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
  35 #include "event.h"
  36 #include "debug.h"
  37 #include "util.h"
  38 #include "probe-finder.h"
  39
  40
  41 /* Dwarf_Die Linkage to parent Die */
  42 struct die_link {
  43         struct die_link *parent;        /* Parent die */
  44         Dwarf_Die die;                  /* Current die */
  45 };
  46
  47 static Dwarf_Debug __dw_debug;
  48 static Dwarf_Error __dw_error;
  49
  50 /*
  51  * Generic dwarf analysis helpers
  52  */
  53
  54 #define X86_32_MAX_REGS 8
  55 const char *x86_32_regs_table[X86_32_MAX_REGS] = {
  56         "%ax",
  57         "%cx",
  58         "%dx",
  59         "%bx",
  60         "$stack",       /* Stack address instead of %sp */
  61         "%bp",
  62         "%si",
  63         "%di",
  64 };
  65
  66 #define X86_64_MAX_REGS 16
  67 const char *x86_64_regs_table[X86_64_MAX_REGS] = {
  68         "%ax",
  69         "%dx",
  70         "%cx",
  71         "%bx",
  72         "%si",
  73         "%di",
  74         "%bp",
  75         "%sp",
  76         "%r8",
  77         "%r9",
  78         "%r10",
  79         "%r11",
  80         "%r12",
  81         "%r13",
  82         "%r14",
  83         "%r15",
  84 };
  85
  86 /* TODO: switching by dwarf address size */
  87 #ifdef __x86_64__
  88 #define ARCH_MAX_REGS X86_64_MAX_REGS
  89 #define arch_regs_table x86_64_regs_table
  90 #else
  91 #define ARCH_MAX_REGS X86_32_MAX_REGS
  92 #define arch_regs_table x86_32_regs_table
  93 #endif
  94
  95 /* Return architecture dependent register string (for kprobe-tracer) */
  96 static const char *get_arch_regstr(unsigned int n)
  97 {
  98         return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
  99 }
 100
 101 /*
 102  * Compare the tail of two strings.
 103  * Return 0 if whole of either string is same as another's tail part.
 104  */
 105 static int strtailcmp(const char *s1, const char *s2)
 106 {
 107         int i1 = strlen(s1);
 108         int i2 = strlen(s2);
 109         while (--i1 > 0 && --i2 > 0) {
 110                 if (s1[i1] != s2[i2])
 111                         return s1[i1] - s2[i2];
 112         }
 113         return 0;
 114 }
 115
 116 /* Find the fileno of the target file. */
 117 static Dwarf_Unsigned die_get_fileno(Dwarf_Die cu_die, const char *fname)
 118 {
 119         Dwarf_Signed cnt, i;
 120         Dwarf_Unsigned found = 0;
 121         char **srcs;
 122         int ret;
 123
 124         if (!fname)
 125                 return 0;
 126
 127         ret = dwarf_srcfiles(cu_die, &srcs, &cnt, &__dw_error);
 128         if (ret == DW_DLV_OK) {
 129                 for (i = 0; i < cnt && !found; i++) {
 130                         if (strtailcmp(srcs[i], fname) == 0)
 131                                 found = i + 1;
 132                         dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
 133                 }
 134                 for (; i < cnt; i++)
 135                         dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
 136                 dwarf_dealloc(__dw_debug, srcs, DW_DLA_LIST);
 137         }
 138         if (found)
 139                 pr_debug("found fno: %d\n", (int)found);
 140         return found;
 141 }
 142
 143 /* Compare diename and tname */
 144 static int die_compare_name(Dwarf_Die dw_die, const char *tname)
 145 {
 146         char *name;
 147         int ret;
 148         ret = dwarf_diename(dw_die, &name, &__dw_error);
 149         DIE_IF(ret == DW_DLV_ERROR);
 150         if (ret == DW_DLV_OK) {
 151                 ret = strcmp(tname, name);
 152                 dwarf_dealloc(__dw_debug, name, DW_DLA_STRING);
 153         } else
 154                 ret = -1;
 155         return ret;
 156 }
 157
 158 /* Check the address is in the subprogram(function). */
 159 static int die_within_subprogram(Dwarf_Die sp_die, Dwarf_Addr addr,
 160                                  Dwarf_Signed *offs)
 161 {
 162         Dwarf_Addr lopc, hipc;
 163         int ret;
 164
 165         /* TODO: check ranges */
 166         ret = dwarf_lowpc(sp_die, &lopc, &__dw_error);
 167         DIE_IF(ret == DW_DLV_ERROR);
 168         if (ret == DW_DLV_NO_ENTRY)
 169                 return 0;
 170         ret = dwarf_highpc(sp_die, &hipc, &__dw_error);
 171         DIE_IF(ret != DW_DLV_OK);
 172         if (lopc <= addr && addr < hipc) {
 173                 *offs = addr - lopc;
 174                 return 1;
 175         } else
 176                 return 0;
 177 }
 178
 179 /* Check the die is inlined function */
 180 static Dwarf_Bool die_inlined_subprogram(Dwarf_Die dw_die)
 181 {
 182         /* TODO: check strictly */
 183         Dwarf_Bool inl;
 184         int ret;
 185
 186         ret = dwarf_hasattr(dw_die, DW_AT_inline, &inl, &__dw_error);
 187         DIE_IF(ret == DW_DLV_ERROR);
 188         return inl;
 189 }
 190
 191 /* Get the offset of abstruct_origin */
 192 static Dwarf_Off die_get_abstract_origin(Dwarf_Die dw_die)
 193 {
 194         Dwarf_Attribute attr;
 195         Dwarf_Off cu_offs;
 196         int ret;
 197
 198         ret = dwarf_attr(dw_die, DW_AT_abstract_origin, &attr, &__dw_error);
 199         DIE_IF(ret != DW_DLV_OK);
 200         ret = dwarf_formref(attr, &cu_offs, &__dw_error);
 201         DIE_IF(ret != DW_DLV_OK);
 202         dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
 203         return cu_offs;
 204 }
 205
 206 /* Get entry pc(or low pc, 1st entry of ranges)  of the die */
 207 static Dwarf_Addr die_get_entrypc(Dwarf_Die dw_die)
 208 {
 209         Dwarf_Attribute attr;
 210         Dwarf_Addr addr;
 211         Dwarf_Off offs;
 212         Dwarf_Ranges *ranges;
 213         Dwarf_Signed cnt;
 214         int ret;
 215
 216         /* Try to get entry pc */
 217         ret = dwarf_attr(dw_die, DW_AT_entry_pc, &attr, &__dw_error);
 218         DIE_IF(ret == DW_DLV_ERROR);
 219         if (ret == DW_DLV_OK) {
 220                 ret = dwarf_formaddr(attr, &addr, &__dw_error);
 221                 DIE_IF(ret != DW_DLV_OK);
 222                 dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
 223                 return addr;
 224         }
 225
 226         /* Try to get low pc */
 227         ret = dwarf_lowpc(dw_die, &addr, &__dw_error);
 228         DIE_IF(ret == DW_DLV_ERROR);
 229         if (ret == DW_DLV_OK)
 230                 return addr;
 231
 232         /* Try to get ranges */
 233         ret = dwarf_attr(dw_die, DW_AT_ranges, &attr, &__dw_error);
 234         DIE_IF(ret != DW_DLV_OK);
 235         ret = dwarf_formref(attr, &offs, &__dw_error);
 236         DIE_IF(ret != DW_DLV_OK);
 237         ret = dwarf_get_ranges(__dw_debug, offs, &ranges, &cnt, NULL,
 238                                 &__dw_error);
 239         DIE_IF(ret != DW_DLV_OK);
 240         addr = ranges[0].dwr_addr1;
 241         dwarf_ranges_dealloc(__dw_debug, ranges, cnt);
 242         return addr;
 243 }
 244
 245 /*
 246  * Search a Die from Die tree.
 247  * Note: cur_link->die should be deallocated in this function.
 248  */
 249 static int __search_die_tree(struct die_link *cur_link,
 250                              int (*die_cb)(struct die_link *, void *),
 251                              void *data)
 252 {
 253         Dwarf_Die new_die;
 254         struct die_link new_link;
 255         int ret;
 256
 257         if (!die_cb)
 258                 return 0;
 259
 260         /* Check current die */
 261         while (!(ret = die_cb(cur_link, data))) {
 262                 /* Check child die */
 263                 ret = dwarf_child(cur_link->die, &new_die, &__dw_error);
 264                 DIE_IF(ret == DW_DLV_ERROR);
 265                 if (ret == DW_DLV_OK) {
 266                         new_link.parent = cur_link;
 267                         new_link.die = new_die;
 268                         ret = __search_die_tree(&new_link, die_cb, data);
 269                         if (ret)
 270                                 break;
 271                 }
 272
 273                 /* Move to next sibling */
 274                 ret = dwarf_siblingof(__dw_debug, cur_link->die, &new_die,
 275                                       &__dw_error);
 276                 DIE_IF(ret == DW_DLV_ERROR);
 277                 dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE);
 278                 cur_link->die = new_die;
 279                 if (ret == DW_DLV_NO_ENTRY)
 280                         return 0;
 281         }
 282         dwarf_dealloc(__dw_debug, cur_link->die, DW_DLA_DIE);
 283         return ret;
 284 }
 285
 286 /* Search a die in its children's die tree */
 287 static int search_die_from_children(Dwarf_Die parent_die,
 288                                     int (*die_cb)(struct die_link *, void *),
 289                                     void *data)
 290 {
 291         struct die_link new_link;
 292         int ret;
 293
 294         new_link.parent = NULL;
 295         ret = dwarf_child(parent_die, &new_link.die, &__dw_error);
 296         DIE_IF(ret == DW_DLV_ERROR);
 297         if (ret == DW_DLV_OK)
 298                 return __search_die_tree(&new_link, die_cb, data);
 299         else
 300                 return 0;
 301 }
 302
 303 /* Find a locdesc corresponding to the address */
 304 static int attr_get_locdesc(Dwarf_Attribute attr, Dwarf_Locdesc *desc,
 305                             Dwarf_Addr addr)
 306 {
 307         Dwarf_Signed lcnt;
 308         Dwarf_Locdesc **llbuf;
 309         int ret, i;
 310
 311         ret = dwarf_loclist_n(attr, &llbuf, &lcnt, &__dw_error);
 312         DIE_IF(ret != DW_DLV_OK);
 313         ret = DW_DLV_NO_ENTRY;
 314         for (i = 0; i < lcnt; ++i) {
 315                 if (llbuf[i]->ld_lopc <= addr &&
 316                     llbuf[i]->ld_hipc > addr) {
 317                         memcpy(desc, llbuf[i], sizeof(Dwarf_Locdesc));
 318                         desc->ld_s =
 319                                 malloc(sizeof(Dwarf_Loc) * llbuf[i]->ld_cents);
 320                         DIE_IF(desc->ld_s == NULL);
 321                         memcpy(desc->ld_s, llbuf[i]->ld_s,
 322                                 sizeof(Dwarf_Loc) * llbuf[i]->ld_cents);
 323                         ret = DW_DLV_OK;
 324                         break;
 325                 }
 326                 dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK);
 327                 dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC);
 328         }
 329         /* Releasing loop */
 330         for (; i < lcnt; ++i) {
 331                 dwarf_dealloc(__dw_debug, llbuf[i]->ld_s, DW_DLA_LOC_BLOCK);
 332                 dwarf_dealloc(__dw_debug, llbuf[i], DW_DLA_LOCDESC);
 333         }
 334         dwarf_dealloc(__dw_debug, llbuf, DW_DLA_LIST);
 335         return ret;
 336 }
 337
 338 /*
 339  * Probe finder related functions
 340  */
 341
 342 /* Show a location */
 343 static void show_location(Dwarf_Loc *loc, struct probe_finder *pf)
 344 {
 345         Dwarf_Small op;
 346         Dwarf_Unsigned regn;
 347         Dwarf_Signed offs;
 348         int deref = 0, ret;
 349         const char *regs;
 350
 351         op = loc->lr_atom;
 352
 353         /* If this is based on frame buffer, set the offset */
 354         if (op == DW_OP_fbreg) {
 355                 deref = 1;
 356                 offs = (Dwarf_Signed)loc->lr_number;
 357                 op = pf->fbloc.ld_s[0].lr_atom;
 358                 loc = &pf->fbloc.ld_s[0];
 359         } else
 360                 offs = 0;
 361
 362         if (op >= DW_OP_breg0 && op <= DW_OP_breg31) {
 363                 regn = op - DW_OP_breg0;
 364                 offs += (Dwarf_Signed)loc->lr_number;
 365                 deref = 1;
 366         } else if (op >= DW_OP_reg0 && op <= DW_OP_reg31) {
 367                 regn = op - DW_OP_reg0;
 368         } else if (op == DW_OP_bregx) {
 369                 regn = loc->lr_number;
 370                 offs += (Dwarf_Signed)loc->lr_number2;
 371                 deref = 1;
 372         } else if (op == DW_OP_regx) {
 373                 regn = loc->lr_number;
 374         } else
 375                 die("Dwarf_OP %d is not supported.\n", op);
 376
 377         regs = get_arch_regstr(regn);
 378         if (!regs)
 379                 die("%lld exceeds max register number.\n", regn);
 380
 381         if (deref)
 382                 ret = snprintf(pf->buf, pf->len,
 383                                  " %s=%+lld(%s)", pf->var, offs, regs);
 384         else
 385                 ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs);
 386         DIE_IF(ret < 0);
 387         DIE_IF(ret >= pf->len);
 388 }
 389
 390 /* Show a variables in kprobe event format */
 391 static void show_variable(Dwarf_Die vr_die, struct probe_finder *pf)
 392 {
 393         Dwarf_Attribute attr;
 394         Dwarf_Locdesc ld;
 395         int ret;
 396
 397         ret = dwarf_attr(vr_die, DW_AT_location, &attr, &__dw_error);
 398         if (ret != DW_DLV_OK)
 399                 goto error;
 400         ret = attr_get_locdesc(attr, &ld, (pf->addr - pf->cu_base));
 401         if (ret != DW_DLV_OK)
 402                 goto error;
 403         /* TODO? */
 404         DIE_IF(ld.ld_cents != 1);
 405         show_location(&ld.ld_s[0], pf);
 406         free(ld.ld_s);
 407         dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
 408         return ;
 409 error:
 410         die("Failed to find the location of %s at this address.\n"
 411             " Perhaps, it has been optimized out.\n", pf->var);
 412 }
 413
 414 static int variable_callback(struct die_link *dlink, void *data)
 415 {
 416         struct probe_finder *pf = (struct probe_finder *)data;
 417         Dwarf_Half tag;
 418         int ret;
 419
 420         ret = dwarf_tag(dlink->die, &tag, &__dw_error);
 421         DIE_IF(ret == DW_DLV_ERROR);
 422         if ((tag == DW_TAG_formal_parameter ||
 423              tag == DW_TAG_variable) &&
 424             (die_compare_name(dlink->die, pf->var) == 0)) {
 425                 show_variable(dlink->die, pf);
 426                 return 1;
 427         }
 428         /* TODO: Support struct members and arrays */
 429         return 0;
 430 }
 431
 432 /* Find a variable in a subprogram die */
 433 static void find_variable(Dwarf_Die sp_die, struct probe_finder *pf)
 434 {
 435         int ret;
 436
 437         if (!is_c_varname(pf->var)) {
 438                 /* Output raw parameters */
 439                 ret = snprintf(pf->buf, pf->len, " %s", pf->var);
 440                 DIE_IF(ret < 0);
 441                 DIE_IF(ret >= pf->len);
 442                 return ;
 443         }
 444
 445         pr_debug("Searching '%s' variable in context.\n", pf->var);
 446         /* Search child die for local variables and parameters. */
 447         ret = search_die_from_children(sp_die, variable_callback, pf);
 448         if (!ret)
 449                 die("Failed to find '%s' in this function.\n", pf->var);
 450 }
 451
 452 /* Get a frame base on the address */
 453 static void get_current_frame_base(Dwarf_Die sp_die, struct probe_finder *pf)
 454 {
 455         Dwarf_Attribute attr;
 456         int ret;
 457
 458         ret = dwarf_attr(sp_die, DW_AT_frame_base, &attr, &__dw_error);
 459         DIE_IF(ret != DW_DLV_OK);
 460         ret = attr_get_locdesc(attr, &pf->fbloc, (pf->addr - pf->cu_base));
 461         DIE_IF(ret != DW_DLV_OK);
 462         dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR);
 463 }
 464
 465 static void free_current_frame_base(struct probe_finder *pf)
 466 {
 467         free(pf->fbloc.ld_s);
 468         memset(&pf->fbloc, 0, sizeof(Dwarf_Locdesc));
 469 }
 470
 471 /* Show a probe point to output buffer */
 472 static void show_probepoint(Dwarf_Die sp_die, Dwarf_Signed offs,
 473                             struct probe_finder *pf)
 474 {
 475         struct probe_point *pp = pf->pp;
 476         char *name;
 477         char tmp[MAX_PROBE_BUFFER];
 478         int ret, i, len;
 479
 480         /* Output name of probe point */
 481         ret = dwarf_diename(sp_die, &name, &__dw_error);
 482         DIE_IF(ret == DW_DLV_ERROR);
 483         if (ret == DW_DLV_OK) {
 484                 ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%u", name,
 485                                 (unsigned int)offs);
 486                 /* Copy the function name if possible */
 487                 if (!pp->function) {
 488                         pp->function = strdup(name);
 489                         pp->offset = offs;
 490                 }
 491                 dwarf_dealloc(__dw_debug, name, DW_DLA_STRING);
 492         } else {
 493                 /* This function has no name. */
 494                 ret = snprintf(tmp, MAX_PROBE_BUFFER, "0x%llx", pf->addr);
 495                 if (!pp->function) {
 496                         /* TODO: Use _stext */
 497                         pp->function = strdup("");
 498                         pp->offset = (int)pf->addr;
 499                 }
 500         }
 501         DIE_IF(ret < 0);
 502         DIE_IF(ret >= MAX_PROBE_BUFFER);
 503         len = ret;
 504
 505         /* Find each argument */
 506         get_current_frame_base(sp_die, pf);
 507         for (i = 0; i < pp->nr_args; i++) {
 508                 pf->var = pp->args[i];
 509                 pf->buf = &tmp[len];
 510                 pf->len = MAX_PROBE_BUFFER - len;
 511                 find_variable(sp_die, pf);
 512                 len += strlen(pf->buf);
 513         }
 514         free_current_frame_base(pf);
 515
 516         pp->probes[pp->found] = strdup(tmp);
 517         pp->found++;
 518 }
 519
 520 static int probeaddr_callback(struct die_link *dlink, void *data)
 521 {
 522         struct probe_finder *pf = (struct probe_finder *)data;
 523         Dwarf_Half tag;
 524         Dwarf_Signed offs;
 525         int ret;
 526
 527         ret = dwarf_tag(dlink->die, &tag, &__dw_error);
 528         DIE_IF(ret == DW_DLV_ERROR);
 529         /* Check the address is in this subprogram */
 530         if (tag == DW_TAG_subprogram &&
 531             die_within_subprogram(dlink->die, pf->addr, &offs)) {
 532                 show_probepoint(dlink->die, offs, pf);
 533                 return 1;
 534         }
 535         return 0;
 536 }
 537
 538 /* Find probe point from its line number */
 539 static void find_by_line(Dwarf_Die cu_die, struct probe_finder *pf)
 540 {
 541         struct probe_point *pp = pf->pp;
 542         Dwarf_Signed cnt, i;
 543         Dwarf_Line *lines;
 544         Dwarf_Unsigned lineno = 0;
 545         Dwarf_Addr addr;
 546         Dwarf_Unsigned fno;
 547         int ret;
 548
 549         ret = dwarf_srclines(cu_die, &lines, &cnt, &__dw_error);
 550         DIE_IF(ret != DW_DLV_OK);
 551
 552         for (i = 0; i < cnt; i++) {
 553                 ret = dwarf_line_srcfileno(lines[i], &fno, &__dw_error);
 554                 DIE_IF(ret != DW_DLV_OK);
 555                 if (fno != pf->fno)
 556                         continue;
 557
 558                 ret = dwarf_lineno(lines[i], &lineno, &__dw_error);
 559                 DIE_IF(ret != DW_DLV_OK);
 560                 if (lineno != (Dwarf_Unsigned)pp->line)
 561                         continue;
 562
 563                 ret = dwarf_lineaddr(lines[i], &addr, &__dw_error);
 564                 DIE_IF(ret != DW_DLV_OK);
 565                 pr_debug("Probe point found: 0x%llx\n", addr);
 566                 pf->addr = addr;
 567                 /* Search a real subprogram including this line, */
 568                 ret = search_die_from_children(cu_die, probeaddr_callback, pf);
 569                 if (ret == 0)
 570                         die("Probe point is not found in subprograms.\n");
 571                 /* Continuing, because target line might be inlined. */
 572         }
 573         dwarf_srclines_dealloc(__dw_debug, lines, cnt);
 574 }
 575
 576 /* Search function from function name */
 577 static int probefunc_callback(struct die_link *dlink, void *data)
 578 {
 579         struct probe_finder *pf = (struct probe_finder *)data;
 580         struct probe_point *pp = pf->pp;
 581         struct die_link *lk;
 582         Dwarf_Signed offs;
 583         Dwarf_Half tag;
 584         int ret;
 585
 586         ret = dwarf_tag(dlink->die, &tag, &__dw_error);
 587         DIE_IF(ret == DW_DLV_ERROR);
 588         if (tag == DW_TAG_subprogram) {
 589                 if (die_compare_name(dlink->die, pp->function) == 0) {
 590                         if (die_inlined_subprogram(dlink->die)) {
 591                                 /* Inlined function, save it. */
 592                                 ret = dwarf_die_CU_offset(dlink->die,
 593                                                           &pf->inl_offs,
 594                                                           &__dw_error);
 595                                 DIE_IF(ret != DW_DLV_OK);
 596                                 pr_debug("inline definition offset %lld\n",
 597                                          pf->inl_offs);
 598                                 return 0;       /* Continue to search */
 599                         }
 600                         /* Get probe address */
 601                         pf->addr = die_get_entrypc(dlink->die);
 602                         pf->addr += pp->offset;
 603                         /* TODO: Check the address in this function */
 604                         show_probepoint(dlink->die, pp->offset, pf);
 605                         return 1; /* Exit; no same symbol in this CU. */
 606                 }
 607         } else if (tag == DW_TAG_inlined_subroutine && pf->inl_offs) {
 608                 if (die_get_abstract_origin(dlink->die) == pf->inl_offs) {
 609                         /* Get probe address */
 610                         pf->addr = die_get_entrypc(dlink->die);
 611                         pf->addr += pp->offset;
 612                         pr_debug("found inline addr: 0x%llx\n", pf->addr);
 613                         /* Inlined function. Get a real subprogram */
 614                         for (lk = dlink->parent; lk != NULL; lk = lk->parent) {
 615                                 tag = 0;
 616                                 dwarf_tag(lk->die, &tag, &__dw_error);
 617                                 DIE_IF(ret == DW_DLV_ERROR);
 618                                 if (tag == DW_TAG_subprogram &&
 619                                     !die_inlined_subprogram(lk->die))
 620                                         goto found;
 621                         }
 622                         die("Failed to find real subprogram.\n");
 623 found:
 624                         /* Get offset from subprogram */
 625                         ret = die_within_subprogram(lk->die, pf->addr, &offs);
 626                         DIE_IF(!ret);
 627                         show_probepoint(lk->die, offs, pf);
 628                         /* Continue to search */
 629                 }
 630         }
 631         return 0;
 632 }
 633
 634 static void find_by_func(Dwarf_Die cu_die, struct probe_finder *pf)
 635 {
 636         search_die_from_children(cu_die, probefunc_callback, pf);
 637 }
 638
 639 /* Find a probe point */
 640 int find_probepoint(int fd, struct probe_point *pp)
 641 {
 642         Dwarf_Half addr_size = 0;
 643         Dwarf_Unsigned next_cuh = 0;
 644         Dwarf_Die cu_die = 0;
 645         int cu_number = 0, ret;
 646         struct probe_finder pf = {.pp = pp};
 647
 648         ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error);
 649         if (ret != DW_DLV_OK)
 650                 die("Failed to call dwarf_init(). Maybe, not a dwarf file.\n");
 651
 652         pp->found = 0;
 653         while (++cu_number) {
 654                 /* Search CU (Compilation Unit) */
 655                 ret = dwarf_next_cu_header(__dw_debug, NULL, NULL, NULL,
 656                         &addr_size, &next_cuh, &__dw_error);
 657                 DIE_IF(ret == DW_DLV_ERROR);
 658                 if (ret == DW_DLV_NO_ENTRY)
 659                         break;
 660
 661                 /* Get the DIE(Debugging Information Entry) of this CU */
 662                 ret = dwarf_siblingof(__dw_debug, 0, &cu_die, &__dw_error);
 663                 DIE_IF(ret != DW_DLV_OK);
 664
 665                 /* Check if target file is included. */
 666                 if (pp->file)
 667                         pf.fno = die_get_fileno(cu_die, pp->file);
 668
 669                 if (!pp->file || pf.fno) {
 670                         /* Save CU base address (for frame_base) */
 671                         ret = dwarf_lowpc(cu_die, &pf.cu_base, &__dw_error);
 672                         DIE_IF(ret == DW_DLV_ERROR);
 673                         if (ret == DW_DLV_NO_ENTRY)
 674                                 pf.cu_base = 0;
 675                         if (pp->line)
 676                                 find_by_line(cu_die, &pf);
 677                         if (pp->function)
 678                                 find_by_func(cu_die, &pf);
 679                 }
 680                 dwarf_dealloc(__dw_debug, cu_die, DW_DLA_DIE);
 681         }
 682         ret = dwarf_finish(__dw_debug, &__dw_error);
 683         DIE_IF(ret != DW_DLV_OK);
 684
 685         return pp->found;
 686 }
 687