| 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 = &qhash[h]; |
| 115 | |
| 116 | return (h >= 0 && (size_t) h < sizeof (qhash) / sizeof (qhash[0]) |
| 117 | && (size_t) len == qp->q_len && |
| 118 | strncmp (qp->q_name, s, qp->q_len) == 0); |
| 119 | } |
| 120 | |
| 121 | /* Attempt to convert the given C type name into the corresponding CTF type ID. |
| 122 | It is not possible to do complete and proper conversion of type names |
| 123 | without implementing a more full-fledged parser, which is necessary to |
| 124 | handle things like types that are function pointers to functions that |
| 125 | have arguments that are function pointers, and fun stuff like that. |
| 126 | Instead, this function implements a very simple conversion algorithm that |
| 127 | finds the things that we actually care about: structs, unions, enums, |
| 128 | integers, floats, typedefs, and pointers to any of these named types. */ |
| 129 | |
| 130 | static ctf_id_t |
| 131 | ctf_lookup_by_name_internal (ctf_dict_t *fp, ctf_dict_t *child, |
| 132 | const char *name) |
| 133 | { |
| 134 | static const char delimiters[] = " \t\n\r\v\f*"; |
| 135 | |
| 136 | const ctf_lookup_t *lp; |
| 137 | const char *p, *q, *end; |
| 138 | ctf_id_t type = 0; |
| 139 | ctf_id_t ntype, ptype; |
| 140 | |
| 141 | if (name == NULL) |
| 142 | return (ctf_set_errno (fp, EINVAL)); |
| 143 | |
| 144 | for (p = name, end = name + strlen (name); *p != '\0'; p = q) |
| 145 | { |
| 146 | while (isspace ((int) *p)) |
| 147 | p++; /* Skip leading whitespace. */ |
| 148 | |
| 149 | if (p == end) |
| 150 | break; |
| 151 | |
| 152 | if ((q = strpbrk (p + 1, delimiters)) == NULL) |
| 153 | q = end; /* Compare until end. */ |
| 154 | |
| 155 | if (*p == '*') |
| 156 | { |
| 157 | /* Find a pointer to type by looking in child->ctf_pptrtab (if child |
| 158 | is set) and fp->ctf_ptrtab. If we can't find a pointer to the |
| 159 | given type, see if we can compute a pointer to the type resulting |
| 160 | from resolving the type down to its base type and use that instead. |
| 161 | This helps with cases where the CTF data includes "struct foo *" |
| 162 | but not "foo_t *" and the user tries to access "foo_t *" in the |
| 163 | debugger. |
| 164 | |
| 165 | There is extra complexity here because uninitialized elements in |
| 166 | the pptrtab and ptrtab are set to zero, but zero (as the type ID |
| 167 | meaning the unimplemented type) is a valid return type from |
| 168 | ctf_lookup_by_name. (Pointers to types are never of type 0, so |
| 169 | this is unambiguous, just fiddly to deal with.) */ |
| 170 | |
| 171 | uint32_t idx = LCTF_TYPE_TO_INDEX (fp, type); |
| 172 | int in_child = 0; |
| 173 | |
| 174 | ntype = CTF_ERR; |
| 175 | if (child && idx <= child->ctf_pptrtab_len) |
| 176 | { |
| 177 | ntype = child->ctf_pptrtab[idx]; |
| 178 | if (ntype) |
| 179 | in_child = 1; |
| 180 | else |
| 181 | ntype = CTF_ERR; |
| 182 | } |
| 183 | |
| 184 | if (ntype == CTF_ERR) |
| 185 | { |
| 186 | ntype = fp->ctf_ptrtab[idx]; |
| 187 | if (ntype == 0) |
| 188 | ntype = CTF_ERR; |
| 189 | } |
| 190 | |
| 191 | /* Try resolving to its base type and check again. */ |
| 192 | if (ntype == CTF_ERR) |
| 193 | { |
| 194 | if (child) |
| 195 | ntype = ctf_type_resolve_unsliced (child, type); |
| 196 | else |
| 197 | ntype = ctf_type_resolve_unsliced (fp, type); |
| 198 | |
| 199 | if (ntype == CTF_ERR) |
| 200 | goto notype; |
| 201 | |
| 202 | idx = LCTF_TYPE_TO_INDEX (fp, ntype); |
| 203 | |
| 204 | ntype = CTF_ERR; |
| 205 | if (child && idx <= child->ctf_pptrtab_len) |
| 206 | { |
| 207 | ntype = child->ctf_pptrtab[idx]; |
| 208 | if (ntype) |
| 209 | in_child = 1; |
| 210 | else |
| 211 | ntype = CTF_ERR; |
| 212 | } |
| 213 | |
| 214 | if (ntype == CTF_ERR) |
| 215 | { |
| 216 | ntype = fp->ctf_ptrtab[idx]; |
| 217 | if (ntype == 0) |
| 218 | ntype = CTF_ERR; |
| 219 | } |
| 220 | if (ntype == CTF_ERR) |
| 221 | goto notype; |
| 222 | } |
| 223 | |
| 224 | type = LCTF_INDEX_TO_TYPE (fp, ntype, (fp->ctf_flags & LCTF_CHILD) |
| 225 | || in_child); |
| 226 | |
| 227 | /* We are looking up a type in the parent, but the pointed-to type is |
| 228 | in the child. Switch to looking in the child: if we need to go |
| 229 | back into the parent, we can recurse again. */ |
| 230 | if (in_child) |
| 231 | { |
| 232 | fp = child; |
| 233 | child = NULL; |
| 234 | } |
| 235 | |
| 236 | q = p + 1; |
| 237 | continue; |
| 238 | } |
| 239 | |
| 240 | if (isqualifier (p, (size_t) (q - p))) |
| 241 | continue; /* Skip qualifier keyword. */ |
| 242 | |
| 243 | for (lp = fp->ctf_lookups; lp->ctl_prefix != NULL; lp++) |
| 244 | { |
| 245 | /* TODO: This is not MT-safe. */ |
| 246 | if ((lp->ctl_prefix[0] == '\0' || |
| 247 | strncmp (p, lp->ctl_prefix, (size_t) (q - p)) == 0) && |
| 248 | (size_t) (q - p) >= lp->ctl_len) |
| 249 | { |
| 250 | for (p += lp->ctl_len; isspace ((int) *p); p++) |
| 251 | continue; /* Skip prefix and next whitespace. */ |
| 252 | |
| 253 | if ((q = strchr (p, '*')) == NULL) |
| 254 | q = end; /* Compare until end. */ |
| 255 | |
| 256 | while (isspace ((int) q[-1])) |
| 257 | q--; /* Exclude trailing whitespace. */ |
| 258 | |
| 259 | /* Expand and/or allocate storage for a slice of the name, then |
| 260 | copy it in. */ |
| 261 | |
| 262 | if (fp->ctf_tmp_typeslicelen >= (size_t) (q - p) + 1) |
| 263 | { |
| 264 | memcpy (fp->ctf_tmp_typeslice, p, (size_t) (q - p)); |
| 265 | fp->ctf_tmp_typeslice[(size_t) (q - p)] = '\0'; |
| 266 | } |
| 267 | else |
| 268 | { |
| 269 | free (fp->ctf_tmp_typeslice); |
| 270 | fp->ctf_tmp_typeslice = xstrndup (p, (size_t) (q - p)); |
| 271 | if (fp->ctf_tmp_typeslice == NULL) |
| 272 | { |
| 273 | ctf_set_errno (fp, ENOMEM); |
| 274 | return CTF_ERR; |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | if ((type = ctf_lookup_by_rawhash (fp, lp->ctl_hash, |
| 279 | fp->ctf_tmp_typeslice)) == 0) |
| 280 | goto notype; |
| 281 | |
| 282 | break; |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | if (lp->ctl_prefix == NULL) |
| 287 | goto notype; |
| 288 | } |
| 289 | |
| 290 | if (*p != '\0' || type == 0) |
| 291 | return (ctf_set_errno (fp, ECTF_SYNTAX)); |
| 292 | |
| 293 | return type; |
| 294 | |
| 295 | notype: |
| 296 | ctf_set_errno (fp, ECTF_NOTYPE); |
| 297 | if (fp->ctf_parent != NULL) |
| 298 | { |
| 299 | /* Need to look up in the parent, from the child's perspective. |
| 300 | Make sure the pptrtab is up to date. */ |
| 301 | |
| 302 | if (fp->ctf_pptrtab_typemax < fp->ctf_typemax) |
| 303 | { |
| 304 | if (refresh_pptrtab (fp, fp->ctf_parent) < 0) |
| 305 | return -1; /* errno is set for us. */ |
| 306 | } |
| 307 | |
| 308 | if ((ptype = ctf_lookup_by_name_internal (fp->ctf_parent, fp, |
| 309 | name)) != CTF_ERR) |
| 310 | return ptype; |
| 311 | return (ctf_set_errno (fp, ctf_errno (fp->ctf_parent))); |
| 312 | } |
| 313 | |
| 314 | return CTF_ERR; |
| 315 | } |
| 316 | |
| 317 | ctf_id_t |
| 318 | ctf_lookup_by_name (ctf_dict_t *fp, const char *name) |
| 319 | { |
| 320 | return ctf_lookup_by_name_internal (fp, NULL, name); |
| 321 | } |
| 322 | |
| 323 | /* Return the pointer to the internal CTF type data corresponding to the |
| 324 | given type ID. If the ID is invalid, the function returns NULL. |
| 325 | This function is not exported outside of the library. */ |
| 326 | |
| 327 | const ctf_type_t * |
| 328 | ctf_lookup_by_id (ctf_dict_t **fpp, ctf_id_t type) |
| 329 | { |
| 330 | ctf_dict_t *fp = *fpp; /* Caller passes in starting CTF dict. */ |
| 331 | ctf_id_t idx; |
| 332 | |
| 333 | if ((fp = ctf_get_dict (fp, type)) == NULL) |
| 334 | { |
| 335 | (void) ctf_set_errno (*fpp, ECTF_NOPARENT); |
| 336 | return NULL; |
| 337 | } |
| 338 | |
| 339 | /* If this dict is writable, check for a dynamic type. */ |
| 340 | |
| 341 | if (fp->ctf_flags & LCTF_RDWR) |
| 342 | { |
| 343 | ctf_dtdef_t *dtd; |
| 344 | |
| 345 | if ((dtd = ctf_dynamic_type (fp, type)) != NULL) |
| 346 | { |
| 347 | *fpp = fp; |
| 348 | return &dtd->dtd_data; |
| 349 | } |
| 350 | (void) ctf_set_errno (*fpp, ECTF_BADID); |
| 351 | return NULL; |
| 352 | } |
| 353 | |
| 354 | /* Check for a type in the static portion. */ |
| 355 | |
| 356 | idx = LCTF_TYPE_TO_INDEX (fp, type); |
| 357 | if (idx > 0 && (unsigned long) idx <= fp->ctf_typemax) |
| 358 | { |
| 359 | *fpp = fp; /* Function returns ending CTF dict. */ |
| 360 | return (LCTF_INDEX_TO_TYPEPTR (fp, idx)); |
| 361 | } |
| 362 | |
| 363 | (void) ctf_set_errno (*fpp, ECTF_BADID); |
| 364 | return NULL; |
| 365 | } |
| 366 | |
| 367 | typedef struct ctf_lookup_idx_key |
| 368 | { |
| 369 | ctf_dict_t *clik_fp; |
| 370 | const char *clik_name; |
| 371 | uint32_t *clik_names; |
| 372 | } ctf_lookup_idx_key_t; |
| 373 | |
| 374 | /* A bsearch function for variable names. */ |
| 375 | |
| 376 | static int |
| 377 | ctf_lookup_var (const void *key_, const void *lookup_) |
| 378 | { |
| 379 | const ctf_lookup_idx_key_t *key = key_; |
| 380 | const ctf_varent_t *lookup = lookup_; |
| 381 | |
| 382 | return (strcmp (key->clik_name, ctf_strptr (key->clik_fp, lookup->ctv_name))); |
| 383 | } |
| 384 | |
| 385 | /* Given a variable name, return the type of the variable with that name. */ |
| 386 | |
| 387 | ctf_id_t |
| 388 | ctf_lookup_variable (ctf_dict_t *fp, const char *name) |
| 389 | { |
| 390 | ctf_varent_t *ent; |
| 391 | ctf_lookup_idx_key_t key = { fp, name, NULL }; |
| 392 | |
| 393 | /* This array is sorted, so we can bsearch for it. */ |
| 394 | |
| 395 | ent = bsearch (&key, fp->ctf_vars, fp->ctf_nvars, sizeof (ctf_varent_t), |
| 396 | ctf_lookup_var); |
| 397 | |
| 398 | if (ent == NULL) |
| 399 | { |
| 400 | if (fp->ctf_parent != NULL) |
| 401 | return ctf_lookup_variable (fp->ctf_parent, name); |
| 402 | |
| 403 | return (ctf_set_errno (fp, ECTF_NOTYPEDAT)); |
| 404 | } |
| 405 | |
| 406 | return ent->ctv_type; |
| 407 | } |
| 408 | |
| 409 | typedef struct ctf_symidx_sort_arg_cb |
| 410 | { |
| 411 | ctf_dict_t *fp; |
| 412 | uint32_t *names; |
| 413 | } ctf_symidx_sort_arg_cb_t; |
| 414 | |
| 415 | static int |
| 416 | sort_symidx_by_name (const void *one_, const void *two_, void *arg_) |
| 417 | { |
| 418 | const uint32_t *one = one_; |
| 419 | const uint32_t *two = two_; |
| 420 | ctf_symidx_sort_arg_cb_t *arg = arg_; |
| 421 | |
| 422 | return (strcmp (ctf_strptr (arg->fp, arg->names[*one]), |
| 423 | ctf_strptr (arg->fp, arg->names[*two]))); |
| 424 | } |
| 425 | |
| 426 | /* Sort a symbol index section by name. Takes a 1:1 mapping of names to the |
| 427 | corresponding symbol table. Returns a lexicographically sorted array of idx |
| 428 | indexes (and thus, of indexes into the corresponding func info / data object |
| 429 | section). */ |
| 430 | |
| 431 | static uint32_t * |
| 432 | ctf_symidx_sort (ctf_dict_t *fp, uint32_t *idx, size_t *nidx, |
| 433 | size_t len) |
| 434 | { |
| 435 | uint32_t *sorted; |
| 436 | size_t i; |
| 437 | |
| 438 | if ((sorted = malloc (len)) == NULL) |
| 439 | { |
| 440 | ctf_set_errno (fp, ENOMEM); |
| 441 | return NULL; |
| 442 | } |
| 443 | |
| 444 | *nidx = len / sizeof (uint32_t); |
| 445 | for (i = 0; i < *nidx; i++) |
| 446 | sorted[i] = i; |
| 447 | |
| 448 | if (!(fp->ctf_header->cth_flags & CTF_F_IDXSORTED)) |
| 449 | { |
| 450 | ctf_symidx_sort_arg_cb_t arg = { fp, idx }; |
| 451 | ctf_dprintf ("Index section unsorted: sorting."); |
| 452 | ctf_qsort_r (sorted, *nidx, sizeof (uint32_t), sort_symidx_by_name, &arg); |
| 453 | fp->ctf_header->cth_flags |= CTF_F_IDXSORTED; |
| 454 | } |
| 455 | |
| 456 | return sorted; |
| 457 | } |
| 458 | |
| 459 | /* Given a symbol index, return the name of that symbol from the table provided |
| 460 | by ctf_link_shuffle_syms, or failing that from the secondary string table, or |
| 461 | the null string. */ |
| 462 | const char * |
| 463 | ctf_lookup_symbol_name (ctf_dict_t *fp, unsigned long symidx) |
| 464 | { |
| 465 | const ctf_sect_t *sp = &fp->ctf_symtab; |
| 466 | ctf_link_sym_t sym; |
| 467 | int err; |
| 468 | |
| 469 | if (fp->ctf_dynsymidx) |
| 470 | { |
| 471 | err = EINVAL; |
| 472 | if (symidx > fp->ctf_dynsymmax) |
| 473 | goto try_parent; |
| 474 | |
| 475 | ctf_link_sym_t *symp = fp->ctf_dynsymidx[symidx]; |
| 476 | |
| 477 | if (!symp) |
| 478 | goto try_parent; |
| 479 | |
| 480 | return symp->st_name; |
| 481 | } |
| 482 | |
| 483 | err = ECTF_NOSYMTAB; |
| 484 | if (sp->cts_data == NULL) |
| 485 | goto try_parent; |
| 486 | |
| 487 | if (symidx >= fp->ctf_nsyms) |
| 488 | goto try_parent; |
| 489 | |
| 490 | switch (sp->cts_entsize) |
| 491 | { |
| 492 | case sizeof (Elf64_Sym): |
| 493 | { |
| 494 | const Elf64_Sym *symp = (Elf64_Sym *) sp->cts_data + symidx; |
| 495 | ctf_elf64_to_link_sym (fp, &sym, symp, symidx); |
| 496 | } |
| 497 | break; |
| 498 | case sizeof (Elf32_Sym): |
| 499 | { |
| 500 | const Elf32_Sym *symp = (Elf32_Sym *) sp->cts_data + symidx; |
| 501 | ctf_elf32_to_link_sym (fp, &sym, symp, symidx); |
| 502 | } |
| 503 | break; |
| 504 | default: |
| 505 | ctf_set_errno (fp, ECTF_SYMTAB); |
| 506 | return _CTF_NULLSTR; |
| 507 | } |
| 508 | |
| 509 | assert (!sym.st_nameidx_set); |
| 510 | |
| 511 | return sym.st_name; |
| 512 | |
| 513 | try_parent: |
| 514 | if (fp->ctf_parent) |
| 515 | return ctf_lookup_symbol_name (fp->ctf_parent, symidx); |
| 516 | else |
| 517 | { |
| 518 | ctf_set_errno (fp, err); |
| 519 | return _CTF_NULLSTR; |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | /* Iterate over all symbols with types: if FUNC, function symbols, otherwise, |
| 524 | data symbols. The name argument is not optional. The return order is |
| 525 | arbitrary, though is likely to be in symbol index or name order. You can |
| 526 | change the value of 'functions' in the middle of iteration over non-dynamic |
| 527 | dicts, but doing so on dynamic dicts will fail. (This is probably not very |
| 528 | useful, but there is no reason to prohibit it.) */ |
| 529 | |
| 530 | ctf_id_t |
| 531 | ctf_symbol_next (ctf_dict_t *fp, ctf_next_t **it, const char **name, |
| 532 | int functions) |
| 533 | { |
| 534 | ctf_id_t sym; |
| 535 | ctf_next_t *i = *it; |
| 536 | int err; |
| 537 | |
| 538 | if (!i) |
| 539 | { |
| 540 | if ((i = ctf_next_create ()) == NULL) |
| 541 | return ctf_set_errno (fp, ENOMEM); |
| 542 | |
| 543 | i->cu.ctn_fp = fp; |
| 544 | i->ctn_iter_fun = (void (*) (void)) ctf_symbol_next; |
| 545 | i->ctn_n = 0; |
| 546 | *it = i; |
| 547 | } |
| 548 | |
| 549 | if ((void (*) (void)) ctf_symbol_next != i->ctn_iter_fun) |
| 550 | return (ctf_set_errno (fp, ECTF_NEXT_WRONGFUN)); |
| 551 | |
| 552 | if (fp != i->cu.ctn_fp) |
| 553 | return (ctf_set_errno (fp, ECTF_NEXT_WRONGFP)); |
| 554 | |
| 555 | /* We intentionally use raw access, not ctf_lookup_by_symbol, to avoid |
| 556 | incurring additional sorting cost for unsorted symtypetabs coming from the |
| 557 | compiler, to allow ctf_symbol_next to work in the absence of a symtab, and |
| 558 | finally because it's easier to work out what the name of each symbol is if |
| 559 | we do that. */ |
| 560 | |
| 561 | if (fp->ctf_flags & LCTF_RDWR) |
| 562 | { |
| 563 | ctf_dynhash_t *dynh = functions ? fp->ctf_funchash : fp->ctf_objthash; |
| 564 | void *dyn_name = NULL, *dyn_value = NULL; |
| 565 | |
| 566 | if (!dynh) |
| 567 | { |
| 568 | ctf_next_destroy (i); |
| 569 | return (ctf_set_errno (fp, ECTF_NEXT_END)); |
| 570 | } |
| 571 | |
| 572 | err = ctf_dynhash_next (dynh, &i->ctn_next, &dyn_name, &dyn_value); |
| 573 | /* This covers errors and also end-of-iteration. */ |
| 574 | if (err != 0) |
| 575 | { |
| 576 | ctf_next_destroy (i); |
| 577 | *it = NULL; |
| 578 | return ctf_set_errno (fp, err); |
| 579 | } |
| 580 | |
| 581 | *name = dyn_name; |
| 582 | sym = (ctf_id_t) (uintptr_t) dyn_value; |
| 583 | } |
| 584 | else if ((!functions && fp->ctf_objtidx_names) || |
| 585 | (functions && fp->ctf_funcidx_names)) |
| 586 | { |
| 587 | ctf_header_t *hp = fp->ctf_header; |
| 588 | uint32_t *idx = functions ? fp->ctf_funcidx_names : fp->ctf_objtidx_names; |
| 589 | uint32_t *tab; |
| 590 | size_t len; |
| 591 | |
| 592 | if (functions) |
| 593 | { |
| 594 | len = (hp->cth_varoff - hp->cth_funcidxoff) / sizeof (uint32_t); |
| 595 | tab = (uint32_t *) (fp->ctf_buf + hp->cth_funcoff); |
| 596 | } |
| 597 | else |
| 598 | { |
| 599 | len = (hp->cth_funcidxoff - hp->cth_objtidxoff) / sizeof (uint32_t); |
| 600 | tab = (uint32_t *) (fp->ctf_buf + hp->cth_objtoff); |
| 601 | } |
| 602 | |
| 603 | do |
| 604 | { |
| 605 | if (i->ctn_n >= len) |
| 606 | goto end; |
| 607 | |
| 608 | *name = ctf_strptr (fp, idx[i->ctn_n]); |
| 609 | sym = tab[i->ctn_n++]; |
| 610 | } while (sym == -1u || sym == 0); |
| 611 | } |
| 612 | else |
| 613 | { |
| 614 | /* Skip over pads in ctf_xslate, padding for typeless symbols in the |
| 615 | symtypetab itself, and symbols in the wrong table. */ |
| 616 | for (; i->ctn_n < fp->ctf_nsyms; i->ctn_n++) |
| 617 | { |
| 618 | ctf_header_t *hp = fp->ctf_header; |
| 619 | |
| 620 | if (fp->ctf_sxlate[i->ctn_n] == -1u) |
| 621 | continue; |
| 622 | |
| 623 | sym = *(uint32_t *) ((uintptr_t) fp->ctf_buf + fp->ctf_sxlate[i->ctn_n]); |
| 624 | |
| 625 | if (sym == 0) |
| 626 | continue; |
| 627 | |
| 628 | if (functions) |
| 629 | { |
| 630 | if (fp->ctf_sxlate[i->ctn_n] >= hp->cth_funcoff |
| 631 | && fp->ctf_sxlate[i->ctn_n] < hp->cth_objtidxoff) |
| 632 | break; |
| 633 | } |
| 634 | else |
| 635 | { |
| 636 | if (fp->ctf_sxlate[i->ctn_n] >= hp->cth_objtoff |
| 637 | && fp->ctf_sxlate[i->ctn_n] < hp->cth_funcoff) |
| 638 | break; |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | if (i->ctn_n >= fp->ctf_nsyms) |
| 643 | goto end; |
| 644 | |
| 645 | *name = ctf_lookup_symbol_name (fp, i->ctn_n++); |
| 646 | } |
| 647 | |
| 648 | return sym; |
| 649 | |
| 650 | end: |
| 651 | ctf_next_destroy (i); |
| 652 | *it = NULL; |
| 653 | return (ctf_set_errno (fp, ECTF_NEXT_END)); |
| 654 | } |
| 655 | |
| 656 | /* A bsearch function for function and object index names. */ |
| 657 | |
| 658 | static int |
| 659 | ctf_lookup_idx_name (const void *key_, const void *idx_) |
| 660 | { |
| 661 | const ctf_lookup_idx_key_t *key = key_; |
| 662 | const uint32_t *idx = idx_; |
| 663 | |
| 664 | return (strcmp (key->clik_name, ctf_strptr (key->clik_fp, key->clik_names[*idx]))); |
| 665 | } |
| 666 | |
| 667 | /* Given a symbol number, look up that symbol in the function or object |
| 668 | index table (which must exist). Return 0 if not found there (or pad). */ |
| 669 | |
| 670 | static ctf_id_t |
| 671 | ctf_try_lookup_indexed (ctf_dict_t *fp, unsigned long symidx, int is_function) |
| 672 | { |
| 673 | const char *symname = ctf_lookup_symbol_name (fp, symidx); |
| 674 | struct ctf_header *hp = fp->ctf_header; |
| 675 | uint32_t *symtypetab; |
| 676 | uint32_t *names; |
| 677 | uint32_t *sxlate; |
| 678 | size_t nidx; |
| 679 | |
| 680 | ctf_dprintf ("Looking up type of object with symtab idx %lx (%s) in " |
| 681 | "indexed symtypetab\n", symidx, symname); |
| 682 | |
| 683 | if (symname[0] == '\0') |
| 684 | return -1; /* errno is set for us. */ |
| 685 | |
| 686 | if (is_function) |
| 687 | { |
| 688 | if (!fp->ctf_funcidx_sxlate) |
| 689 | { |
| 690 | if ((fp->ctf_funcidx_sxlate |
| 691 | = ctf_symidx_sort (fp, (uint32_t *) |
| 692 | (fp->ctf_buf + hp->cth_funcidxoff), |
| 693 | &fp->ctf_nfuncidx, |
| 694 | hp->cth_varoff - hp->cth_funcidxoff)) |
| 695 | == NULL) |
| 696 | { |
| 697 | ctf_err_warn (fp, 0, 0, _("cannot sort function symidx")); |
| 698 | return -1; /* errno is set for us. */ |
| 699 | } |
| 700 | } |
| 701 | symtypetab = (uint32_t *) (fp->ctf_buf + hp->cth_funcoff); |
| 702 | sxlate = fp->ctf_funcidx_sxlate; |
| 703 | names = fp->ctf_funcidx_names; |
| 704 | nidx = fp->ctf_nfuncidx; |
| 705 | } |
| 706 | else |
| 707 | { |
| 708 | if (!fp->ctf_objtidx_sxlate) |
| 709 | { |
| 710 | if ((fp->ctf_objtidx_sxlate |
| 711 | = ctf_symidx_sort (fp, (uint32_t *) |
| 712 | (fp->ctf_buf + hp->cth_objtidxoff), |
| 713 | &fp->ctf_nobjtidx, |
| 714 | hp->cth_funcidxoff - hp->cth_objtidxoff)) |
| 715 | == NULL) |
| 716 | { |
| 717 | ctf_err_warn (fp, 0, 0, _("cannot sort object symidx")); |
| 718 | return -1; /* errno is set for us. */ |
| 719 | } |
| 720 | } |
| 721 | |
| 722 | symtypetab = (uint32_t *) (fp->ctf_buf + hp->cth_objtoff); |
| 723 | sxlate = fp->ctf_objtidx_sxlate; |
| 724 | names = fp->ctf_objtidx_names; |
| 725 | nidx = fp->ctf_nobjtidx; |
| 726 | } |
| 727 | |
| 728 | ctf_lookup_idx_key_t key = { fp, symname, names }; |
| 729 | uint32_t *idx; |
| 730 | |
| 731 | idx = bsearch (&key, sxlate, nidx, sizeof (uint32_t), ctf_lookup_idx_name); |
| 732 | |
| 733 | if (!idx) |
| 734 | { |
| 735 | ctf_dprintf ("%s not found in idx\n", symname); |
| 736 | return 0; |
| 737 | } |
| 738 | |
| 739 | /* Should be impossible, but be paranoid. */ |
| 740 | if ((idx - sxlate) > (ptrdiff_t) nidx) |
| 741 | return (ctf_set_errno (fp, ECTF_CORRUPT)); |
| 742 | |
| 743 | ctf_dprintf ("Symbol %lx (%s) is of type %x\n", symidx, symname, |
| 744 | symtypetab[*idx]); |
| 745 | return symtypetab[*idx]; |
| 746 | } |
| 747 | |
| 748 | /* Given a symbol table index, return the type of the function or data object |
| 749 | described by the corresponding entry in the symbol table. We can only return |
| 750 | symbols in read-only dicts and in dicts for which ctf_link_shuffle_syms has |
| 751 | been called to assign symbol indexes to symbol names. */ |
| 752 | |
| 753 | ctf_id_t |
| 754 | ctf_lookup_by_symbol (ctf_dict_t *fp, unsigned long symidx) |
| 755 | { |
| 756 | const ctf_sect_t *sp = &fp->ctf_symtab; |
| 757 | ctf_id_t type = 0; |
| 758 | int err = 0; |
| 759 | |
| 760 | /* Shuffled dynsymidx present? Use that. */ |
| 761 | if (fp->ctf_dynsymidx) |
| 762 | { |
| 763 | const ctf_link_sym_t *sym; |
| 764 | |
| 765 | ctf_dprintf ("Looking up type of object with symtab idx %lx in " |
| 766 | "writable dict symtypetab\n", symidx); |
| 767 | |
| 768 | /* The dict must be dynamic. */ |
| 769 | if (!ctf_assert (fp, fp->ctf_flags & LCTF_RDWR)) |
| 770 | return CTF_ERR; |
| 771 | |
| 772 | err = EINVAL; |
| 773 | if (symidx > fp->ctf_dynsymmax) |
| 774 | goto try_parent; |
| 775 | |
| 776 | sym = fp->ctf_dynsymidx[symidx]; |
| 777 | err = ECTF_NOTYPEDAT; |
| 778 | if (!sym || (sym->st_shndx != STT_OBJECT && sym->st_shndx != STT_FUNC)) |
| 779 | goto try_parent; |
| 780 | |
| 781 | if (!ctf_assert (fp, !sym->st_nameidx_set)) |
| 782 | return CTF_ERR; |
| 783 | |
| 784 | if (fp->ctf_objthash == NULL |
| 785 | || ((type = (ctf_id_t) (uintptr_t) |
| 786 | ctf_dynhash_lookup (fp->ctf_objthash, sym->st_name)) == 0)) |
| 787 | { |
| 788 | if (fp->ctf_funchash == NULL |
| 789 | || ((type = (ctf_id_t) (uintptr_t) |
| 790 | ctf_dynhash_lookup (fp->ctf_funchash, sym->st_name)) == 0)) |
| 791 | goto try_parent; |
| 792 | } |
| 793 | |
| 794 | return type; |
| 795 | } |
| 796 | |
| 797 | err = ECTF_NOSYMTAB; |
| 798 | if (sp->cts_data == NULL) |
| 799 | goto try_parent; |
| 800 | |
| 801 | /* This covers both out-of-range lookups and a dynamic dict which hasn't been |
| 802 | shuffled yet. */ |
| 803 | err = EINVAL; |
| 804 | if (symidx >= fp->ctf_nsyms) |
| 805 | goto try_parent; |
| 806 | |
| 807 | if (fp->ctf_objtidx_names) |
| 808 | { |
| 809 | if ((type = ctf_try_lookup_indexed (fp, symidx, 0)) == CTF_ERR) |
| 810 | return CTF_ERR; /* errno is set for us. */ |
| 811 | } |
| 812 | if (type == 0 && fp->ctf_funcidx_names) |
| 813 | { |
| 814 | if ((type = ctf_try_lookup_indexed (fp, symidx, 1)) == CTF_ERR) |
| 815 | return CTF_ERR; /* errno is set for us. */ |
| 816 | } |
| 817 | if (type != 0) |
| 818 | return type; |
| 819 | |
| 820 | err = ECTF_NOTYPEDAT; |
| 821 | if (fp->ctf_objtidx_names && fp->ctf_funcidx_names) |
| 822 | goto try_parent; |
| 823 | |
| 824 | /* Table must be nonindexed. */ |
| 825 | |
| 826 | ctf_dprintf ("Looking up object type %lx in 1:1 dict symtypetab\n", symidx); |
| 827 | |
| 828 | if (fp->ctf_sxlate[symidx] == -1u) |
| 829 | goto try_parent; |
| 830 | |
| 831 | type = *(uint32_t *) ((uintptr_t) fp->ctf_buf + fp->ctf_sxlate[symidx]); |
| 832 | |
| 833 | if (type == 0) |
| 834 | goto try_parent; |
| 835 | |
| 836 | return type; |
| 837 | try_parent: |
| 838 | if (fp->ctf_parent) |
| 839 | return ctf_lookup_by_symbol (fp->ctf_parent, symidx); |
| 840 | else |
| 841 | return (ctf_set_errno (fp, err)); |
| 842 | } |
| 843 | |
| 844 | /* Given a symbol table index, return the info for the function described |
| 845 | by the corresponding entry in the symbol table, which may be a function |
| 846 | symbol or may be a data symbol that happens to be a function pointer. */ |
| 847 | |
| 848 | int |
| 849 | ctf_func_info (ctf_dict_t *fp, unsigned long symidx, ctf_funcinfo_t *fip) |
| 850 | { |
| 851 | ctf_id_t type; |
| 852 | |
| 853 | if ((type = ctf_lookup_by_symbol (fp, symidx)) == CTF_ERR) |
| 854 | return -1; /* errno is set for us. */ |
| 855 | |
| 856 | if (ctf_type_kind (fp, type) != CTF_K_FUNCTION) |
| 857 | return (ctf_set_errno (fp, ECTF_NOTFUNC)); |
| 858 | |
| 859 | return ctf_func_type_info (fp, type, fip); |
| 860 | } |
| 861 | |
| 862 | /* Given a symbol table index, return the arguments for the function described |
| 863 | by the corresponding entry in the symbol table. */ |
| 864 | |
| 865 | int |
| 866 | ctf_func_args (ctf_dict_t *fp, unsigned long symidx, uint32_t argc, |
| 867 | ctf_id_t *argv) |
| 868 | { |
| 869 | ctf_id_t type; |
| 870 | |
| 871 | if ((type = ctf_lookup_by_symbol (fp, symidx)) == CTF_ERR) |
| 872 | return -1; /* errno is set for us. */ |
| 873 | |
| 874 | if (ctf_type_kind (fp, type) != CTF_K_FUNCTION) |
| 875 | return (ctf_set_errno (fp, ECTF_NOTFUNC)); |
| 876 | |
| 877 | return ctf_func_type_args (fp, type, argc, argv); |
| 878 | } |