SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 "string.h"
  36 #include "event.h"
  37 #include "debug.h"
  38 #include "util.h"
  39 #include "probe-finder.h"
  40
  41
  42 /*
  43  * Generic dwarf analysis helpers
  44  */
  45
  46 #define X86_32_MAX_REGS 8
  47 const char *x86_32_regs_table[X86_32_MAX_REGS] = {
  48         "%ax",
  49         "%cx",
  50         "%dx",
  51         "%bx",
  52         "$stack",       /* Stack address instead of %sp */
  53         "%bp",
  54         "%si",
  55         "%di",
  56 };
  57
  58 #define X86_64_MAX_REGS 16
  59 const char *x86_64_regs_table[X86_64_MAX_REGS] = {
  60         "%ax",
  61         "%dx",
  62         "%cx",
  63         "%bx",
  64         "%si",
  65         "%di",
  66         "%bp",
  67         "%sp",
  68         "%r8",
  69         "%r9",
  70         "%r10",
  71         "%r11",
  72         "%r12",
  73         "%r13",
  74         "%r14",
  75         "%r15",
  76 };
  77
  78 /* TODO: switching by dwarf address size */
  79 #ifdef __x86_64__
  80 #define ARCH_MAX_REGS X86_64_MAX_REGS
  81 #define arch_regs_table x86_64_regs_table
  82 #else
  83 #define ARCH_MAX_REGS X86_32_MAX_REGS
  84 #define arch_regs_table x86_32_regs_table
  85 #endif
  86
  87 /* Kprobe tracer basic type is up to u64 */
  88 #define MAX_BASIC_TYPE_BITS     64
  89
  90 /* Return architecture dependent register string (for kprobe-tracer) */
  91 static const char *get_arch_regstr(unsigned int n)
  92 {
  93         return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
  94 }
  95
  96 /*
  97  * Compare the tail of two strings.
  98  * Return 0 if whole of either string is same as another's tail part.
  99  */
 100 static int strtailcmp(const char *s1, const char *s2)
 101 {
 102         int i1 = strlen(s1);
 103         int i2 = strlen(s2);
 104         while (--i1 >= 0 && --i2 >= 0) {
 105                 if (s1[i1] != s2[i2])
 106                         return s1[i1] - s2[i2];
 107         }
 108         return 0;
 109 }
 110
 111 /* Line number list operations */
 112
 113 /* Add a line to line number list */
 114 static int line_list__add_line(struct list_head *head, unsigned int line)
 115 {
 116         struct line_node *ln;
 117         struct list_head *p;
 118
 119         /* Reverse search, because new line will be the last one */
 120         list_for_each_entry_reverse(ln, head, list) {
 121                 if (ln->line < line) {
 122                         p = &ln->list;
 123                         goto found;
 124                 } else if (ln->line == line)    /* Already exist */
 125                         return 1;
 126         }
 127         /* List is empty, or the smallest entry */
 128         p = head;
 129 found:
 130         pr_debug("line list: add a line %u\n", line);
 131         ln = zalloc(sizeof(struct line_node));
 132         if (ln == NULL)
 133                 return -ENOMEM;
 134         ln->line = line;
 135         INIT_LIST_HEAD(&ln->list);
 136         list_add(&ln->list, p);
 137         return 0;
 138 }
 139
 140 /* Check if the line in line number list */
 141 static int line_list__has_line(struct list_head *head, unsigned int line)
 142 {
 143         struct line_node *ln;
 144
 145         /* Reverse search, because new line will be the last one */
 146         list_for_each_entry(ln, head, list)
 147                 if (ln->line == line)
 148                         return 1;
 149
 150         return 0;
 151 }
 152
 153 /* Init line number list */
 154 static void line_list__init(struct list_head *head)
 155 {
 156         INIT_LIST_HEAD(head);
 157 }
 158
 159 /* Free line number list */
 160 static void line_list__free(struct list_head *head)
 161 {
 162         struct line_node *ln;
 163         while (!list_empty(head)) {
 164                 ln = list_first_entry(head, struct line_node, list);
 165                 list_del(&ln->list);
 166                 free(ln);
 167         }
 168 }
 169
 170 /* Dwarf wrappers */
 171
 172 /* Find the realpath of the target file. */
 173 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
 174 {
 175         Dwarf_Files *files;
 176         size_t nfiles, i;
 177         const char *src = NULL;
 178         int ret;
 179
 180         if (!fname)
 181                 return NULL;
 182
 183         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
 184         if (ret != 0)
 185                 return NULL;
 186
 187         for (i = 0; i < nfiles; i++) {
 188                 src = dwarf_filesrc(files, i, NULL, NULL);
 189                 if (strtailcmp(src, fname) == 0)
 190                         break;
 191         }
 192         if (i == nfiles)
 193                 return NULL;
 194         return src;
 195 }
 196
 197 /* Compare diename and tname */
 198 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 199 {
 200         const char *name;
 201         name = dwarf_diename(dw_die);
 202         return name ? strcmp(tname, name) : -1;
 203 }
 204
 205 /* Get type die, but skip qualifiers and typedef */
 206 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
 207 {
 208         Dwarf_Attribute attr;
 209         int tag;
 210
 211         do {
 212                 if (dwarf_attr(vr_die, DW_AT_type, &attr) == NULL ||
 213                     dwarf_formref_die(&attr, die_mem) == NULL)
 214                         return NULL;
 215
 216                 tag = dwarf_tag(die_mem);
 217                 vr_die = die_mem;
 218         } while (tag == DW_TAG_const_type ||
 219                  tag == DW_TAG_restrict_type ||
 220                  tag == DW_TAG_volatile_type ||
 221                  tag == DW_TAG_shared_type ||
 222                  tag == DW_TAG_typedef);
 223
 224         return die_mem;
 225 }
 226
 227 static bool die_is_signed_type(Dwarf_Die *tp_die)
 228 {
 229         Dwarf_Attribute attr;
 230         Dwarf_Word ret;
 231
 232         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
 233             dwarf_formudata(&attr, &ret) != 0)
 234                 return false;
 235
 236         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
 237                 ret == DW_ATE_signed_fixed);
 238 }
 239
 240 static int die_get_byte_size(Dwarf_Die *tp_die)
 241 {
 242         Dwarf_Attribute attr;
 243         Dwarf_Word ret;
 244
 245         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
 246             dwarf_formudata(&attr, &ret) != 0)
 247                 return 0;
 248
 249         return (int)ret;
 250 }
 251
 252 /* Return values for die_find callbacks */
 253 enum {
 254         DIE_FIND_CB_FOUND = 0,          /* End of Search */
 255         DIE_FIND_CB_CHILD = 1,          /* Search only children */
 256         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
 257         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
 258 };
 259
 260 /* Search a child die */
 261 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
 262                                  int (*callback)(Dwarf_Die *, void *),
 263                                  void *data, Dwarf_Die *die_mem)
 264 {
 265         Dwarf_Die child_die;
 266         int ret;
 267
 268         ret = dwarf_child(rt_die, die_mem);
 269         if (ret != 0)
 270                 return NULL;
 271
 272         do {
 273                 ret = callback(die_mem, data);
 274                 if (ret == DIE_FIND_CB_FOUND)
 275                         return die_mem;
 276
 277                 if ((ret & DIE_FIND_CB_CHILD) &&
 278                     die_find_child(die_mem, callback, data, &child_die)) {
 279                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
 280                         return die_mem;
 281                 }
 282         } while ((ret & DIE_FIND_CB_SIBLING) &&
 283                  dwarf_siblingof(die_mem, die_mem) == 0);
 284
 285         return NULL;
 286 }
 287
 288 struct __addr_die_search_param {
 289         Dwarf_Addr      addr;
 290         Dwarf_Die       *die_mem;
 291 };
 292
 293 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 294 {
 295         struct __addr_die_search_param *ad = data;
 296
 297         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
 298             dwarf_haspc(fn_die, ad->addr)) {
 299                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
 300                 return DWARF_CB_ABORT;
 301         }
 302         return DWARF_CB_OK;
 303 }
 304
 305 /* Search a real subprogram including this line, */
 306 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
 307                                            Dwarf_Die *die_mem)
 308 {
 309         struct __addr_die_search_param ad;
 310         ad.addr = addr;
 311         ad.die_mem = die_mem;
 312         /* dwarf_getscopes can't find subprogram. */
 313         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
 314                 return NULL;
 315         else
 316                 return die_mem;
 317 }
 318
 319 /* die_find callback for inline function search */
 320 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 321 {
 322         Dwarf_Addr *addr = data;
 323
 324         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
 325             dwarf_haspc(die_mem, *addr))
 326                 return DIE_FIND_CB_FOUND;
 327
 328         return DIE_FIND_CB_CONTINUE;
 329 }
 330
 331 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
 332 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 333                                       Dwarf_Die *die_mem)
 334 {
 335         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 336 }
 337
 338 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 339 {
 340         const char *name = data;
 341         int tag;
 342
 343         tag = dwarf_tag(die_mem);
 344         if ((tag == DW_TAG_formal_parameter ||
 345              tag == DW_TAG_variable) &&
 346             (die_compare_name(die_mem, name) == 0))
 347                 return DIE_FIND_CB_FOUND;
 348
 349         return DIE_FIND_CB_CONTINUE;
 350 }
 351
 352 /* Find a variable called 'name' */
 353 static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
 354                                     Dwarf_Die *die_mem)
 355 {
 356         return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
 357                               die_mem);
 358 }
 359
 360 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
 361 {
 362         const char *name = data;
 363
 364         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
 365             (die_compare_name(die_mem, name) == 0))
 366                 return DIE_FIND_CB_FOUND;
 367
 368         return DIE_FIND_CB_SIBLING;
 369 }
 370
 371 /* Find a member called 'name' */
 372 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
 373                                   Dwarf_Die *die_mem)
 374 {
 375         return die_find_child(st_die, __die_find_member_cb, (void *)name,
 376                               die_mem);
 377 }
 378
 379 /*
 380  * Probe finder related functions
 381  */
 382
 383 /* Show a location */
 384 static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
 385 {
 386         unsigned int regn;
 387         Dwarf_Word offs = 0;
 388         bool ref = false;
 389         const char *regs;
 390         struct kprobe_trace_arg *tvar = pf->tvar;
 391
 392         /* If this is based on frame buffer, set the offset */
 393         if (op->atom == DW_OP_fbreg) {
 394                 if (pf->fb_ops == NULL) {
 395                         pr_warning("The attribute of frame base is not "
 396                                    "supported.\n");
 397                         return -ENOTSUP;
 398                 }
 399                 ref = true;
 400                 offs = op->number;
 401                 op = &pf->fb_ops[0];
 402         }
 403
 404         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
 405                 regn = op->atom - DW_OP_breg0;
 406                 offs += op->number;
 407                 ref = true;
 408         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
 409                 regn = op->atom - DW_OP_reg0;
 410         } else if (op->atom == DW_OP_bregx) {
 411                 regn = op->number;
 412                 offs += op->number2;
 413                 ref = true;
 414         } else if (op->atom == DW_OP_regx) {
 415                 regn = op->number;
 416         } else {
 417                 pr_warning("DW_OP %x is not supported.\n", op->atom);
 418                 return -ENOTSUP;
 419         }
 420
 421         regs = get_arch_regstr(regn);
 422         if (!regs) {
 423                 pr_warning("%u exceeds max register number.\n", regn);
 424                 return -ERANGE;
 425         }
 426
 427         tvar->value = strdup(regs);
 428         if (tvar->value == NULL)
 429                 return -ENOMEM;
 430
 431         if (ref) {
 432                 tvar->ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
 433                 if (tvar->ref == NULL)
 434                         return -ENOMEM;
 435                 tvar->ref->offset = (long)offs;
 436         }
 437         return 0;
 438 }
 439
 440 static int convert_variable_type(Dwarf_Die *vr_die,
 441                                  struct kprobe_trace_arg *targ)
 442 {
 443         Dwarf_Die type;
 444         char buf[16];
 445         int ret;
 446
 447         if (die_get_real_type(vr_die, &type) == NULL) {
 448                 pr_warning("Failed to get a type information of %s.\n",
 449                            dwarf_diename(vr_die));
 450                 return -ENOENT;
 451         }
 452
 453         ret = die_get_byte_size(&type) * 8;
 454         if (ret) {
 455                 /* Check the bitwidth */
 456                 if (ret > MAX_BASIC_TYPE_BITS) {
 457                         pr_info("%s exceeds max-bitwidth."
 458                                 " Cut down to %d bits.\n",
 459                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 460                         ret = MAX_BASIC_TYPE_BITS;
 461                 }
 462
 463                 ret = snprintf(buf, 16, "%c%d",
 464                                die_is_signed_type(&type) ? 's' : 'u', ret);
 465                 if (ret < 0 || ret >= 16) {
 466                         if (ret >= 16)
 467                                 ret = -E2BIG;
 468                         pr_warning("Failed to convert variable type: %s\n",
 469                                    strerror(-ret));
 470                         return ret;
 471                 }
 472                 targ->type = strdup(buf);
 473                 if (targ->type == NULL)
 474                         return -ENOMEM;
 475         }
 476         return 0;
 477 }
 478
 479 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 480                                     struct perf_probe_arg_field *field,
 481                                     struct kprobe_trace_arg_ref **ref_ptr,
 482                                     Dwarf_Die *die_mem)
 483 {
 484         struct kprobe_trace_arg_ref *ref = *ref_ptr;
 485         Dwarf_Attribute attr;
 486         Dwarf_Die type;
 487         Dwarf_Word offs;
 488
 489         pr_debug("converting %s in %s\n", field->name, varname);
 490         if (die_get_real_type(vr_die, &type) == NULL) {
 491                 pr_warning("Failed to get the type of %s.\n", varname);
 492                 return -ENOENT;
 493         }
 494
 495         /* Check the pointer and dereference */
 496         if (dwarf_tag(&type) == DW_TAG_pointer_type) {
 497                 if (!field->ref) {
 498                         pr_err("Semantic error: %s must be referred by '->'\n",
 499                                field->name);
 500                         return -EINVAL;
 501                 }
 502                 /* Get the type pointed by this pointer */
 503                 if (die_get_real_type(&type, &type) == NULL) {
 504                         pr_warning("Failed to get the type of %s.\n", varname);
 505                         return -ENOENT;
 506                 }
 507                 /* Verify it is a data structure  */
 508                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 509                         pr_warning("%s is not a data structure.\n", varname);
 510                         return -EINVAL;
 511                 }
 512
 513                 ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
 514                 if (ref == NULL)
 515                         return -ENOMEM;
 516                 if (*ref_ptr)
 517                         (*ref_ptr)->next = ref;
 518                 else
 519                         *ref_ptr = ref;
 520         } else {
 521                 /* Verify it is a data structure  */
 522                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 523                         pr_warning("%s is not a data structure.\n", varname);
 524                         return -EINVAL;
 525                 }
 526                 if (field->ref) {
 527                         pr_err("Semantic error: %s must be referred by '.'\n",
 528                                field->name);
 529                         return -EINVAL;
 530                 }
 531                 if (!ref) {
 532                         pr_warning("Structure on a register is not "
 533                                    "supported yet.\n");
 534                         return -ENOTSUP;
 535                 }
 536         }
 537
 538         if (die_find_member(&type, field->name, die_mem) == NULL) {
 539                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 540                            dwarf_diename(&type), field->name);
 541                 return -EINVAL;
 542         }
 543
 544         /* Get the offset of the field */
 545         if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL ||
 546             dwarf_formudata(&attr, &offs) != 0) {
 547                 pr_warning("Failed to get the offset of %s.\n", field->name);
 548                 return -ENOENT;
 549         }
 550         ref->offset += (long)offs;
 551
 552         /* Converting next field */
 553         if (field->next)
 554                 return convert_variable_fields(die_mem, field->name,
 555                                                field->next, &ref, die_mem);
 556         else
 557                 return 0;
 558 }
 559
 560 /* Show a variables in kprobe event format */
 561 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 562 {
 563         Dwarf_Attribute attr;
 564         Dwarf_Die die_mem;
 565         Dwarf_Op *expr;
 566         size_t nexpr;
 567         int ret;
 568
 569         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
 570                 goto error;
 571         /* TODO: handle more than 1 exprs */
 572         ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
 573         if (ret <= 0 || nexpr == 0)
 574                 goto error;
 575
 576         ret = convert_location(expr, pf);
 577         if (ret == 0 && pf->pvar->field) {
 578                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 579                                               pf->pvar->field, &pf->tvar->ref,
 580                                               &die_mem);
 581                 vr_die = &die_mem;
 582         }
 583         if (ret == 0) {
 584                 if (pf->pvar->type) {
 585                         pf->tvar->type = strdup(pf->pvar->type);
 586                         if (pf->tvar->type == NULL)
 587                                 ret = -ENOMEM;
 588                 } else
 589                         ret = convert_variable_type(vr_die, pf->tvar);
 590         }
 591         /* *expr will be cached in libdw. Don't free it. */
 592         return ret;
 593 error:
 594         /* TODO: Support const_value */
 595         pr_err("Failed to find the location of %s at this address.\n"
 596                " Perhaps, it has been optimized out.\n", pf->pvar->var);
 597         return -ENOENT;
 598 }
 599
 600 /* Find a variable in a subprogram die */
 601 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 602 {
 603         Dwarf_Die vr_die;
 604         char buf[32], *ptr;
 605         int ret;
 606
 607         /* TODO: Support arrays */
 608         if (pf->pvar->name)
 609                 pf->tvar->name = strdup(pf->pvar->name);
 610         else {
 611                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 612                 if (ret < 0)
 613                         return ret;
 614                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 615                 if (ptr)
 616                         *ptr = '_';
 617                 pf->tvar->name = strdup(buf);
 618         }
 619         if (pf->tvar->name == NULL)
 620                 return -ENOMEM;
 621
 622         if (!is_c_varname(pf->pvar->var)) {
 623                 /* Copy raw parameters */
 624                 pf->tvar->value = strdup(pf->pvar->var);
 625                 if (pf->tvar->value == NULL)
 626                         return -ENOMEM;
 627                 else
 628                         return 0;
 629         }
 630
 631         pr_debug("Searching '%s' variable in context.\n",
 632                  pf->pvar->var);
 633         /* Search child die for local variables and parameters. */
 634         if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
 635                 pr_warning("Failed to find '%s' in this function.\n",
 636                            pf->pvar->var);
 637                 return -ENOENT;
 638         }
 639         return convert_variable(&vr_die, pf);
 640 }
 641
 642 /* Show a probe point to output buffer */
 643 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 644 {
 645         struct kprobe_trace_event *tev;
 646         Dwarf_Addr eaddr;
 647         Dwarf_Die die_mem;
 648         const char *name;
 649         int ret, i;
 650         Dwarf_Attribute fb_attr;
 651         size_t nops;
 652
 653         if (pf->ntevs == MAX_PROBES) {
 654                 pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
 655                 return -ERANGE;
 656         }
 657         tev = &pf->tevs[pf->ntevs++];
 658
 659         /* If no real subprogram, find a real one */
 660         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
 661                 sp_die = die_find_real_subprogram(&pf->cu_die,
 662                                                  pf->addr, &die_mem);
 663                 if (!sp_die) {
 664                         pr_warning("Failed to find probe point in any "
 665                                    "functions.\n");
 666                         return -ENOENT;
 667                 }
 668         }
 669
 670         /* Copy the name of probe point */
 671         name = dwarf_diename(sp_die);
 672         if (name) {
 673                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 674                         pr_warning("Failed to get entry pc of %s\n",
 675                                    dwarf_diename(sp_die));
 676                         return -ENOENT;
 677                 }
 678                 tev->point.symbol = strdup(name);
 679                 if (tev->point.symbol == NULL)
 680                         return -ENOMEM;
 681                 tev->point.offset = (unsigned long)(pf->addr - eaddr);
 682         } else
 683                 /* This function has no name. */
 684                 tev->point.offset = (unsigned long)pf->addr;
 685
 686         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
 687                  tev->point.offset);
 688
 689         /* Get the frame base attribute/ops */
 690         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
 691         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 692         if (ret <= 0 || nops == 0) {
 693                 pf->fb_ops = NULL;
 694         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 695                    pf->cfi != NULL) {
 696                 Dwarf_Frame *frame;
 697                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
 698                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
 699                         pr_warning("Failed to get CFA on 0x%jx\n",
 700                                    (uintmax_t)pf->addr);
 701                         return -ENOENT;
 702                 }
 703         }
 704
 705         /* Find each argument */
 706         tev->nargs = pf->pev->nargs;
 707         tev->args = zalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
 708         if (tev->args == NULL)
 709                 return -ENOMEM;
 710         for (i = 0; i < pf->pev->nargs; i++) {
 711                 pf->pvar = &pf->pev->args[i];
 712                 pf->tvar = &tev->args[i];
 713                 ret = find_variable(sp_die, pf);
 714                 if (ret != 0)
 715                         return ret;
 716         }
 717
 718         /* *pf->fb_ops will be cached in libdw. Don't free it. */
 719         pf->fb_ops = NULL;
 720         return 0;
 721 }
 722
 723 /* Find probe point from its line number */
 724 static int find_probe_point_by_line(struct probe_finder *pf)
 725 {
 726         Dwarf_Lines *lines;
 727         Dwarf_Line *line;
 728         size_t nlines, i;
 729         Dwarf_Addr addr;
 730         int lineno;
 731         int ret = 0;
 732
 733         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
 734                 pr_warning("No source lines found in this CU.\n");
 735                 return -ENOENT;
 736         }
 737
 738         for (i = 0; i < nlines && ret == 0; i++) {
 739                 line = dwarf_onesrcline(lines, i);
 740                 if (dwarf_lineno(line, &lineno) != 0 ||
 741                     lineno != pf->lno)
 742                         continue;
 743
 744                 /* TODO: Get fileno from line, but how? */
 745                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
 746                         continue;
 747
 748                 if (dwarf_lineaddr(line, &addr) != 0) {
 749                         pr_warning("Failed to get the address of the line.\n");
 750                         return -ENOENT;
 751                 }
 752                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
 753                          (int)i, lineno, (uintmax_t)addr);
 754                 pf->addr = addr;
 755
 756                 ret = convert_probe_point(NULL, pf);
 757                 /* Continuing, because target line might be inlined. */
 758         }
 759         return ret;
 760 }
 761
 762 /* Find lines which match lazy pattern */
 763 static int find_lazy_match_lines(struct list_head *head,
 764                                  const char *fname, const char *pat)
 765 {
 766         char *fbuf, *p1, *p2;
 767         int fd, ret, line, nlines = 0;
 768         struct stat st;
 769
 770         fd = open(fname, O_RDONLY);
 771         if (fd < 0) {
 772                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
 773                 return fd;
 774         }
 775
 776         ret = fstat(fd, &st);
 777         if (ret < 0) {
 778                 pr_warning("Failed to get the size of %s: %s\n",
 779                            fname, strerror(errno));
 780                 return ret;
 781         }
 782         fbuf = xmalloc(st.st_size + 2);
 783         ret = read(fd, fbuf, st.st_size);
 784         if (ret < 0) {
 785                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
 786                 return ret;
 787         }
 788         close(fd);
 789         fbuf[st.st_size] = '\n';        /* Dummy line */
 790         fbuf[st.st_size + 1] = '\0';
 791         p1 = fbuf;
 792         line = 1;
 793         while ((p2 = strchr(p1, '\n')) != NULL) {
 794                 *p2 = '\0';
 795                 if (strlazymatch(p1, pat)) {
 796                         line_list__add_line(head, line);
 797                         nlines++;
 798                 }
 799                 line++;
 800                 p1 = p2 + 1;
 801         }
 802         free(fbuf);
 803         return nlines;
 804 }
 805
 806 /* Find probe points from lazy pattern  */
 807 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 808 {
 809         Dwarf_Lines *lines;
 810         Dwarf_Line *line;
 811         size_t nlines, i;
 812         Dwarf_Addr addr;
 813         Dwarf_Die die_mem;
 814         int lineno;
 815         int ret = 0;
 816
 817         if (list_empty(&pf->lcache)) {
 818                 /* Matching lazy line pattern */
 819                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
 820                                             pf->pev->point.lazy_line);
 821                 if (ret == 0) {
 822                         pr_debug("No matched lines found in %s.\n", pf->fname);
 823                         return 0;
 824                 } else if (ret < 0)
 825                         return ret;
 826         }
 827
 828         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
 829                 pr_warning("No source lines found in this CU.\n");
 830                 return -ENOENT;
 831         }
 832
 833         for (i = 0; i < nlines && ret >= 0; i++) {
 834                 line = dwarf_onesrcline(lines, i);
 835
 836                 if (dwarf_lineno(line, &lineno) != 0 ||
 837                     !line_list__has_line(&pf->lcache, lineno))
 838                         continue;
 839
 840                 /* TODO: Get fileno from line, but how? */
 841                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
 842                         continue;
 843
 844                 if (dwarf_lineaddr(line, &addr) != 0) {
 845                         pr_debug("Failed to get the address of line %d.\n",
 846                                  lineno);
 847                         continue;
 848                 }
 849                 if (sp_die) {
 850                         /* Address filtering 1: does sp_die include addr? */
 851                         if (!dwarf_haspc(sp_die, addr))
 852                                 continue;
 853                         /* Address filtering 2: No child include addr? */
 854                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
 855                                 continue;
 856                 }
 857
 858                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
 859                          (int)i, lineno, (unsigned long long)addr);
 860                 pf->addr = addr;
 861
 862                 ret = convert_probe_point(sp_die, pf);
 863                 /* Continuing, because target line might be inlined. */
 864         }
 865         /* TODO: deallocate lines, but how? */
 866         return ret;
 867 }
 868
 869 /* Callback parameter with return value */
 870 struct dwarf_callback_param {
 871         void *data;
 872         int retval;
 873 };
 874
 875 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 876 {
 877         struct dwarf_callback_param *param = data;
 878         struct probe_finder *pf = param->data;
 879         struct perf_probe_point *pp = &pf->pev->point;
 880         Dwarf_Addr addr;
 881
 882         if (pp->lazy_line)
 883                 param->retval = find_probe_point_lazy(in_die, pf);
 884         else {
 885                 /* Get probe address */
 886                 if (dwarf_entrypc(in_die, &addr) != 0) {
 887                         pr_warning("Failed to get entry pc of %s.\n",
 888                                    dwarf_diename(in_die));
 889                         param->retval = -ENOENT;
 890                         return DWARF_CB_ABORT;
 891                 }
 892                 pf->addr = addr;
 893                 pf->addr += pp->offset;
 894                 pr_debug("found inline addr: 0x%jx\n",
 895                          (uintmax_t)pf->addr);
 896
 897                 param->retval = convert_probe_point(in_die, pf);
 898         }
 899
 900         return DWARF_CB_OK;
 901 }
 902
 903 /* Search function from function name */
 904 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 905 {
 906         struct dwarf_callback_param *param = data;
 907         struct probe_finder *pf = param->data;
 908         struct perf_probe_point *pp = &pf->pev->point;
 909
 910         /* Check tag and diename */
 911         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
 912             die_compare_name(sp_die, pp->function) != 0)
 913                 return DWARF_CB_OK;
 914
 915         pf->fname = dwarf_decl_file(sp_die);
 916         if (pp->line) { /* Function relative line */
 917                 dwarf_decl_line(sp_die, &pf->lno);
 918                 pf->lno += pp->line;
 919                 param->retval = find_probe_point_by_line(pf);
 920         } else if (!dwarf_func_inline(sp_die)) {
 921                 /* Real function */
 922                 if (pp->lazy_line)
 923                         param->retval = find_probe_point_lazy(sp_die, pf);
 924                 else {
 925                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
 926                                 pr_warning("Failed to get entry pc of %s.\n",
 927                                            dwarf_diename(sp_die));
 928                                 param->retval = -ENOENT;
 929                                 return DWARF_CB_ABORT;
 930                         }
 931                         pf->addr += pp->offset;
 932                         /* TODO: Check the address in this function */
 933                         param->retval = convert_probe_point(sp_die, pf);
 934                 }
 935         } else {
 936                 struct dwarf_callback_param _param = {.data = (void *)pf,
 937                                                       .retval = 0};
 938                 /* Inlined function: search instances */
 939                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
 940                                             &_param);
 941                 param->retval = _param.retval;
 942         }
 943
 944         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 945 }
 946
 947 static int find_probe_point_by_func(struct probe_finder *pf)
 948 {
 949         struct dwarf_callback_param _param = {.data = (void *)pf,
 950                                               .retval = 0};
 951         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
 952         return _param.retval;
 953 }
 954
 955 /* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
 956 int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
 957                              struct kprobe_trace_event **tevs)
 958 {
 959         struct probe_finder pf = {.pev = pev};
 960         struct perf_probe_point *pp = &pev->point;
 961         Dwarf_Off off, noff;
 962         size_t cuhl;
 963         Dwarf_Die *diep;
 964         Dwarf *dbg;
 965         int ret = 0;
 966
 967         pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
 968         if (pf.tevs == NULL)
 969                 return -ENOMEM;
 970         *tevs = pf.tevs;
 971         pf.ntevs = 0;
 972
 973         dbg = dwarf_begin(fd, DWARF_C_READ);
 974         if (!dbg) {
 975                 pr_warning("No dwarf info found in the vmlinux - "
 976                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
 977                 return -EBADF;
 978         }
 979
 980         /* Get the call frame information from this dwarf */
 981         pf.cfi = dwarf_getcfi(dbg);
 982
 983         off = 0;
 984         line_list__init(&pf.lcache);
 985         /* Loop on CUs (Compilation Unit) */
 986         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
 987                ret >= 0) {
 988                 /* Get the DIE(Debugging Information Entry) of this CU */
 989                 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
 990                 if (!diep)
 991                         continue;
 992
 993                 /* Check if target file is included. */
 994                 if (pp->file)
 995                         pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
 996                 else
 997                         pf.fname = NULL;
 998
 999                 if (!pp->file || pf.fname) {
1000                         if (pp->function)
1001                                 ret = find_probe_point_by_func(&pf);
1002                         else if (pp->lazy_line)
1003                                 ret = find_probe_point_lazy(NULL, &pf);
1004                         else {
1005                                 pf.lno = pp->line;
1006                                 ret = find_probe_point_by_line(&pf);
1007                         }
1008                 }
1009                 off = noff;
1010         }
1011         line_list__free(&pf.lcache);
1012         dwarf_end(dbg);
1013
1014         return (ret < 0) ? ret : pf.ntevs;
1015 }
1016
1017 /* Reverse search */
1018 int find_perf_probe_point(int fd, unsigned long addr,
1019                           struct perf_probe_point *ppt)
1020 {
1021         Dwarf_Die cudie, spdie, indie;
1022         Dwarf *dbg;
1023         Dwarf_Line *line;
1024         Dwarf_Addr laddr, eaddr;
1025         const char *tmp;
1026         int lineno, ret = 0;
1027         bool found = false;
1028
1029         dbg = dwarf_begin(fd, DWARF_C_READ);
1030         if (!dbg)
1031                 return -EBADF;
1032
1033         /* Find cu die */
1034         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1035                 ret = -EINVAL;
1036                 goto end;
1037         }
1038
1039         /* Find a corresponding line */
1040         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1041         if (line) {
1042                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1043                     (Dwarf_Addr)addr == laddr &&
1044                     dwarf_lineno(line, &lineno) == 0) {
1045                         tmp = dwarf_linesrc(line, NULL, NULL);
1046                         if (tmp) {
1047                                 ppt->line = lineno;
1048                                 ppt->file = strdup(tmp);
1049                                 if (ppt->file == NULL) {
1050                                         ret = -ENOMEM;
1051                                         goto end;
1052                                 }
1053                                 found = true;
1054                         }
1055                 }
1056         }
1057
1058         /* Find a corresponding function */
1059         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1060                 tmp = dwarf_diename(&spdie);
1061                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1062                         goto end;
1063
1064                 if (ppt->line) {
1065                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1066                                                 &indie)) {
1067                                 /* addr in an inline function */
1068                                 tmp = dwarf_diename(&indie);
1069                                 if (!tmp)
1070                                         goto end;
1071                                 ret = dwarf_decl_line(&indie, &lineno);
1072                         } else {
1073                                 if (eaddr == addr) {    /* Function entry */
1074                                         lineno = ppt->line;
1075                                         ret = 0;
1076                                 } else
1077                                         ret = dwarf_decl_line(&spdie, &lineno);
1078                         }
1079                         if (ret == 0) {
1080                                 /* Make a relative line number */
1081                                 ppt->line -= lineno;
1082                                 goto found;
1083                         }
1084                 }
1085                 /* We don't have a line number, let's use offset */
1086                 ppt->offset = addr - (unsigned long)eaddr;
1087 found:
1088                 ppt->function = strdup(tmp);
1089                 if (ppt->function == NULL) {
1090                         ret = -ENOMEM;
1091                         goto end;
1092                 }
1093                 found = true;
1094         }
1095
1096 end:
1097         dwarf_end(dbg);
1098         if (ret >= 0)
1099                 ret = found ? 1 : 0;
1100         return ret;
1101 }
1102
1103
1104 /* Find line range from its line number */
1105 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1106 {
1107         Dwarf_Lines *lines;
1108         Dwarf_Line *line;
1109         size_t nlines, i;
1110         Dwarf_Addr addr;
1111         int lineno;
1112         const char *src;
1113         Dwarf_Die die_mem;
1114
1115         line_list__init(&lf->lr->line_list);
1116         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1117                 pr_warning("No source lines found in this CU.\n");
1118                 return -ENOENT;
1119         }
1120
1121         for (i = 0; i < nlines; i++) {
1122                 line = dwarf_onesrcline(lines, i);
1123                 if (dwarf_lineno(line, &lineno) != 0 ||
1124                     (lf->lno_s > lineno || lf->lno_e < lineno))
1125                         continue;
1126
1127                 if (sp_die) {
1128                         /* Address filtering 1: does sp_die include addr? */
1129                         if (dwarf_lineaddr(line, &addr) != 0 ||
1130                             !dwarf_haspc(sp_die, addr))
1131                                 continue;
1132
1133                         /* Address filtering 2: No child include addr? */
1134                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1135                                 continue;
1136                 }
1137
1138                 /* TODO: Get fileno from line, but how? */
1139                 src = dwarf_linesrc(line, NULL, NULL);
1140                 if (strtailcmp(src, lf->fname) != 0)
1141                         continue;
1142
1143                 /* Copy real path */
1144                 if (!lf->lr->path) {
1145                         lf->lr->path = strdup(src);
1146                         if (lf->lr->path == NULL)
1147                                 return -ENOMEM;
1148                 }
1149                 line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
1150         }
1151         /* Update status */
1152         if (!list_empty(&lf->lr->line_list))
1153                 lf->found = 1;
1154         else {
1155                 free(lf->lr->path);
1156                 lf->lr->path = NULL;
1157         }
1158         return lf->found;
1159 }
1160
1161 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1162 {
1163         struct dwarf_callback_param *param = data;
1164
1165         param->retval = find_line_range_by_line(in_die, param->data);
1166         return DWARF_CB_ABORT;  /* No need to find other instances */
1167 }
1168
1169 /* Search function from function name */
1170 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1171 {
1172         struct dwarf_callback_param *param = data;
1173         struct line_finder *lf = param->data;
1174         struct line_range *lr = lf->lr;
1175
1176         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1177             die_compare_name(sp_die, lr->function) == 0) {
1178                 lf->fname = dwarf_decl_file(sp_die);
1179                 dwarf_decl_line(sp_die, &lr->offset);
1180                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1181                 lf->lno_s = lr->offset + lr->start;
1182                 if (!lr->end)
1183                         lf->lno_e = INT_MAX;
1184                 else
1185                         lf->lno_e = lr->offset + lr->end;
1186                 lr->start = lf->lno_s;
1187                 lr->end = lf->lno_e;
1188                 if (dwarf_func_inline(sp_die)) {
1189                         struct dwarf_callback_param _param;
1190                         _param.data = (void *)lf;
1191                         _param.retval = 0;
1192                         dwarf_func_inline_instances(sp_die,
1193                                                     line_range_inline_cb,
1194                                                     &_param);
1195                         param->retval = _param.retval;
1196                 } else
1197                         param->retval = find_line_range_by_line(sp_die, lf);
1198                 return DWARF_CB_ABORT;
1199         }
1200         return DWARF_CB_OK;
1201 }
1202
1203 static int find_line_range_by_func(struct line_finder *lf)
1204 {
1205         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1206         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1207         return param.retval;
1208 }
1209
1210 int find_line_range(int fd, struct line_range *lr)
1211 {
1212         struct line_finder lf = {.lr = lr, .found = 0};
1213         int ret = 0;
1214         Dwarf_Off off = 0, noff;
1215         size_t cuhl;
1216         Dwarf_Die *diep;
1217         Dwarf *dbg;
1218
1219         dbg = dwarf_begin(fd, DWARF_C_READ);
1220         if (!dbg) {
1221                 pr_warning("No dwarf info found in the vmlinux - "
1222                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1223                 return -EBADF;
1224         }
1225
1226         /* Loop on CUs (Compilation Unit) */
1227         while (!lf.found && ret >= 0) {
1228                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1229                         break;
1230
1231                 /* Get the DIE(Debugging Information Entry) of this CU */
1232                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1233                 if (!diep)
1234                         continue;
1235
1236                 /* Check if target file is included. */
1237                 if (lr->file)
1238                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1239                 else
1240                         lf.fname = 0;
1241
1242                 if (!lr->file || lf.fname) {
1243                         if (lr->function)
1244                                 ret = find_line_range_by_func(&lf);
1245                         else {
1246                                 lf.lno_s = lr->start;
1247                                 if (!lr->end)
1248                                         lf.lno_e = INT_MAX;
1249                                 else
1250                                         lf.lno_e = lr->end;
1251                                 ret = find_line_range_by_line(NULL, &lf);
1252                         }
1253                 }
1254                 off = noff;
1255         }
1256         pr_debug("path: %lx\n", (unsigned long)lr->path);
1257         dwarf_end(dbg);
1258
1259         return (ret < 0) ? ret : lf.found;
1260 }
1261