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 DWARF register number %u "
 631                            "missing on this architecture.", 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.",
 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 information.");
 684                                 return -ENOENT;
 685                         }
 686                         while (*ref_ptr)
 687                                 ref_ptr = &(*ref_ptr)->next;
 688                         /* Add new reference with offset +0 */
 689                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 690                         if (*ref_ptr == NULL) {
 691                                 pr_warning("Out of memory error\n");
 692                                 return -ENOMEM;
 693                         }
 694                 }
 695                 if (!die_compare_name(&type, "char") &&
 696                     !die_compare_name(&type, "unsigned char")) {
 697                         pr_warning("Failed to cast into string: "
 698                                    "%s is not (unsigned) char *.",
 699                                    dwarf_diename(vr_die));
 700                         return -EINVAL;
 701                 }
 702                 tvar->type = strdup(cast);
 703                 return (tvar->type == NULL) ? -ENOMEM : 0;
 704         }
 705
 706         ret = die_get_byte_size(&type) * 8;
 707         if (ret) {
 708                 /* Check the bitwidth */
 709                 if (ret > MAX_BASIC_TYPE_BITS) {
 710                         pr_info("%s exceeds max-bitwidth."
 711                                 " Cut down to %d bits.\n",
 712                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 713                         ret = MAX_BASIC_TYPE_BITS;
 714                 }
 715
 716                 ret = snprintf(buf, 16, "%c%d",
 717                                die_is_signed_type(&type) ? 's' : 'u', ret);
 718                 if (ret < 0 || ret >= 16) {
 719                         if (ret >= 16)
 720                                 ret = -E2BIG;
 721                         pr_warning("Failed to convert variable type: %s\n",
 722                                    strerror(-ret));
 723                         return ret;
 724                 }
 725                 tvar->type = strdup(buf);
 726                 if (tvar->type == NULL)
 727                         return -ENOMEM;
 728         }
 729         return 0;
 730 }
 731
 732 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 733                                     struct perf_probe_arg_field *field,
 734                                     struct probe_trace_arg_ref **ref_ptr,
 735                                     Dwarf_Die *die_mem)
 736 {
 737         struct probe_trace_arg_ref *ref = *ref_ptr;
 738         Dwarf_Die type;
 739         Dwarf_Word offs;
 740         int ret, tag;
 741
 742         pr_debug("converting %s in %s\n", field->name, varname);
 743         if (die_get_real_type(vr_die, &type) == NULL) {
 744                 pr_warning("Failed to get the type of %s.\n", varname);
 745                 return -ENOENT;
 746         }
 747         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 748         tag = dwarf_tag(&type);
 749
 750         if (field->name[0] == '[' &&
 751             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 752                 if (field->next)
 753                         /* Save original type for next field */
 754                         memcpy(die_mem, &type, sizeof(*die_mem));
 755                 /* Get the type of this array */
 756                 if (die_get_real_type(&type, &type) == NULL) {
 757                         pr_warning("Failed to get the type of %s.\n", varname);
 758                         return -ENOENT;
 759                 }
 760                 pr_debug2("Array real type: (%x)\n",
 761                          (unsigned)dwarf_dieoffset(&type));
 762                 if (tag == DW_TAG_pointer_type) {
 763                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 764                         if (ref == NULL)
 765                                 return -ENOMEM;
 766                         if (*ref_ptr)
 767                                 (*ref_ptr)->next = ref;
 768                         else
 769                                 *ref_ptr = ref;
 770                 }
 771                 ref->offset += die_get_byte_size(&type) * field->index;
 772                 if (!field->next)
 773                         /* Save vr_die for converting types */
 774                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 775                 goto next;
 776         } else if (tag == DW_TAG_pointer_type) {
 777                 /* Check the pointer and dereference */
 778                 if (!field->ref) {
 779                         pr_err("Semantic error: %s must be referred by '->'\n",
 780                                field->name);
 781                         return -EINVAL;
 782                 }
 783                 /* Get the type pointed by this pointer */
 784                 if (die_get_real_type(&type, &type) == NULL) {
 785                         pr_warning("Failed to get the type of %s.\n", varname);
 786                         return -ENOENT;
 787                 }
 788                 /* Verify it is a data structure  */
 789                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 790                         pr_warning("%s is not a data structure.\n", varname);
 791                         return -EINVAL;
 792                 }
 793
 794                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 795                 if (ref == NULL)
 796                         return -ENOMEM;
 797                 if (*ref_ptr)
 798                         (*ref_ptr)->next = ref;
 799                 else
 800                         *ref_ptr = ref;
 801         } else {
 802                 /* Verify it is a data structure  */
 803                 if (tag != DW_TAG_structure_type) {
 804                         pr_warning("%s is not a data structure.\n", varname);
 805                         return -EINVAL;
 806                 }
 807                 if (field->name[0] == '[') {
 808                         pr_err("Semantic error: %s is not a pointor nor array.",
 809                                varname);
 810                         return -EINVAL;
 811                 }
 812                 if (field->ref) {
 813                         pr_err("Semantic error: %s must be referred by '.'\n",
 814                                field->name);
 815                         return -EINVAL;
 816                 }
 817                 if (!ref) {
 818                         pr_warning("Structure on a register is not "
 819                                    "supported yet.\n");
 820                         return -ENOTSUP;
 821                 }
 822         }
 823
 824         if (die_find_member(&type, field->name, die_mem) == NULL) {
 825                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 826                            dwarf_diename(&type), field->name);
 827                 return -EINVAL;
 828         }
 829
 830         /* Get the offset of the field */
 831         ret = die_get_data_member_location(die_mem, &offs);
 832         if (ret < 0) {
 833                 pr_warning("Failed to get the offset of %s.\n", field->name);
 834                 return ret;
 835         }
 836         ref->offset += (long)offs;
 837
 838 next:
 839         /* Converting next field */
 840         if (field->next)
 841                 return convert_variable_fields(die_mem, field->name,
 842                                         field->next, &ref, die_mem);
 843         else
 844                 return 0;
 845 }
 846
 847 /* Show a variables in kprobe event format */
 848 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 849 {
 850         Dwarf_Die die_mem;
 851         int ret;
 852
 853         pr_debug("Converting variable %s into trace event.\n",
 854                  dwarf_diename(vr_die));
 855
 856         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 857                                         pf->tvar);
 858         if (ret == -ENOENT)
 859                 pr_err("Failed to find the location of %s at this address.\n"
 860                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 861         else if (ret == -ENOTSUP)
 862                 pr_err("Sorry, we don't support this variable location yet.\n");
 863         else if (pf->pvar->field) {
 864                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 865                                               pf->pvar->field, &pf->tvar->ref,
 866                                               &die_mem);
 867                 vr_die = &die_mem;
 868         }
 869         if (ret == 0)
 870                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 871         /* *expr will be cached in libdw. Don't free it. */
 872         return ret;
 873 }
 874
 875 /* Find a variable in a subprogram die */
 876 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 877 {
 878         Dwarf_Die vr_die, *scopes;
 879         char buf[32], *ptr;
 880         int ret, nscopes;
 881
 882         if (!is_c_varname(pf->pvar->var)) {
 883                 /* Copy raw parameters */
 884                 pf->tvar->value = strdup(pf->pvar->var);
 885                 if (pf->tvar->value == NULL)
 886                         return -ENOMEM;
 887                 if (pf->pvar->type) {
 888                         pf->tvar->type = strdup(pf->pvar->type);
 889                         if (pf->tvar->type == NULL)
 890                                 return -ENOMEM;
 891                 }
 892                 if (pf->pvar->name) {
 893                         pf->tvar->name = strdup(pf->pvar->name);
 894                         if (pf->tvar->name == NULL)
 895                                 return -ENOMEM;
 896                 } else
 897                         pf->tvar->name = NULL;
 898                 return 0;
 899         }
 900
 901         if (pf->pvar->name)
 902                 pf->tvar->name = strdup(pf->pvar->name);
 903         else {
 904                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 905                 if (ret < 0)
 906                         return ret;
 907                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 908                 if (ptr)
 909                         *ptr = '_';
 910                 pf->tvar->name = strdup(buf);
 911         }
 912         if (pf->tvar->name == NULL)
 913                 return -ENOMEM;
 914
 915         pr_debug("Searching '%s' variable in context.\n",
 916                  pf->pvar->var);
 917         /* Search child die for local variables and parameters. */
 918         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
 919                 ret = convert_variable(&vr_die, pf);
 920         else {
 921                 /* Search upper class */
 922                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 923                 while (nscopes-- > 1) {
 924                         pr_debug("Searching variables in %s\n",
 925                                  dwarf_diename(&scopes[nscopes]));
 926                         /* We should check this scope, so give dummy address */
 927                         if (die_find_variable_at(&scopes[nscopes],
 928                                                  pf->pvar->var, 0,
 929                                                  &vr_die)) {
 930                                 ret = convert_variable(&vr_die, pf);
 931                                 goto found;
 932                         }
 933                 }
 934                 if (scopes)
 935                         free(scopes);
 936                 ret = -ENOENT;
 937         }
 938 found:
 939         if (ret < 0)
 940                 pr_warning("Failed to find '%s' in this function.\n",
 941                            pf->pvar->var);
 942         return ret;
 943 }
 944
 945 /* Convert subprogram DIE to trace point */
 946 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
 947                                   bool retprobe, struct probe_trace_point *tp)
 948 {
 949         Dwarf_Addr eaddr;
 950         const char *name;
 951
 952         /* Copy the name of probe point */
 953         name = dwarf_diename(sp_die);
 954         if (name) {
 955                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 956                         pr_warning("Failed to get entry pc of %s\n",
 957                                    dwarf_diename(sp_die));
 958                         return -ENOENT;
 959                 }
 960                 tp->symbol = strdup(name);
 961                 if (tp->symbol == NULL)
 962                         return -ENOMEM;
 963                 tp->offset = (unsigned long)(paddr - eaddr);
 964         } else
 965                 /* This function has no name. */
 966                 tp->offset = (unsigned long)paddr;
 967
 968         /* Return probe must be on the head of a subprogram */
 969         if (retprobe) {
 970                 if (eaddr != paddr) {
 971                         pr_warning("Return probe must be on the head of"
 972                                    " a real function\n");
 973                         return -EINVAL;
 974                 }
 975                 tp->retprobe = true;
 976         }
 977
 978         return 0;
 979 }
 980
 981 /* Call probe_finder callback with real subprogram DIE */
 982 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
 983 {
 984         Dwarf_Die die_mem;
 985         Dwarf_Attribute fb_attr;
 986         size_t nops;
 987         int ret;
 988
 989         /* If no real subprogram, find a real one */
 990         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
 991                 sp_die = die_find_real_subprogram(&pf->cu_die,
 992                                                   pf->addr, &die_mem);
 993                 if (!sp_die) {
 994                         pr_warning("Failed to find probe point in any "
 995                                    "functions.\n");
 996                         return -ENOENT;
 997                 }
 998         }
 999
1000         /* Get the frame base attribute/ops */
1001         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1002         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1003         if (ret <= 0 || nops == 0) {
1004                 pf->fb_ops = NULL;
1005 #if _ELFUTILS_PREREQ(0, 142)
1006         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1007                    pf->cfi != NULL) {
1008                 Dwarf_Frame *frame;
1009                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1010                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1011                         pr_warning("Failed to get CFA on 0x%jx\n",
1012                                    (uintmax_t)pf->addr);
1013                         return -ENOENT;
1014                 }
1015 #endif
1016         }
1017
1018         /* Call finder's callback handler */
1019         ret = pf->callback(sp_die, pf);
1020
1021         /* *pf->fb_ops will be cached in libdw. Don't free it. */
1022         pf->fb_ops = NULL;
1023
1024         return ret;
1025 }
1026
1027 /* Find probe point from its line number */
1028 static int find_probe_point_by_line(struct probe_finder *pf)
1029 {
1030         Dwarf_Lines *lines;
1031         Dwarf_Line *line;
1032         size_t nlines, i;
1033         Dwarf_Addr addr;
1034         int lineno;
1035         int ret = 0;
1036
1037         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1038                 pr_warning("No source lines found in this CU.\n");
1039                 return -ENOENT;
1040         }
1041
1042         for (i = 0; i < nlines && ret == 0; i++) {
1043                 line = dwarf_onesrcline(lines, i);
1044                 if (dwarf_lineno(line, &lineno) != 0 ||
1045                     lineno != pf->lno)
1046                         continue;
1047
1048                 /* TODO: Get fileno from line, but how? */
1049                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1050                         continue;
1051
1052                 if (dwarf_lineaddr(line, &addr) != 0) {
1053                         pr_warning("Failed to get the address of the line.\n");
1054                         return -ENOENT;
1055                 }
1056                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1057                          (int)i, lineno, (uintmax_t)addr);
1058                 pf->addr = addr;
1059
1060                 ret = call_probe_finder(NULL, pf);
1061                 /* Continuing, because target line might be inlined. */
1062         }
1063         return ret;
1064 }
1065
1066 /* Find lines which match lazy pattern */
1067 static int find_lazy_match_lines(struct list_head *head,
1068                                  const char *fname, const char *pat)
1069 {
1070         char *fbuf, *p1, *p2;
1071         int fd, line, nlines = -1;
1072         struct stat st;
1073
1074         fd = open(fname, O_RDONLY);
1075         if (fd < 0) {
1076                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1077                 return -errno;
1078         }
1079
1080         if (fstat(fd, &st) < 0) {
1081                 pr_warning("Failed to get the size of %s: %s\n",
1082                            fname, strerror(errno));
1083                 nlines = -errno;
1084                 goto out_close;
1085         }
1086
1087         nlines = -ENOMEM;
1088         fbuf = malloc(st.st_size + 2);
1089         if (fbuf == NULL)
1090                 goto out_close;
1091         if (read(fd, fbuf, st.st_size) < 0) {
1092                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1093                 nlines = -errno;
1094                 goto out_free_fbuf;
1095         }
1096         fbuf[st.st_size] = '\n';        /* Dummy line */
1097         fbuf[st.st_size + 1] = '\0';
1098         p1 = fbuf;
1099         line = 1;
1100         nlines = 0;
1101         while ((p2 = strchr(p1, '\n')) != NULL) {
1102                 *p2 = '\0';
1103                 if (strlazymatch(p1, pat)) {
1104                         line_list__add_line(head, line);
1105                         nlines++;
1106                 }
1107                 line++;
1108                 p1 = p2 + 1;
1109         }
1110 out_free_fbuf:
1111         free(fbuf);
1112 out_close:
1113         close(fd);
1114         return nlines;
1115 }
1116
1117 /* Find probe points from lazy pattern  */
1118 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1119 {
1120         Dwarf_Lines *lines;
1121         Dwarf_Line *line;
1122         size_t nlines, i;
1123         Dwarf_Addr addr;
1124         Dwarf_Die die_mem;
1125         int lineno;
1126         int ret = 0;
1127
1128         if (list_empty(&pf->lcache)) {
1129                 /* Matching lazy line pattern */
1130                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1131                                             pf->pev->point.lazy_line);
1132                 if (ret == 0) {
1133                         pr_debug("No matched lines found in %s.\n", pf->fname);
1134                         return 0;
1135                 } else if (ret < 0)
1136                         return ret;
1137         }
1138
1139         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1140                 pr_warning("No source lines found in this CU.\n");
1141                 return -ENOENT;
1142         }
1143
1144         for (i = 0; i < nlines && ret >= 0; i++) {
1145                 line = dwarf_onesrcline(lines, i);
1146
1147                 if (dwarf_lineno(line, &lineno) != 0 ||
1148                     !line_list__has_line(&pf->lcache, lineno))
1149                         continue;
1150
1151                 /* TODO: Get fileno from line, but how? */
1152                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1153                         continue;
1154
1155                 if (dwarf_lineaddr(line, &addr) != 0) {
1156                         pr_debug("Failed to get the address of line %d.\n",
1157                                  lineno);
1158                         continue;
1159                 }
1160                 if (sp_die) {
1161                         /* Address filtering 1: does sp_die include addr? */
1162                         if (!dwarf_haspc(sp_die, addr))
1163                                 continue;
1164                         /* Address filtering 2: No child include addr? */
1165                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1166                                 continue;
1167                 }
1168
1169                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1170                          (int)i, lineno, (unsigned long long)addr);
1171                 pf->addr = addr;
1172
1173                 ret = call_probe_finder(sp_die, pf);
1174                 /* Continuing, because target line might be inlined. */
1175         }
1176         /* TODO: deallocate lines, but how? */
1177         return ret;
1178 }
1179
1180 /* Callback parameter with return value */
1181 struct dwarf_callback_param {
1182         void *data;
1183         int retval;
1184 };
1185
1186 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1187 {
1188         struct dwarf_callback_param *param = data;
1189         struct probe_finder *pf = param->data;
1190         struct perf_probe_point *pp = &pf->pev->point;
1191         Dwarf_Addr addr;
1192
1193         if (pp->lazy_line)
1194                 param->retval = find_probe_point_lazy(in_die, pf);
1195         else {
1196                 /* Get probe address */
1197                 if (dwarf_entrypc(in_die, &addr) != 0) {
1198                         pr_warning("Failed to get entry pc of %s.\n",
1199                                    dwarf_diename(in_die));
1200                         param->retval = -ENOENT;
1201                         return DWARF_CB_ABORT;
1202                 }
1203                 pf->addr = addr;
1204                 pf->addr += pp->offset;
1205                 pr_debug("found inline addr: 0x%jx\n",
1206                          (uintmax_t)pf->addr);
1207
1208                 param->retval = call_probe_finder(in_die, pf);
1209                 if (param->retval < 0)
1210                         return DWARF_CB_ABORT;
1211         }
1212
1213         return DWARF_CB_OK;
1214 }
1215
1216 /* Search function from function name */
1217 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1218 {
1219         struct dwarf_callback_param *param = data;
1220         struct probe_finder *pf = param->data;
1221         struct perf_probe_point *pp = &pf->pev->point;
1222
1223         /* Check tag and diename */
1224         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1225             !die_compare_name(sp_die, pp->function))
1226                 return DWARF_CB_OK;
1227
1228         pf->fname = dwarf_decl_file(sp_die);
1229         if (pp->line) { /* Function relative line */
1230                 dwarf_decl_line(sp_die, &pf->lno);
1231                 pf->lno += pp->line;
1232                 param->retval = find_probe_point_by_line(pf);
1233         } else if (!dwarf_func_inline(sp_die)) {
1234                 /* Real function */
1235                 if (pp->lazy_line)
1236                         param->retval = find_probe_point_lazy(sp_die, pf);
1237                 else {
1238                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1239                                 pr_warning("Failed to get entry pc of %s.\n",
1240                                            dwarf_diename(sp_die));
1241                                 param->retval = -ENOENT;
1242                                 return DWARF_CB_ABORT;
1243                         }
1244                         pf->addr += pp->offset;
1245                         /* TODO: Check the address in this function */
1246                         param->retval = call_probe_finder(sp_die, pf);
1247                 }
1248         } else {
1249                 struct dwarf_callback_param _param = {.data = (void *)pf,
1250                                                       .retval = 0};
1251                 /* Inlined function: search instances */
1252                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1253                                             &_param);
1254                 param->retval = _param.retval;
1255         }
1256
1257         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1258 }
1259
1260 static int find_probe_point_by_func(struct probe_finder *pf)
1261 {
1262         struct dwarf_callback_param _param = {.data = (void *)pf,
1263                                               .retval = 0};
1264         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1265         return _param.retval;
1266 }
1267
1268 /* Find probe points from debuginfo */
1269 static int find_probes(int fd, struct probe_finder *pf)
1270 {
1271         struct perf_probe_point *pp = &pf->pev->point;
1272         Dwarf_Off off, noff;
1273         size_t cuhl;
1274         Dwarf_Die *diep;
1275         Dwarf *dbg = NULL;
1276         Dwfl *dwfl;
1277         Dwarf_Addr bias;        /* Currently ignored */
1278         int ret = 0;
1279
1280         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1281         if (!dbg) {
1282                 pr_warning("No dwarf info found in the vmlinux - "
1283                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1284                 return -EBADF;
1285         }
1286
1287 #if _ELFUTILS_PREREQ(0, 142)
1288         /* Get the call frame information from this dwarf */
1289         pf->cfi = dwarf_getcfi(dbg);
1290 #endif
1291
1292         off = 0;
1293         line_list__init(&pf->lcache);
1294         /* Loop on CUs (Compilation Unit) */
1295         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1296                ret >= 0) {
1297                 /* Get the DIE(Debugging Information Entry) of this CU */
1298                 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1299                 if (!diep)
1300                         continue;
1301
1302                 /* Check if target file is included. */
1303                 if (pp->file)
1304                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1305                 else
1306                         pf->fname = NULL;
1307
1308                 if (!pp->file || pf->fname) {
1309                         if (pp->function)
1310                                 ret = find_probe_point_by_func(pf);
1311                         else if (pp->lazy_line)
1312                                 ret = find_probe_point_lazy(NULL, pf);
1313                         else {
1314                                 pf->lno = pp->line;
1315                                 ret = find_probe_point_by_line(pf);
1316                         }
1317                 }
1318                 off = noff;
1319         }
1320         line_list__free(&pf->lcache);
1321         if (dwfl)
1322                 dwfl_end(dwfl);
1323
1324         return ret;
1325 }
1326
1327 /* Add a found probe point into trace event list */
1328 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1329 {
1330         struct trace_event_finder *tf =
1331                         container_of(pf, struct trace_event_finder, pf);
1332         struct probe_trace_event *tev;
1333         int ret, i;
1334
1335         /* Check number of tevs */
1336         if (tf->ntevs == tf->max_tevs) {
1337                 pr_warning("Too many( > %d) probe point found.\n",
1338                            tf->max_tevs);
1339                 return -ERANGE;
1340         }
1341         tev = &tf->tevs[tf->ntevs++];
1342
1343         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1344                                      &tev->point);
1345         if (ret < 0)
1346                 return ret;
1347
1348         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1349                  tev->point.offset);
1350
1351         /* Find each argument */
1352         tev->nargs = pf->pev->nargs;
1353         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1354         if (tev->args == NULL)
1355                 return -ENOMEM;
1356         for (i = 0; i < pf->pev->nargs; i++) {
1357                 pf->pvar = &pf->pev->args[i];
1358                 pf->tvar = &tev->args[i];
1359                 ret = find_variable(sp_die, pf);
1360                 if (ret != 0)
1361                         return ret;
1362         }
1363
1364         return 0;
1365 }
1366
1367 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1368 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1369                             struct probe_trace_event **tevs, int max_tevs)
1370 {
1371         struct trace_event_finder tf = {
1372                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1373                         .max_tevs = max_tevs};
1374         int ret;
1375
1376         /* Allocate result tevs array */
1377         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1378         if (*tevs == NULL)
1379                 return -ENOMEM;
1380
1381         tf.tevs = *tevs;
1382         tf.ntevs = 0;
1383
1384         ret = find_probes(fd, &tf.pf);
1385         if (ret < 0) {
1386                 free(*tevs);
1387                 *tevs = NULL;
1388                 return ret;
1389         }
1390
1391         return (ret < 0) ? ret : tf.ntevs;
1392 }
1393
1394 #define MAX_VAR_LEN 64
1395
1396 /* Collect available variables in this scope */
1397 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1398 {
1399         struct available_var_finder *af = data;
1400         struct variable_list *vl;
1401         char buf[MAX_VAR_LEN];
1402         int tag, ret;
1403
1404         vl = &af->vls[af->nvls - 1];
1405
1406         tag = dwarf_tag(die_mem);
1407         if (tag == DW_TAG_formal_parameter ||
1408             tag == DW_TAG_variable) {
1409                 ret = convert_variable_location(die_mem, af->pf.addr,
1410                                                 af->pf.fb_ops, NULL);
1411                 if (ret == 0) {
1412                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1413                         pr_debug2("Add new var: %s\n", buf);
1414                         if (ret > 0)
1415                                 strlist__add(vl->vars, buf);
1416                 }
1417         }
1418
1419         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1420                 return DIE_FIND_CB_CONTINUE;
1421         else
1422                 return DIE_FIND_CB_SIBLING;
1423 }
1424
1425 /* Add a found vars into available variables list */
1426 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1427 {
1428         struct available_var_finder *af =
1429                         container_of(pf, struct available_var_finder, pf);
1430         struct variable_list *vl;
1431         Dwarf_Die die_mem, *scopes = NULL;
1432         int ret, nscopes;
1433
1434         /* Check number of tevs */
1435         if (af->nvls == af->max_vls) {
1436                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1437                 return -ERANGE;
1438         }
1439         vl = &af->vls[af->nvls++];
1440
1441         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1442                                      &vl->point);
1443         if (ret < 0)
1444                 return ret;
1445
1446         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1447                  vl->point.offset);
1448
1449         /* Find local variables */
1450         vl->vars = strlist__new(true, NULL);
1451         if (vl->vars == NULL)
1452                 return -ENOMEM;
1453         af->child = true;
1454         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1455
1456         /* Find external variables */
1457         if (!af->externs)
1458                 goto out;
1459         /* Don't need to search child DIE for externs. */
1460         af->child = false;
1461         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1462         while (nscopes-- > 1)
1463                 die_find_child(&scopes[nscopes], collect_variables_cb,
1464                                (void *)af, &die_mem);
1465         if (scopes)
1466                 free(scopes);
1467
1468 out:
1469         if (strlist__empty(vl->vars)) {
1470                 strlist__delete(vl->vars);
1471                 vl->vars = NULL;
1472         }
1473
1474         return ret;
1475 }
1476
1477 /* Find available variables at given probe point */
1478 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1479                            struct variable_list **vls, int max_vls,
1480                            bool externs)
1481 {
1482         struct available_var_finder af = {
1483                         .pf = {.pev = pev, .callback = add_available_vars},
1484                         .max_vls = max_vls, .externs = externs};
1485         int ret;
1486
1487         /* Allocate result vls array */
1488         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1489         if (*vls == NULL)
1490                 return -ENOMEM;
1491
1492         af.vls = *vls;
1493         af.nvls = 0;
1494
1495         ret = find_probes(fd, &af.pf);
1496         if (ret < 0) {
1497                 /* Free vlist for error */
1498                 while (af.nvls--) {
1499                         if (af.vls[af.nvls].point.symbol)
1500                                 free(af.vls[af.nvls].point.symbol);
1501                         if (af.vls[af.nvls].vars)
1502                                 strlist__delete(af.vls[af.nvls].vars);
1503                 }
1504                 free(af.vls);
1505                 *vls = NULL;
1506                 return ret;
1507         }
1508
1509         return (ret < 0) ? ret : af.nvls;
1510 }
1511
1512 /* Reverse search */
1513 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1514 {
1515         Dwarf_Die cudie, spdie, indie;
1516         Dwarf *dbg = NULL;
1517         Dwfl *dwfl = NULL;
1518         Dwarf_Line *line;
1519         Dwarf_Addr laddr, eaddr, bias = 0;
1520         const char *tmp;
1521         int lineno, ret = 0;
1522         bool found = false;
1523
1524         /* Open the live linux kernel */
1525         dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1526         if (!dbg) {
1527                 pr_warning("No dwarf info found in the vmlinux - "
1528                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1529                 ret = -EINVAL;
1530                 goto end;
1531         }
1532
1533         /* Adjust address with bias */
1534         addr += bias;
1535         /* Find cu die */
1536         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1537                 pr_warning("No CU DIE is found at %lx\n", addr);
1538                 ret = -EINVAL;
1539                 goto end;
1540         }
1541
1542         /* Find a corresponding line */
1543         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1544         if (line) {
1545                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1546                     (Dwarf_Addr)addr == laddr &&
1547                     dwarf_lineno(line, &lineno) == 0) {
1548                         tmp = dwarf_linesrc(line, NULL, NULL);
1549                         if (tmp) {
1550                                 ppt->line = lineno;
1551                                 ppt->file = strdup(tmp);
1552                                 if (ppt->file == NULL) {
1553                                         ret = -ENOMEM;
1554                                         goto end;
1555                                 }
1556                                 found = true;
1557                         }
1558                 }
1559         }
1560
1561         /* Find a corresponding function */
1562         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1563                 tmp = dwarf_diename(&spdie);
1564                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1565                         goto end;
1566
1567                 if (ppt->line) {
1568                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1569                                                 &indie)) {
1570                                 /* addr in an inline function */
1571                                 tmp = dwarf_diename(&indie);
1572                                 if (!tmp)
1573                                         goto end;
1574                                 ret = dwarf_decl_line(&indie, &lineno);
1575                         } else {
1576                                 if (eaddr == addr) {    /* Function entry */
1577                                         lineno = ppt->line;
1578                                         ret = 0;
1579                                 } else
1580                                         ret = dwarf_decl_line(&spdie, &lineno);
1581                         }
1582                         if (ret == 0) {
1583                                 /* Make a relative line number */
1584                                 ppt->line -= lineno;
1585                                 goto found;
1586                         }
1587                 }
1588                 /* We don't have a line number, let's use offset */
1589                 ppt->offset = addr - (unsigned long)eaddr;
1590 found:
1591                 ppt->function = strdup(tmp);
1592                 if (ppt->function == NULL) {
1593                         ret = -ENOMEM;
1594                         goto end;
1595                 }
1596                 found = true;
1597         }
1598
1599 end:
1600         if (dwfl)
1601                 dwfl_end(dwfl);
1602         if (ret >= 0)
1603                 ret = found ? 1 : 0;
1604         return ret;
1605 }
1606
1607 /* Add a line and store the src path */
1608 static int line_range_add_line(const char *src, unsigned int lineno,
1609                                struct line_range *lr)
1610 {
1611         /* Copy source path */
1612         if (!lr->path) {
1613                 lr->path = strdup(src);
1614                 if (lr->path == NULL)
1615                         return -ENOMEM;
1616         }
1617         return line_list__add_line(&lr->line_list, lineno);
1618 }
1619
1620 /* Search function declaration lines */
1621 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1622 {
1623         struct dwarf_callback_param *param = data;
1624         struct line_finder *lf = param->data;
1625         const char *src;
1626         int lineno;
1627
1628         src = dwarf_decl_file(sp_die);
1629         if (src && strtailcmp(src, lf->fname) != 0)
1630                 return DWARF_CB_OK;
1631
1632         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1633             (lf->lno_s > lineno || lf->lno_e < lineno))
1634                 return DWARF_CB_OK;
1635
1636         param->retval = line_range_add_line(src, lineno, lf->lr);
1637         if (param->retval < 0)
1638                 return DWARF_CB_ABORT;
1639         return DWARF_CB_OK;
1640 }
1641
1642 static int find_line_range_func_decl_lines(struct line_finder *lf)
1643 {
1644         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1645         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1646         return param.retval;
1647 }
1648
1649 /* Find line range from its line number */
1650 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1651 {
1652         Dwarf_Lines *lines;
1653         Dwarf_Line *line;
1654         size_t nlines, i;
1655         Dwarf_Addr addr;
1656         int lineno, ret = 0;
1657         const char *src;
1658         Dwarf_Die die_mem;
1659
1660         line_list__init(&lf->lr->line_list);
1661         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1662                 pr_warning("No source lines found in this CU.\n");
1663                 return -ENOENT;
1664         }
1665
1666         /* Search probable lines on lines list */
1667         for (i = 0; i < nlines; i++) {
1668                 line = dwarf_onesrcline(lines, i);
1669                 if (dwarf_lineno(line, &lineno) != 0 ||
1670                     (lf->lno_s > lineno || lf->lno_e < lineno))
1671                         continue;
1672
1673                 if (sp_die) {
1674                         /* Address filtering 1: does sp_die include addr? */
1675                         if (dwarf_lineaddr(line, &addr) != 0 ||
1676                             !dwarf_haspc(sp_die, addr))
1677                                 continue;
1678
1679                         /* Address filtering 2: No child include addr? */
1680                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1681                                 continue;
1682                 }
1683
1684                 /* TODO: Get fileno from line, but how? */
1685                 src = dwarf_linesrc(line, NULL, NULL);
1686                 if (strtailcmp(src, lf->fname) != 0)
1687                         continue;
1688
1689                 ret = line_range_add_line(src, lineno, lf->lr);
1690                 if (ret < 0)
1691                         return ret;
1692         }
1693
1694         /*
1695          * Dwarf lines doesn't include function declarations. We have to
1696          * check functions list or given function.
1697          */
1698         if (sp_die) {
1699                 src = dwarf_decl_file(sp_die);
1700                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1701                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1702                         ret = line_range_add_line(src, lineno, lf->lr);
1703         } else
1704                 ret = find_line_range_func_decl_lines(lf);
1705
1706         /* Update status */
1707         if (ret >= 0)
1708                 if (!list_empty(&lf->lr->line_list))
1709                         ret = lf->found = 1;
1710                 else
1711                         ret = 0;        /* Lines are not found */
1712         else {
1713                 free(lf->lr->path);
1714                 lf->lr->path = NULL;
1715         }
1716         return ret;
1717 }
1718
1719 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1720 {
1721         struct dwarf_callback_param *param = data;
1722
1723         param->retval = find_line_range_by_line(in_die, param->data);
1724         return DWARF_CB_ABORT;  /* No need to find other instances */
1725 }
1726
1727 /* Search function from function name */
1728 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1729 {
1730         struct dwarf_callback_param *param = data;
1731         struct line_finder *lf = param->data;
1732         struct line_range *lr = lf->lr;
1733
1734         pr_debug("find (%llx) %s\n",
1735                  (unsigned long long)dwarf_dieoffset(sp_die),
1736                  dwarf_diename(sp_die));
1737         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1738             die_compare_name(sp_die, lr->function)) {
1739                 lf->fname = dwarf_decl_file(sp_die);
1740                 dwarf_decl_line(sp_die, &lr->offset);
1741                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1742                 lf->lno_s = lr->offset + lr->start;
1743                 if (lf->lno_s < 0)      /* Overflow */
1744                         lf->lno_s = INT_MAX;
1745                 lf->lno_e = lr->offset + lr->end;
1746                 if (lf->lno_e < 0)      /* Overflow */
1747                         lf->lno_e = INT_MAX;
1748                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1749                 lr->start = lf->lno_s;
1750                 lr->end = lf->lno_e;
1751                 if (dwarf_func_inline(sp_die)) {
1752                         struct dwarf_callback_param _param;
1753                         _param.data = (void *)lf;
1754                         _param.retval = 0;
1755                         dwarf_func_inline_instances(sp_die,
1756                                                     line_range_inline_cb,
1757                                                     &_param);
1758                         param->retval = _param.retval;
1759                 } else
1760                         param->retval = find_line_range_by_line(sp_die, lf);
1761                 return DWARF_CB_ABORT;
1762         }
1763         return DWARF_CB_OK;
1764 }
1765
1766 static int find_line_range_by_func(struct line_finder *lf)
1767 {
1768         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1769         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1770         return param.retval;
1771 }
1772
1773 int find_line_range(int fd, struct line_range *lr)
1774 {
1775         struct line_finder lf = {.lr = lr, .found = 0};
1776         int ret = 0;
1777         Dwarf_Off off = 0, noff;
1778         size_t cuhl;
1779         Dwarf_Die *diep;
1780         Dwarf *dbg = NULL;
1781         Dwfl *dwfl;
1782         Dwarf_Addr bias;        /* Currently ignored */
1783         const char *comp_dir;
1784
1785         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1786         if (!dbg) {
1787                 pr_warning("No dwarf info found in the vmlinux - "
1788                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1789                 return -EBADF;
1790         }
1791
1792         /* Loop on CUs (Compilation Unit) */
1793         while (!lf.found && ret >= 0) {
1794                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1795                         break;
1796
1797                 /* Get the DIE(Debugging Information Entry) of this CU */
1798                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1799                 if (!diep)
1800                         continue;
1801
1802                 /* Check if target file is included. */
1803                 if (lr->file)
1804                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1805                 else
1806                         lf.fname = 0;
1807
1808                 if (!lr->file || lf.fname) {
1809                         if (lr->function)
1810                                 ret = find_line_range_by_func(&lf);
1811                         else {
1812                                 lf.lno_s = lr->start;
1813                                 lf.lno_e = lr->end;
1814                                 ret = find_line_range_by_line(NULL, &lf);
1815                         }
1816                 }
1817                 off = noff;
1818         }
1819
1820         /* Store comp_dir */
1821         if (lf.found) {
1822                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1823                 if (comp_dir) {
1824                         lr->comp_dir = strdup(comp_dir);
1825                         if (!lr->comp_dir)
1826                                 ret = -ENOMEM;
1827                 }
1828         }
1829
1830         pr_debug("path: %s\n", lr->path);
1831         dwfl_end(dwfl);
1832         return (ret < 0) ? ret : lf.found;
1833 }
1834