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 static char *debuginfo_path;    /* Currently dummy */
 121
 122 static const Dwfl_Callbacks offline_callbacks = {
 123         .find_debuginfo = dwfl_standard_find_debuginfo,
 124         .debuginfo_path = &debuginfo_path,
 125
 126         .section_address = dwfl_offline_section_address,
 127
 128         /* We use this table for core files too.  */
 129         .find_elf = dwfl_build_id_find_elf,
 130 };
 131
 132 /* Get a Dwarf from offline image */
 133 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
 134 {
 135         Dwfl_Module *mod;
 136         Dwarf *dbg = NULL;
 137
 138         if (!dwflp)
 139                 return NULL;
 140
 141         *dwflp = dwfl_begin(&offline_callbacks);
 142         if (!*dwflp)
 143                 return NULL;
 144
 145         mod = dwfl_report_offline(*dwflp, "", "", fd);
 146         if (!mod)
 147                 goto error;
 148
 149         dbg = dwfl_module_getdwarf(mod, bias);
 150         if (!dbg) {
 151 error:
 152                 dwfl_end(*dwflp);
 153                 *dwflp = NULL;
 154         }
 155         return dbg;
 156 }
 157
 158 #if _ELFUTILS_PREREQ(0, 148)
 159 /* This method is buggy if elfutils is older than 0.148 */
 160 static int __linux_kernel_find_elf(Dwfl_Module *mod,
 161                                    void **userdata,
 162                                    const char *module_name,
 163                                    Dwarf_Addr base,
 164                                    char **file_name, Elf **elfp)
 165 {
 166         int fd;
 167         const char *path = kernel_get_module_path(module_name);
 168
 169         pr_debug2("Use file %s for %s\n", path, module_name);
 170         if (path) {
 171                 fd = open(path, O_RDONLY);
 172                 if (fd >= 0) {
 173                         *file_name = strdup(path);
 174                         return fd;
 175                 }
 176         }
 177         /* If failed, try to call standard method */
 178         return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
 179                                           file_name, elfp);
 180 }
 181
 182 static const Dwfl_Callbacks kernel_callbacks = {
 183         .find_debuginfo = dwfl_standard_find_debuginfo,
 184         .debuginfo_path = &debuginfo_path,
 185
 186         .find_elf = __linux_kernel_find_elf,
 187         .section_address = dwfl_linux_kernel_module_section_address,
 188 };
 189
 190 /* Get a Dwarf from live kernel image */
 191 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
 192                                           Dwarf_Addr *bias)
 193 {
 194         Dwarf *dbg;
 195
 196         if (!dwflp)
 197                 return NULL;
 198
 199         *dwflp = dwfl_begin(&kernel_callbacks);
 200         if (!*dwflp)
 201                 return NULL;
 202
 203         /* Load the kernel dwarves: Don't care the result here */
 204         dwfl_linux_kernel_report_kernel(*dwflp);
 205         dwfl_linux_kernel_report_modules(*dwflp);
 206
 207         dbg = dwfl_addrdwarf(*dwflp, addr, bias);
 208         /* Here, check whether we could get a real dwarf */
 209         if (!dbg) {
 210                 pr_debug("Failed to find kernel dwarf at %lx\n",
 211                          (unsigned long)addr);
 212                 dwfl_end(*dwflp);
 213                 *dwflp = NULL;
 214         }
 215         return dbg;
 216 }
 217 #else
 218 /* With older elfutils, this just support kernel module... */
 219 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
 220                                           Dwarf_Addr *bias)
 221 {
 222         int fd;
 223         const char *path = kernel_get_module_path("kernel");
 224
 225         if (!path) {
 226                 pr_err("Failed to find vmlinux path\n");
 227                 return NULL;
 228         }
 229
 230         pr_debug2("Use file %s for debuginfo\n", path);
 231         fd = open(path, O_RDONLY);
 232         if (fd < 0)
 233                 return NULL;
 234
 235         return dwfl_init_offline_dwarf(fd, dwflp, bias);
 236 }
 237 #endif
 238
 239 /* Dwarf wrappers */
 240
 241 /* Find the realpath of the target file. */
 242 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
 243 {
 244         Dwarf_Files *files;
 245         size_t nfiles, i;
 246         const char *src = NULL;
 247         int ret;
 248
 249         if (!fname)
 250                 return NULL;
 251
 252         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
 253         if (ret != 0)
 254                 return NULL;
 255
 256         for (i = 0; i < nfiles; i++) {
 257                 src = dwarf_filesrc(files, i, NULL, NULL);
 258                 if (strtailcmp(src, fname) == 0)
 259                         break;
 260         }
 261         if (i == nfiles)
 262                 return NULL;
 263         return src;
 264 }
 265
 266 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
 267 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
 268 {
 269         Dwarf_Attribute attr;
 270         if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
 271                 return NULL;
 272         return dwarf_formstring(&attr);
 273 }
 274
 275 /* Compare diename and tname */
 276 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 277 {
 278         const char *name;
 279         name = dwarf_diename(dw_die);
 280         return name ? (strcmp(tname, name) == 0) : false;
 281 }
 282
 283 /* Get type die */
 284 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 285 {
 286         Dwarf_Attribute attr;
 287
 288         if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
 289             dwarf_formref_die(&attr, die_mem))
 290                 return die_mem;
 291         else
 292                 return NULL;
 293 }
 294
 295 /* Get a type die, but skip qualifiers */
 296 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 297 {
 298         int tag;
 299
 300         do {
 301                 vr_die = die_get_type(vr_die, die_mem);
 302                 if (!vr_die)
 303                         break;
 304                 tag = dwarf_tag(vr_die);
 305         } while (tag == DW_TAG_const_type ||
 306                  tag == DW_TAG_restrict_type ||
 307                  tag == DW_TAG_volatile_type ||
 308                  tag == DW_TAG_shared_type);
 309
 310         return vr_die;
 311 }
 312
 313 /* Get a type die, but skip qualifiers and typedef */
 314 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 315 {
 316         do {
 317                 vr_die = __die_get_real_type(vr_die, die_mem);
 318         } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
 319
 320         return vr_die;
 321 }
 322
 323 static bool die_is_signed_type(Dwarf_Die *tp_die)
 324 {
 325         Dwarf_Attribute attr;
 326         Dwarf_Word ret;
 327
 328         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
 329             dwarf_formudata(&attr, &ret) != 0)
 330                 return false;
 331
 332         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
 333                 ret == DW_ATE_signed_fixed);
 334 }
 335
 336 static int die_get_byte_size(Dwarf_Die *tp_die)
 337 {
 338         Dwarf_Attribute attr;
 339         Dwarf_Word ret;
 340
 341         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
 342             dwarf_formudata(&attr, &ret) != 0)
 343                 return 0;
 344
 345         return (int)ret;
 346 }
 347
 348 /* Get data_member_location offset */
 349 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
 350 {
 351         Dwarf_Attribute attr;
 352         Dwarf_Op *expr;
 353         size_t nexpr;
 354         int ret;
 355
 356         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
 357                 return -ENOENT;
 358
 359         if (dwarf_formudata(&attr, offs) != 0) {
 360                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
 361                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
 362                 if (ret < 0 || nexpr == 0)
 363                         return -ENOENT;
 364
 365                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
 366                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
 367                                  expr[0].atom, nexpr);
 368                         return -ENOTSUP;
 369                 }
 370                 *offs = (Dwarf_Word)expr[0].number;
 371         }
 372         return 0;
 373 }
 374
 375 /* Return values for die_find callbacks */
 376 enum {
 377         DIE_FIND_CB_FOUND = 0,          /* End of Search */
 378         DIE_FIND_CB_CHILD = 1,          /* Search only children */
 379         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
 380         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
 381 };
 382
 383 /* Search a child die */
 384 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
 385                                  int (*callback)(Dwarf_Die *, void *),
 386                                  void *data, Dwarf_Die *die_mem)
 387 {
 388         Dwarf_Die child_die;
 389         int ret;
 390
 391         ret = dwarf_child(rt_die, die_mem);
 392         if (ret != 0)
 393                 return NULL;
 394
 395         do {
 396                 ret = callback(die_mem, data);
 397                 if (ret == DIE_FIND_CB_FOUND)
 398                         return die_mem;
 399
 400                 if ((ret & DIE_FIND_CB_CHILD) &&
 401                     die_find_child(die_mem, callback, data, &child_die)) {
 402                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
 403                         return die_mem;
 404                 }
 405         } while ((ret & DIE_FIND_CB_SIBLING) &&
 406                  dwarf_siblingof(die_mem, die_mem) == 0);
 407
 408         return NULL;
 409 }
 410
 411 struct __addr_die_search_param {
 412         Dwarf_Addr      addr;
 413         Dwarf_Die       *die_mem;
 414 };
 415
 416 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 417 {
 418         struct __addr_die_search_param *ad = data;
 419
 420         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
 421             dwarf_haspc(fn_die, ad->addr)) {
 422                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
 423                 return DWARF_CB_ABORT;
 424         }
 425         return DWARF_CB_OK;
 426 }
 427
 428 /* Search a real subprogram including this line, */
 429 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
 430                                            Dwarf_Die *die_mem)
 431 {
 432         struct __addr_die_search_param ad;
 433         ad.addr = addr;
 434         ad.die_mem = die_mem;
 435         /* dwarf_getscopes can't find subprogram. */
 436         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
 437                 return NULL;
 438         else
 439                 return die_mem;
 440 }
 441
 442 /* die_find callback for inline function search */
 443 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 444 {
 445         Dwarf_Addr *addr = data;
 446
 447         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
 448             dwarf_haspc(die_mem, *addr))
 449                 return DIE_FIND_CB_FOUND;
 450
 451         return DIE_FIND_CB_CONTINUE;
 452 }
 453
 454 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
 455 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 456                                       Dwarf_Die *die_mem)
 457 {
 458         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 459 }
 460
 461 struct __find_variable_param {
 462         const char *name;
 463         Dwarf_Addr addr;
 464 };
 465
 466 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 467 {
 468         struct __find_variable_param *fvp = data;
 469         int tag;
 470
 471         tag = dwarf_tag(die_mem);
 472         if ((tag == DW_TAG_formal_parameter ||
 473              tag == DW_TAG_variable) &&
 474             die_compare_name(die_mem, fvp->name))
 475                 return DIE_FIND_CB_FOUND;
 476
 477         if (dwarf_haspc(die_mem, fvp->addr))
 478                 return DIE_FIND_CB_CONTINUE;
 479         else
 480                 return DIE_FIND_CB_SIBLING;
 481 }
 482
 483 /* Find a variable called 'name' at given address */
 484 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
 485                                        Dwarf_Addr addr, Dwarf_Die *die_mem)
 486 {
 487         struct __find_variable_param fvp = { .name = name, .addr = addr};
 488
 489         return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
 490                               die_mem);
 491 }
 492
 493 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
 494 {
 495         const char *name = data;
 496
 497         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
 498             die_compare_name(die_mem, name))
 499                 return DIE_FIND_CB_FOUND;
 500
 501         return DIE_FIND_CB_SIBLING;
 502 }
 503
 504 /* Find a member called 'name' */
 505 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
 506                                   Dwarf_Die *die_mem)
 507 {
 508         return die_find_child(st_die, __die_find_member_cb, (void *)name,
 509                               die_mem);
 510 }
 511
 512 /* Get the name of given variable DIE */
 513 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
 514 {
 515         Dwarf_Die type;
 516         int tag, ret, ret2;
 517         const char *tmp = "";
 518
 519         if (__die_get_real_type(vr_die, &type) == NULL)
 520                 return -ENOENT;
 521
 522         tag = dwarf_tag(&type);
 523         if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
 524                 tmp = "*";
 525         else if (tag == DW_TAG_subroutine_type) {
 526                 /* Function pointer */
 527                 ret = snprintf(buf, len, "(function_type)");
 528                 return (ret >= len) ? -E2BIG : ret;
 529         } else {
 530                 if (!dwarf_diename(&type))
 531                         return -ENOENT;
 532                 if (tag == DW_TAG_union_type)
 533                         tmp = "union ";
 534                 else if (tag == DW_TAG_structure_type)
 535                         tmp = "struct ";
 536                 /* Write a base name */
 537                 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
 538                 return (ret >= len) ? -E2BIG : ret;
 539         }
 540         ret = die_get_typename(&type, buf, len);
 541         if (ret > 0) {
 542                 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
 543                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 544         }
 545         return ret;
 546 }
 547
 548 /* Get the name and type of given variable DIE, stored as "type\tname" */
 549 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
 550 {
 551         int ret, ret2;
 552
 553         ret = die_get_typename(vr_die, buf, len);
 554         if (ret < 0) {
 555                 pr_debug("Failed to get type, make it unknown.\n");
 556                 ret = snprintf(buf, len, "(unknown_type)");
 557         }
 558         if (ret > 0) {
 559                 ret2 = snprintf(buf + ret, len - ret, "\t%s",
 560                                 dwarf_diename(vr_die));
 561                 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
 562         }
 563         return ret;
 564 }
 565
 566 /*
 567  * Probe finder related functions
 568  */
 569
 570 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
 571 {
 572         struct probe_trace_arg_ref *ref;
 573         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 574         if (ref != NULL)
 575                 ref->offset = offs;
 576         return ref;
 577 }
 578
 579 /*
 580  * Convert a location into trace_arg.
 581  * If tvar == NULL, this just checks variable can be converted.
 582  */
 583 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 584                                      Dwarf_Op *fb_ops,
 585                                      struct probe_trace_arg *tvar)
 586 {
 587         Dwarf_Attribute attr;
 588         Dwarf_Op *op;
 589         size_t nops;
 590         unsigned int regn;
 591         Dwarf_Word offs = 0;
 592         bool ref = false;
 593         const char *regs;
 594         int ret;
 595
 596         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
 597                 goto static_var;
 598
 599         /* TODO: handle more than 1 exprs */
 600         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
 601             dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
 602             nops == 0) {
 603                 /* TODO: Support const_value */
 604                 return -ENOENT;
 605         }
 606
 607         if (op->atom == DW_OP_addr) {
 608 static_var:
 609                 if (!tvar)
 610                         return 0;
 611                 /* Static variables on memory (not stack), make @varname */
 612                 ret = strlen(dwarf_diename(vr_die));
 613                 tvar->value = zalloc(ret + 2);
 614                 if (tvar->value == NULL)
 615                         return -ENOMEM;
 616                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
 617                 tvar->ref = alloc_trace_arg_ref((long)offs);
 618                 if (tvar->ref == NULL)
 619                         return -ENOMEM;
 620                 return 0;
 621         }
 622
 623         /* If this is based on frame buffer, set the offset */
 624         if (op->atom == DW_OP_fbreg) {
 625                 if (fb_ops == NULL)
 626                         return -ENOTSUP;
 627                 ref = true;
 628                 offs = op->number;
 629                 op = &fb_ops[0];
 630         }
 631
 632         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 633                 regn = op->atom - DW_OP_breg0;
 634                 offs += op->number;
 635                 ref = true;
 636         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 637                 regn = op->atom - DW_OP_reg0;
 638         } else if (op->atom == DW_OP_bregx) {
 639                 regn = op->number;
 640                 offs += op->number2;
 641                 ref = true;
 642         } else if (op->atom == DW_OP_regx) {
 643                 regn = op->number;
 644         } else {
 645                 pr_debug("DW_OP %x is not supported.\n", op->atom);
 646                 return -ENOTSUP;
 647         }
 648
 649         if (!tvar)
 650                 return 0;
 651
 652         regs = get_arch_regstr(regn);
 653         if (!regs) {
 654                 /* This should be a bug in DWARF or this tool */
 655                 pr_warning("Mapping for DWARF register number %u "
 656                            "missing on this architecture.", regn);
 657                 return -ERANGE;
 658         }
 659
 660         tvar->value = strdup(regs);
 661         if (tvar->value == NULL)
 662                 return -ENOMEM;
 663
 664         if (ref) {
 665                 tvar->ref = alloc_trace_arg_ref((long)offs);
 666                 if (tvar->ref == NULL)
 667                         return -ENOMEM;
 668         }
 669         return 0;
 670 }
 671
 672 static int convert_variable_type(Dwarf_Die *vr_die,
 673                                  struct probe_trace_arg *tvar,
 674                                  const char *cast)
 675 {
 676         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
 677         Dwarf_Die type;
 678         char buf[16];
 679         int ret;
 680
 681         /* TODO: check all types */
 682         if (cast && strcmp(cast, "string") != 0) {
 683                 /* Non string type is OK */
 684                 tvar->type = strdup(cast);
 685                 return (tvar->type == NULL) ? -ENOMEM : 0;
 686         }
 687
 688         if (die_get_real_type(vr_die, &type) == NULL) {
 689                 pr_warning("Failed to get a type information of %s.\n",
 690                            dwarf_diename(vr_die));
 691                 return -ENOENT;
 692         }
 693
 694         pr_debug("%s type is %s.\n",
 695                  dwarf_diename(vr_die), dwarf_diename(&type));
 696
 697         if (cast && strcmp(cast, "string") == 0) {      /* String type */
 698                 ret = dwarf_tag(&type);
 699                 if (ret != DW_TAG_pointer_type &&
 700                     ret != DW_TAG_array_type) {
 701                         pr_warning("Failed to cast into string: "
 702                                    "%s(%s) is not a pointer nor array.",
 703                                    dwarf_diename(vr_die), dwarf_diename(&type));
 704                         return -EINVAL;
 705                 }
 706                 if (ret == DW_TAG_pointer_type) {
 707                         if (die_get_real_type(&type, &type) == NULL) {
 708                                 pr_warning("Failed to get a type information.");
 709                                 return -ENOENT;
 710                         }
 711                         while (*ref_ptr)
 712                                 ref_ptr = &(*ref_ptr)->next;
 713                         /* Add new reference with offset +0 */
 714                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 715                         if (*ref_ptr == NULL) {
 716                                 pr_warning("Out of memory error\n");
 717                                 return -ENOMEM;
 718                         }
 719                 }
 720                 if (!die_compare_name(&type, "char") &&
 721                     !die_compare_name(&type, "unsigned char")) {
 722                         pr_warning("Failed to cast into string: "
 723                                    "%s is not (unsigned) char *.",
 724                                    dwarf_diename(vr_die));
 725                         return -EINVAL;
 726                 }
 727                 tvar->type = strdup(cast);
 728                 return (tvar->type == NULL) ? -ENOMEM : 0;
 729         }
 730
 731         ret = die_get_byte_size(&type) * 8;
 732         if (ret) {
 733                 /* Check the bitwidth */
 734                 if (ret > MAX_BASIC_TYPE_BITS) {
 735                         pr_info("%s exceeds max-bitwidth."
 736                                 " Cut down to %d bits.\n",
 737                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 738                         ret = MAX_BASIC_TYPE_BITS;
 739                 }
 740
 741                 ret = snprintf(buf, 16, "%c%d",
 742                                die_is_signed_type(&type) ? 's' : 'u', ret);
 743                 if (ret < 0 || ret >= 16) {
 744                         if (ret >= 16)
 745                                 ret = -E2BIG;
 746                         pr_warning("Failed to convert variable type: %s\n",
 747                                    strerror(-ret));
 748                         return ret;
 749                 }
 750                 tvar->type = strdup(buf);
 751                 if (tvar->type == NULL)
 752                         return -ENOMEM;
 753         }
 754         return 0;
 755 }
 756
 757 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 758                                     struct perf_probe_arg_field *field,
 759                                     struct probe_trace_arg_ref **ref_ptr,
 760                                     Dwarf_Die *die_mem)
 761 {
 762         struct probe_trace_arg_ref *ref = *ref_ptr;
 763         Dwarf_Die type;
 764         Dwarf_Word offs;
 765         int ret, tag;
 766
 767         pr_debug("converting %s in %s\n", field->name, varname);
 768         if (die_get_real_type(vr_die, &type) == NULL) {
 769                 pr_warning("Failed to get the type of %s.\n", varname);
 770                 return -ENOENT;
 771         }
 772         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 773         tag = dwarf_tag(&type);
 774
 775         if (field->name[0] == '[' &&
 776             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 777                 if (field->next)
 778                         /* Save original type for next field */
 779                         memcpy(die_mem, &type, sizeof(*die_mem));
 780                 /* Get the type of this array */
 781                 if (die_get_real_type(&type, &type) == NULL) {
 782                         pr_warning("Failed to get the type of %s.\n", varname);
 783                         return -ENOENT;
 784                 }
 785                 pr_debug2("Array real type: (%x)\n",
 786                          (unsigned)dwarf_dieoffset(&type));
 787                 if (tag == DW_TAG_pointer_type) {
 788                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 789                         if (ref == NULL)
 790                                 return -ENOMEM;
 791                         if (*ref_ptr)
 792                                 (*ref_ptr)->next = ref;
 793                         else
 794                                 *ref_ptr = ref;
 795                 }
 796                 ref->offset += die_get_byte_size(&type) * field->index;
 797                 if (!field->next)
 798                         /* Save vr_die for converting types */
 799                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 800                 goto next;
 801         } else if (tag == DW_TAG_pointer_type) {
 802                 /* Check the pointer and dereference */
 803                 if (!field->ref) {
 804                         pr_err("Semantic error: %s must be referred by '->'\n",
 805                                field->name);
 806                         return -EINVAL;
 807                 }
 808                 /* Get the type pointed by this pointer */
 809                 if (die_get_real_type(&type, &type) == NULL) {
 810                         pr_warning("Failed to get the type of %s.\n", varname);
 811                         return -ENOENT;
 812                 }
 813                 /* Verify it is a data structure  */
 814                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 815                         pr_warning("%s is not a data structure.\n", varname);
 816                         return -EINVAL;
 817                 }
 818
 819                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 820                 if (ref == NULL)
 821                         return -ENOMEM;
 822                 if (*ref_ptr)
 823                         (*ref_ptr)->next = ref;
 824                 else
 825                         *ref_ptr = ref;
 826         } else {
 827                 /* Verify it is a data structure  */
 828                 if (tag != DW_TAG_structure_type) {
 829                         pr_warning("%s is not a data structure.\n", varname);
 830                         return -EINVAL;
 831                 }
 832                 if (field->name[0] == '[') {
 833                         pr_err("Semantic error: %s is not a pointor nor array.",
 834                                varname);
 835                         return -EINVAL;
 836                 }
 837                 if (field->ref) {
 838                         pr_err("Semantic error: %s must be referred by '.'\n",
 839                                field->name);
 840                         return -EINVAL;
 841                 }
 842                 if (!ref) {
 843                         pr_warning("Structure on a register is not "
 844                                    "supported yet.\n");
 845                         return -ENOTSUP;
 846                 }
 847         }
 848
 849         if (die_find_member(&type, field->name, die_mem) == NULL) {
 850                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 851                            dwarf_diename(&type), field->name);
 852                 return -EINVAL;
 853         }
 854
 855         /* Get the offset of the field */
 856         ret = die_get_data_member_location(die_mem, &offs);
 857         if (ret < 0) {
 858                 pr_warning("Failed to get the offset of %s.\n", field->name);
 859                 return ret;
 860         }
 861         ref->offset += (long)offs;
 862
 863 next:
 864         /* Converting next field */
 865         if (field->next)
 866                 return convert_variable_fields(die_mem, field->name,
 867                                         field->next, &ref, die_mem);
 868         else
 869                 return 0;
 870 }
 871
 872 /* Show a variables in kprobe event format */
 873 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 874 {
 875         Dwarf_Die die_mem;
 876         int ret;
 877
 878         pr_debug("Converting variable %s into trace event.\n",
 879                  dwarf_diename(vr_die));
 880
 881         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 882                                         pf->tvar);
 883         if (ret == -ENOENT)
 884                 pr_err("Failed to find the location of %s at this address.\n"
 885                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 886         else if (ret == -ENOTSUP)
 887                 pr_err("Sorry, we don't support this variable location yet.\n");
 888         else if (pf->pvar->field) {
 889                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 890                                               pf->pvar->field, &pf->tvar->ref,
 891                                               &die_mem);
 892                 vr_die = &die_mem;
 893         }
 894         if (ret == 0)
 895                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 896         /* *expr will be cached in libdw. Don't free it. */
 897         return ret;
 898 }
 899
 900 /* Find a variable in a subprogram die */
 901 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 902 {
 903         Dwarf_Die vr_die, *scopes;
 904         char buf[32], *ptr;
 905         int ret, nscopes;
 906
 907         if (!is_c_varname(pf->pvar->var)) {
 908                 /* Copy raw parameters */
 909                 pf->tvar->value = strdup(pf->pvar->var);
 910                 if (pf->tvar->value == NULL)
 911                         return -ENOMEM;
 912                 if (pf->pvar->type) {
 913                         pf->tvar->type = strdup(pf->pvar->type);
 914                         if (pf->tvar->type == NULL)
 915                                 return -ENOMEM;
 916                 }
 917                 if (pf->pvar->name) {
 918                         pf->tvar->name = strdup(pf->pvar->name);
 919                         if (pf->tvar->name == NULL)
 920                                 return -ENOMEM;
 921                 } else
 922                         pf->tvar->name = NULL;
 923                 return 0;
 924         }
 925
 926         if (pf->pvar->name)
 927                 pf->tvar->name = strdup(pf->pvar->name);
 928         else {
 929                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 930                 if (ret < 0)
 931                         return ret;
 932                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 933                 if (ptr)
 934                         *ptr = '_';
 935                 pf->tvar->name = strdup(buf);
 936         }
 937         if (pf->tvar->name == NULL)
 938                 return -ENOMEM;
 939
 940         pr_debug("Searching '%s' variable in context.\n",
 941                  pf->pvar->var);
 942         /* Search child die for local variables and parameters. */
 943         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
 944                 ret = convert_variable(&vr_die, pf);
 945         else {
 946                 /* Search upper class */
 947                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 948                 while (nscopes-- > 1) {
 949                         pr_debug("Searching variables in %s\n",
 950                                  dwarf_diename(&scopes[nscopes]));
 951                         /* We should check this scope, so give dummy address */
 952                         if (die_find_variable_at(&scopes[nscopes],
 953                                                  pf->pvar->var, 0,
 954                                                  &vr_die)) {
 955                                 ret = convert_variable(&vr_die, pf);
 956                                 goto found;
 957                         }
 958                 }
 959                 if (scopes)
 960                         free(scopes);
 961                 ret = -ENOENT;
 962         }
 963 found:
 964         if (ret < 0)
 965                 pr_warning("Failed to find '%s' in this function.\n",
 966                            pf->pvar->var);
 967         return ret;
 968 }
 969
 970 /* Convert subprogram DIE to trace point */
 971 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
 972                                   bool retprobe, struct probe_trace_point *tp)
 973 {
 974         Dwarf_Addr eaddr;
 975         const char *name;
 976
 977         /* Copy the name of probe point */
 978         name = dwarf_diename(sp_die);
 979         if (name) {
 980                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 981                         pr_warning("Failed to get entry pc of %s\n",
 982                                    dwarf_diename(sp_die));
 983                         return -ENOENT;
 984                 }
 985                 tp->symbol = strdup(name);
 986                 if (tp->symbol == NULL)
 987                         return -ENOMEM;
 988                 tp->offset = (unsigned long)(paddr - eaddr);
 989         } else
 990                 /* This function has no name. */
 991                 tp->offset = (unsigned long)paddr;
 992
 993         /* Return probe must be on the head of a subprogram */
 994         if (retprobe) {
 995                 if (eaddr != paddr) {
 996                         pr_warning("Return probe must be on the head of"
 997                                    " a real function\n");
 998                         return -EINVAL;
 999                 }
1000                 tp->retprobe = true;
1001         }
1002
1003         return 0;
1004 }
1005
1006 /* Call probe_finder callback with real subprogram DIE */
1007 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1008 {
1009         Dwarf_Die die_mem;
1010         Dwarf_Attribute fb_attr;
1011         size_t nops;
1012         int ret;
1013
1014         /* If no real subprogram, find a real one */
1015         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1016                 sp_die = die_find_real_subprogram(&pf->cu_die,
1017                                                   pf->addr, &die_mem);
1018                 if (!sp_die) {
1019                         pr_warning("Failed to find probe point in any "
1020                                    "functions.\n");
1021                         return -ENOENT;
1022                 }
1023         }
1024
1025         /* Get the frame base attribute/ops */
1026         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1027         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1028         if (ret <= 0 || nops == 0) {
1029                 pf->fb_ops = NULL;
1030 #if _ELFUTILS_PREREQ(0, 142)
1031         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1032                    pf->cfi != NULL) {
1033                 Dwarf_Frame *frame;
1034                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1035                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1036                         pr_warning("Failed to get CFA on 0x%jx\n",
1037                                    (uintmax_t)pf->addr);
1038                         return -ENOENT;
1039                 }
1040 #endif
1041         }
1042
1043         /* Call finder's callback handler */
1044         ret = pf->callback(sp_die, pf);
1045
1046         /* *pf->fb_ops will be cached in libdw. Don't free it. */
1047         pf->fb_ops = NULL;
1048
1049         return ret;
1050 }
1051
1052 /* Find probe point from its line number */
1053 static int find_probe_point_by_line(struct probe_finder *pf)
1054 {
1055         Dwarf_Lines *lines;
1056         Dwarf_Line *line;
1057         size_t nlines, i;
1058         Dwarf_Addr addr;
1059         int lineno;
1060         int ret = 0;
1061
1062         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1063                 pr_warning("No source lines found in this CU.\n");
1064                 return -ENOENT;
1065         }
1066
1067         for (i = 0; i < nlines && ret == 0; i++) {
1068                 line = dwarf_onesrcline(lines, i);
1069                 if (dwarf_lineno(line, &lineno) != 0 ||
1070                     lineno != pf->lno)
1071                         continue;
1072
1073                 /* TODO: Get fileno from line, but how? */
1074                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1075                         continue;
1076
1077                 if (dwarf_lineaddr(line, &addr) != 0) {
1078                         pr_warning("Failed to get the address of the line.\n");
1079                         return -ENOENT;
1080                 }
1081                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1082                          (int)i, lineno, (uintmax_t)addr);
1083                 pf->addr = addr;
1084
1085                 ret = call_probe_finder(NULL, pf);
1086                 /* Continuing, because target line might be inlined. */
1087         }
1088         return ret;
1089 }
1090
1091 /* Find lines which match lazy pattern */
1092 static int find_lazy_match_lines(struct list_head *head,
1093                                  const char *fname, const char *pat)
1094 {
1095         char *fbuf, *p1, *p2;
1096         int fd, line, nlines = -1;
1097         struct stat st;
1098
1099         fd = open(fname, O_RDONLY);
1100         if (fd < 0) {
1101                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1102                 return -errno;
1103         }
1104
1105         if (fstat(fd, &st) < 0) {
1106                 pr_warning("Failed to get the size of %s: %s\n",
1107                            fname, strerror(errno));
1108                 nlines = -errno;
1109                 goto out_close;
1110         }
1111
1112         nlines = -ENOMEM;
1113         fbuf = malloc(st.st_size + 2);
1114         if (fbuf == NULL)
1115                 goto out_close;
1116         if (read(fd, fbuf, st.st_size) < 0) {
1117                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1118                 nlines = -errno;
1119                 goto out_free_fbuf;
1120         }
1121         fbuf[st.st_size] = '\n';        /* Dummy line */
1122         fbuf[st.st_size + 1] = '\0';
1123         p1 = fbuf;
1124         line = 1;
1125         nlines = 0;
1126         while ((p2 = strchr(p1, '\n')) != NULL) {
1127                 *p2 = '\0';
1128                 if (strlazymatch(p1, pat)) {
1129                         line_list__add_line(head, line);
1130                         nlines++;
1131                 }
1132                 line++;
1133                 p1 = p2 + 1;
1134         }
1135 out_free_fbuf:
1136         free(fbuf);
1137 out_close:
1138         close(fd);
1139         return nlines;
1140 }
1141
1142 /* Find probe points from lazy pattern  */
1143 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1144 {
1145         Dwarf_Lines *lines;
1146         Dwarf_Line *line;
1147         size_t nlines, i;
1148         Dwarf_Addr addr;
1149         Dwarf_Die die_mem;
1150         int lineno;
1151         int ret = 0;
1152
1153         if (list_empty(&pf->lcache)) {
1154                 /* Matching lazy line pattern */
1155                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1156                                             pf->pev->point.lazy_line);
1157                 if (ret == 0) {
1158                         pr_debug("No matched lines found in %s.\n", pf->fname);
1159                         return 0;
1160                 } else if (ret < 0)
1161                         return ret;
1162         }
1163
1164         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1165                 pr_warning("No source lines found in this CU.\n");
1166                 return -ENOENT;
1167         }
1168
1169         for (i = 0; i < nlines && ret >= 0; i++) {
1170                 line = dwarf_onesrcline(lines, i);
1171
1172                 if (dwarf_lineno(line, &lineno) != 0 ||
1173                     !line_list__has_line(&pf->lcache, lineno))
1174                         continue;
1175
1176                 /* TODO: Get fileno from line, but how? */
1177                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1178                         continue;
1179
1180                 if (dwarf_lineaddr(line, &addr) != 0) {
1181                         pr_debug("Failed to get the address of line %d.\n",
1182                                  lineno);
1183                         continue;
1184                 }
1185                 if (sp_die) {
1186                         /* Address filtering 1: does sp_die include addr? */
1187                         if (!dwarf_haspc(sp_die, addr))
1188                                 continue;
1189                         /* Address filtering 2: No child include addr? */
1190                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1191                                 continue;
1192                 }
1193
1194                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1195                          (int)i, lineno, (unsigned long long)addr);
1196                 pf->addr = addr;
1197
1198                 ret = call_probe_finder(sp_die, pf);
1199                 /* Continuing, because target line might be inlined. */
1200         }
1201         /* TODO: deallocate lines, but how? */
1202         return ret;
1203 }
1204
1205 /* Callback parameter with return value */
1206 struct dwarf_callback_param {
1207         void *data;
1208         int retval;
1209 };
1210
1211 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1212 {
1213         struct dwarf_callback_param *param = data;
1214         struct probe_finder *pf = param->data;
1215         struct perf_probe_point *pp = &pf->pev->point;
1216         Dwarf_Addr addr;
1217
1218         if (pp->lazy_line)
1219                 param->retval = find_probe_point_lazy(in_die, pf);
1220         else {
1221                 /* Get probe address */
1222                 if (dwarf_entrypc(in_die, &addr) != 0) {
1223                         pr_warning("Failed to get entry pc of %s.\n",
1224                                    dwarf_diename(in_die));
1225                         param->retval = -ENOENT;
1226                         return DWARF_CB_ABORT;
1227                 }
1228                 pf->addr = addr;
1229                 pf->addr += pp->offset;
1230                 pr_debug("found inline addr: 0x%jx\n",
1231                          (uintmax_t)pf->addr);
1232
1233                 param->retval = call_probe_finder(in_die, pf);
1234                 if (param->retval < 0)
1235                         return DWARF_CB_ABORT;
1236         }
1237
1238         return DWARF_CB_OK;
1239 }
1240
1241 /* Search function from function name */
1242 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1243 {
1244         struct dwarf_callback_param *param = data;
1245         struct probe_finder *pf = param->data;
1246         struct perf_probe_point *pp = &pf->pev->point;
1247
1248         /* Check tag and diename */
1249         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1250             !die_compare_name(sp_die, pp->function))
1251                 return DWARF_CB_OK;
1252
1253         pf->fname = dwarf_decl_file(sp_die);
1254         if (pp->line) { /* Function relative line */
1255                 dwarf_decl_line(sp_die, &pf->lno);
1256                 pf->lno += pp->line;
1257                 param->retval = find_probe_point_by_line(pf);
1258         } else if (!dwarf_func_inline(sp_die)) {
1259                 /* Real function */
1260                 if (pp->lazy_line)
1261                         param->retval = find_probe_point_lazy(sp_die, pf);
1262                 else {
1263                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1264                                 pr_warning("Failed to get entry pc of %s.\n",
1265                                            dwarf_diename(sp_die));
1266                                 param->retval = -ENOENT;
1267                                 return DWARF_CB_ABORT;
1268                         }
1269                         pf->addr += pp->offset;
1270                         /* TODO: Check the address in this function */
1271                         param->retval = call_probe_finder(sp_die, pf);
1272                 }
1273         } else {
1274                 struct dwarf_callback_param _param = {.data = (void *)pf,
1275                                                       .retval = 0};
1276                 /* Inlined function: search instances */
1277                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1278                                             &_param);
1279                 param->retval = _param.retval;
1280         }
1281
1282         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1283 }
1284
1285 static int find_probe_point_by_func(struct probe_finder *pf)
1286 {
1287         struct dwarf_callback_param _param = {.data = (void *)pf,
1288                                               .retval = 0};
1289         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1290         return _param.retval;
1291 }
1292
1293 /* Find probe points from debuginfo */
1294 static int find_probes(int fd, struct probe_finder *pf)
1295 {
1296         struct perf_probe_point *pp = &pf->pev->point;
1297         Dwarf_Off off, noff;
1298         size_t cuhl;
1299         Dwarf_Die *diep;
1300         Dwarf *dbg = NULL;
1301         Dwfl *dwfl;
1302         Dwarf_Addr bias;        /* Currently ignored */
1303         int ret = 0;
1304
1305         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1306         if (!dbg) {
1307                 pr_warning("No dwarf info found in the vmlinux - "
1308                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1309                 return -EBADF;
1310         }
1311
1312 #if _ELFUTILS_PREREQ(0, 142)
1313         /* Get the call frame information from this dwarf */
1314         pf->cfi = dwarf_getcfi(dbg);
1315 #endif
1316
1317         off = 0;
1318         line_list__init(&pf->lcache);
1319         /* Loop on CUs (Compilation Unit) */
1320         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1321                ret >= 0) {
1322                 /* Get the DIE(Debugging Information Entry) of this CU */
1323                 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1324                 if (!diep)
1325                         continue;
1326
1327                 /* Check if target file is included. */
1328                 if (pp->file)
1329                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1330                 else
1331                         pf->fname = NULL;
1332
1333                 if (!pp->file || pf->fname) {
1334                         if (pp->function)
1335                                 ret = find_probe_point_by_func(pf);
1336                         else if (pp->lazy_line)
1337                                 ret = find_probe_point_lazy(NULL, pf);
1338                         else {
1339                                 pf->lno = pp->line;
1340                                 ret = find_probe_point_by_line(pf);
1341                         }
1342                 }
1343                 off = noff;
1344         }
1345         line_list__free(&pf->lcache);
1346         if (dwfl)
1347                 dwfl_end(dwfl);
1348
1349         return ret;
1350 }
1351
1352 /* Add a found probe point into trace event list */
1353 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1354 {
1355         struct trace_event_finder *tf =
1356                         container_of(pf, struct trace_event_finder, pf);
1357         struct probe_trace_event *tev;
1358         int ret, i;
1359
1360         /* Check number of tevs */
1361         if (tf->ntevs == tf->max_tevs) {
1362                 pr_warning("Too many( > %d) probe point found.\n",
1363                            tf->max_tevs);
1364                 return -ERANGE;
1365         }
1366         tev = &tf->tevs[tf->ntevs++];
1367
1368         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1369                                      &tev->point);
1370         if (ret < 0)
1371                 return ret;
1372
1373         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1374                  tev->point.offset);
1375
1376         /* Find each argument */
1377         tev->nargs = pf->pev->nargs;
1378         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1379         if (tev->args == NULL)
1380                 return -ENOMEM;
1381         for (i = 0; i < pf->pev->nargs; i++) {
1382                 pf->pvar = &pf->pev->args[i];
1383                 pf->tvar = &tev->args[i];
1384                 ret = find_variable(sp_die, pf);
1385                 if (ret != 0)
1386                         return ret;
1387         }
1388
1389         return 0;
1390 }
1391
1392 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1393 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1394                             struct probe_trace_event **tevs, int max_tevs)
1395 {
1396         struct trace_event_finder tf = {
1397                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1398                         .max_tevs = max_tevs};
1399         int ret;
1400
1401         /* Allocate result tevs array */
1402         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1403         if (*tevs == NULL)
1404                 return -ENOMEM;
1405
1406         tf.tevs = *tevs;
1407         tf.ntevs = 0;
1408
1409         ret = find_probes(fd, &tf.pf);
1410         if (ret < 0) {
1411                 free(*tevs);
1412                 *tevs = NULL;
1413                 return ret;
1414         }
1415
1416         return (ret < 0) ? ret : tf.ntevs;
1417 }
1418
1419 #define MAX_VAR_LEN 64
1420
1421 /* Collect available variables in this scope */
1422 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1423 {
1424         struct available_var_finder *af = data;
1425         struct variable_list *vl;
1426         char buf[MAX_VAR_LEN];
1427         int tag, ret;
1428
1429         vl = &af->vls[af->nvls - 1];
1430
1431         tag = dwarf_tag(die_mem);
1432         if (tag == DW_TAG_formal_parameter ||
1433             tag == DW_TAG_variable) {
1434                 ret = convert_variable_location(die_mem, af->pf.addr,
1435                                                 af->pf.fb_ops, NULL);
1436                 if (ret == 0) {
1437                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1438                         pr_debug2("Add new var: %s\n", buf);
1439                         if (ret > 0)
1440                                 strlist__add(vl->vars, buf);
1441                 }
1442         }
1443
1444         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1445                 return DIE_FIND_CB_CONTINUE;
1446         else
1447                 return DIE_FIND_CB_SIBLING;
1448 }
1449
1450 /* Add a found vars into available variables list */
1451 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1452 {
1453         struct available_var_finder *af =
1454                         container_of(pf, struct available_var_finder, pf);
1455         struct variable_list *vl;
1456         Dwarf_Die die_mem, *scopes = NULL;
1457         int ret, nscopes;
1458
1459         /* Check number of tevs */
1460         if (af->nvls == af->max_vls) {
1461                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1462                 return -ERANGE;
1463         }
1464         vl = &af->vls[af->nvls++];
1465
1466         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1467                                      &vl->point);
1468         if (ret < 0)
1469                 return ret;
1470
1471         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1472                  vl->point.offset);
1473
1474         /* Find local variables */
1475         vl->vars = strlist__new(true, NULL);
1476         if (vl->vars == NULL)
1477                 return -ENOMEM;
1478         af->child = true;
1479         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1480
1481         /* Find external variables */
1482         if (!af->externs)
1483                 goto out;
1484         /* Don't need to search child DIE for externs. */
1485         af->child = false;
1486         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1487         while (nscopes-- > 1)
1488                 die_find_child(&scopes[nscopes], collect_variables_cb,
1489                                (void *)af, &die_mem);
1490         if (scopes)
1491                 free(scopes);
1492
1493 out:
1494         if (strlist__empty(vl->vars)) {
1495                 strlist__delete(vl->vars);
1496                 vl->vars = NULL;
1497         }
1498
1499         return ret;
1500 }
1501
1502 /* Find available variables at given probe point */
1503 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1504                            struct variable_list **vls, int max_vls,
1505                            bool externs)
1506 {
1507         struct available_var_finder af = {
1508                         .pf = {.pev = pev, .callback = add_available_vars},
1509                         .max_vls = max_vls, .externs = externs};
1510         int ret;
1511
1512         /* Allocate result vls array */
1513         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1514         if (*vls == NULL)
1515                 return -ENOMEM;
1516
1517         af.vls = *vls;
1518         af.nvls = 0;
1519
1520         ret = find_probes(fd, &af.pf);
1521         if (ret < 0) {
1522                 /* Free vlist for error */
1523                 while (af.nvls--) {
1524                         if (af.vls[af.nvls].point.symbol)
1525                                 free(af.vls[af.nvls].point.symbol);
1526                         if (af.vls[af.nvls].vars)
1527                                 strlist__delete(af.vls[af.nvls].vars);
1528                 }
1529                 free(af.vls);
1530                 *vls = NULL;
1531                 return ret;
1532         }
1533
1534         return (ret < 0) ? ret : af.nvls;
1535 }
1536
1537 /* Reverse search */
1538 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1539 {
1540         Dwarf_Die cudie, spdie, indie;
1541         Dwarf *dbg = NULL;
1542         Dwfl *dwfl = NULL;
1543         Dwarf_Line *line;
1544         Dwarf_Addr laddr, eaddr, bias = 0;
1545         const char *tmp;
1546         int lineno, ret = 0;
1547         bool found = false;
1548
1549         /* Open the live linux kernel */
1550         dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1551         if (!dbg) {
1552                 pr_warning("No dwarf info found in the vmlinux - "
1553                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1554                 ret = -EINVAL;
1555                 goto end;
1556         }
1557
1558         /* Adjust address with bias */
1559         addr += bias;
1560         /* Find cu die */
1561         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1562                 pr_warning("No CU DIE is found at %lx\n", addr);
1563                 ret = -EINVAL;
1564                 goto end;
1565         }
1566
1567         /* Find a corresponding line */
1568         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1569         if (line) {
1570                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1571                     (Dwarf_Addr)addr == laddr &&
1572                     dwarf_lineno(line, &lineno) == 0) {
1573                         tmp = dwarf_linesrc(line, NULL, NULL);
1574                         if (tmp) {
1575                                 ppt->line = lineno;
1576                                 ppt->file = strdup(tmp);
1577                                 if (ppt->file == NULL) {
1578                                         ret = -ENOMEM;
1579                                         goto end;
1580                                 }
1581                                 found = true;
1582                         }
1583                 }
1584         }
1585
1586         /* Find a corresponding function */
1587         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1588                 tmp = dwarf_diename(&spdie);
1589                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1590                         goto end;
1591
1592                 if (ppt->line) {
1593                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1594                                                 &indie)) {
1595                                 /* addr in an inline function */
1596                                 tmp = dwarf_diename(&indie);
1597                                 if (!tmp)
1598                                         goto end;
1599                                 ret = dwarf_decl_line(&indie, &lineno);
1600                         } else {
1601                                 if (eaddr == addr) {    /* Function entry */
1602                                         lineno = ppt->line;
1603                                         ret = 0;
1604                                 } else
1605                                         ret = dwarf_decl_line(&spdie, &lineno);
1606                         }
1607                         if (ret == 0) {
1608                                 /* Make a relative line number */
1609                                 ppt->line -= lineno;
1610                                 goto found;
1611                         }
1612                 }
1613                 /* We don't have a line number, let's use offset */
1614                 ppt->offset = addr - (unsigned long)eaddr;
1615 found:
1616                 ppt->function = strdup(tmp);
1617                 if (ppt->function == NULL) {
1618                         ret = -ENOMEM;
1619                         goto end;
1620                 }
1621                 found = true;
1622         }
1623
1624 end:
1625         if (dwfl)
1626                 dwfl_end(dwfl);
1627         if (ret >= 0)
1628                 ret = found ? 1 : 0;
1629         return ret;
1630 }
1631
1632 /* Add a line and store the src path */
1633 static int line_range_add_line(const char *src, unsigned int lineno,
1634                                struct line_range *lr)
1635 {
1636         /* Copy source path */
1637         if (!lr->path) {
1638                 lr->path = strdup(src);
1639                 if (lr->path == NULL)
1640                         return -ENOMEM;
1641         }
1642         return line_list__add_line(&lr->line_list, lineno);
1643 }
1644
1645 /* Search function declaration lines */
1646 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1647 {
1648         struct dwarf_callback_param *param = data;
1649         struct line_finder *lf = param->data;
1650         const char *src;
1651         int lineno;
1652
1653         src = dwarf_decl_file(sp_die);
1654         if (src && strtailcmp(src, lf->fname) != 0)
1655                 return DWARF_CB_OK;
1656
1657         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1658             (lf->lno_s > lineno || lf->lno_e < lineno))
1659                 return DWARF_CB_OK;
1660
1661         param->retval = line_range_add_line(src, lineno, lf->lr);
1662         if (param->retval < 0)
1663                 return DWARF_CB_ABORT;
1664         return DWARF_CB_OK;
1665 }
1666
1667 static int find_line_range_func_decl_lines(struct line_finder *lf)
1668 {
1669         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1670         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1671         return param.retval;
1672 }
1673
1674 /* Find line range from its line number */
1675 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1676 {
1677         Dwarf_Lines *lines;
1678         Dwarf_Line *line;
1679         size_t nlines, i;
1680         Dwarf_Addr addr;
1681         int lineno, ret = 0;
1682         const char *src;
1683         Dwarf_Die die_mem;
1684
1685         line_list__init(&lf->lr->line_list);
1686         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1687                 pr_warning("No source lines found in this CU.\n");
1688                 return -ENOENT;
1689         }
1690
1691         /* Search probable lines on lines list */
1692         for (i = 0; i < nlines; i++) {
1693                 line = dwarf_onesrcline(lines, i);
1694                 if (dwarf_lineno(line, &lineno) != 0 ||
1695                     (lf->lno_s > lineno || lf->lno_e < lineno))
1696                         continue;
1697
1698                 if (sp_die) {
1699                         /* Address filtering 1: does sp_die include addr? */
1700                         if (dwarf_lineaddr(line, &addr) != 0 ||
1701                             !dwarf_haspc(sp_die, addr))
1702                                 continue;
1703
1704                         /* Address filtering 2: No child include addr? */
1705                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1706                                 continue;
1707                 }
1708
1709                 /* TODO: Get fileno from line, but how? */
1710                 src = dwarf_linesrc(line, NULL, NULL);
1711                 if (strtailcmp(src, lf->fname) != 0)
1712                         continue;
1713
1714                 ret = line_range_add_line(src, lineno, lf->lr);
1715                 if (ret < 0)
1716                         return ret;
1717         }
1718
1719         /*
1720          * Dwarf lines doesn't include function declarations. We have to
1721          * check functions list or given function.
1722          */
1723         if (sp_die) {
1724                 src = dwarf_decl_file(sp_die);
1725                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1726                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1727                         ret = line_range_add_line(src, lineno, lf->lr);
1728         } else
1729                 ret = find_line_range_func_decl_lines(lf);
1730
1731         /* Update status */
1732         if (ret >= 0)
1733                 if (!list_empty(&lf->lr->line_list))
1734                         ret = lf->found = 1;
1735                 else
1736                         ret = 0;        /* Lines are not found */
1737         else {
1738                 free(lf->lr->path);
1739                 lf->lr->path = NULL;
1740         }
1741         return ret;
1742 }
1743
1744 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1745 {
1746         struct dwarf_callback_param *param = data;
1747
1748         param->retval = find_line_range_by_line(in_die, param->data);
1749         return DWARF_CB_ABORT;  /* No need to find other instances */
1750 }
1751
1752 /* Search function from function name */
1753 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1754 {
1755         struct dwarf_callback_param *param = data;
1756         struct line_finder *lf = param->data;
1757         struct line_range *lr = lf->lr;
1758
1759         pr_debug("find (%llx) %s\n",
1760                  (unsigned long long)dwarf_dieoffset(sp_die),
1761                  dwarf_diename(sp_die));
1762         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1763             die_compare_name(sp_die, lr->function)) {
1764                 lf->fname = dwarf_decl_file(sp_die);
1765                 dwarf_decl_line(sp_die, &lr->offset);
1766                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1767                 lf->lno_s = lr->offset + lr->start;
1768                 if (lf->lno_s < 0)      /* Overflow */
1769                         lf->lno_s = INT_MAX;
1770                 lf->lno_e = lr->offset + lr->end;
1771                 if (lf->lno_e < 0)      /* Overflow */
1772                         lf->lno_e = INT_MAX;
1773                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1774                 lr->start = lf->lno_s;
1775                 lr->end = lf->lno_e;
1776                 if (dwarf_func_inline(sp_die)) {
1777                         struct dwarf_callback_param _param;
1778                         _param.data = (void *)lf;
1779                         _param.retval = 0;
1780                         dwarf_func_inline_instances(sp_die,
1781                                                     line_range_inline_cb,
1782                                                     &_param);
1783                         param->retval = _param.retval;
1784                 } else
1785                         param->retval = find_line_range_by_line(sp_die, lf);
1786                 return DWARF_CB_ABORT;
1787         }
1788         return DWARF_CB_OK;
1789 }
1790
1791 static int find_line_range_by_func(struct line_finder *lf)
1792 {
1793         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1794         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1795         return param.retval;
1796 }
1797
1798 int find_line_range(int fd, struct line_range *lr)
1799 {
1800         struct line_finder lf = {.lr = lr, .found = 0};
1801         int ret = 0;
1802         Dwarf_Off off = 0, noff;
1803         size_t cuhl;
1804         Dwarf_Die *diep;
1805         Dwarf *dbg = NULL;
1806         Dwfl *dwfl;
1807         Dwarf_Addr bias;        /* Currently ignored */
1808         const char *comp_dir;
1809
1810         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1811         if (!dbg) {
1812                 pr_warning("No dwarf info found in the vmlinux - "
1813                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1814                 return -EBADF;
1815         }
1816
1817         /* Loop on CUs (Compilation Unit) */
1818         while (!lf.found && ret >= 0) {
1819                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1820                         break;
1821
1822                 /* Get the DIE(Debugging Information Entry) of this CU */
1823                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1824                 if (!diep)
1825                         continue;
1826
1827                 /* Check if target file is included. */
1828                 if (lr->file)
1829                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1830                 else
1831                         lf.fname = 0;
1832
1833                 if (!lr->file || lf.fname) {
1834                         if (lr->function)
1835                                 ret = find_line_range_by_func(&lf);
1836                         else {
1837                                 lf.lno_s = lr->start;
1838                                 lf.lno_e = lr->end;
1839                                 ret = find_line_range_by_line(NULL, &lf);
1840                         }
1841                 }
1842                 off = noff;
1843         }
1844
1845         /* Store comp_dir */
1846         if (lf.found) {
1847                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1848                 if (comp_dir) {
1849                         lr->comp_dir = strdup(comp_dir);
1850                         if (!lr->comp_dir)
1851                                 ret = -ENOMEM;
1852                 }
1853         }
1854
1855         pr_debug("path: %s\n", lr->path);
1856         dwfl_end(dwfl);
1857         return (ret < 0) ? ret : lf.found;
1858 }
1859