| 1 | /* Symbol, variable and name lookup. |
| 2 | Copyright (C) 2019-2021 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of libctf. |
| 5 | |
| 6 | libctf is free software; you can redistribute it and/or modify it under |
| 7 | the terms of the GNU General Public License as published by the Free |
| 8 | Software Foundation; either version 3, or (at your option) any later |
| 9 | version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, but |
| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 14 | See the 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; see the file COPYING. If not see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <ctf-impl.h> |
| 21 | #include <elf.h> |
| 22 | #include <string.h> |
| 23 | #include <assert.h> |
| 24 | |
| 25 | /* Grow the pptrtab so that it is at least NEW_LEN long. */ |
| 26 | static int |
| 27 | grow_pptrtab (ctf_dict_t *fp, size_t new_len) |
| 28 | { |
| 29 | uint32_t *new_pptrtab; |
| 30 | |
| 31 | if ((new_pptrtab = realloc (fp->ctf_pptrtab, sizeof (uint32_t) |
| 32 | * new_len)) == NULL) |
| 33 | return (ctf_set_errno (fp, ENOMEM)); |
| 34 | |
| 35 | fp->ctf_pptrtab = new_pptrtab; |
| 36 | |
| 37 | memset (fp->ctf_pptrtab + fp->ctf_pptrtab_len, 0, |
| 38 | sizeof (uint32_t) * (new_len - fp->ctf_pptrtab_len)); |
| 39 | |
| 40 | fp->ctf_pptrtab_len = new_len; |
| 41 | return 0; |
| 42 | } |
| 43 | |
| 44 | /* Update entries in the pptrtab that relate to types newly added in the |
| 45 | child. */ |
| 46 | static int |
| 47 | refresh_pptrtab (ctf_dict_t *fp, ctf_dict_t *pfp) |
| 48 | { |
| 49 | uint32_t i; |
| 50 | for (i = fp->ctf_pptrtab_typemax; i <= fp->ctf_typemax; i++) |
| 51 | { |
| 52 | ctf_id_t type = LCTF_INDEX_TO_TYPE (fp, i, 1); |
| 53 | ctf_id_t reffed_type; |
| 54 | |
| 55 | if (ctf_type_kind (fp, type) != CTF_K_POINTER) |
| 56 | continue; |
| 57 | |
| 58 | reffed_type = ctf_type_reference (fp, type); |
| 59 | |
| 60 | if (LCTF_TYPE_ISPARENT (fp, reffed_type)) |
| 61 | { |
| 62 | uint32_t idx = LCTF_TYPE_TO_INDEX (fp, reffed_type); |
| 63 | |
| 64 | /* Guard against references to invalid types. No need to consider |
| 65 | the CTF dict corrupt in this case: this pointer just can't be a |
| 66 | pointer to any type we know about. */ |
| 67 | if (idx <= pfp->ctf_typemax) |
| 68 | { |
| 69 | if (idx >= fp->ctf_pptrtab_len |
| 70 | && grow_pptrtab (fp, pfp->ctf_ptrtab_len) < 0) |
| 71 | return -1; /* errno is set for us. */ |
| 72 | |
| 73 | fp->ctf_pptrtab[idx] = i; |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | fp->ctf_pptrtab_typemax = fp->ctf_typemax; |
| 79 | |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | /* Compare the given input string and length against a table of known C storage |
| 84 | qualifier keywords. We just ignore these in ctf_lookup_by_name, below. To |
| 85 | do this quickly, we use a pre-computed Perfect Hash Function similar to the |
| 86 | technique originally described in the classic paper: |
| 87 | |
| 88 | R.J. Cichelli, "Minimal Perfect Hash Functions Made Simple", |
| 89 | Communications of the ACM, Volume 23, Issue 1, January 1980, pp. 17-19. |
| 90 | |
| 91 | For an input string S of length N, we use hash H = S[N - 1] + N - 105, which |
| 92 | for the current set of qualifiers yields a unique H in the range [0 .. 20]. |
| 93 | The hash can be modified when the keyword set changes as necessary. We also |
| 94 | store the length of each keyword and check it prior to the final strcmp(). |
| 95 | |
| 96 | TODO: just use gperf. */ |
| 97 | |
| 98 | static int |
| 99 | isqualifier (const char *s, size_t len) |
| 100 | { |
| 101 | static const struct qual |
| 102 | { |
| 103 | const char *q_name; |
| 104 | size_t q_len; |
| 105 | } qhash[] = { |
| 106 | {"static", 6}, {"", 0}, {"", 0}, {"", 0}, |
| 107 | {"volatile", 8}, {"", 0}, {"", 0}, {"", 0}, {"", 0}, |
| 108 | {"", 0}, {"auto", 4}, {"extern", 6}, {"", 0}, {"", 0}, |
| 109 | {"", 0}, {"", 0}, {"const", 5}, {"register", 8}, |
| 110 | {"", 0}, {"restrict", 8}, {"_Restrict", 9} |
| 111 | }; |
| 112 | |
| 113 | int h = s[len - 1] + (int) len - 105; |
| 114 | const struct qual *qp; |
| 115 | |
| 116 | if (h < 0 || (size_t) h >= sizeof (qhash) / sizeof (qhash[0])) |
| 117 | return 0; |
| 118 | |
| 119 | qp = &qhash[h]; |
| 120 | |
| 121 | return ((size_t) len == qp->q_len && |
| 122 | strncmp (qp->q_name, s, qp->q_len) == 0); |
| 123 | } |
| 124 | |
| 125 | /* Attempt to convert the given C type name into the corresponding CTF type ID. |
| 126 | It is not possible to do complete and proper conversion of type names |
| 127 | without implementing a more full-fledged parser, which is necessary to |
| 128 | handle things like types that are function pointers to functions that |
| 129 | have arguments that are function pointers, and fun stuff like that. |
| 130 | Instead, this function implements a very simple conversion algorithm that |
| 131 | finds the things that we actually care about: structs, unions, enums, |
| 132 | integers, floats, typedefs, and pointers to any of these named types. */ |
| 133 | |
| 134 | static ctf_id_t |
| 135 | ctf_lookup_by_name_internal (ctf_dict_t *fp, ctf_dict_t *child, |
| 136 | const char *name) |
| 137 | { |
| 138 | static const char delimiters[] = " \t\n\r\v\f*"; |
| 139 | |
| 140 | const ctf_lookup_t *lp; |
| 141 | const char *p, *q, *end; |
| 142 | ctf_id_t type = 0; |
| 143 | ctf_id_t ntype, ptype; |
| 144 | |
| 145 | if (name == NULL) |
| 146 | return (ctf_set_errno (fp, EINVAL)); |
| 147 | |
| 148 | for (p = name, end = name + strlen (name); *p != '\0'; p = q) |
| 149 | { |
| 150 | while (isspace ((int) *p)) |
| 151 | p++; /* Skip leading whitespace. */ |
| 152 | |
| 153 | if (p == end) |
| 154 | break; |
| 155 | |
| 156 | if ((q = strpbrk (p + 1, delimiters)) == NULL) |
| 157 | q = end; /* Compare until end. */ |
| 158 | |
| 159 | if (*p == '*') |
| 160 | { |
| 161 | /* Find a pointer to type by looking in child->ctf_pptrtab (if child |
| 162 | is set) and fp->ctf_ptrtab. If we can't find a pointer to the |
| 163 | given type, see if we can compute a pointer to the type resulting |
| 164 | from resolving the type down to its base type and use that instead. |
| 165 | This helps with cases where the CTF data includes "struct foo *" |
| 166 | but not "foo_t *" and the user tries to access "foo_t *" in the |
| 167 | debugger. |
| 168 | |
| 169 | There is extra complexity here because uninitialized elements in |
| 170 | the pptrtab and ptrtab are set to zero, but zero (as the type ID |
| 171 | meaning the unimplemented type) is a valid return type from |
| 172 | ctf_lookup_by_name. (Pointers to types are never of type 0, so |
| 173 | this is unambiguous, just fiddly to deal with.) */ |
| 174 | |
| 175 | uint32_t idx = LCTF_TYPE_TO_INDEX (fp, type); |
| 176 | int in_child = 0; |
| 177 | |
| 178 | ntype = CTF_ERR; |
| 179 | if (child && idx <= child->ctf_pptrtab_len) |
| 180 | { |
| 181 | ntype = child->ctf_pptrtab[idx]; |
| 182 | if (ntype) |
| 183 | in_child = 1; |
| 184 | else |
| 185 | ntype = CTF_ERR; |
| 186 | } |
| 187 | |
| 188 | if (ntype == CTF_ERR) |
| 189 | { |
| 190 | ntype = fp->ctf_ptrtab[idx]; |
| 191 | if (ntype == 0) |
| 192 | ntype = CTF_ERR; |
| 193 | } |
| 194 | |
| 195 | /* Try resolving to its base type and check again. */ |
| 196 | if (ntype == CTF_ERR) |
| 197 | { |
| 198 | if (child) |
| 199 | ntype = ctf_type_resolve_unsliced (child, type); |
| 200 | else |
| 201 | ntype = ctf_type_resolve_unsliced (fp, type); |
| 202 | |
| 203 | if (ntype == CTF_ERR) |
| 204 | goto notype; |
| 205 | |
| 206 | idx = LCTF_TYPE_TO_INDEX (fp, ntype); |
| 207 | |
| 208 | ntype = CTF_ERR; |
| 209 | if (child && idx <= child->ctf_pptrtab_len) |
| 210 | { |
| 211 | ntype = child->ctf_pptrtab[idx]; |
| 212 | if (ntype) |
| 213 | in_child = 1; |
| 214 | else |
| 215 | ntype = CTF_ERR; |
| 216 | } |
| 217 | |
| 218 | if (ntype == CTF_ERR) |
| 219 | { |
| 220 | ntype = fp->ctf_ptrtab[idx]; |
| 221 | if (ntype == 0) |
| 222 | ntype = CTF_ERR; |
| 223 | } |
| 224 | if (ntype == CTF_ERR) |
| 225 | goto notype; |
| 226 | } |
| 227 | |
| 228 | type = LCTF_INDEX_TO_TYPE (fp, ntype, (fp->ctf_flags & LCTF_CHILD) |
| 229 | || in_child); |
| 230 | |
| 231 | /* We are looking up a type in the parent, but the pointed-to type is |
| 232 | in the child. Switch to looking in the child: if we need to go |
| 233 | back into the parent, we can recurse again. */ |
| 234 | if (in_child) |
| 235 | { |
| 236 | fp = child; |
| 237 | child = NULL; |
| 238 | } |
| 239 | |
| 240 | q = p + 1; |
| 241 | continue; |
| 242 | } |
| 243 | |
| 244 | if (isqualifier (p, (size_t) (q - p))) |
| 245 | continue; /* Skip qualifier keyword. */ |
| 246 | |
| 247 | for (lp = fp->ctf_lookups; lp->ctl_prefix != NULL; lp++) |
| 248 | { |
| 249 | /* TODO: This is not MT-safe. */ |
| 250 | if ((lp->ctl_prefix[0] == '\0' || |
| 251 | strncmp (p, lp->ctl_prefix, (size_t) (q - p)) == 0) && |
| 252 | (size_t) (q - p) >= lp->ctl_len) |
| 253 | { |
| 254 | for (p += lp->ctl_len; isspace ((int) *p); p++) |
| 255 | continue; /* Skip prefix and next whitespace. */ |
| 256 | |
| 257 | if ((q = strchr (p, '*')) == NULL) |
| 258 | q = end; /* Compare until end. */ |
| 259 | |
| 260 | while (isspace ((int) q[-1])) |
| 261 | q--; /* Exclude trailing whitespace. */ |
| 262 | |
| 263 | /* Expand and/or allocate storage for a slice of the name, then |
| 264 | copy it in. */ |
| 265 | |
| 266 | if (fp->ctf_tmp_typeslicelen >= (size_t) (q - p) + 1) |
| 267 | { |
| 268 | memcpy (fp->ctf_tmp_typeslice, p, (size_t) (q - p)); |
| 269 | fp->ctf_tmp_typeslice[(size_t) (q - p)] = '\0'; |
| 270 | } |
| 271 | else |
| 272 | { |
| 273 | free (fp->ctf_tmp_typeslice); |
| 274 | fp->ctf_tmp_typeslice = xstrndup (p, (size_t) (q - p)); |
| 275 | if (fp->ctf_tmp_typeslice == NULL) |
| 276 | { |
| 277 | ctf_set_errno (fp, ENOMEM); |
| 278 | return CTF_ERR; |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | if ((type = ctf_lookup_by_rawhash (fp, lp->ctl_hash, |
| 283 | fp->ctf_tmp_typeslice)) == 0) |
| 284 | goto notype; |
| 285 | |
| 286 | break; |
| 287 | } |
| 288 | } |
| 289 | |
| 290 | if (lp->ctl_prefix == NULL) |
| 291 | goto notype; |
| 292 | } |
| 293 | |
| 294 | if (*p != '\0' || type == 0) |
| 295 | return (ctf_set_errno (fp, ECTF_SYNTAX)); |
| 296 | |
| 297 | return type; |
| 298 | |
| 299 | notype: |
| 300 | ctf_set_errno (fp, ECTF_NOTYPE); |
| 301 | if (fp->ctf_parent != NULL) |
| 302 | { |
| 303 | /* Need to look up in the parent, from the child's perspective. |
| 304 | Make sure the pptrtab is up to date. */ |
| 305 | |
| 306 | if (fp->ctf_pptrtab_typemax < fp->ctf_typemax) |
| 307 | { |
| 308 | if (refresh_pptrtab (fp, fp->ctf_parent) < 0) |
| 309 | return -1; /* errno is set for us. */ |
| 310 | } |
| 311 | |
| 312 | if ((ptype = ctf_lookup_by_name_internal (fp->ctf_parent, fp, |
| 313 | name)) != CTF_ERR) |
| 314 | return ptype; |
| 315 | return (ctf_set_errno (fp, ctf_errno (fp->ctf_parent))); |
| 316 | } |
| 317 | |
| 318 | return CTF_ERR; |
| 319 | } |
| 320 | |
| 321 | ctf_id_t |
| 322 | ctf_lookup_by_name (ctf_dict_t *fp, const char *name) |
| 323 | { |
| 324 | return ctf_lookup_by_name_internal (fp, NULL, name); |
| 325 | } |
| 326 | |
| 327 | /* Return the pointer to the internal CTF type data corresponding to the |
| 328 | given type ID. If the ID is invalid, the function returns NULL. |
| 329 | This function is not exported outside of the library. */ |
| 330 | |
| 331 | const ctf_type_t * |
| 332 | ctf_lookup_by_id (ctf_dict_t **fpp, ctf_id_t type) |
| 333 | { |
| 334 | ctf_dict_t *fp = *fpp; /* Caller passes in starting CTF dict. */ |
| 335 | ctf_id_t idx; |
| 336 | |
| 337 | if ((fp = ctf_get_dict (fp, type)) == NULL) |
| 338 | { |
| 339 | (void) ctf_set_errno (*fpp, ECTF_NOPARENT); |
| 340 | return NULL; |
| 341 | } |
| 342 | |
| 343 | /* If this dict is writable, check for a dynamic type. */ |
| 344 | |
| 345 | if (fp->ctf_flags & LCTF_RDWR) |
| 346 | { |
| 347 | ctf_dtdef_t *dtd; |
| 348 | |
| 349 | if ((dtd = ctf_dynamic_type (fp, type)) != NULL) |
| 350 | { |
| 351 | *fpp = fp; |
| 352 | return &dtd->dtd_data; |
| 353 | } |
| 354 | (void) ctf_set_errno (*fpp, ECTF_BADID); |
| 355 | return NULL; |
| 356 | } |
| 357 | |
| 358 | /* Check for a type in the static portion. */ |
| 359 | |
| 360 | idx = LCTF_TYPE_TO_INDEX (fp, type); |
| 361 | if (idx > 0 && (unsigned long) idx <= fp->ctf_typemax) |
| 362 | { |
| 363 | *fpp = fp; /* Function returns ending CTF dict. */ |
| 364 | return (LCTF_INDEX_TO_TYPEPTR (fp, idx)); |
| 365 | } |
| 366 | |
| 367 | (void) ctf_set_errno (*fpp, ECTF_BADID); |
| 368 | return NULL; |
| 369 | } |
| 370 | |
| 371 | typedef struct ctf_lookup_idx_key |
| 372 | { |
| 373 | ctf_dict_t *clik_fp; |
| 374 | const char *clik_name; |
| 375 | uint32_t *clik_names; |
| 376 | } ctf_lookup_idx_key_t; |
| 377 | |
| 378 | /* A bsearch function for variable names. */ |
| 379 | |
| 380 | static int |
| 381 | ctf_lookup_var (const void *key_, const void *lookup_) |
| 382 | { |
| 383 | const ctf_lookup_idx_key_t *key = key_; |
| 384 | const ctf_varent_t *lookup = lookup_; |
| 385 | |
| 386 | return (strcmp (key->clik_name, ctf_strptr (key->clik_fp, lookup->ctv_name))); |
| 387 | } |
| 388 | |
| 389 | /* Given a variable name, return the type of the variable with that name. */ |
| 390 | |
| 391 | ctf_id_t |
| 392 | ctf_lookup_variable (ctf_dict_t *fp, const char *name) |
| 393 | { |
| 394 | ctf_varent_t *ent; |
| 395 | ctf_lookup_idx_key_t key = { fp, name, NULL }; |
| 396 | |
| 397 | /* This array is sorted, so we can bsearch for it. */ |
| 398 | |
| 399 | ent = bsearch (&key, fp->ctf_vars, fp->ctf_nvars, sizeof (ctf_varent_t), |
| 400 | ctf_lookup_var); |
| 401 | |
| 402 | if (ent == NULL) |
| 403 | { |
| 404 | if (fp->ctf_parent != NULL) |
| 405 | return ctf_lookup_variable (fp->ctf_parent, name); |
| 406 | |
| 407 | return (ctf_set_errno (fp, ECTF_NOTYPEDAT)); |
| 408 | } |
| 409 | |
| 410 | return ent->ctv_type; |
| 411 | } |
| 412 | |
| 413 | typedef struct ctf_symidx_sort_arg_cb |
| 414 | { |
| 415 | ctf_dict_t *fp; |
| 416 | uint32_t *names; |
| 417 | } ctf_symidx_sort_arg_cb_t; |
| 418 | |
| 419 | static int |
| 420 | sort_symidx_by_name (const void *one_, const void *two_, void *arg_) |
| 421 | { |
| 422 | const uint32_t *one = one_; |
| 423 | const uint32_t *two = two_; |
| 424 | ctf_symidx_sort_arg_cb_t *arg = arg_; |
| 425 | |
| 426 | return (strcmp (ctf_strptr (arg->fp, arg->names[*one]), |
| 427 | ctf_strptr (arg->fp, arg->names[*two]))); |
| 428 | } |
| 429 | |
| 430 | /* Sort a symbol index section by name. Takes a 1:1 mapping of names to the |
| 431 | corresponding symbol table. Returns a lexicographically sorted array of idx |
| 432 | indexes (and thus, of indexes into the corresponding func info / data object |
| 433 | section). */ |
| 434 | |
| 435 | static uint32_t * |
| 436 | ctf_symidx_sort (ctf_dict_t *fp, uint32_t *idx, size_t *nidx, |
| 437 | size_t len) |
| 438 | { |
| 439 | uint32_t *sorted; |
| 440 | size_t i; |
| 441 | |
| 442 | if ((sorted = malloc (len)) == NULL) |
| 443 | { |
| 444 | ctf_set_errno (fp, ENOMEM); |
| 445 | return NULL; |
| 446 | } |
| 447 | |
| 448 | *nidx = len / sizeof (uint32_t); |
| 449 | for (i = 0; i < *nidx; i++) |
| 450 | sorted[i] = i; |
| 451 | |
| 452 | if (!(fp->ctf_header->cth_flags & CTF_F_IDXSORTED)) |
| 453 | { |
| 454 | ctf_symidx_sort_arg_cb_t arg = { fp, idx }; |
| 455 | ctf_dprintf ("Index section unsorted: sorting."); |
| 456 | ctf_qsort_r (sorted, *nidx, sizeof (uint32_t), sort_symidx_by_name, &arg); |
| 457 | fp->ctf_header->cth_flags |= CTF_F_IDXSORTED; |
| 458 | } |
| 459 | |
| 460 | return sorted; |
| 461 | } |
| 462 | |
| 463 | /* Given a symbol index, return the name of that symbol from the table provided |
| 464 | by ctf_link_shuffle_syms, or failing that from the secondary string table, or |
| 465 | the null string. */ |
| 466 | static const char * |
| 467 | ctf_lookup_symbol_name (ctf_dict_t *fp, unsigned long symidx) |
| 468 | { |
| 469 | const ctf_sect_t *sp = &fp->ctf_symtab; |
| 470 | ctf_link_sym_t sym; |
| 471 | int err; |
| 472 | |
| 473 | if (fp->ctf_dynsymidx) |
| 474 | { |
| 475 | err = EINVAL; |
| 476 | if (symidx > fp->ctf_dynsymmax) |
| 477 | goto try_parent; |
| 478 | |
| 479 | ctf_link_sym_t *symp = fp->ctf_dynsymidx[symidx]; |
| 480 | |
| 481 | if (!symp) |
| 482 | goto try_parent; |
| 483 | |
| 484 | return symp->st_name; |
| 485 | } |
| 486 | |
| 487 | err = ECTF_NOSYMTAB; |
| 488 | if (sp->cts_data == NULL) |
| 489 | goto try_parent; |
| 490 | |
| 491 | if (symidx >= fp->ctf_nsyms) |
| 492 | goto try_parent; |
| 493 | |
| 494 | switch (sp->cts_entsize) |
| 495 | { |
| 496 | case sizeof (Elf64_Sym): |
| 497 | { |
| 498 | const Elf64_Sym *symp = (Elf64_Sym *) sp->cts_data + symidx; |
| 499 | ctf_elf64_to_link_sym (fp, &sym, symp, symidx); |
| 500 | } |
| 501 | break; |
| 502 | case sizeof (Elf32_Sym): |
| 503 | { |
| 504 | const Elf32_Sym *symp = (Elf32_Sym *) sp->cts_data + symidx; |
| 505 | ctf_elf32_to_link_sym (fp, &sym, symp, symidx); |
| 506 | } |
| 507 | break; |
| 508 | default: |
| 509 | ctf_set_errno (fp, ECTF_SYMTAB); |
| 510 | return _CTF_NULLSTR; |
| 511 | } |
| 512 | |
| 513 | assert (!sym.st_nameidx_set); |
| 514 | |
| 515 | return sym.st_name; |
| 516 | |
| 517 | try_parent: |
| 518 | if (fp->ctf_parent) |
| 519 | { |
| 520 | const char *ret; |
| 521 | ret = ctf_lookup_symbol_name (fp->ctf_parent, symidx); |
| 522 | if (ret == NULL) |
| 523 | ctf_set_errno (fp, ctf_errno (fp->ctf_parent)); |
| 524 | return ret; |
| 525 | } |
| 526 | else |
| 527 | { |
| 528 | ctf_set_errno (fp, err); |
| 529 | return _CTF_NULLSTR; |
| 530 | } |
| 531 | } |
| 532 | |
| 533 | /* Given a symbol name, return the index of that symbol, or -1 on error or if |
| 534 | not found. */ |
| 535 | static unsigned long |
| 536 | ctf_lookup_symbol_idx (ctf_dict_t *fp, const char *symname) |
| 537 | { |
| 538 | const ctf_sect_t *sp = &fp->ctf_symtab; |
| 539 | ctf_link_sym_t sym; |
| 540 | void *known_idx; |
| 541 | int err; |
| 542 | ctf_dict_t *cache = fp; |
| 543 | |
| 544 | if (fp->ctf_dynsyms) |
| 545 | { |
| 546 | err = EINVAL; |
| 547 | |
| 548 | ctf_link_sym_t *symp; |
| 549 | |
| 550 | if ((symp = ctf_dynhash_lookup (fp->ctf_dynsyms, symname)) == NULL) |
| 551 | goto try_parent; |
| 552 | |
| 553 | return symp->st_symidx; |
| 554 | } |
| 555 | |
| 556 | err = ECTF_NOSYMTAB; |
| 557 | if (sp->cts_data == NULL) |
| 558 | goto try_parent; |
| 559 | |
| 560 | /* First, try a hash lookup to see if we have already spotted this symbol |
| 561 | during a past iteration: create the hash first if need be. The lifespan |
| 562 | of the strings is equal to the lifespan of the cts_data, so we don't |
| 563 | need to strdup them. If this dict was opened as part of an archive, |
| 564 | and this archive has designed a crossdict_cache to cache results that |
| 565 | are the same across all dicts in an archive, use it. */ |
| 566 | |
| 567 | if (fp->ctf_archive && fp->ctf_archive->ctfi_crossdict_cache) |
| 568 | cache = fp->ctf_archive->ctfi_crossdict_cache; |
| 569 | |
| 570 | if (!cache->ctf_symhash) |
| 571 | if ((cache->ctf_symhash = ctf_dynhash_create (ctf_hash_string, |
| 572 | ctf_hash_eq_string, |
| 573 | NULL, NULL)) == NULL) |
| 574 | goto oom; |
| 575 | |
| 576 | if (ctf_dynhash_lookup_kv (cache->ctf_symhash, symname, NULL, &known_idx)) |
| 577 | return (unsigned long) (uintptr_t) known_idx; |
| 578 | |
| 579 | /* Hash lookup unsuccessful: linear search, populating the hashtab for later |
| 580 | lookups as we go. */ |
| 581 | |
| 582 | for (; cache->ctf_symhash_latest < sp->cts_size / sp->cts_entsize; |
| 583 | cache->ctf_symhash_latest++) |
| 584 | { |
| 585 | switch (sp->cts_entsize) |
| 586 | { |
| 587 | case sizeof (Elf64_Sym): |
| 588 | { |
| 589 | Elf64_Sym *symp = (Elf64_Sym *) sp->cts_data; |
| 590 | ctf_elf64_to_link_sym (fp, &sym, &symp[cache->ctf_symhash_latest], |
| 591 | cache->ctf_symhash_latest); |
| 592 | if (!ctf_dynhash_lookup_kv (cache->ctf_symhash, sym.st_name, |
| 593 | NULL, NULL)) |
| 594 | if (ctf_dynhash_cinsert (cache->ctf_symhash, sym.st_name, |
| 595 | (const void *) (uintptr_t) |
| 596 | cache->ctf_symhash_latest) < 0) |
| 597 | goto oom; |
| 598 | if (strcmp (sym.st_name, symname) == 0) |
| 599 | return cache->ctf_symhash_latest++; |
| 600 | } |
| 601 | break; |
| 602 | case sizeof (Elf32_Sym): |
| 603 | { |
| 604 | Elf32_Sym *symp = (Elf32_Sym *) sp->cts_data; |
| 605 | ctf_elf32_to_link_sym (fp, &sym, &symp[cache->ctf_symhash_latest], |
| 606 | cache->ctf_symhash_latest); |
| 607 | if (!ctf_dynhash_lookup_kv (cache->ctf_symhash, sym.st_name, |
| 608 | NULL, NULL)) |
| 609 | if (ctf_dynhash_cinsert (cache->ctf_symhash, sym.st_name, |
| 610 | (const void *) (uintptr_t) |
| 611 | cache->ctf_symhash_latest) < 0) |
| 612 | goto oom; |
| 613 | if (strcmp (sym.st_name, symname) == 0) |
| 614 | return cache->ctf_symhash_latest++; |
| 615 | } |
| 616 | break; |
| 617 | default: |
| 618 | ctf_set_errno (fp, ECTF_SYMTAB); |
| 619 | return (unsigned long) -1; |
| 620 | } |
| 621 | } |
| 622 | |
| 623 | /* Searched everything, still not found. */ |
| 624 | |
| 625 | return (unsigned long) -1; |
| 626 | |
| 627 | try_parent: |
| 628 | if (fp->ctf_parent) |
| 629 | return ctf_lookup_symbol_idx (fp->ctf_parent, symname); |
| 630 | else |
| 631 | { |
| 632 | ctf_set_errno (fp, err); |
| 633 | return (unsigned long) -1; |
| 634 | } |
| 635 | oom: |
| 636 | ctf_set_errno (fp, ENOMEM); |
| 637 | ctf_err_warn (fp, 0, ENOMEM, _("cannot allocate memory for symbol " |
| 638 | "lookup hashtab")); |
| 639 | return (unsigned long) -1; |
| 640 | |
| 641 | } |
| 642 | |
| 643 | /* Iterate over all symbols with types: if FUNC, function symbols, otherwise, |
| 644 | data symbols. The name argument is not optional. The return order is |
| 645 | arbitrary, though is likely to be in symbol index or name order. You can |
| 646 | change the value of 'functions' in the middle of iteration over non-dynamic |
| 647 | dicts, but doing so on dynamic dicts will fail. (This is probably not very |
| 648 | useful, but there is no reason to prohibit it.) */ |
| 649 | |
| 650 | ctf_id_t |
| 651 | ctf_symbol_next (ctf_dict_t *fp, ctf_next_t **it, const char **name, |
| 652 | int functions) |
| 653 | { |
| 654 | ctf_id_t sym; |
| 655 | ctf_next_t *i = *it; |
| 656 | int err; |
| 657 | |
| 658 | if (!i) |
| 659 | { |
| 660 | if ((i = ctf_next_create ()) == NULL) |
| 661 | return ctf_set_errno (fp, ENOMEM); |
| 662 | |
| 663 | i->cu.ctn_fp = fp; |
| 664 | i->ctn_iter_fun = (void (*) (void)) ctf_symbol_next; |
| 665 | i->ctn_n = 0; |
| 666 | *it = i; |
| 667 | } |
| 668 | |
| 669 | if ((void (*) (void)) ctf_symbol_next != i->ctn_iter_fun) |
| 670 | return (ctf_set_errno (fp, ECTF_NEXT_WRONGFUN)); |
| 671 | |
| 672 | if (fp != i->cu.ctn_fp) |
| 673 | return (ctf_set_errno (fp, ECTF_NEXT_WRONGFP)); |
| 674 | |
| 675 | /* We intentionally use raw access, not ctf_lookup_by_symbol, to avoid |
| 676 | incurring additional sorting cost for unsorted symtypetabs coming from the |
| 677 | compiler, to allow ctf_symbol_next to work in the absence of a symtab, and |
| 678 | finally because it's easier to work out what the name of each symbol is if |
| 679 | we do that. */ |
| 680 | |
| 681 | if (fp->ctf_flags & LCTF_RDWR) |
| 682 | { |
| 683 | ctf_dynhash_t *dynh = functions ? fp->ctf_funchash : fp->ctf_objthash; |
| 684 | void *dyn_name = NULL, *dyn_value = NULL; |
| 685 | |
| 686 | if (!dynh) |
| 687 | { |
| 688 | ctf_next_destroy (i); |
| 689 | return (ctf_set_errno (fp, ECTF_NEXT_END)); |
| 690 | } |
| 691 | |
| 692 | err = ctf_dynhash_next (dynh, &i->ctn_next, &dyn_name, &dyn_value); |
| 693 | /* This covers errors and also end-of-iteration. */ |
| 694 | if (err != 0) |
| 695 | { |
| 696 | ctf_next_destroy (i); |
| 697 | *it = NULL; |
| 698 | return ctf_set_errno (fp, err); |
| 699 | } |
| 700 | |
| 701 | *name = dyn_name; |
| 702 | sym = (ctf_id_t) (uintptr_t) dyn_value; |
| 703 | } |
| 704 | else if ((!functions && fp->ctf_objtidx_names) || |
| 705 | (functions && fp->ctf_funcidx_names)) |
| 706 | { |
| 707 | ctf_header_t *hp = fp->ctf_header; |
| 708 | uint32_t *idx = functions ? fp->ctf_funcidx_names : fp->ctf_objtidx_names; |
| 709 | uint32_t *tab; |
| 710 | size_t len; |
| 711 | |
| 712 | if (functions) |
| 713 | { |
| 714 | len = (hp->cth_varoff - hp->cth_funcidxoff) / sizeof (uint32_t); |
| 715 | tab = (uint32_t *) (fp->ctf_buf + hp->cth_funcoff); |
| 716 | } |
| 717 | else |
| 718 | { |
| 719 | len = (hp->cth_funcidxoff - hp->cth_objtidxoff) / sizeof (uint32_t); |
| 720 | tab = (uint32_t *) (fp->ctf_buf + hp->cth_objtoff); |
| 721 | } |
| 722 | |
| 723 | do |
| 724 | { |
| 725 | if (i->ctn_n >= len) |
| 726 | goto end; |
| 727 | |
| 728 | *name = ctf_strptr (fp, idx[i->ctn_n]); |
| 729 | sym = tab[i->ctn_n++]; |
| 730 | } |
| 731 | while (sym == -1u || sym == 0); |
| 732 | } |
| 733 | else |
| 734 | { |
| 735 | /* Skip over pads in ctf_xslate, padding for typeless symbols in the |
| 736 | symtypetab itself, and symbols in the wrong table. */ |
| 737 | for (; i->ctn_n < fp->ctf_nsyms; i->ctn_n++) |
| 738 | { |
| 739 | ctf_header_t *hp = fp->ctf_header; |
| 740 | |
| 741 | if (fp->ctf_sxlate[i->ctn_n] == -1u) |
| 742 | continue; |
| 743 | |
| 744 | sym = *(uint32_t *) ((uintptr_t) fp->ctf_buf + fp->ctf_sxlate[i->ctn_n]); |
| 745 | |
| 746 | if (sym == 0) |
| 747 | continue; |
| 748 | |
| 749 | if (functions) |
| 750 | { |
| 751 | if (fp->ctf_sxlate[i->ctn_n] >= hp->cth_funcoff |
| 752 | && fp->ctf_sxlate[i->ctn_n] < hp->cth_objtidxoff) |
| 753 | break; |
| 754 | } |
| 755 | else |
| 756 | { |
| 757 | if (fp->ctf_sxlate[i->ctn_n] >= hp->cth_objtoff |
| 758 | && fp->ctf_sxlate[i->ctn_n] < hp->cth_funcoff) |
| 759 | break; |
| 760 | } |
| 761 | } |
| 762 | |
| 763 | if (i->ctn_n >= fp->ctf_nsyms) |
| 764 | goto end; |
| 765 | |
| 766 | *name = ctf_lookup_symbol_name (fp, i->ctn_n++); |
| 767 | } |
| 768 | |
| 769 | return sym; |
| 770 | |
| 771 | end: |
| 772 | ctf_next_destroy (i); |
| 773 | *it = NULL; |
| 774 | return (ctf_set_errno (fp, ECTF_NEXT_END)); |
| 775 | } |
| 776 | |
| 777 | /* A bsearch function for function and object index names. */ |
| 778 | |
| 779 | static int |
| 780 | ctf_lookup_idx_name (const void *key_, const void *idx_) |
| 781 | { |
| 782 | const ctf_lookup_idx_key_t *key = key_; |
| 783 | const uint32_t *idx = idx_; |
| 784 | |
| 785 | return (strcmp (key->clik_name, ctf_strptr (key->clik_fp, key->clik_names[*idx]))); |
| 786 | } |
| 787 | |
| 788 | /* Given a symbol name or (failing that) number, look up that symbol in the |
| 789 | function or object index table (which must exist). Return 0 if not found |
| 790 | there (or pad). */ |
| 791 | |
| 792 | static ctf_id_t |
| 793 | ctf_try_lookup_indexed (ctf_dict_t *fp, unsigned long symidx, |
| 794 | const char *symname, int is_function) |
| 795 | { |
| 796 | struct ctf_header *hp = fp->ctf_header; |
| 797 | uint32_t *symtypetab; |
| 798 | uint32_t *names; |
| 799 | uint32_t *sxlate; |
| 800 | size_t nidx; |
| 801 | |
| 802 | if (symname == NULL) |
| 803 | symname = ctf_lookup_symbol_name (fp, symidx); |
| 804 | |
| 805 | ctf_dprintf ("Looking up type of object with symtab idx %lx or name %s in " |
| 806 | "indexed symtypetab\n", symidx, symname); |
| 807 | |
| 808 | if (symname[0] == '\0') |
| 809 | return -1; /* errno is set for us. */ |
| 810 | |
| 811 | if (is_function) |
| 812 | { |
| 813 | if (!fp->ctf_funcidx_sxlate) |
| 814 | { |
| 815 | if ((fp->ctf_funcidx_sxlate |
| 816 | = ctf_symidx_sort (fp, (uint32_t *) |
| 817 | (fp->ctf_buf + hp->cth_funcidxoff), |
| 818 | &fp->ctf_nfuncidx, |
| 819 | hp->cth_varoff - hp->cth_funcidxoff)) |
| 820 | == NULL) |
| 821 | { |
| 822 | ctf_err_warn (fp, 0, 0, _("cannot sort function symidx")); |
| 823 | return -1; /* errno is set for us. */ |
| 824 | } |
| 825 | } |
| 826 | symtypetab = (uint32_t *) (fp->ctf_buf + hp->cth_funcoff); |
| 827 | sxlate = fp->ctf_funcidx_sxlate; |
| 828 | names = fp->ctf_funcidx_names; |
| 829 | nidx = fp->ctf_nfuncidx; |
| 830 | } |
| 831 | else |
| 832 | { |
| 833 | if (!fp->ctf_objtidx_sxlate) |
| 834 | { |
| 835 | if ((fp->ctf_objtidx_sxlate |
| 836 | = ctf_symidx_sort (fp, (uint32_t *) |
| 837 | (fp->ctf_buf + hp->cth_objtidxoff), |
| 838 | &fp->ctf_nobjtidx, |
| 839 | hp->cth_funcidxoff - hp->cth_objtidxoff)) |
| 840 | == NULL) |
| 841 | { |
| 842 | ctf_err_warn (fp, 0, 0, _("cannot sort object symidx")); |
| 843 | return -1; /* errno is set for us. */ |
| 844 | } |
| 845 | } |
| 846 | |
| 847 | symtypetab = (uint32_t *) (fp->ctf_buf + hp->cth_objtoff); |
| 848 | sxlate = fp->ctf_objtidx_sxlate; |
| 849 | names = fp->ctf_objtidx_names; |
| 850 | nidx = fp->ctf_nobjtidx; |
| 851 | } |
| 852 | |
| 853 | ctf_lookup_idx_key_t key = { fp, symname, names }; |
| 854 | uint32_t *idx; |
| 855 | |
| 856 | idx = bsearch (&key, sxlate, nidx, sizeof (uint32_t), ctf_lookup_idx_name); |
| 857 | |
| 858 | if (!idx) |
| 859 | { |
| 860 | ctf_dprintf ("%s not found in idx\n", symname); |
| 861 | return 0; |
| 862 | } |
| 863 | |
| 864 | /* Should be impossible, but be paranoid. */ |
| 865 | if ((idx - sxlate) > (ptrdiff_t) nidx) |
| 866 | return (ctf_set_errno (fp, ECTF_CORRUPT)); |
| 867 | |
| 868 | ctf_dprintf ("Symbol %lx (%s) is of type %x\n", symidx, symname, |
| 869 | symtypetab[*idx]); |
| 870 | return symtypetab[*idx]; |
| 871 | } |
| 872 | |
| 873 | /* Given a symbol name or (if NULL) symbol index, return the type of the |
| 874 | function or data object described by the corresponding entry in the symbol |
| 875 | table. We can only return symbols in read-only dicts and in dicts for which |
| 876 | ctf_link_shuffle_syms has been called to assign symbol indexes to symbol |
| 877 | names. */ |
| 878 | |
| 879 | static ctf_id_t |
| 880 | ctf_lookup_by_sym_or_name (ctf_dict_t *fp, unsigned long symidx, |
| 881 | const char *symname) |
| 882 | { |
| 883 | const ctf_sect_t *sp = &fp->ctf_symtab; |
| 884 | ctf_id_t type = 0; |
| 885 | int err = 0; |
| 886 | |
| 887 | /* Shuffled dynsymidx present? Use that. */ |
| 888 | if (fp->ctf_dynsymidx) |
| 889 | { |
| 890 | const ctf_link_sym_t *sym; |
| 891 | |
| 892 | if (symname) |
| 893 | ctf_dprintf ("Looking up type of object with symname %s in " |
| 894 | "writable dict symtypetab\n", symname); |
| 895 | else |
| 896 | ctf_dprintf ("Looking up type of object with symtab idx %lx in " |
| 897 | "writable dict symtypetab\n", symidx); |
| 898 | |
| 899 | /* The dict must be dynamic. */ |
| 900 | if (!ctf_assert (fp, fp->ctf_flags & LCTF_RDWR)) |
| 901 | return CTF_ERR; |
| 902 | |
| 903 | /* No name? Need to look it up. */ |
| 904 | if (!symname) |
| 905 | { |
| 906 | err = EINVAL; |
| 907 | if (symidx > fp->ctf_dynsymmax) |
| 908 | goto try_parent; |
| 909 | |
| 910 | sym = fp->ctf_dynsymidx[symidx]; |
| 911 | err = ECTF_NOTYPEDAT; |
| 912 | if (!sym || (sym->st_shndx != STT_OBJECT && sym->st_shndx != STT_FUNC)) |
| 913 | goto try_parent; |
| 914 | |
| 915 | if (!ctf_assert (fp, !sym->st_nameidx_set)) |
| 916 | return CTF_ERR; |
| 917 | symname = sym->st_name; |
| 918 | } |
| 919 | |
| 920 | if (fp->ctf_objthash == NULL |
| 921 | || ((type = (ctf_id_t) (uintptr_t) |
| 922 | ctf_dynhash_lookup (fp->ctf_objthash, symname)) == 0)) |
| 923 | { |
| 924 | if (fp->ctf_funchash == NULL |
| 925 | || ((type = (ctf_id_t) (uintptr_t) |
| 926 | ctf_dynhash_lookup (fp->ctf_funchash, symname)) == 0)) |
| 927 | goto try_parent; |
| 928 | } |
| 929 | |
| 930 | return type; |
| 931 | } |
| 932 | |
| 933 | /* Lookup by name in a dynamic dict: just do it directly. */ |
| 934 | if (symname && fp->ctf_flags & LCTF_RDWR) |
| 935 | { |
| 936 | if (fp->ctf_objthash == NULL |
| 937 | || ((type = (ctf_id_t) (uintptr_t) |
| 938 | ctf_dynhash_lookup (fp->ctf_objthash, symname)) == 0)) |
| 939 | { |
| 940 | if (fp->ctf_funchash == NULL |
| 941 | || ((type = (ctf_id_t) (uintptr_t) |
| 942 | ctf_dynhash_lookup (fp->ctf_funchash, symname)) == 0)) |
| 943 | goto try_parent; |
| 944 | } |
| 945 | return type; |
| 946 | } |
| 947 | |
| 948 | err = ECTF_NOSYMTAB; |
| 949 | if (sp->cts_data == NULL) |
| 950 | goto try_parent; |
| 951 | |
| 952 | /* This covers both out-of-range lookups and a dynamic dict which hasn't been |
| 953 | shuffled yet. */ |
| 954 | err = EINVAL; |
| 955 | if (symname == NULL && symidx >= fp->ctf_nsyms) |
| 956 | goto try_parent; |
| 957 | |
| 958 | if (fp->ctf_objtidx_names) |
| 959 | { |
| 960 | if ((type = ctf_try_lookup_indexed (fp, symidx, symname, 0)) == CTF_ERR) |
| 961 | return CTF_ERR; /* errno is set for us. */ |
| 962 | } |
| 963 | if (type == 0 && fp->ctf_funcidx_names) |
| 964 | { |
| 965 | if ((type = ctf_try_lookup_indexed (fp, symidx, symname, 1)) == CTF_ERR) |
| 966 | return CTF_ERR; /* errno is set for us. */ |
| 967 | } |
| 968 | if (type != 0) |
| 969 | return type; |
| 970 | |
| 971 | err = ECTF_NOTYPEDAT; |
| 972 | if (fp->ctf_objtidx_names && fp->ctf_funcidx_names) |
| 973 | goto try_parent; |
| 974 | |
| 975 | /* Table must be nonindexed. */ |
| 976 | |
| 977 | ctf_dprintf ("Looking up object type %lx in 1:1 dict symtypetab\n", symidx); |
| 978 | |
| 979 | if (symname != NULL) |
| 980 | if ((symidx = ctf_lookup_symbol_idx (fp, symname)) == (unsigned long) -1) |
| 981 | goto try_parent; |
| 982 | |
| 983 | if (fp->ctf_sxlate[symidx] == -1u) |
| 984 | goto try_parent; |
| 985 | |
| 986 | type = *(uint32_t *) ((uintptr_t) fp->ctf_buf + fp->ctf_sxlate[symidx]); |
| 987 | |
| 988 | if (type == 0) |
| 989 | goto try_parent; |
| 990 | |
| 991 | return type; |
| 992 | try_parent: |
| 993 | if (fp->ctf_parent) |
| 994 | { |
| 995 | ctf_id_t ret = ctf_lookup_by_sym_or_name (fp->ctf_parent, symidx, |
| 996 | symname); |
| 997 | if (ret == CTF_ERR) |
| 998 | ctf_set_errno (fp, ctf_errno (fp->ctf_parent)); |
| 999 | return ret; |
| 1000 | } |
| 1001 | else |
| 1002 | return (ctf_set_errno (fp, err)); |
| 1003 | } |
| 1004 | |
| 1005 | /* Given a symbol table index, return the type of the function or data object |
| 1006 | described by the corresponding entry in the symbol table. */ |
| 1007 | ctf_id_t |
| 1008 | ctf_lookup_by_symbol (ctf_dict_t *fp, unsigned long symidx) |
| 1009 | { |
| 1010 | return ctf_lookup_by_sym_or_name (fp, symidx, NULL); |
| 1011 | } |
| 1012 | |
| 1013 | /* Given a symbol name, return the type of the function or data object described |
| 1014 | by the corresponding entry in the symbol table. */ |
| 1015 | ctf_id_t |
| 1016 | ctf_lookup_by_symbol_name (ctf_dict_t *fp, const char *symname) |
| 1017 | { |
| 1018 | return ctf_lookup_by_sym_or_name (fp, 0, symname); |
| 1019 | } |
| 1020 | |
| 1021 | /* Given a symbol table index, return the info for the function described |
| 1022 | by the corresponding entry in the symbol table, which may be a function |
| 1023 | symbol or may be a data symbol that happens to be a function pointer. */ |
| 1024 | |
| 1025 | int |
| 1026 | ctf_func_info (ctf_dict_t *fp, unsigned long symidx, ctf_funcinfo_t *fip) |
| 1027 | { |
| 1028 | ctf_id_t type; |
| 1029 | |
| 1030 | if ((type = ctf_lookup_by_symbol (fp, symidx)) == CTF_ERR) |
| 1031 | return -1; /* errno is set for us. */ |
| 1032 | |
| 1033 | if (ctf_type_kind (fp, type) != CTF_K_FUNCTION) |
| 1034 | return (ctf_set_errno (fp, ECTF_NOTFUNC)); |
| 1035 | |
| 1036 | return ctf_func_type_info (fp, type, fip); |
| 1037 | } |
| 1038 | |
| 1039 | /* Given a symbol table index, return the arguments for the function described |
| 1040 | by the corresponding entry in the symbol table. */ |
| 1041 | |
| 1042 | int |
| 1043 | ctf_func_args (ctf_dict_t *fp, unsigned long symidx, uint32_t argc, |
| 1044 | ctf_id_t *argv) |
| 1045 | { |
| 1046 | ctf_id_t type; |
| 1047 | |
| 1048 | if ((type = ctf_lookup_by_symbol (fp, symidx)) == CTF_ERR) |
| 1049 | return -1; /* errno is set for us. */ |
| 1050 | |
| 1051 | if (ctf_type_kind (fp, type) != CTF_K_FUNCTION) |
| 1052 | return (ctf_set_errno (fp, ECTF_NOTFUNC)); |
| 1053 | |
| 1054 | return ctf_func_type_args (fp, type, argc, argv); |
| 1055 | } |