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 the register number %u "
 656                            "missing on this architecture.\n", 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.\n",
 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"
 709                                            " information.\n");
 710                                 return -ENOENT;
 711                         }
 712                         while (*ref_ptr)
 713                                 ref_ptr = &(*ref_ptr)->next;
 714                         /* Add new reference with offset +0 */
 715                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
 716                         if (*ref_ptr == NULL) {
 717                                 pr_warning("Out of memory error\n");
 718                                 return -ENOMEM;
 719                         }
 720                 }
 721                 if (!die_compare_name(&type, "char") &&
 722                     !die_compare_name(&type, "unsigned char")) {
 723                         pr_warning("Failed to cast into string: "
 724                                    "%s is not (unsigned) char *.\n",
 725                                    dwarf_diename(vr_die));
 726                         return -EINVAL;
 727                 }
 728                 tvar->type = strdup(cast);
 729                 return (tvar->type == NULL) ? -ENOMEM : 0;
 730         }
 731
 732         ret = die_get_byte_size(&type) * 8;
 733         if (ret) {
 734                 /* Check the bitwidth */
 735                 if (ret > MAX_BASIC_TYPE_BITS) {
 736                         pr_info("%s exceeds max-bitwidth."
 737                                 " Cut down to %d bits.\n",
 738                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
 739                         ret = MAX_BASIC_TYPE_BITS;
 740                 }
 741
 742                 ret = snprintf(buf, 16, "%c%d",
 743                                die_is_signed_type(&type) ? 's' : 'u', ret);
 744                 if (ret < 0 || ret >= 16) {
 745                         if (ret >= 16)
 746                                 ret = -E2BIG;
 747                         pr_warning("Failed to convert variable type: %s\n",
 748                                    strerror(-ret));
 749                         return ret;
 750                 }
 751                 tvar->type = strdup(buf);
 752                 if (tvar->type == NULL)
 753                         return -ENOMEM;
 754         }
 755         return 0;
 756 }
 757
 758 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
 759                                     struct perf_probe_arg_field *field,
 760                                     struct probe_trace_arg_ref **ref_ptr,
 761                                     Dwarf_Die *die_mem)
 762 {
 763         struct probe_trace_arg_ref *ref = *ref_ptr;
 764         Dwarf_Die type;
 765         Dwarf_Word offs;
 766         int ret, tag;
 767
 768         pr_debug("converting %s in %s\n", field->name, varname);
 769         if (die_get_real_type(vr_die, &type) == NULL) {
 770                 pr_warning("Failed to get the type of %s.\n", varname);
 771                 return -ENOENT;
 772         }
 773         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
 774         tag = dwarf_tag(&type);
 775
 776         if (field->name[0] == '[' &&
 777             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
 778                 if (field->next)
 779                         /* Save original type for next field */
 780                         memcpy(die_mem, &type, sizeof(*die_mem));
 781                 /* Get the type of this array */
 782                 if (die_get_real_type(&type, &type) == NULL) {
 783                         pr_warning("Failed to get the type of %s.\n", varname);
 784                         return -ENOENT;
 785                 }
 786                 pr_debug2("Array real type: (%x)\n",
 787                          (unsigned)dwarf_dieoffset(&type));
 788                 if (tag == DW_TAG_pointer_type) {
 789                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
 790                         if (ref == NULL)
 791                                 return -ENOMEM;
 792                         if (*ref_ptr)
 793                                 (*ref_ptr)->next = ref;
 794                         else
 795                                 *ref_ptr = ref;
 796                 }
 797                 ref->offset += die_get_byte_size(&type) * field->index;
 798                 if (!field->next)
 799                         /* Save vr_die for converting types */
 800                         memcpy(die_mem, vr_die, sizeof(*die_mem));
 801                 goto next;
 802         } else if (tag == DW_TAG_pointer_type) {
 803                 /* Check the pointer and dereference */
 804                 if (!field->ref) {
 805                         pr_err("Semantic error: %s must be referred by '->'\n",
 806                                field->name);
 807                         return -EINVAL;
 808                 }
 809                 /* Get the type pointed by this pointer */
 810                 if (die_get_real_type(&type, &type) == NULL) {
 811                         pr_warning("Failed to get the type of %s.\n", varname);
 812                         return -ENOENT;
 813                 }
 814                 /* Verify it is a data structure  */
 815                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
 816                         pr_warning("%s is not a data structure.\n", varname);
 817                         return -EINVAL;
 818                 }
 819
 820                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
 821                 if (ref == NULL)
 822                         return -ENOMEM;
 823                 if (*ref_ptr)
 824                         (*ref_ptr)->next = ref;
 825                 else
 826                         *ref_ptr = ref;
 827         } else {
 828                 /* Verify it is a data structure  */
 829                 if (tag != DW_TAG_structure_type) {
 830                         pr_warning("%s is not a data structure.\n", varname);
 831                         return -EINVAL;
 832                 }
 833                 if (field->name[0] == '[') {
 834                         pr_err("Semantic error: %s is not a pointor"
 835                                " nor array.\n", varname);
 836                         return -EINVAL;
 837                 }
 838                 if (field->ref) {
 839                         pr_err("Semantic error: %s must be referred by '.'\n",
 840                                field->name);
 841                         return -EINVAL;
 842                 }
 843                 if (!ref) {
 844                         pr_warning("Structure on a register is not "
 845                                    "supported yet.\n");
 846                         return -ENOTSUP;
 847                 }
 848         }
 849
 850         if (die_find_member(&type, field->name, die_mem) == NULL) {
 851                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
 852                            dwarf_diename(&type), field->name);
 853                 return -EINVAL;
 854         }
 855
 856         /* Get the offset of the field */
 857         ret = die_get_data_member_location(die_mem, &offs);
 858         if (ret < 0) {
 859                 pr_warning("Failed to get the offset of %s.\n", field->name);
 860                 return ret;
 861         }
 862         ref->offset += (long)offs;
 863
 864 next:
 865         /* Converting next field */
 866         if (field->next)
 867                 return convert_variable_fields(die_mem, field->name,
 868                                         field->next, &ref, die_mem);
 869         else
 870                 return 0;
 871 }
 872
 873 /* Show a variables in kprobe event format */
 874 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 875 {
 876         Dwarf_Die die_mem;
 877         int ret;
 878
 879         pr_debug("Converting variable %s into trace event.\n",
 880                  dwarf_diename(vr_die));
 881
 882         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
 883                                         pf->tvar);
 884         if (ret == -ENOENT)
 885                 pr_err("Failed to find the location of %s at this address.\n"
 886                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
 887         else if (ret == -ENOTSUP)
 888                 pr_err("Sorry, we don't support this variable location yet.\n");
 889         else if (pf->pvar->field) {
 890                 ret = convert_variable_fields(vr_die, pf->pvar->var,
 891                                               pf->pvar->field, &pf->tvar->ref,
 892                                               &die_mem);
 893                 vr_die = &die_mem;
 894         }
 895         if (ret == 0)
 896                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
 897         /* *expr will be cached in libdw. Don't free it. */
 898         return ret;
 899 }
 900
 901 /* Find a variable in a subprogram die */
 902 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 903 {
 904         Dwarf_Die vr_die, *scopes;
 905         char buf[32], *ptr;
 906         int ret, nscopes;
 907
 908         if (!is_c_varname(pf->pvar->var)) {
 909                 /* Copy raw parameters */
 910                 pf->tvar->value = strdup(pf->pvar->var);
 911                 if (pf->tvar->value == NULL)
 912                         return -ENOMEM;
 913                 if (pf->pvar->type) {
 914                         pf->tvar->type = strdup(pf->pvar->type);
 915                         if (pf->tvar->type == NULL)
 916                                 return -ENOMEM;
 917                 }
 918                 if (pf->pvar->name) {
 919                         pf->tvar->name = strdup(pf->pvar->name);
 920                         if (pf->tvar->name == NULL)
 921                                 return -ENOMEM;
 922                 } else
 923                         pf->tvar->name = NULL;
 924                 return 0;
 925         }
 926
 927         if (pf->pvar->name)
 928                 pf->tvar->name = strdup(pf->pvar->name);
 929         else {
 930                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
 931                 if (ret < 0)
 932                         return ret;
 933                 ptr = strchr(buf, ':'); /* Change type separator to _ */
 934                 if (ptr)
 935                         *ptr = '_';
 936                 pf->tvar->name = strdup(buf);
 937         }
 938         if (pf->tvar->name == NULL)
 939                 return -ENOMEM;
 940
 941         pr_debug("Searching '%s' variable in context.\n",
 942                  pf->pvar->var);
 943         /* Search child die for local variables and parameters. */
 944         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
 945                 ret = convert_variable(&vr_die, pf);
 946         else {
 947                 /* Search upper class */
 948                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
 949                 while (nscopes-- > 1) {
 950                         pr_debug("Searching variables in %s\n",
 951                                  dwarf_diename(&scopes[nscopes]));
 952                         /* We should check this scope, so give dummy address */
 953                         if (die_find_variable_at(&scopes[nscopes],
 954                                                  pf->pvar->var, 0,
 955                                                  &vr_die)) {
 956                                 ret = convert_variable(&vr_die, pf);
 957                                 goto found;
 958                         }
 959                 }
 960                 if (scopes)
 961                         free(scopes);
 962                 ret = -ENOENT;
 963         }
 964 found:
 965         if (ret < 0)
 966                 pr_warning("Failed to find '%s' in this function.\n",
 967                            pf->pvar->var);
 968         return ret;
 969 }
 970
 971 /* Convert subprogram DIE to trace point */
 972 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
 973                                   bool retprobe, struct probe_trace_point *tp)
 974 {
 975         Dwarf_Addr eaddr;
 976         const char *name;
 977
 978         /* Copy the name of probe point */
 979         name = dwarf_diename(sp_die);
 980         if (name) {
 981                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
 982                         pr_warning("Failed to get entry address of %s\n",
 983                                    dwarf_diename(sp_die));
 984                         return -ENOENT;
 985                 }
 986                 tp->symbol = strdup(name);
 987                 if (tp->symbol == NULL)
 988                         return -ENOMEM;
 989                 tp->offset = (unsigned long)(paddr - eaddr);
 990         } else
 991                 /* This function has no name. */
 992                 tp->offset = (unsigned long)paddr;
 993
 994         /* Return probe must be on the head of a subprogram */
 995         if (retprobe) {
 996                 if (eaddr != paddr) {
 997                         pr_warning("Return probe must be on the head of"
 998                                    " a real function.\n");
 999                         return -EINVAL;
1000                 }
1001                 tp->retprobe = true;
1002         }
1003
1004         return 0;
1005 }
1006
1007 /* Call probe_finder callback with real subprogram DIE */
1008 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1009 {
1010         Dwarf_Die die_mem;
1011         Dwarf_Attribute fb_attr;
1012         size_t nops;
1013         int ret;
1014
1015         /* If no real subprogram, find a real one */
1016         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1017                 sp_die = die_find_real_subprogram(&pf->cu_die,
1018                                                   pf->addr, &die_mem);
1019                 if (!sp_die) {
1020                         pr_warning("Failed to find probe point in any "
1021                                    "functions.\n");
1022                         return -ENOENT;
1023                 }
1024         }
1025
1026         /* Get the frame base attribute/ops */
1027         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1028         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1029         if (ret <= 0 || nops == 0) {
1030                 pf->fb_ops = NULL;
1031 #if _ELFUTILS_PREREQ(0, 142)
1032         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1033                    pf->cfi != NULL) {
1034                 Dwarf_Frame *frame;
1035                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1036                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1037                         pr_warning("Failed to get call frame on 0x%jx\n",
1038                                    (uintmax_t)pf->addr);
1039                         return -ENOENT;
1040                 }
1041 #endif
1042         }
1043
1044         /* Call finder's callback handler */
1045         ret = pf->callback(sp_die, pf);
1046
1047         /* *pf->fb_ops will be cached in libdw. Don't free it. */
1048         pf->fb_ops = NULL;
1049
1050         return ret;
1051 }
1052
1053 /* Find probe point from its line number */
1054 static int find_probe_point_by_line(struct probe_finder *pf)
1055 {
1056         Dwarf_Lines *lines;
1057         Dwarf_Line *line;
1058         size_t nlines, i;
1059         Dwarf_Addr addr;
1060         int lineno;
1061         int ret = 0;
1062
1063         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1064                 pr_warning("No source lines found.\n");
1065                 return -ENOENT;
1066         }
1067
1068         for (i = 0; i < nlines && ret == 0; i++) {
1069                 line = dwarf_onesrcline(lines, i);
1070                 if (dwarf_lineno(line, &lineno) != 0 ||
1071                     lineno != pf->lno)
1072                         continue;
1073
1074                 /* TODO: Get fileno from line, but how? */
1075                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1076                         continue;
1077
1078                 if (dwarf_lineaddr(line, &addr) != 0) {
1079                         pr_warning("Failed to get the address of the line.\n");
1080                         return -ENOENT;
1081                 }
1082                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1083                          (int)i, lineno, (uintmax_t)addr);
1084                 pf->addr = addr;
1085
1086                 ret = call_probe_finder(NULL, pf);
1087                 /* Continuing, because target line might be inlined. */
1088         }
1089         return ret;
1090 }
1091
1092 /* Find lines which match lazy pattern */
1093 static int find_lazy_match_lines(struct list_head *head,
1094                                  const char *fname, const char *pat)
1095 {
1096         char *fbuf, *p1, *p2;
1097         int fd, line, nlines = -1;
1098         struct stat st;
1099
1100         fd = open(fname, O_RDONLY);
1101         if (fd < 0) {
1102                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1103                 return -errno;
1104         }
1105
1106         if (fstat(fd, &st) < 0) {
1107                 pr_warning("Failed to get the size of %s: %s\n",
1108                            fname, strerror(errno));
1109                 nlines = -errno;
1110                 goto out_close;
1111         }
1112
1113         nlines = -ENOMEM;
1114         fbuf = malloc(st.st_size + 2);
1115         if (fbuf == NULL)
1116                 goto out_close;
1117         if (read(fd, fbuf, st.st_size) < 0) {
1118                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1119                 nlines = -errno;
1120                 goto out_free_fbuf;
1121         }
1122         fbuf[st.st_size] = '\n';        /* Dummy line */
1123         fbuf[st.st_size + 1] = '\0';
1124         p1 = fbuf;
1125         line = 1;
1126         nlines = 0;
1127         while ((p2 = strchr(p1, '\n')) != NULL) {
1128                 *p2 = '\0';
1129                 if (strlazymatch(p1, pat)) {
1130                         line_list__add_line(head, line);
1131                         nlines++;
1132                 }
1133                 line++;
1134                 p1 = p2 + 1;
1135         }
1136 out_free_fbuf:
1137         free(fbuf);
1138 out_close:
1139         close(fd);
1140         return nlines;
1141 }
1142
1143 /* Find probe points from lazy pattern  */
1144 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1145 {
1146         Dwarf_Lines *lines;
1147         Dwarf_Line *line;
1148         size_t nlines, i;
1149         Dwarf_Addr addr;
1150         Dwarf_Die die_mem;
1151         int lineno;
1152         int ret = 0;
1153
1154         if (list_empty(&pf->lcache)) {
1155                 /* Matching lazy line pattern */
1156                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1157                                             pf->pev->point.lazy_line);
1158                 if (ret == 0) {
1159                         pr_debug("No matched lines found in %s.\n", pf->fname);
1160                         return 0;
1161                 } else if (ret < 0)
1162                         return ret;
1163         }
1164
1165         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1166                 pr_warning("No source lines found.\n");
1167                 return -ENOENT;
1168         }
1169
1170         for (i = 0; i < nlines && ret >= 0; i++) {
1171                 line = dwarf_onesrcline(lines, i);
1172
1173                 if (dwarf_lineno(line, &lineno) != 0 ||
1174                     !line_list__has_line(&pf->lcache, lineno))
1175                         continue;
1176
1177                 /* TODO: Get fileno from line, but how? */
1178                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1179                         continue;
1180
1181                 if (dwarf_lineaddr(line, &addr) != 0) {
1182                         pr_debug("Failed to get the address of line %d.\n",
1183                                  lineno);
1184                         continue;
1185                 }
1186                 if (sp_die) {
1187                         /* Address filtering 1: does sp_die include addr? */
1188                         if (!dwarf_haspc(sp_die, addr))
1189                                 continue;
1190                         /* Address filtering 2: No child include addr? */
1191                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1192                                 continue;
1193                 }
1194
1195                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1196                          (int)i, lineno, (unsigned long long)addr);
1197                 pf->addr = addr;
1198
1199                 ret = call_probe_finder(sp_die, pf);
1200                 /* Continuing, because target line might be inlined. */
1201         }
1202         /* TODO: deallocate lines, but how? */
1203         return ret;
1204 }
1205
1206 /* Callback parameter with return value */
1207 struct dwarf_callback_param {
1208         void *data;
1209         int retval;
1210 };
1211
1212 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1213 {
1214         struct dwarf_callback_param *param = data;
1215         struct probe_finder *pf = param->data;
1216         struct perf_probe_point *pp = &pf->pev->point;
1217         Dwarf_Addr addr;
1218
1219         if (pp->lazy_line)
1220                 param->retval = find_probe_point_lazy(in_die, pf);
1221         else {
1222                 /* Get probe address */
1223                 if (dwarf_entrypc(in_die, &addr) != 0) {
1224                         pr_warning("Failed to get entry address of %s.\n",
1225                                    dwarf_diename(in_die));
1226                         param->retval = -ENOENT;
1227                         return DWARF_CB_ABORT;
1228                 }
1229                 pf->addr = addr;
1230                 pf->addr += pp->offset;
1231                 pr_debug("found inline addr: 0x%jx\n",
1232                          (uintmax_t)pf->addr);
1233
1234                 param->retval = call_probe_finder(in_die, pf);
1235                 if (param->retval < 0)
1236                         return DWARF_CB_ABORT;
1237         }
1238
1239         return DWARF_CB_OK;
1240 }
1241
1242 /* Search function from function name */
1243 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1244 {
1245         struct dwarf_callback_param *param = data;
1246         struct probe_finder *pf = param->data;
1247         struct perf_probe_point *pp = &pf->pev->point;
1248
1249         /* Check tag and diename */
1250         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1251             !die_compare_name(sp_die, pp->function))
1252                 return DWARF_CB_OK;
1253
1254         pf->fname = dwarf_decl_file(sp_die);
1255         if (pp->line) { /* Function relative line */
1256                 dwarf_decl_line(sp_die, &pf->lno);
1257                 pf->lno += pp->line;
1258                 param->retval = find_probe_point_by_line(pf);
1259         } else if (!dwarf_func_inline(sp_die)) {
1260                 /* Real function */
1261                 if (pp->lazy_line)
1262                         param->retval = find_probe_point_lazy(sp_die, pf);
1263                 else {
1264                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1265                                 pr_warning("Failed to get entry address of "
1266                                            "%s.\n", dwarf_diename(sp_die));
1267                                 param->retval = -ENOENT;
1268                                 return DWARF_CB_ABORT;
1269                         }
1270                         pf->addr += pp->offset;
1271                         /* TODO: Check the address in this function */
1272                         param->retval = call_probe_finder(sp_die, pf);
1273                 }
1274         } else {
1275                 struct dwarf_callback_param _param = {.data = (void *)pf,
1276                                                       .retval = 0};
1277                 /* Inlined function: search instances */
1278                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1279                                             &_param);
1280                 param->retval = _param.retval;
1281         }
1282
1283         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1284 }
1285
1286 static int find_probe_point_by_func(struct probe_finder *pf)
1287 {
1288         struct dwarf_callback_param _param = {.data = (void *)pf,
1289                                               .retval = 0};
1290         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1291         return _param.retval;
1292 }
1293
1294 /* Find probe points from debuginfo */
1295 static int find_probes(int fd, struct probe_finder *pf)
1296 {
1297         struct perf_probe_point *pp = &pf->pev->point;
1298         Dwarf_Off off, noff;
1299         size_t cuhl;
1300         Dwarf_Die *diep;
1301         Dwarf *dbg = NULL;
1302         Dwfl *dwfl;
1303         Dwarf_Addr bias;        /* Currently ignored */
1304         int ret = 0;
1305
1306         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1307         if (!dbg) {
1308                 pr_warning("No debug information found in the vmlinux - "
1309                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1310                 return -EBADF;
1311         }
1312
1313 #if _ELFUTILS_PREREQ(0, 142)
1314         /* Get the call frame information from this dwarf */
1315         pf->cfi = dwarf_getcfi(dbg);
1316 #endif
1317
1318         off = 0;
1319         line_list__init(&pf->lcache);
1320         /* Loop on CUs (Compilation Unit) */
1321         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1322                ret >= 0) {
1323                 /* Get the DIE(Debugging Information Entry) of this CU */
1324                 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1325                 if (!diep)
1326                         continue;
1327
1328                 /* Check if target file is included. */
1329                 if (pp->file)
1330                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1331                 else
1332                         pf->fname = NULL;
1333
1334                 if (!pp->file || pf->fname) {
1335                         if (pp->function)
1336                                 ret = find_probe_point_by_func(pf);
1337                         else if (pp->lazy_line)
1338                                 ret = find_probe_point_lazy(NULL, pf);
1339                         else {
1340                                 pf->lno = pp->line;
1341                                 ret = find_probe_point_by_line(pf);
1342                         }
1343                 }
1344                 off = noff;
1345         }
1346         line_list__free(&pf->lcache);
1347         if (dwfl)
1348                 dwfl_end(dwfl);
1349
1350         return ret;
1351 }
1352
1353 /* Add a found probe point into trace event list */
1354 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1355 {
1356         struct trace_event_finder *tf =
1357                         container_of(pf, struct trace_event_finder, pf);
1358         struct probe_trace_event *tev;
1359         int ret, i;
1360
1361         /* Check number of tevs */
1362         if (tf->ntevs == tf->max_tevs) {
1363                 pr_warning("Too many( > %d) probe point found.\n",
1364                            tf->max_tevs);
1365                 return -ERANGE;
1366         }
1367         tev = &tf->tevs[tf->ntevs++];
1368
1369         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1370                                      &tev->point);
1371         if (ret < 0)
1372                 return ret;
1373
1374         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1375                  tev->point.offset);
1376
1377         /* Find each argument */
1378         tev->nargs = pf->pev->nargs;
1379         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1380         if (tev->args == NULL)
1381                 return -ENOMEM;
1382         for (i = 0; i < pf->pev->nargs; i++) {
1383                 pf->pvar = &pf->pev->args[i];
1384                 pf->tvar = &tev->args[i];
1385                 ret = find_variable(sp_die, pf);
1386                 if (ret != 0)
1387                         return ret;
1388         }
1389
1390         return 0;
1391 }
1392
1393 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1394 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1395                             struct probe_trace_event **tevs, int max_tevs)
1396 {
1397         struct trace_event_finder tf = {
1398                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1399                         .max_tevs = max_tevs};
1400         int ret;
1401
1402         /* Allocate result tevs array */
1403         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1404         if (*tevs == NULL)
1405                 return -ENOMEM;
1406
1407         tf.tevs = *tevs;
1408         tf.ntevs = 0;
1409
1410         ret = find_probes(fd, &tf.pf);
1411         if (ret < 0) {
1412                 free(*tevs);
1413                 *tevs = NULL;
1414                 return ret;
1415         }
1416
1417         return (ret < 0) ? ret : tf.ntevs;
1418 }
1419
1420 #define MAX_VAR_LEN 64
1421
1422 /* Collect available variables in this scope */
1423 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1424 {
1425         struct available_var_finder *af = data;
1426         struct variable_list *vl;
1427         char buf[MAX_VAR_LEN];
1428         int tag, ret;
1429
1430         vl = &af->vls[af->nvls - 1];
1431
1432         tag = dwarf_tag(die_mem);
1433         if (tag == DW_TAG_formal_parameter ||
1434             tag == DW_TAG_variable) {
1435                 ret = convert_variable_location(die_mem, af->pf.addr,
1436                                                 af->pf.fb_ops, NULL);
1437                 if (ret == 0) {
1438                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1439                         pr_debug2("Add new var: %s\n", buf);
1440                         if (ret > 0)
1441                                 strlist__add(vl->vars, buf);
1442                 }
1443         }
1444
1445         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1446                 return DIE_FIND_CB_CONTINUE;
1447         else
1448                 return DIE_FIND_CB_SIBLING;
1449 }
1450
1451 /* Add a found vars into available variables list */
1452 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1453 {
1454         struct available_var_finder *af =
1455                         container_of(pf, struct available_var_finder, pf);
1456         struct variable_list *vl;
1457         Dwarf_Die die_mem, *scopes = NULL;
1458         int ret, nscopes;
1459
1460         /* Check number of tevs */
1461         if (af->nvls == af->max_vls) {
1462                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1463                 return -ERANGE;
1464         }
1465         vl = &af->vls[af->nvls++];
1466
1467         ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1468                                      &vl->point);
1469         if (ret < 0)
1470                 return ret;
1471
1472         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1473                  vl->point.offset);
1474
1475         /* Find local variables */
1476         vl->vars = strlist__new(true, NULL);
1477         if (vl->vars == NULL)
1478                 return -ENOMEM;
1479         af->child = true;
1480         die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1481
1482         /* Find external variables */
1483         if (!af->externs)
1484                 goto out;
1485         /* Don't need to search child DIE for externs. */
1486         af->child = false;
1487         nscopes = dwarf_getscopes_die(sp_die, &scopes);
1488         while (nscopes-- > 1)
1489                 die_find_child(&scopes[nscopes], collect_variables_cb,
1490                                (void *)af, &die_mem);
1491         if (scopes)
1492                 free(scopes);
1493
1494 out:
1495         if (strlist__empty(vl->vars)) {
1496                 strlist__delete(vl->vars);
1497                 vl->vars = NULL;
1498         }
1499
1500         return ret;
1501 }
1502
1503 /* Find available variables at given probe point */
1504 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1505                            struct variable_list **vls, int max_vls,
1506                            bool externs)
1507 {
1508         struct available_var_finder af = {
1509                         .pf = {.pev = pev, .callback = add_available_vars},
1510                         .max_vls = max_vls, .externs = externs};
1511         int ret;
1512
1513         /* Allocate result vls array */
1514         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1515         if (*vls == NULL)
1516                 return -ENOMEM;
1517
1518         af.vls = *vls;
1519         af.nvls = 0;
1520
1521         ret = find_probes(fd, &af.pf);
1522         if (ret < 0) {
1523                 /* Free vlist for error */
1524                 while (af.nvls--) {
1525                         if (af.vls[af.nvls].point.symbol)
1526                                 free(af.vls[af.nvls].point.symbol);
1527                         if (af.vls[af.nvls].vars)
1528                                 strlist__delete(af.vls[af.nvls].vars);
1529                 }
1530                 free(af.vls);
1531                 *vls = NULL;
1532                 return ret;
1533         }
1534
1535         return (ret < 0) ? ret : af.nvls;
1536 }
1537
1538 /* Reverse search */
1539 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1540 {
1541         Dwarf_Die cudie, spdie, indie;
1542         Dwarf *dbg = NULL;
1543         Dwfl *dwfl = NULL;
1544         Dwarf_Line *line;
1545         Dwarf_Addr laddr, eaddr, bias = 0;
1546         const char *tmp;
1547         int lineno, ret = 0;
1548         bool found = false;
1549
1550         /* Open the live linux kernel */
1551         dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1552         if (!dbg) {
1553                 pr_warning("No debug information found in the vmlinux - "
1554                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1555                 ret = -EINVAL;
1556                 goto end;
1557         }
1558
1559         /* Adjust address with bias */
1560         addr += bias;
1561         /* Find cu die */
1562         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1563                 pr_warning("Failed to find debug information for address %lx\n",
1564                            addr);
1565                 ret = -EINVAL;
1566                 goto end;
1567         }
1568
1569         /* Find a corresponding line */
1570         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1571         if (line) {
1572                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1573                     (Dwarf_Addr)addr == laddr &&
1574                     dwarf_lineno(line, &lineno) == 0) {
1575                         tmp = dwarf_linesrc(line, NULL, NULL);
1576                         if (tmp) {
1577                                 ppt->line = lineno;
1578                                 ppt->file = strdup(tmp);
1579                                 if (ppt->file == NULL) {
1580                                         ret = -ENOMEM;
1581                                         goto end;
1582                                 }
1583                                 found = true;
1584                         }
1585                 }
1586         }
1587
1588         /* Find a corresponding function */
1589         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1590                 tmp = dwarf_diename(&spdie);
1591                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1592                         goto end;
1593
1594                 if (ppt->line) {
1595                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1596                                                 &indie)) {
1597                                 /* addr in an inline function */
1598                                 tmp = dwarf_diename(&indie);
1599                                 if (!tmp)
1600                                         goto end;
1601                                 ret = dwarf_decl_line(&indie, &lineno);
1602                         } else {
1603                                 if (eaddr == addr) {    /* Function entry */
1604                                         lineno = ppt->line;
1605                                         ret = 0;
1606                                 } else
1607                                         ret = dwarf_decl_line(&spdie, &lineno);
1608                         }
1609                         if (ret == 0) {
1610                                 /* Make a relative line number */
1611                                 ppt->line -= lineno;
1612                                 goto found;
1613                         }
1614                 }
1615                 /* We don't have a line number, let's use offset */
1616                 ppt->offset = addr - (unsigned long)eaddr;
1617 found:
1618                 ppt->function = strdup(tmp);
1619                 if (ppt->function == NULL) {
1620                         ret = -ENOMEM;
1621                         goto end;
1622                 }
1623                 found = true;
1624         }
1625
1626 end:
1627         if (dwfl)
1628                 dwfl_end(dwfl);
1629         if (ret >= 0)
1630                 ret = found ? 1 : 0;
1631         return ret;
1632 }
1633
1634 /* Add a line and store the src path */
1635 static int line_range_add_line(const char *src, unsigned int lineno,
1636                                struct line_range *lr)
1637 {
1638         /* Copy source path */
1639         if (!lr->path) {
1640                 lr->path = strdup(src);
1641                 if (lr->path == NULL)
1642                         return -ENOMEM;
1643         }
1644         return line_list__add_line(&lr->line_list, lineno);
1645 }
1646
1647 /* Search function declaration lines */
1648 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1649 {
1650         struct dwarf_callback_param *param = data;
1651         struct line_finder *lf = param->data;
1652         const char *src;
1653         int lineno;
1654
1655         src = dwarf_decl_file(sp_die);
1656         if (src && strtailcmp(src, lf->fname) != 0)
1657                 return DWARF_CB_OK;
1658
1659         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1660             (lf->lno_s > lineno || lf->lno_e < lineno))
1661                 return DWARF_CB_OK;
1662
1663         param->retval = line_range_add_line(src, lineno, lf->lr);
1664         if (param->retval < 0)
1665                 return DWARF_CB_ABORT;
1666         return DWARF_CB_OK;
1667 }
1668
1669 static int find_line_range_func_decl_lines(struct line_finder *lf)
1670 {
1671         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1672         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1673         return param.retval;
1674 }
1675
1676 /* Find line range from its line number */
1677 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1678 {
1679         Dwarf_Lines *lines;
1680         Dwarf_Line *line;
1681         size_t nlines, i;
1682         Dwarf_Addr addr;
1683         int lineno, ret = 0;
1684         const char *src;
1685         Dwarf_Die die_mem;
1686
1687         line_list__init(&lf->lr->line_list);
1688         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1689                 pr_warning("No source lines found.\n");
1690                 return -ENOENT;
1691         }
1692
1693         /* Search probable lines on lines list */
1694         for (i = 0; i < nlines; i++) {
1695                 line = dwarf_onesrcline(lines, i);
1696                 if (dwarf_lineno(line, &lineno) != 0 ||
1697                     (lf->lno_s > lineno || lf->lno_e < lineno))
1698                         continue;
1699
1700                 if (sp_die) {
1701                         /* Address filtering 1: does sp_die include addr? */
1702                         if (dwarf_lineaddr(line, &addr) != 0 ||
1703                             !dwarf_haspc(sp_die, addr))
1704                                 continue;
1705
1706                         /* Address filtering 2: No child include addr? */
1707                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1708                                 continue;
1709                 }
1710
1711                 /* TODO: Get fileno from line, but how? */
1712                 src = dwarf_linesrc(line, NULL, NULL);
1713                 if (strtailcmp(src, lf->fname) != 0)
1714                         continue;
1715
1716                 ret = line_range_add_line(src, lineno, lf->lr);
1717                 if (ret < 0)
1718                         return ret;
1719         }
1720
1721         /*
1722          * Dwarf lines doesn't include function declarations. We have to
1723          * check functions list or given function.
1724          */
1725         if (sp_die) {
1726                 src = dwarf_decl_file(sp_die);
1727                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1728                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1729                         ret = line_range_add_line(src, lineno, lf->lr);
1730         } else
1731                 ret = find_line_range_func_decl_lines(lf);
1732
1733         /* Update status */
1734         if (ret >= 0)
1735                 if (!list_empty(&lf->lr->line_list))
1736                         ret = lf->found = 1;
1737                 else
1738                         ret = 0;        /* Lines are not found */
1739         else {
1740                 free(lf->lr->path);
1741                 lf->lr->path = NULL;
1742         }
1743         return ret;
1744 }
1745
1746 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1747 {
1748         struct dwarf_callback_param *param = data;
1749
1750         param->retval = find_line_range_by_line(in_die, param->data);
1751         return DWARF_CB_ABORT;  /* No need to find other instances */
1752 }
1753
1754 /* Search function from function name */
1755 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1756 {
1757         struct dwarf_callback_param *param = data;
1758         struct line_finder *lf = param->data;
1759         struct line_range *lr = lf->lr;
1760
1761         pr_debug("find (%llx) %s\n",
1762                  (unsigned long long)dwarf_dieoffset(sp_die),
1763                  dwarf_diename(sp_die));
1764         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1765             die_compare_name(sp_die, lr->function)) {
1766                 lf->fname = dwarf_decl_file(sp_die);
1767                 dwarf_decl_line(sp_die, &lr->offset);
1768                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1769                 lf->lno_s = lr->offset + lr->start;
1770                 if (lf->lno_s < 0)      /* Overflow */
1771                         lf->lno_s = INT_MAX;
1772                 lf->lno_e = lr->offset + lr->end;
1773                 if (lf->lno_e < 0)      /* Overflow */
1774                         lf->lno_e = INT_MAX;
1775                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1776                 lr->start = lf->lno_s;
1777                 lr->end = lf->lno_e;
1778                 if (dwarf_func_inline(sp_die)) {
1779                         struct dwarf_callback_param _param;
1780                         _param.data = (void *)lf;
1781                         _param.retval = 0;
1782                         dwarf_func_inline_instances(sp_die,
1783                                                     line_range_inline_cb,
1784                                                     &_param);
1785                         param->retval = _param.retval;
1786                 } else
1787                         param->retval = find_line_range_by_line(sp_die, lf);
1788                 return DWARF_CB_ABORT;
1789         }
1790         return DWARF_CB_OK;
1791 }
1792
1793 static int find_line_range_by_func(struct line_finder *lf)
1794 {
1795         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1796         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1797         return param.retval;
1798 }
1799
1800 int find_line_range(int fd, struct line_range *lr)
1801 {
1802         struct line_finder lf = {.lr = lr, .found = 0};
1803         int ret = 0;
1804         Dwarf_Off off = 0, noff;
1805         size_t cuhl;
1806         Dwarf_Die *diep;
1807         Dwarf *dbg = NULL;
1808         Dwfl *dwfl;
1809         Dwarf_Addr bias;        /* Currently ignored */
1810         const char *comp_dir;
1811
1812         dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1813         if (!dbg) {
1814                 pr_warning("No debug information found in the vmlinux - "
1815                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1816                 return -EBADF;
1817         }
1818
1819         /* Loop on CUs (Compilation Unit) */
1820         while (!lf.found && ret >= 0) {
1821                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1822                         break;
1823
1824                 /* Get the DIE(Debugging Information Entry) of this CU */
1825                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1826                 if (!diep)
1827                         continue;
1828
1829                 /* Check if target file is included. */
1830                 if (lr->file)
1831                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1832                 else
1833                         lf.fname = 0;
1834
1835                 if (!lr->file || lf.fname) {
1836                         if (lr->function)
1837                                 ret = find_line_range_by_func(&lf);
1838                         else {
1839                                 lf.lno_s = lr->start;
1840                                 lf.lno_e = lr->end;
1841                                 ret = find_line_range_by_line(NULL, &lf);
1842                         }
1843                 }
1844                 off = noff;
1845         }
1846
1847         /* Store comp_dir */
1848         if (lf.found) {
1849                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1850                 if (comp_dir) {
1851                         lr->comp_dir = strdup(comp_dir);
1852                         if (!lr->comp_dir)
1853                                 ret = -ENOMEM;
1854                 }
1855         }
1856
1857         pr_debug("path: %s\n", lr->path);
1858         dwfl_end(dwfl);
1859         return (ret < 0) ? ret : lf.found;
1860 }
1861