tools/perf/util/probe-finder.c

   1 /*
   2  * probe-finder.c : C expression to kprobe event converter
   3  *
   4  * Written by Masami Hiramatsu <mhiramat@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  */
  21
  22 #include <sys/utsname.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include <unistd.h>
  29 #include <getopt.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdarg.h>
  33 #include <ctype.h>
  34 #include <dwarf-regs.h>
  35
  36 #include <linux/bitops.h>
  37 #include "event.h"
  38 #include "debug.h"
  39 #include "util.h"
  40 #include "symbol.h"
  41 #include "probe-finder.h"
  42
  43 /* Kprobe tracer basic type is up to u64 */
  44 #define MAX_BASIC_TYPE_BITS     64
  45
  46 /*
  47  * Compare the tail of two strings.
  48  * Return 0 if whole of either string is same as another's tail part.
  49  */
  50 static int strtailcmp(const char *s1, const char *s2)
  51 {
  52         int i1 = strlen(s1);
  53         int i2 = strlen(s2);
  54         while (--i1 >= 0 && --i2 >= 0) {
  55                 if (s1[i1] != s2[i2])
  56                         return s1[i1] - s2[i2];
  57         }
  58         return 0;
  59 }
  60
  61 /* Line number list operations */
  62
  63 /* Add a line to line number list */
  64 static int line_list__add_line(struct list_head *head, int line)
  65 {
  66         struct line_node *ln;
  67         struct list_head *p;
  68
  69         /* Reverse search, because new line will be the last one */
  70         list_for_each_entry_reverse(ln, head, list) {
  71                 if (ln->line < line) {
  72                         p = &ln->list;
  73                         goto found;
  74                 } else if (ln->line == line)    /* Already exist */
  75                         return 1;
  76         }
  77         /* List is empty, or the smallest entry */
  78         p = head;
  79 found:
  80         pr_debug("line list: add a line %u\n", line);
  81         ln = zalloc(sizeof(struct line_node));
  82         if (ln == NULL)
  83                 return -ENOMEM;
  84         ln->line = line;
  85         INIT_LIST_HEAD(&ln->list);
  86         list_add(&ln->list, p);
  87         return 0;
  88 }
  89
  90 /* Check if the line in line number list */
  91 static int line_list__has_line(struct list_head *head, int line)
  92 {
  93         struct line_node *ln;
  94
  95         /* Reverse search, because new line will be the last one */
  96         list_for_each_entry(ln, head, list)
  97                 if (ln->line == line)
  98                         return 1;
  99
 100         return 0;
 101 }
 102
 103 /* Init line number list */
 104 static void line_list__init(struct list_head *head)
 105 {
 106         INIT_LIST_HEAD(head);
 107 }
 108
 109 /* Free line number list */
 110 static void line_list__free(struct list_head *head)
 111 {
 112         struct line_node *ln;
 113         while (!list_empty(head)) {
 114                 ln = list_first_entry(head, struct line_node, list);
 115                 list_del(&ln->list);
 116                 free(ln);
 117         }
 118 }
 119
 120 /* Dwarf FL wrappers */
 121 static char *debuginfo_path;    /* Currently dummy */
 122
 123 static const Dwfl_Callbacks offline_callbacks = {
 124         .find_debuginfo = dwfl_standard_find_debuginfo,
 125         .debuginfo_path = &debuginfo_path,
 126
 127         .section_address = dwfl_offline_section_address,
 128
 129         /* We use this table for core files too.  */
 130         .find_elf = dwfl_build_id_find_elf,
 131 };
 132
 133 /* Get a Dwarf from offline image */
 134 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
 135 {
 136         Dwfl_Module *mod;
 137         Dwarf *dbg = NULL;
 138
 139         if (!dwflp)
 140                 return NULL;
 141
 142         *dwflp = dwfl_begin(&offline_callbacks);
 143         if (!*dwflp)
 144                 return NULL;
 145
 146         mod = dwfl_report_offline(*dwflp, "", "", fd);
 147         if (!mod)
 148                 goto error;
 149
 150         dbg = dwfl_module_getdwarf(mod, bias);
 151         if (!dbg) {
 152 error:
 153                 dwfl_end(*dwflp);
 154                 *dwflp = NULL;
 155         }
 156         return dbg;
 157 }
 158
 159 #if _ELFUTILS_PREREQ(0, 148)
 160 /* This method is buggy if elfutils is older than 0.148 */
 161 static int __linux_kernel_find_elf(Dwfl_Module *mod,
 162                                    void **userdata,
 163                                    const char *module_name,
 164                                    Dwarf_Addr base,
 165                                    char **file_name, Elf **elfp)
 166 {
 167         int fd;
 168         const char *path = kernel_get_module_path(module_name);
 169
 170         pr_debug2("Use file %s for %s\n", path, module_name);
 171         if (path) {
 172                 fd = open(path, O_RDONLY);
 173                 if (fd >= 0) {
 174                         *file_name = strdup(path);
 175                         return fd;
 176                 }
 177         }
 178         /* If failed, try to call standard method */
 179         return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
 180                                           file_name, elfp);
 181 }
 182
 183 static const Dwfl_Callbacks kernel_callbacks = {
 184         .find_debuginfo = dwfl_standard_find_debuginfo,
 185         .debuginfo_path = &debuginfo_path,
 186
 187         .find_elf = __linux_kernel_find_elf,
 188         .section_address = dwfl_linux_kernel_module_section_address,
 189 };
 190
 191 /* Get a Dwarf from live kernel image */
 192 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
 193                                           Dwarf_Addr *bias)
 194 {
 195         Dwarf *dbg;
 196
 197         if (!dwflp)
 198                 return NULL;
 199
 200         *dwflp = dwfl_begin(&kernel_callbacks);
 201         if (!*dwflp)
 202                 return NULL;
 203
 204         /* Load the kernel dwarves: Don't care the result here */
 205         dwfl_linux_kernel_report_kernel(*dwflp);
 206         dwfl_linux_kernel_report_modules(*dwflp);
 207
 208         dbg = dwfl_addrdwarf(*dwflp, addr, bias);
 209         /* Here, check whether we could get a real dwarf */
 210         if (!dbg) {
 211                 pr_debug("Failed to find kernel dwarf at %lx\n",
 212                          (unsigned long)addr);
 213                 dwfl_end(*dwflp);
 214                 *dwflp = NULL;
 215         }
 216         return dbg;
 217 }
 218 #else
 219 /* With older elfutils, this just support kernel module... */
 220 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
 221                                           Dwarf_Addr *bias)
 222 {
 223         int fd;
 224         const char *path = kernel_get_module_path("kernel");
 225
 226         if (!path) {
 227                 pr_err("Failed to find vmlinux path\n");
 228                 return NULL;
 229         }
 230
 231         pr_debug2("Use file %s for debuginfo\n", path);
 232         fd = open(path, O_RDONLY);
 233         if (fd < 0)
 234                 return NULL;
 235
 236         return dwfl_init_offline_dwarf(fd, dwflp, bias);
 237 }
 238 #endif
 239
 240 /* Dwarf wrappers */
 241
 242 /* Find the realpath of the target file. */
 243 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
 244 {
 245         Dwarf_Files *files;
 246         size_t nfiles, i;
 247         const char *src = NULL;
 248         int ret;
 249
 250         if (!fname)
 251                 return NULL;
 252
 253         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
 254         if (ret != 0)
 255                 return NULL;
 256
 257         for (i = 0; i < nfiles; i++) {
 258                 src = dwarf_filesrc(files, i, NULL, NULL);
 259                 if (strtailcmp(src, fname) == 0)
 260                         break;
 261         }
 262         if (i == nfiles)
 263                 return NULL;
 264         return src;
 265 }
 266
 267 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
 268 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
 269 {
 270         Dwarf_Attribute attr;
 271         if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
 272                 return NULL;
 273         return dwarf_formstring(&attr);
 274 }
 275
 276 /* Compare diename and tname */
 277 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 278 {
 279         const char *name;
 280         name = dwarf_diename(dw_die);
 281         return name ? (strcmp(tname, name) == 0) : false;
 282 }
 283
 284 /* Get callsite line number of inline-function instance */
 285 static int die_get_call_lineno(Dwarf_Die *in_die)
 286 {
 287         Dwarf_Attribute attr;
 288         Dwarf_Word ret;
 289
 290         if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
 291                 return -ENOENT;
 292
 293         dwarf_formudata(&attr, &ret);
 294         return (int)ret;
 295 }
 296
 297 /* Get type die */
 298 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 299 {
 300         Dwarf_Attribute attr;
 301
 302         if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
 303             dwarf_formref_die(&attr, die_mem))
 304                 return die_mem;
 305         else
 306                 return NULL;
 307 }
 308
 309 /* Get a type die, but skip qualifiers */
 310 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 311 {
 312         int tag;
 313
 314         do {
 315                 vr_die = die_get_type(vr_die, die_mem);
 316                 if (!vr_die)
 317                         break;
 318                 tag = dwarf_tag(vr_die);
 319         } while (tag == DW_TAG_const_type ||
 320                  tag == DW_TAG_restrict_type ||
 321                  tag == DW_TAG_volatile_type ||
 322                  tag == DW_TAG_shared_type);
 323
 324         return vr_die;
 325 }
 326
 327 /* Get a type die, but skip qualifiers and typedef */
 328 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 329 {
 330         do {
 331                 vr_die = __die_get_real_type(vr_die, die_mem);
 332         } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
 333
 334         return vr_die;
 335 }
 336
 337 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
 338                               Dwarf_Word *result)
 339 {
 340         Dwarf_Attribute attr;
 341
 342         if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
 343             dwarf_formudata(&attr, result) != 0)
 344                 return -ENOENT;
 345
 346         return 0;
 347 }
 348
 349 static bool die_is_signed_type(Dwarf_Die *tp_die)
 350 {
 351         Dwarf_Word ret;
 352
 353         if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
 354                 return false;
 355
 356         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
 357                 ret == DW_ATE_signed_fixed);
 358 }
 359
 360 static int die_get_byte_size(Dwarf_Die *tp_die)
 361 {
 362         Dwarf_Word ret;
 363
 364         if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
 365                 return 0;
 366
 367         return (int)ret;
 368 }
 369
 370 static int die_get_bit_size(Dwarf_Die *tp_die)
 371 {
 372         Dwarf_Word ret;
 373
 374         if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
 375                 return 0;
 376
 377         return (int)ret;
 378 }
 379
 380 static int die_get_bit_offset(Dwarf_Die *tp_die)
 381 {
 382         Dwarf_Word ret;
 383
 384         if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
 385                 return 0;
 386
 387         return (int)ret;
 388 }
 389
 390 /* Get data_member_location offset */
 391 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
 392 {
 393         Dwarf_Attribute attr;
 394         Dwarf_Op *expr;
 395         size_t nexpr;
 396         int ret;
 397
 398         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
 399                 return -ENOENT;
 400
 401         if (dwarf_formudata(&attr, offs) != 0) {
 402                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
 403                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
 404                 if (ret < 0 || nexpr == 0)
 405                         return -ENOENT;
 406
 407                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
 408                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
 409                                  expr[0].atom, nexpr);
 410                         return -ENOTSUP;
 411                 }
 412                 *offs = (Dwarf_Word)expr[0].number;
 413         }
 414         return 0;
 415 }
 416
 417 /* Return values for die_find callbacks */
 418 enum {
 419         DIE_FIND_CB_FOUND = 0,          /* End of Search */
 420         DIE_FIND_CB_CHILD = 1,          /* Search only children */
 421         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
 422         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
 423 };
 424
 425 /* Search a child die */
 426 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
 427                                  int (*callback)(Dwarf_Die *, void *),
 428                                  void *data, Dwarf_Die *die_mem)
 429 {
 430         Dwarf_Die child_die;
 431         int ret;
 432
 433         ret = dwarf_child(rt_die, die_mem);
 434         if (ret != 0)
 435                 return NULL;
 436
 437         do {
 438                 ret = callback(die_mem, data);
 439                 if (ret == DIE_FIND_CB_FOUND)
 440                         return die_mem;
 441
 442                 if ((ret & DIE_FIND_CB_CHILD) &&
 443                     die_find_child(die_mem, callback, data, &child_die)) {
 444                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
 445                         return die_mem;
 446                 }
 447         } while ((ret & DIE_FIND_CB_SIBLING) &&
 448                  dwarf_siblingof(die_mem, die_mem) == 0);
 449
 450         return NULL;
 451 }
 452
 453 struct __addr_die_search_param {
 454         Dwarf_Addr      addr;
 455         Dwarf_Die       *die_mem;
 456 };
 457
 458 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 459 {
 460         struct __addr_die_search_param *ad = data;
 461
 462         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
 463             dwarf_haspc(fn_die, ad->addr)) {
 464                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
 465                 return DWARF_CB_ABORT;
 466         }
 467         return DWARF_CB_OK;
 468 }
 469
 470 /* Search a real subprogram including this line, */
 471 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
 472                                            Dwarf_Die *die_mem)
 473 {
 474         struct __addr_die_search_param ad;
 475         ad.addr = addr;
 476         ad.die_mem = die_mem;
 477         /* dwarf_getscopes can't find subprogram. */
 478         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
 479                 return NULL;
 480         else
 481                 return die_mem;
 482 }
 483
 484 /* die_find callback for inline function search */
 485 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 486 {
 487         Dwarf_Addr *addr = data;
 488
 489         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
 490             dwarf_haspc(die_mem, *addr))
 491                 return DIE_FIND_CB_FOUND;
 492
 493         return DIE_FIND_CB_CONTINUE;
 494 }
 495
 496 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
 497 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 498                                       Dwarf_Die *die_mem)
 499 {
 500         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 501 }
 502
 503 /* Walker on lines (Note: line number will not be sorted) */
 504 typedef int (* line_walk_handler_t) (const char *fname, int lineno,
 505                                      Dwarf_Addr addr, void *data);
 506
 507 struct __line_walk_param {
 508         const char *fname;
 509         line_walk_handler_t handler;
 510         void *data;
 511         int retval;
 512 };
 513
 514 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
 515 {
 516         struct __line_walk_param *lw = data;
 517         Dwarf_Addr addr;
 518         int lineno;
 519
 520         if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
 521                 lineno = die_get_call_lineno(in_die);
 522                 if (lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
 523                         lw->retval = lw->handler(lw->fname, lineno, addr,
 524                                                  lw->data);
 525                         if (lw->retval != 0)
 526                                 return DIE_FIND_CB_FOUND;
 527                 }
 528         }
 529         return DIE_FIND_CB_SIBLING;
 530 }
 531
 532 /* Walk on lines of blocks included in given DIE */
 533 static int __die_walk_funclines(Dwarf_Die *sp_die,
 534                                 line_walk_handler_t handler, void *data)
 535 {
 536         struct __line_walk_param lw = {
 537                 .handler = handler,
 538                 .data = data,
 539                 .retval = 0,
 540         };
 541         Dwarf_Die die_mem;
 542         Dwarf_Addr addr;
 543         int lineno;
 544
 545         /* Handle function declaration line */
 546         lw.fname = dwarf_decl_file(sp_die);
 547         if (lw.fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
 548             dwarf_entrypc(sp_die, &addr) == 0) {
 549                 lw.retval = handler(lw.fname, lineno, addr, data);
 550                 if (lw.retval != 0)
 551                         goto done;
 552         }
 553         die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
 554 done:
 555         return lw.retval;
 556 }
 557
 558 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
 559 {
 560         struct __line_walk_param *lw = data;
 561
 562         lw->retval = __die_walk_funclines(sp_die, lw->handler, lw->data);
 563         if (lw->retval != 0)
 564                 return DWARF_CB_ABORT;
 565
 566         return DWARF_CB_OK;
 567 }
 568
 569 /*
 570  * Walk on lines inside given PDIE. If the PDIE is subprogram, walk only on
 571  * the lines inside the subprogram, otherwise PDIE must be a CU DIE.
 572  */
 573 static int die_walk_lines(Dwarf_Die *pdie, line_walk_handler_t handler,
 574                           void *data)
 575 {
 576         Dwarf_Lines *lines;
 577         Dwarf_Line *line;
 578         Dwarf_Addr addr;
 579         const char *fname;
 580         int lineno, ret = 0;
 581         Dwarf_Die die_mem, *cu_die;
 582         size_t nlines, i;
 583
 584         /* Get the CU die */
 585         if (dwarf_tag(pdie) == DW_TAG_subprogram)
 586                 cu_die = dwarf_diecu(pdie, &die_mem, NULL, NULL);
 587         else
 588                 cu_die = pdie;
 589         if (!cu_die) {
 590                 pr_debug2("Failed to get CU from subprogram\n");
 591                 return -EINVAL;
 592         }
 593
 594         /* Get lines list in the CU */
 595         if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
 596                 pr_debug2("Failed to get source lines on this CU.\n");
 597                 return -ENOENT;
 598         }
 599         pr_debug2("Get %zd lines from this CU\n", nlines);
 600
 601         /* Walk on the lines on lines list */
 602         for (i = 0; i < nlines; i++) {
 603                 line = dwarf_onesrcline(lines, i);
 604                 if (line == NULL ||
 605                     dwarf_lineno(line, &lineno) != 0 ||
 606                     dwarf_lineaddr(line, &addr) != 0) {
 607                         pr_debug2("Failed to get line info. "
 608                                   "Possible error in debuginfo.\n");
 609                         continue;
 610                 }
 611                 /* Filter lines based on address */
 612                 if (pdie != cu_die)
 613                         /*
 614                          * Address filtering
 615                          * The line is included in given function, and
 616                          * no inline block includes it.
 617                          */
 618                         if (!dwarf_haspc(pdie, addr) ||
 619                             die_find_inlinefunc(pdie, addr, &die_mem))
 620                                 continue;
 621                 /* Get source line */
 622                 fname = dwarf_linesrc(line, NULL, NULL);
 623
 624                 ret = handler(fname, lineno, addr, data);
 625                 if (ret != 0)
 626                         return ret;
 627         }
 628
 629         /*
 630          * Dwarf lines doesn't include function declarations and inlined
 631          * subroutines. We have to check functions list or given function.
 632          */
 633         if (pdie != cu_die)
 634                 ret = __die_walk_funclines(pdie, handler, data);
 635         else {
 636                 struct __line_walk_param param = {
 637                         .handler = handler,
 638                         .data = data,
 639                         .retval = 0,
 640                 };
 641                 dwarf_getfuncs(cu_die, __die_walk_culines_cb, &param, 0);
 642                 ret = param.retval;
 643         }
 644
 645         return ret;
 646 }
 647
 648 struct __find_variable_param {
 649         const char *name;
 650         Dwarf_Addr addr;
 651 };
 652
 653 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 654 {
 655         struct __find_variable_param *fvp = data;
 656         int tag;
 657
 658         tag = dwarf_tag(die_mem);
 659         if ((tag == DW_TAG_formal_parameter ||
 660              tag == DW_TAG_variable) &&
 661             die_compare_name(die_mem, fvp->name))
 662                 return DIE_FIND_CB_FOUND;
 663
 664         if (dwarf_haspc(die_mem, fvp->addr))
 665                 return DIE_FIND_CB_CONTINUE;
 666         else
 667                 return DIE_FIND_CB_SIBLING;
 668 }
 669
 670 /* Find a variable called 'name' at given address */
 671 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
 672                                        Dwarf_Addr addr, Dwarf_Die *die_mem)
 673 {
 674         struct __find_variable_param fvp = { .name = name, .addr = addr};
 675
 676         return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
 677                               die_mem);
 678 }
 679
 680 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
 681 {
 682         const char *name = data;
 683
 684         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
 685             die_compare_name(die_mem, name))
 686                 return DIE_FIND_CB_FOUND;
 687
 688         return DIE_FIND_CB_SIBLING;
 689 }
 690
 691 /* Find a member called 'name' */
 692 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
 693                                   Dwarf_Die *die_mem)
 694 {
 695         return die_find_child(st_die, __die_find_member_cb, (void *)name,
 696                               die_mem);
 697 }
 698
 699 /* Get the name of given variable DIE */
 700 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
 701 {
 702         Dwarf_Die type;
 703         int tag, ret, ret2;
 704         const char *tmp = "";
 705
 706         if (__die_get_real_type(vr_die, &type) == NULL)
 707                 return -ENOENT;
 708
 709         tag = dwarf_tag(&type);
 710         if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
 711                 tmp = "*";
 712         else if (tag == DW_TAG_subroutine_type) {
 713                 /* Function pointer */
 714                 ret = snprintf(buf, len, "(function_type)");
 715                 return (ret >= len) ? -E2BIG : ret;
 716         } else {
 717                 if (!dwarf_diename(&type))
 718                         return -ENOENT;
 719                 if (tag == DW_TAG_union_type)
 720                         tmp = "union ";
 721                 else if (tag == DW_TAG_structure_type)
 722                         tmp = "struct ";
 723                 /* Write a base name */
 724                 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
 725                 return (ret >= len) ? -E2BIG : ret;
 726         }
 727         ret = die_get_typename(&type, buf, len);
 728         if (ret > 0) {
 729                 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
 730                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 731         }
 732         return ret;
 733 }
 734
 735 /* Get the name and type of given variable DIE, stored as "type\tname" */
 736 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
 737 {
 738         int ret, ret2;
 739
 740         ret = die_get_typename(vr_die, buf, len);
 741         if (ret < 0) {
 742                 pr_debug("Failed to get type, make it unknown.\n");
 743                 ret = snprintf(buf, len, "(unknown_type)");
 744         }
 745         if (ret > 0) {
 746                 ret2 = snprintf(buf + ret, len - ret, "\t%s",
 747                                 dwarf_diename(vr_die));
 748                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 749         }
 750         return ret;
 751 }
 752
 753 /*
 754  * Probe finder related functions
 755  */
 756
 757 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 758 {
 759         struct probe_trace_arg_ref *ref;
 760         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 761         if (ref != NULL)
 762                 ref->offset = offs;
 763         return ref;
 764 }
 765
 766 /*
 767  * Convert a location into trace_arg.
 768  * If tvar == NULL, this just checks variable can be converted.
 769  */
 770 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 771                                      Dwarf_Op *fb_ops,
 772                                      struct probe_trace_arg *tvar)
 773 {
 774         Dwarf_Attribute attr;
 775         Dwarf_Op *op;
 776         size_t nops;
 777         unsigned int regn;
 778         Dwarf_Word offs = 0;
 779         bool ref = false;
 780         const char *regs;
 781         int ret;
 782
 783         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 784                 goto static_var;
 785
 786         /* TODO: handle more than 1 exprs */
 787         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
 788             dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
 789             nops == 0) {
 790                 /* TODO: Support const_value */
 791                 return -ENOENT;
 792         }
 793
 794         if (op->atom == DW_OP_addr) {
 795 static_var:
 796                 if (!tvar)
 797                         return 0;
 798                 /* Static variables on memory (not stack), make @varname */
 799                 ret = strlen(dwarf_diename(vr_die));
 800                 tvar->value = zalloc(ret + 2);
 801                 if (tvar->value == NULL)
 802                         return -ENOMEM;
 803                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 804                 tvar->ref = alloc_trace_arg_ref((long)offs);
 805                 if (tvar->ref == NULL)
 806                         return -ENOMEM;
 807                 return 0;
 808         }
 809
 810         /* If this is based on frame buffer, set the offset */
 811         if (op->atom == DW_OP_fbreg) {
 812                 if (fb_ops == NULL)
 813                         return -ENOTSUP;
 814                 ref = true;
 815                 offs = op->number;
 816                 op = &fb_ops[0];
 817         }
 818
 819         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 820                 regn = op->atom - DW_OP_breg0;
 821                 offs += op->number;
 822                 ref = true;
 823         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 824                 regn = op->atom - DW_OP_reg0;
 825         } else if (op->atom == DW_OP_bregx) {
 826                 regn = op->number;
 827                 offs += op->number2;
 828                 ref = true;
 829         } else if (op->atom == DW_OP_regx) {
 830                 regn = op->number;
 831         } else {
 832                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 833                 return -ENOTSUP;
 834         }
 835
 836         if (!tvar)
 837                 return 0;
 838
 839         regs = get_arch_regstr(regn);
 840         if (!regs) {
 841                 /* This should be a bug in DWARF or this tool */
 842                 pr_warning("Mapping for the register number %u "
 843                            "missing on this architecture.\n", regn);
 844                 return -ERANGE;
 845         }
 846
 847         tvar->value = strdup(regs);
 848         if (tvar->value == NULL)
 849                 return -ENOMEM;
 850
 851         if (ref) {
 852                 tvar->ref = alloc_trace_arg_ref((long)offs);
 853                 if (tvar->ref == NULL)
 854                         return -ENOMEM;
 855         }
 856         return 0;
 857 }
 858
 859 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
 860
 861 static int convert_variable_type(Dwarf_Die *vr_die,
 862                                  struct probe_trace_arg *tvar,
 863                                  const char *cast)
 864 {
 865         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 866         Dwarf_Die type;
 867         char buf[16];
 868         int ret;
 869
 870         /* TODO: check all types */
 871         if (cast && strcmp(cast, "string") != 0) {
 872                 /* Non string type is OK */
 873                 tvar->type = strdup(cast);
 874                 return (tvar->type == NULL) ? -ENOMEM : 0;
 875         }
 876
 877         if (die_get_bit_size(vr_die) != 0) {
 878                 /* This is a bitfield */
 879                 ret = snprintf(buf, 16, "b%d@%d/%zd", die_get_bit_size(vr_die),
 880                                 die_get_bit_offset(vr_die),
 881                                 BYTES_TO_BITS(die_get_byte_size(vr_die)));
 882                 goto formatted;
 883         }
 884
 885         if (die_get_real_type(vr_die, &type) == NULL) {
 886                 pr_warning("Failed to get a type information of %s.\n",
 887                            dwarf_diename(vr_die));
 888                 return -ENOENT;
 889         }
 890
 891         pr_debug("%s type is %s.\n",
 892                  dwarf_diename(vr_die), dwarf_diename(&type));
 893
 894         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 895                 ret = dwarf_tag(&type);
 896                 if (ret != DW_TAG_pointer_type &&
 897                     ret != DW_TAG_array_type) {
 898                         pr_warning("Failed to cast into string: "
 899                                    "%s(%s) is not a pointer nor array.\n",
 900                                    dwarf_diename(vr_die), dwarf_diename(&type));
 901                         return -EINVAL;
 902                 }
 903                 if (ret == DW_TAG_pointer_type) {
 904                         if (die_get_real_type(&type, &type) == NULL) {
 905                                 pr_warning("Failed to get a type"
 906                                            " information.\n");
 907                                 return -ENOENT;
 908                         }
 909                         while (*ref_ptr)
 910                                 ref_ptr = &(*ref_ptr)->next;
 911                         /* Add new reference with offset +0 */
 912                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 913                         if (*ref_ptr == NULL) {
 914                                 pr_warning("Out of memory error\n");
 915                                 return -ENOMEM;
 916                         }
 917                 }
 918                 if (!die_compare_name(&type, "char") &&
 919                     !die_compare_name(&type, "unsigned char")) {
 920                         pr_warning("Failed to cast into string: "
 921                                    "%s is not (unsigned) char *.\n",
 922                                    dwarf_diename(vr_die));
 923                         return -EINVAL;
 924                 }
 925                 tvar->type = strdup(cast);
 926                 return (tvar->type == NULL) ? -ENOMEM : 0;
 927         }
 928
 929         ret = BYTES_TO_BITS(die_get_byte_size(&type));
 930         if (!ret)
 931                 /* No size ... try to use default type */
 932                 return 0;
 933
 934         /* Check the bitwidth */
 935         if (ret > MAX_BASIC_TYPE_BITS) {
 936                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
 937                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 938                 ret = MAX_BASIC_TYPE_BITS;
 939         }
 940         ret = snprintf(buf, 16, "%c%d",
 941                        die_is_signed_type(&type) ? 's' : 'u', ret);
 942
 943 formatted:
 944         if (ret < 0 || ret >= 16) {
 945                 if (ret >= 16)
 946                         ret = -E2BIG;
 947                 pr_warning("Failed to convert variable type: %s\n",
 948                            strerror(-ret));
 949                 return ret;
 950         }
 951         tvar->type = strdup(buf);
 952         if (tvar->type == NULL)
 953                 return -ENOMEM;
 954         return 0;
 955 }
 956
 957 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 958                                     struct perf_probe_arg_field *field,
 959                                     struct probe_trace_arg_ref **ref_ptr,
 960                                     Dwarf_Die *die_mem)
 961 {
 962         struct probe_trace_arg_ref *ref = *ref_ptr;
 963         Dwarf_Die type;
 964         Dwarf_Word offs;
 965         int ret, tag;
 966
 967         pr_debug("converting %s in %s\n", field->name, varname);
 968         if (die_get_real_type(vr_die, &type) == NULL) {
 969                 pr_warning("Failed to get the type of %s.\n", varname);
 970                 return -ENOENT;
 971         }
 972         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 973         tag = dwarf_tag(&type);
 974
 975         if (field->name[0] == '[' &&
 976             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 977                 if (field->next)
 978                         /* Save original type for next field */
 979                         memcpy(die_mem, &type, sizeof(*die_mem));
 980                 /* Get the type of this array */
 981                 if (die_get_real_type(&type, &type) == NULL) {
 982                         pr_warning("Failed to get the type of %s.\n", varname);
 983                         return -ENOENT;
 984                 }
 985                 pr_debug2("Array real type: (%x)\n",
 986                          (unsigned)dwarf_dieoffset(&type));
 987                 if (tag == DW_TAG_pointer_type) {
 988                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 989                         if (ref == NULL)
 990                                 return -ENOMEM;
 991                         if (*ref_ptr)
 992                                 (*ref_ptr)->next = ref;
 993                         else
 994                                 *ref_ptr = ref;
 995                 }
 996                 ref->offset += die_get_byte_size(&type) * field->index;
 997                 if (!field->next)
 998                         /* Save vr_die for converting types */
 999                         memcpy(die_mem, vr_die, sizeof(*die_mem));
1000                 goto next;
1001         } else if (tag == DW_TAG_pointer_type) {
1002                 /* Check the pointer and dereference */
1003                 if (!field->ref) {
1004                         pr_err("Semantic error: %s must be referred by '->'\n",
1005                                field->name);
1006                         return -EINVAL;
1007                 }
1008                 /* Get the type pointed by this pointer */
1009                 if (die_get_real_type(&type, &type) == NULL) {
1010                         pr_warning("Failed to get the type of %s.\n", varname);
1011                         return -ENOENT;
1012                 }
1013                 /* Verify it is a data structure  */
1014                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
1015                         pr_warning("%s is not a data structure.\n", varname);
1016                         return -EINVAL;
1017                 }
1018
1019                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
1020                 if (ref == NULL)
1021                         return -ENOMEM;
1022                 if (*ref_ptr)
1023                         (*ref_ptr)->next = ref;
1024                 else
1025                         *ref_ptr = ref;
1026         } else {
1027                 /* Verify it is a data structure  */
1028                 if (tag != DW_TAG_structure_type) {
1029                         pr_warning("%s is not a data structure.\n", varname);
1030                         return -EINVAL;
1031                 }
1032                 if (field->name[0] == '[') {
1033                         pr_err("Semantic error: %s is not a pointor"
1034                                " nor array.\n", varname);
1035                         return -EINVAL;
1036                 }
1037                 if (field->ref) {
1038                         pr_err("Semantic error: %s must be referred by '.'\n",
1039                                field->name);
1040                         return -EINVAL;
1041                 }
1042                 if (!ref) {
1043                         pr_warning("Structure on a register is not "
1044                                    "supported yet.\n");
1045                         return -ENOTSUP;
1046                 }
1047         }
1048
1049         if (die_find_member(&type, field->name, die_mem) == NULL) {
1050                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
1051                            dwarf_diename(&type), field->name);
1052                 return -EINVAL;
1053         }
1054
1055         /* Get the offset of the field */
1056         ret = die_get_data_member_location(die_mem, &offs);
1057         if (ret < 0) {
1058                 pr_warning("Failed to get the offset of %s.\n", field->name);
1059                 return ret;
1060         }
1061         ref->offset += (long)offs;
1062
1063 next:
1064         /* Converting next field */
1065         if (field->next)
1066                 return convert_variable_fields(die_mem, field->name,
1067                                         field->next, &ref, die_mem);
1068         else
1069                 return 0;
1070 }
1071
1072 /* Show a variables in kprobe event format */
1073 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
1074 {
1075         Dwarf_Die die_mem;
1076         int ret;
1077
1078         pr_debug("Converting variable %s into trace event.\n",
1079                  dwarf_diename(vr_die));
1080
1081         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
1082                                         pf->tvar);
1083         if (ret == -ENOENT)
1084                 pr_err("Failed to find the location of %s at this address.\n"
1085                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
1086         else if (ret == -ENOTSUP)
1087                 pr_err("Sorry, we don't support this variable location yet.\n");
1088         else if (pf->pvar->field) {
1089                 ret = convert_variable_fields(vr_die, pf->pvar->var,
1090                                               pf->pvar->field, &pf->tvar->ref,
1091                                               &die_mem);
1092                 vr_die = &die_mem;
1093         }
1094         if (ret == 0)
1095                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
1096         /* *expr will be cached in libdw. Don't free it. */
1097         return ret;
1098 }
1099
1100 /* Find a variable in a subprogram die */
1101 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
1102 {
1103         Dwarf_Die vr_die, *scopes;
1104         char buf[32], *ptr;
1105         int ret, nscopes;
1106
1107         if (!is_c_varname(pf->pvar->var)) {
1108                 /* Copy raw parameters */
1109                 pf->tvar->value = strdup(pf->pvar->var);
1110                 if (pf->tvar->value == NULL)
1111                         return -ENOMEM;
1112                 if (pf->pvar->type) {
1113                         pf->tvar->type = strdup(pf->pvar->type);
1114                         if (pf->tvar->type == NULL)
1115                                 return -ENOMEM;
1116                 }
1117                 if (pf->pvar->name) {
1118                         pf->tvar->name = strdup(pf->pvar->name);
1119                         if (pf->tvar->name == NULL)
1120                                 return -ENOMEM;
1121                 } else
1122                         pf->tvar->name = NULL;
1123                 return 0;
1124         }
1125
1126         if (pf->pvar->name)
1127                 pf->tvar->name = strdup(pf->pvar->name);
1128         else {
1129                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
1130                 if (ret < 0)
1131                         return ret;
1132                 ptr = strchr(buf, ':'); /* Change type separator to _ */
1133                 if (ptr)
1134                         *ptr = '_';
1135                 pf->tvar->name = strdup(buf);
1136         }
1137         if (pf->tvar->name == NULL)
1138                 return -ENOMEM;
1139
1140         pr_debug("Searching '%s' variable in context.\n",
1141                  pf->pvar->var);
1142         /* Search child die for local variables and parameters. */
1143         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
1144                 ret = convert_variable(&vr_die, pf);
1145         else {
1146                 /* Search upper class */
1147                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1148                 while (nscopes-- > 1) {
1149                         pr_debug("Searching variables in %s\n",
1150                                  dwarf_diename(&scopes[nscopes]));
1151                         /* We should check this scope, so give dummy address */
1152                         if (die_find_variable_at(&scopes[nscopes],
1153                                                  pf->pvar->var, 0,
1154                                                  &vr_die)) {
1155                                 ret = convert_variable(&vr_die, pf);
1156                                 goto found;
1157                         }
1158                 }
1159                 if (scopes)
1160                         free(scopes);
1161                 ret = -ENOENT;
1162         }
1163 found:
1164         if (ret < 0)
1165                 pr_warning("Failed to find '%s' in this function.\n",
1166                            pf->pvar->var);
1167         return ret;
1168 }
1169
1170 /* Convert subprogram DIE to trace point */
1171 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
1172                                   bool retprobe, struct probe_trace_point *tp)
1173 {
1174         Dwarf_Addr eaddr;
1175         const char *name;
1176
1177         /* Copy the name of probe point */
1178         name = dwarf_diename(sp_die);
1179         if (name) {
1180                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
1181                         pr_warning("Failed to get entry address of %s\n",
1182                                    dwarf_diename(sp_die));
1183                         return -ENOENT;
1184                 }
1185                 tp->symbol = strdup(name);
1186                 if (tp->symbol == NULL)
1187                         return -ENOMEM;
1188                 tp->offset = (unsigned long)(paddr - eaddr);
1189         } else
1190                 /* This function has no name. */
1191                 tp->offset = (unsigned long)paddr;
1192
1193         /* Return probe must be on the head of a subprogram */
1194         if (retprobe) {
1195                 if (eaddr != paddr) {
1196                         pr_warning("Return probe must be on the head of"
1197                                    " a real function.\n");
1198                         return -EINVAL;
1199                 }
1200                 tp->retprobe = true;
1201         }
1202
1203         return 0;
1204 }
1205
1206 /* Call probe_finder callback with real subprogram DIE */
1207 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1208 {
1209         Dwarf_Die die_mem;
1210         Dwarf_Attribute fb_attr;
1211         size_t nops;
1212         int ret;
1213
1214         /* If no real subprogram, find a real one */
1215         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1216                 sp_die = die_find_real_subprogram(&pf->cu_die,
1217                                                   pf->addr, &die_mem);
1218                 if (!sp_die) {
1219                         pr_warning("Failed to find probe point in any "
1220                                    "functions.\n");
1221                         return -ENOENT;
1222                 }
1223         }
1224
1225         /* Get the frame base attribute/ops */
1226         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1227         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1228         if (ret <= 0 || nops == 0) {
1229                 pf->fb_ops = NULL;
1230 #if _ELFUTILS_PREREQ(0, 142)
1231         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1232                    pf->cfi != NULL) {
1233                 Dwarf_Frame *frame;
1234                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1235                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1236                         pr_warning("Failed to get call frame on 0x%jx\n",
1237                                    (uintmax_t)pf->addr);
1238                         return -ENOENT;
1239                 }
1240 #endif
1241         }
1242
1243         /* Call finder's callback handler */
1244         ret = pf->callback(sp_die, pf);
1245
1246         /* *pf->fb_ops will be cached in libdw. Don't free it. */
1247         pf->fb_ops = NULL;
1248
1249         return ret;
1250 }
1251
1252 static int probe_point_line_walker(const char *fname, int lineno,
1253                                    Dwarf_Addr addr, void *data)
1254 {
1255         struct probe_finder *pf = data;
1256         int ret;
1257
1258         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
1259                 return 0;
1260
1261         pf->addr = addr;
1262         ret = call_probe_finder(NULL, pf);
1263
1264         /* Continue if no error, because the line will be in inline function */
1265         return ret < 0 ?: 0;
1266 }
1267
1268 /* Find probe point from its line number */
1269 static int find_probe_point_by_line(struct probe_finder *pf)
1270 {
1271         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
1272 }
1273
1274 /* Find lines which match lazy pattern */
1275 static int find_lazy_match_lines(struct list_head *head,
1276                                  const char *fname, const char *pat)
1277 {
1278         FILE *fp;
1279         char *line = NULL;
1280         size_t line_len;
1281         ssize_t len;
1282         int count = 0, linenum = 1;
1283
1284         fp = fopen(fname, "r");
1285         if (!fp) {
1286                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
1287                 return -errno;
1288         }
1289
1290         while ((len = getline(&line, &line_len, fp)) > 0) {
1291
1292                 if (line[len - 1] == '\n')
1293                         line[len - 1] = '\0';
1294
1295                 if (strlazymatch(line, pat)) {
1296                         line_list__add_line(head, linenum);
1297                         count++;
1298                 }
1299                 linenum++;
1300         }
1301
1302         if (ferror(fp))
1303                 count = -errno;
1304         free(line);
1305         fclose(fp);
1306
1307         if (count == 0)
1308                 pr_debug("No matched lines found in %s.\n", fname);
1309         return count;
1310 }
1311
1312 static int probe_point_lazy_walker(const char *fname, int lineno,
1313                                    Dwarf_Addr addr, void *data)
1314 {
1315         struct probe_finder *pf = data;
1316         int ret;
1317
1318         if (!line_list__has_line(&pf->lcache, lineno) ||
1319             strtailcmp(fname, pf->fname) != 0)
1320                 return 0;
1321
1322         pr_debug("Probe line found: line:%d addr:0x%llx\n",
1323                  lineno, (unsigned long long)addr);
1324         pf->addr = addr;
1325         ret = call_probe_finder(NULL, pf);
1326
1327         /*
1328          * Continue if no error, because the lazy pattern will match
1329          * to other lines
1330          */
1331         return ret < 0 ?: 0;
1332 }
1333
1334 /* Find probe points from lazy pattern  */
1335 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1336 {
1337         int ret = 0;
1338
1339         if (list_empty(&pf->lcache)) {
1340                 /* Matching lazy line pattern */
1341                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1342                                             pf->pev->point.lazy_line);
1343                 if (ret <= 0)
1344                         return ret;
1345         }
1346
1347         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
1348 }
1349
1350 /* Callback parameter with return value */
1351 struct dwarf_callback_param {
1352         void *data;
1353         int retval;
1354 };
1355
1356 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1357 {
1358         struct dwarf_callback_param *param = data;
1359         struct probe_finder *pf = param->data;
1360         struct perf_probe_point *pp = &pf->pev->point;
1361         Dwarf_Addr addr;
1362
1363         if (pp->lazy_line)
1364                 param->retval = find_probe_point_lazy(in_die, pf);
1365         else {
1366                 /* Get probe address */
1367                 if (dwarf_entrypc(in_die, &addr) != 0) {
1368                         pr_warning("Failed to get entry address of %s.\n",
1369                                    dwarf_diename(in_die));
1370                         param->retval = -ENOENT;
1371                         return DWARF_CB_ABORT;
1372                 }
1373                 pf->addr = addr;
1374                 pf->addr += pp->offset;
1375                 pr_debug("found inline addr: 0x%jx\n",
1376                          (uintmax_t)pf->addr);
1377
1378                 param->retval = call_probe_finder(in_die, pf);
1379                 if (param->retval < 0)
1380                         return DWARF_CB_ABORT;
1381         }
1382
1383         return DWARF_CB_OK;
1384 }
1385
1386 /* Search function from function name */
1387 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1388 {
1389         struct dwarf_callback_param *param = data;
1390         struct probe_finder *pf = param->data;
1391         struct perf_probe_point *pp = &pf->pev->point;
1392
1393         /* Check tag and diename */
1394         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1395             !die_compare_name(sp_die, pp->function))
1396                 return DWARF_CB_OK;
1397
1398         pf->fname = dwarf_decl_file(sp_die);
1399         if (pp->line) { /* Function relative line */
1400                 dwarf_decl_line(sp_die, &pf->lno);
1401                 pf->lno += pp->line;
1402                 param->retval = find_probe_point_by_line(pf);
1403         } else if (!dwarf_func_inline(sp_die)) {
1404                 /* Real function */
1405                 if (pp->lazy_line)
1406                         param->retval = find_probe_point_lazy(sp_die, pf);
1407                 else {
1408                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1409                                 pr_warning("Failed to get entry address of "
1410                                            "%s.\n", dwarf_diename(sp_die));
1411                                 param->retval = -ENOENT;
1412                                 return DWARF_CB_ABORT;
1413                         }
1414                         pf->addr += pp->offset;
1415                         /* TODO: Check the address in this function */
1416                         param->retval = call_probe_finder(sp_die, pf);
1417                 }
1418         } else {
1419                 struct dwarf_callback_param _param = {.data = (void *)pf,
1420                                                       .retval = 0};
1421                 /* Inlined function: search instances */
1422                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1423                                             &_param);
1424                 param->retval = _param.retval;
1425         }
1426
1427         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1428 }
1429
1430 static int find_probe_point_by_func(struct probe_finder *pf)
1431 {
1432         struct dwarf_callback_param _param = {.data = (void *)pf,
1433                                               .retval = 0};
1434         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1435         return _param.retval;
1436 }
1437
1438 /* Find probe points from debuginfo */
1439 static int find_probes(int fd, struct probe_finder *pf)
1440 {
1441         struct perf_probe_point *pp = &pf->pev->point;
1442         Dwarf_Off off, noff;
1443         size_t cuhl;
1444         Dwarf_Die *diep;
1445         Dwarf *dbg = NULL;
1446         Dwfl *dwfl;
1447         Dwarf_Addr bias;        /* Currently ignored */
1448         int ret = 0;
1449
1450         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1451         if (!dbg) {
1452                 pr_warning("No debug information found in the vmlinux - "
1453                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1454                 return -EBADF;
1455         }
1456
1457 #if _ELFUTILS_PREREQ(0, 142)
1458         /* Get the call frame information from this dwarf */
1459         pf->cfi = dwarf_getcfi(dbg);
1460 #endif
1461
1462         off = 0;
1463         line_list__init(&pf->lcache);
1464         /* Loop on CUs (Compilation Unit) */
1465         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1466                ret >= 0) {
1467                 /* Get the DIE(Debugging Information Entry) of this CU */
1468                 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1469                 if (!diep)
1470                         continue;
1471
1472                 /* Check if target file is included. */
1473                 if (pp->file)
1474                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1475                 else
1476                         pf->fname = NULL;
1477
1478                 if (!pp->file || pf->fname) {
1479                         if (pp->function)
1480                                 ret = find_probe_point_by_func(pf);
1481                         else if (pp->lazy_line)
1482                                 ret = find_probe_point_lazy(NULL, pf);
1483                         else {
1484                                 pf->lno = pp->line;
1485                                 ret = find_probe_point_by_line(pf);
1486                         }
1487                 }
1488                 off = noff;
1489         }
1490         line_list__free(&pf->lcache);
1491         if (dwfl)
1492                 dwfl_end(dwfl);
1493
1494         return ret;
1495 }
1496
1497 /* Add a found probe point into trace event list */
1498 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1499 {
1500         struct trace_event_finder *tf =
1501                         container_of(pf, struct trace_event_finder, pf);
1502         struct probe_trace_event *tev;
1503         int ret, i;
1504
1505         /* Check number of tevs */
1506         if (tf->ntevs == tf->max_tevs) {
1507                 pr_warning("Too many( > %d) probe point found.\n",
1508                            tf->max_tevs);
1509                 return -ERANGE;
1510         }
1511         tev = &tf->tevs[tf->ntevs++];
1512
1513         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1514                                      &tev->point);
1515         if (ret < 0)
1516                 return ret;
1517
1518         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1519                  tev->point.offset);
1520
1521         /* Find each argument */
1522         tev->nargs = pf->pev->nargs;
1523         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1524         if (tev->args == NULL)
1525                 return -ENOMEM;
1526         for (i = 0; i < pf->pev->nargs; i++) {
1527                 pf->pvar = &pf->pev->args[i];
1528                 pf->tvar = &tev->args[i];
1529                 ret = find_variable(sp_die, pf);
1530                 if (ret != 0)
1531                         return ret;
1532         }
1533
1534         return 0;
1535 }
1536
1537 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1538 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1539                             struct probe_trace_event **tevs, int max_tevs)
1540 {
1541         struct trace_event_finder tf = {
1542                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1543                         .max_tevs = max_tevs};
1544         int ret;
1545
1546         /* Allocate result tevs array */
1547         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1548         if (*tevs == NULL)
1549                 return -ENOMEM;
1550
1551         tf.tevs = *tevs;
1552         tf.ntevs = 0;
1553
1554         ret = find_probes(fd, &tf.pf);
1555         if (ret < 0) {
1556                 free(*tevs);
1557                 *tevs = NULL;
1558                 return ret;
1559         }
1560
1561         return (ret < 0) ? ret : tf.ntevs;
1562 }
1563
1564 #define MAX_VAR_LEN 64
1565
1566 /* Collect available variables in this scope */
1567 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1568 {
1569         struct available_var_finder *af = data;
1570         struct variable_list *vl;
1571         char buf[MAX_VAR_LEN];
1572         int tag, ret;
1573
1574         vl = &af->vls[af->nvls - 1];
1575
1576         tag = dwarf_tag(die_mem);
1577         if (tag == DW_TAG_formal_parameter ||
1578             tag == DW_TAG_variable) {
1579                 ret = convert_variable_location(die_mem, af->pf.addr,
1580                                                 af->pf.fb_ops, NULL);
1581                 if (ret == 0) {
1582                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1583                         pr_debug2("Add new var: %s\n", buf);
1584                         if (ret > 0)
1585                                 strlist__add(vl->vars, buf);
1586                 }
1587         }
1588
1589         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1590                 return DIE_FIND_CB_CONTINUE;
1591         else
1592                 return DIE_FIND_CB_SIBLING;
1593 }
1594
1595 /* Add a found vars into available variables list */
1596 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1597 {
1598         struct available_var_finder *af =
1599                         container_of(pf, struct available_var_finder, pf);
1600         struct variable_list *vl;
1601         Dwarf_Die die_mem, *scopes = NULL;
1602         int ret, nscopes;
1603
1604         /* Check number of tevs */
1605         if (af->nvls == af->max_vls) {
1606                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1607                 return -ERANGE;
1608         }
1609         vl = &af->vls[af->nvls++];
1610
1611         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1612                                      &vl->point);
1613         if (ret < 0)
1614                 return ret;
1615
1616         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1617                  vl->point.offset);
1618
1619         /* Find local variables */
1620         vl->vars = strlist__new(true, NULL);
1621         if (vl->vars == NULL)
1622                 return -ENOMEM;
1623         af->child = true;
1624         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1625
1626         /* Find external variables */
1627         if (!af->externs)
1628                 goto out;
1629         /* Don't need to search child DIE for externs. */
1630         af->child = false;
1631         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1632         while (nscopes-- > 1)
1633                 die_find_child(&scopes[nscopes], collect_variables_cb,
1634                                (void *)af, &die_mem);
1635         if (scopes)
1636                 free(scopes);
1637
1638 out:
1639         if (strlist__empty(vl->vars)) {
1640                 strlist__delete(vl->vars);
1641                 vl->vars = NULL;
1642         }
1643
1644         return ret;
1645 }
1646
1647 /* Find available variables at given probe point */
1648 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1649                            struct variable_list **vls, int max_vls,
1650                            bool externs)
1651 {
1652         struct available_var_finder af = {
1653                         .pf = {.pev = pev, .callback = add_available_vars},
1654                         .max_vls = max_vls, .externs = externs};
1655         int ret;
1656
1657         /* Allocate result vls array */
1658         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1659         if (*vls == NULL)
1660                 return -ENOMEM;
1661
1662         af.vls = *vls;
1663         af.nvls = 0;
1664
1665         ret = find_probes(fd, &af.pf);
1666         if (ret < 0) {
1667                 /* Free vlist for error */
1668                 while (af.nvls--) {
1669                         if (af.vls[af.nvls].point.symbol)
1670                                 free(af.vls[af.nvls].point.symbol);
1671                         if (af.vls[af.nvls].vars)
1672                                 strlist__delete(af.vls[af.nvls].vars);
1673                 }
1674                 free(af.vls);
1675                 *vls = NULL;
1676                 return ret;
1677         }
1678
1679         return (ret < 0) ? ret : af.nvls;
1680 }
1681
1682 /* Reverse search */
1683 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1684 {
1685         Dwarf_Die cudie, spdie, indie;
1686         Dwarf *dbg = NULL;
1687         Dwfl *dwfl = NULL;
1688         Dwarf_Line *line;
1689         Dwarf_Addr laddr, eaddr, bias = 0;
1690         const char *tmp;
1691         int lineno, ret = 0;
1692         bool found = false;
1693
1694         /* Open the live linux kernel */
1695         dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1696         if (!dbg) {
1697                 pr_warning("No debug information found in the vmlinux - "
1698                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1699                 ret = -EINVAL;
1700                 goto end;
1701         }
1702
1703         /* Adjust address with bias */
1704         addr += bias;
1705         /* Find cu die */
1706         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1707                 pr_warning("Failed to find debug information for address %lx\n",
1708                            addr);
1709                 ret = -EINVAL;
1710                 goto end;
1711         }
1712
1713         /* Find a corresponding line */
1714         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1715         if (line) {
1716                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1717                     (Dwarf_Addr)addr == laddr &&
1718                     dwarf_lineno(line, &lineno) == 0) {
1719                         tmp = dwarf_linesrc(line, NULL, NULL);
1720                         if (tmp) {
1721                                 ppt->line = lineno;
1722                                 ppt->file = strdup(tmp);
1723                                 if (ppt->file == NULL) {
1724                                         ret = -ENOMEM;
1725                                         goto end;
1726                                 }
1727                                 found = true;
1728                         }
1729                 }
1730         }
1731
1732         /* Find a corresponding function */
1733         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1734                 tmp = dwarf_diename(&spdie);
1735                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1736                         goto end;
1737
1738                 if (ppt->line) {
1739                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1740                                                 &indie)) {
1741                                 /* addr in an inline function */
1742                                 tmp = dwarf_diename(&indie);
1743                                 if (!tmp)
1744                                         goto end;
1745                                 ret = dwarf_decl_line(&indie, &lineno);
1746                         } else {
1747                                 if (eaddr == addr) {    /* Function entry */
1748                                         lineno = ppt->line;
1749                                         ret = 0;
1750                                 } else
1751                                         ret = dwarf_decl_line(&spdie, &lineno);
1752                         }
1753                         if (ret == 0) {
1754                                 /* Make a relative line number */
1755                                 ppt->line -= lineno;
1756                                 goto found;
1757                         }
1758                 }
1759                 /* We don't have a line number, let's use offset */
1760                 ppt->offset = addr - (unsigned long)eaddr;
1761 found:
1762                 ppt->function = strdup(tmp);
1763                 if (ppt->function == NULL) {
1764                         ret = -ENOMEM;
1765                         goto end;
1766                 }
1767                 found = true;
1768         }
1769
1770 end:
1771         if (dwfl)
1772                 dwfl_end(dwfl);
1773         if (ret >= 0)
1774                 ret = found ? 1 : 0;
1775         return ret;
1776 }
1777
1778 /* Add a line and store the src path */
1779 static int line_range_add_line(const char *src, unsigned int lineno,
1780                                struct line_range *lr)
1781 {
1782         /* Copy source path */
1783         if (!lr->path) {
1784                 lr->path = strdup(src);
1785                 if (lr->path == NULL)
1786                         return -ENOMEM;
1787         }
1788         return line_list__add_line(&lr->line_list, lineno);
1789 }
1790
1791 static int line_range_walk_cb(const char *fname, int lineno,
1792                               Dwarf_Addr addr __used,
1793                               void *data)
1794 {
1795         struct line_finder *lf = data;
1796
1797         if ((strtailcmp(fname, lf->fname) != 0) ||
1798             (lf->lno_s > lineno || lf->lno_e < lineno))
1799                 return 0;
1800
1801         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1802                 return -EINVAL;
1803
1804         return 0;
1805 }
1806
1807 /* Find line range from its line number */
1808 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1809 {
1810         int ret;
1811
1812         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1813
1814         /* Update status */
1815         if (ret >= 0)
1816                 if (!list_empty(&lf->lr->line_list))
1817                         ret = lf->found = 1;
1818                 else
1819                         ret = 0;        /* Lines are not found */
1820         else {
1821                 free(lf->lr->path);
1822                 lf->lr->path = NULL;
1823         }
1824         return ret;
1825 }
1826
1827 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1828 {
1829         struct dwarf_callback_param *param = data;
1830
1831         param->retval = find_line_range_by_line(in_die, param->data);
1832         return DWARF_CB_ABORT;  /* No need to find other instances */
1833 }
1834
1835 /* Search function from function name */
1836 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1837 {
1838         struct dwarf_callback_param *param = data;
1839         struct line_finder *lf = param->data;
1840         struct line_range *lr = lf->lr;
1841
1842         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1843             die_compare_name(sp_die, lr->function)) {
1844                 lf->fname = dwarf_decl_file(sp_die);
1845                 dwarf_decl_line(sp_die, &lr->offset);
1846                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1847                 lf->lno_s = lr->offset + lr->start;
1848                 if (lf->lno_s < 0)      /* Overflow */
1849                         lf->lno_s = INT_MAX;
1850                 lf->lno_e = lr->offset + lr->end;
1851                 if (lf->lno_e < 0)      /* Overflow */
1852                         lf->lno_e = INT_MAX;
1853                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1854                 lr->start = lf->lno_s;
1855                 lr->end = lf->lno_e;
1856                 if (dwarf_func_inline(sp_die)) {
1857                         struct dwarf_callback_param _param;
1858                         _param.data = (void *)lf;
1859                         _param.retval = 0;
1860                         dwarf_func_inline_instances(sp_die,
1861                                                     line_range_inline_cb,
1862                                                     &_param);
1863                         param->retval = _param.retval;
1864                 } else
1865                         param->retval = find_line_range_by_line(sp_die, lf);
1866                 return DWARF_CB_ABORT;
1867         }
1868         return DWARF_CB_OK;
1869 }
1870
1871 static int find_line_range_by_func(struct line_finder *lf)
1872 {
1873         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1874         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1875         return param.retval;
1876 }
1877
1878 int find_line_range(int fd, struct line_range *lr)
1879 {
1880         struct line_finder lf = {.lr = lr, .found = 0};
1881         int ret = 0;
1882         Dwarf_Off off = 0, noff;
1883         size_t cuhl;
1884         Dwarf_Die *diep;
1885         Dwarf *dbg = NULL;
1886         Dwfl *dwfl;
1887         Dwarf_Addr bias;        /* Currently ignored */
1888         const char *comp_dir;
1889
1890         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1891         if (!dbg) {
1892                 pr_warning("No debug information found in the vmlinux - "
1893                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1894                 return -EBADF;
1895         }
1896
1897         /* Loop on CUs (Compilation Unit) */
1898         while (!lf.found && ret >= 0) {
1899                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1900                         break;
1901
1902                 /* Get the DIE(Debugging Information Entry) of this CU */
1903                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1904                 if (!diep)
1905                         continue;
1906
1907                 /* Check if target file is included. */
1908                 if (lr->file)
1909                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1910                 else
1911                         lf.fname = 0;
1912
1913                 if (!lr->file || lf.fname) {
1914                         if (lr->function)
1915                                 ret = find_line_range_by_func(&lf);
1916                         else {
1917                                 lf.lno_s = lr->start;
1918                                 lf.lno_e = lr->end;
1919                                 ret = find_line_range_by_line(NULL, &lf);
1920                         }
1921                 }
1922                 off = noff;
1923         }
1924
1925         /* Store comp_dir */
1926         if (lf.found) {
1927                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1928                 if (comp_dir) {
1929                         lr->comp_dir = strdup(comp_dir);
1930                         if (!lr->comp_dir)
1931                                 ret = -ENOMEM;
1932                 }
1933         }
1934
1935         pr_debug("path: %s\n", lr->path);
1936         dwfl_end(dwfl);
1937         return (ret < 0) ? ret : lf.found;
1938 }
1939