1313                                 ret = find_probe_point_lazy(NULL, pf);
1314                         else {
1315                                 pf->lno = pp->line;
1316                                 ret = find_probe_point_by_line(pf);
1317                         }
1318                 }
1319                 off = noff;
1320         }
1321         line_list__free(&pf->lcache);
1322         if (dwfl)
1323                 dwfl_end(dwfl);
1324
1325         return ret;
1326 }
1327
1328 /* Add a found probe point into trace event list */
1329 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1330 {
1331         struct trace_event_finder *tf =
1332                         container_of(pf, struct trace_event_finder, pf);
1333         struct probe_trace_event *tev;
1334         int ret, i;
1335
1336         /* Check number of tevs */
1337         if (tf->ntevs == tf->max_tevs) {
1338                 pr_warning("Too many( > %d) probe point found.\n",
1339                            tf->max_tevs);
1340                 return -ERANGE;
1341         }
1342         tev = &tf->tevs[tf->ntevs++];
1343
1344         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1345                                      &tev->point);
1346         if (ret < 0)
1347                 return ret;
1348
1349         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1350                  tev->point.offset);
1351
1352         /* Find each argument */
1353         tev->nargs = pf->pev->nargs;
1354         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1355         if (tev->args == NULL)
1356                 return -ENOMEM;
1357         for (i = 0; i < pf->pev->nargs; i++) {
1358                 pf->pvar = &pf->pev->args[i];
1359                 pf->tvar = &tev->args[i];
1360                 ret = find_variable(sp_die, pf);
1361                 if (ret != 0)
1362                         return ret;
1363         }
1364
1365         return 0;
1366 }
1367
1368 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1369 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1370                             struct probe_trace_event **tevs, int max_tevs)
1371 {
1372         struct trace_event_finder tf = {
1373                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1374                         .max_tevs = max_tevs};
1375         int ret;
1376
1377         /* Allocate result tevs array */
1378         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1379         if (*tevs == NULL)
1380                 return -ENOMEM;
1381
1382         tf.tevs = *tevs;
1383         tf.ntevs = 0;
1384
1385         ret = find_probes(fd, &tf.pf);
1386         if (ret < 0) {
1387                 free(*tevs);
1388                 *tevs = NULL;
1389                 return ret;
1390         }
1391
1392         return (ret < 0) ? ret : tf.ntevs;
1393 }
1394
1395 #define MAX_VAR_LEN 64
1396
1397 /* Collect available variables in this scope */
1398 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1399 {
1400         struct available_var_finder *af = data;
1401         struct variable_list *vl;
1402         char buf[MAX_VAR_LEN];
1403         int tag, ret;
1404
1405         vl = &af->vls[af->nvls - 1];
1406
1407         tag = dwarf_tag(die_mem);
1408         if (tag == DW_TAG_formal_parameter ||
1409             tag == DW_TAG_variable) {
1410                 ret = convert_variable_location(die_mem, af->pf.addr,
1411                                                 af->pf.fb_ops, NULL);
1412                 if (ret == 0) {
1413                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1414                         pr_debug2("Add new var: %s\n", buf);
1415                         if (ret > 0)
1416                                 strlist__add(vl->vars, buf);
1417                 }
1418         }
1419
1420         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1421                 return DIE_FIND_CB_CONTINUE;
1422         else
1423                 return DIE_FIND_CB_SIBLING;
1424 }
1425
1426 /* Add a found vars into available variables list */
1427 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1428 {
1429         struct available_var_finder *af =
1430                         container_of(pf, struct available_var_finder, pf);
1431         struct variable_list *vl;
1432         Dwarf_Die die_mem, *scopes = NULL;
1433         int ret, nscopes;
1434
1435         /* Check number of tevs */
1436         if (af->nvls == af->max_vls) {
1437                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1438                 return -ERANGE;
1439         }
1440         vl = &af->vls[af->nvls++];
1441
1442         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1443                                      &vl->point);
1444         if (ret < 0)
1445                 return ret;
1446
1447         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1448                  vl->point.offset);
1449
1450         /* Find local variables */
1451         vl->vars = strlist__new(true, NULL);
1452         if (vl->vars == NULL)
1453                 return -ENOMEM;
1454         af->child = true;
1455         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1456
1457         /* Find external variables */
1458         if (!af->externs)
1459                 goto out;
1460         /* Don't need to search child DIE for externs. */
1461         af->child = false;
1462         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1463         while (nscopes-- > 1)
1464                 die_find_child(&scopes[nscopes], collect_variables_cb,
1465                                (void *)af, &die_mem);
1466         if (scopes)
1467                 free(scopes);
1468
1469 out:
1470         if (strlist__empty(vl->vars)) {
1471                 strlist__delete(vl->vars);
1472                 vl->vars = NULL;
1473         }
1474
1475         return ret;
1476 }
1477
1478 /* Find available variables at given probe point */
1479 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1480                            struct variable_list **vls, int max_vls,
1481                            bool externs)
1482 {
1483         struct available_var_finder af = {
1484                         .pf = {.pev = pev, .callback = add_available_vars},
1485                         .max_vls = max_vls, .externs = externs};
1486         int ret;
1487
1488         /* Allocate result vls array */
1489         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1490         if (*vls == NULL)
1491                 return -ENOMEM;
1492
1493         af.vls = *vls;
1494         af.nvls = 0;
1495
1496         ret = find_probes(fd, &af.pf);
1497         if (ret < 0) {
1498                 /* Free vlist for error */
1499                 while (af.nvls--) {
1500                         if (af.vls[af.nvls].point.symbol)
1501                                 free(af.vls[af.nvls].point.symbol);
1502                         if (af.vls[af.nvls].vars)
1503                                 strlist__delete(af.vls[af.nvls].vars);
1504                 }
1505                 free(af.vls);
1506                 *vls = NULL;
1507                 return ret;
1508         }
1509
1510         return (ret < 0) ? ret : af.nvls;
1511 }
1512
1513 /* Reverse search */
1514 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1515 {
1516         Dwarf_Die cudie, spdie, indie;
1517         Dwarf *dbg = NULL;
1518         Dwfl *dwfl = NULL;
1519         Dwarf_Line *line;
1520         Dwarf_Addr laddr, eaddr, bias = 0;
1521         const char *tmp;
1522         int lineno, ret = 0;
1523         bool found = false;
1524
1525         /* Open the live linux kernel */
1526         dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1527         if (!dbg) {
1528                 pr_warning("No debug information found in the vmlinux - "
1529                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1530                 ret = -EINVAL;
1531                 goto end;
1532         }
1533
1534         /* Adjust address with bias */
1535         addr += bias;
1536         /* Find cu die */
1537         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1538                 pr_warning("Failed to find debug information for address %lx\n",
1539                            addr);
1540                 ret = -EINVAL;
1541                 goto end;
1542         }
1543
1544         /* Find a corresponding line */
1545         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1546         if (line) {
1547                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1548                     (Dwarf_Addr)addr == laddr &&
1549                     dwarf_lineno(line, &lineno) == 0) {
1550                         tmp = dwarf_linesrc(line, NULL, NULL);
1551                         if (tmp) {
1552                                 ppt->line = lineno;
1553                                 ppt->file = strdup(tmp);
1554                                 if (ppt->file == NULL) {
1555                                         ret = -ENOMEM;
1556                                         goto end;
1557                                 }
1558                                 found = true;
1559                         }
1560                 }
1561         }
1562
1563         /* Find a corresponding function */
1564         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1565                 tmp = dwarf_diename(&spdie);
1566                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1567                         goto end;
1568
1569                 if (ppt->line) {
1570                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1571                                                 &indie)) {
1572                                 /* addr in an inline function */
1573                                 tmp = dwarf_diename(&indie);
1574                                 if (!tmp)
1575                                         goto end;
1576                                 ret = dwarf_decl_line(&indie, &lineno);
1577                         } else {
1578                                 if (eaddr == addr) {    /* Function entry */
1579                                         lineno = ppt->line;
1580                                         ret = 0;
1581                                 } else
1582                                         ret = dwarf_decl_line(&spdie, &lineno);
1583                         }
1584                         if (ret == 0) {
1585                                 /* Make a relative line number */
1586                                 ppt->line -= lineno;
1587                                 goto found;
1588                         }
1589                 }
1590                 /* We don't have a line number, let's use offset */
1591                 ppt->offset = addr - (unsigned long)eaddr;
1592 found:
1593                 ppt->function = strdup(tmp);
1594                 if (ppt->function == NULL) {
1595                         ret = -ENOMEM;
1596                         goto end;
1597                 }
1598                 found = true;
1599         }
1600
1601 end:
1602         if (dwfl)
1603                 dwfl_end(dwfl);
1604         if (ret >= 0)
1605                 ret = found ? 1 : 0;
1606         return ret;
1607 }
1608
1609 /* Add a line and store the src path */
1610 static int line_range_add_line(const char *src, unsigned int lineno,
1611                                struct line_range *lr)
1612 {
1613         /* Copy source path */
1614         if (!lr->path) {
1615                 lr->path = strdup(src);
1616                 if (lr->path == NULL)
1617                         return -ENOMEM;
1618         }
1619         return line_list__add_line(&lr->line_list, lineno);
1620 }
1621
1622 /* Search function declaration lines */
1623 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1624 {
1625         struct dwarf_callback_param *param = data;
1626         struct line_finder *lf = param->data;
1627         const char *src;
1628         int lineno;
1629
1630         src = dwarf_decl_file(sp_die);
1631         if (src && strtailcmp(src, lf->fname) != 0)
1632                 return DWARF_CB_OK;
1633
1634         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1635             (lf->lno_s > lineno || lf->lno_e < lineno))
1636                 return DWARF_CB_OK;
1637
1638         param->retval = line_range_add_line(src, lineno, lf->lr);
1639         if (param->retval < 0)
1640                 return DWARF_CB_ABORT;
1641         return DWARF_CB_OK;
1642 }
1643
1644 static int find_line_range_func_decl_lines(struct line_finder *lf)
1645 {
1646         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1647         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1648         return param.retval;
1649 }
1650
1651 /* Find line range from its line number */
1652 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1653 {
1654         Dwarf_Lines *lines;
1655         Dwarf_Line *line;
1656         size_t nlines, i;
1657         Dwarf_Addr addr;
1658         int lineno, ret = 0;
1659         const char *src;
1660         Dwarf_Die die_mem;
1661
1662         line_list__init(&lf->lr->line_list);
1663         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1664                 pr_warning("No source lines found.\n");
1665                 return -ENOENT;
1666         }
1667
1668         /* Search probable lines on lines list */
1669         for (i = 0; i < nlines; i++) {
1670                 line = dwarf_onesrcline(lines, i);
1671                 if (dwarf_lineno(line, &lineno) != 0 ||
1672                     (lf->lno_s > lineno || lf->lno_e < lineno))
1673                         continue;
1674
1675                 if (sp_die) {
1676                         /* Address filtering 1: does sp_die include addr? */
1677                         if (dwarf_lineaddr(line, &addr) != 0 ||
1678                             !dwarf_haspc(sp_die, addr))
1679                                 continue;
1680
1681                         /* Address filtering 2: No child include addr? */
1682                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1683                                 continue;
1684                 }
1685
1686                 /* TODO: Get fileno from line, but how? */
1687                 src = dwarf_linesrc(line, NULL, NULL);
1688                 if (strtailcmp(src, lf->fname) != 0)
1689                         continue;
1690
1691                 ret = line_range_add_line(src, lineno, lf->lr);
1692                 if (ret < 0)
1693                         return ret;
1694         }
1695
1696         /*
1697          * Dwarf lines doesn't include function declarations. We have to
1698          * check functions list or given function.
1699          */
1700         if (sp_die) {
1701                 src = dwarf_decl_file(sp_die);
1702                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1703                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1704                         ret = line_range_add_line(src, lineno, lf->lr);
1705         } else
1706                 ret = find_line_range_func_decl_lines(lf);
1707
1708         /* Update status */
1709         if (ret >= 0)
1710                 if (!list_empty(&lf->lr->line_list))
1711                         ret = lf->found = 1;
1712                 else
1713                         ret = 0;        /* Lines are not found */
1714         else {
1715                 free(lf->lr->path);
1716                 lf->lr->path = NULL;
1717         }
1718         return ret;
1719 }
1720
1721 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1722 {
1723         struct dwarf_callback_param *param = data;
1724
1725         param->retval = find_line_range_by_line(in_die, param->data);
1726         return DWARF_CB_ABORT;  /* No need to find other instances */
1727 }
1728
1729 /* Search function from function name */
1730 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1731 {
1732         struct dwarf_callback_param *param = data;
1733         struct line_finder *lf = param->data;
1734         struct line_range *lr = lf->lr;
1735
1736         pr_debug("find (%llx) %s\n",
1737                  (unsigned long long)dwarf_dieoffset(sp_die),
1738                  dwarf_diename(sp_die));
1739         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1740             die_compare_name(sp_die, lr->function)) {
1741                 lf->fname = dwarf_decl_file(sp_die);
1742                 dwarf_decl_line(sp_die, &lr->offset);
1743                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1744                 lf->lno_s = lr->offset + lr->start;
1745                 if (lf->lno_s < 0)      /* Overflow */
1746                         lf->lno_s = INT_MAX;
1747                 lf->lno_e = lr->offset + lr->end;
1748                 if (lf->lno_e < 0)      /* Overflow */
1749                         lf->lno_e = INT_MAX;
1750                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1751                 lr->start = lf->lno_s;
1752                 lr->end = lf->lno_e;
1753                 if (dwarf_func_inline(sp_die)) {
1754                         struct dwarf_callback_param _param;
1755                         _param.data = (void *)lf;
1756                         _param.retval = 0;
1757                         dwarf_func_inline_instances(sp_die,
1758                                                     line_range_inline_cb,
1759                                                     &_param);
1760                         param->retval = _param.retval;
1761                 } else
1762                         param->retval = find_line_range_by_line(sp_die, lf);
1763                 return DWARF_CB_ABORT;
1764         }
1765         return DWARF_CB_OK;
1766 }
1767
1768 static int find_line_range_by_func(struct line_finder *lf)
1769 {
1770         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1771         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1772         return param.retval;
1773 }
1774
1775 int find_line_range(int fd, struct line_range *lr)
1776 {
1777         struct line_finder lf = {.lr = lr, .found = 0};
1778         int ret = 0;
1779         Dwarf_Off off = 0, noff;
1780         size_t cuhl;
1781         Dwarf_Die *diep;
1782         Dwarf *dbg = NULL;
1783         Dwfl *dwfl;
1784         Dwarf_Addr bias;        /* Currently ignored */
1785         const char *comp_dir;
1786
1787         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1788         if (!dbg) {
1789                 pr_warning("No debug information found in the vmlinux - "
1790                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1791                 return -EBADF;
1792         }
1793
1794         /* Loop on CUs (Compilation Unit) */
1795         while (!lf.found && ret >= 0) {
1796                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1797                         break;
1798
1799                 /* Get the DIE(Debugging Information Entry) of this CU */
1800                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1801                 if (!diep)
1802                         continue;
1803
1804                 /* Check if target file is included. */
1805                 if (lr->file)
1806                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1807                 else
1808                         lf.fname = 0;
1809
1810                 if (!lr->file || lf.fname) {
1811                         if (lr->function)
1812                                 ret = find_line_range_by_func(&lf);
1813                         else {
1814                                 lf.lno_s = lr->start;
1815                                 lf.lno_e = lr->end;
1816                                 ret = find_line_range_by_line(NULL, &lf);
1817                         }
1818                 }
1819                 off = noff;
1820         }
1821
1822         /* Store comp_dir */
1823         if (lf.found) {
1824                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1825                 if (comp_dir) {
1826                         lr->comp_dir = strdup(comp_dir);
1827                         if (!lr->comp_dir)
1828                                 ret = -ENOMEM;
1829                 }
1830         }
1831
1832         pr_debug("path: %s\n", lr->path);
1833         dwfl_end(dwfl);
1834         return (ret < 0) ? ret : lf.found;
1835 }
1836