1 /* $OpenBSD: rtld_machine.c,v 1.36 2023/01/29 20:30:21 gnezdo Exp $ */ 2 3 /* 4 * Copyright (c) 2004 Dale Rahn 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #define _DYN_LOADER 30 #define LDSO_ARCH_IS_RELA_ 31 32 #include <sys/types.h> 33 #include <sys/exec_elf.h> 34 #include <sys/syscall.h> 35 #include <sys/unistd.h> 36 37 #include <machine/reloc.h> 38 39 #include "util.h" 40 #include "resolve.h" 41 42 int64_t pcookie __attribute__((section(".openbsd.randomdata"))) __dso_hidden; 43 44 void _dl_bind_start(void); /* XXX */ 45 Elf_Addr _dl_bind(elf_object_t *object, int reloff); 46 #define _RF_S 0x80000000 /* Resolve symbol */ 47 #define _RF_A 0x40000000 /* Use addend */ 48 #define _RF_P 0x20000000 /* Location relative */ 49 #define _RF_G 0x10000000 /* GOT offset */ 50 #define _RF_B 0x08000000 /* Load address relative */ 51 #define _RF_E 0x02000000 /* ERROR */ 52 #define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */ 53 #define _RF_RS(s) ((s) & 0xff) /* right shift */ 54 static const int reloc_target_flags[] = { 55 0, /* 0 R_SH_NONE */ 56 _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 1 R_SH_DIR32 */ 57 _RF_S|_RF_P|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 2 REL32 */ 58 _RF_E, /* 3 R_SH_DIR8WPN */ 59 _RF_E, /* 4 R_SH_IND12W */ 60 _RF_E, /* 5 R_SH_DIR8WPL */ 61 _RF_E, /* 6 R_SH_DIR8WPZ */ 62 _RF_E, /* 7 R_SH_DIR8BP */ 63 _RF_E, /* 8 R_SH_DIR8W */ 64 _RF_E, /* 9 R_SH_DIR8L */ 65 _RF_E, /* 10 R_SH_LOOP_START */ 66 _RF_E, /* 11 R_SH_LOOP_END */ 67 _RF_E, /* 12 Unused */ 68 _RF_E, /* 13 Unused */ 69 _RF_E, /* 14 Unused */ 70 _RF_E, /* 15 Unused */ 71 _RF_E, /* 16 Unused */ 72 _RF_E, /* 17 Unused */ 73 _RF_E, /* 18 Unused */ 74 _RF_E, /* 19 Unused */ 75 _RF_E, /* 20 Unused */ 76 _RF_E, /* 21 Unused */ 77 _RF_E, /* 22 R_SH_GNU_VTINHERIT */ 78 _RF_E, /* 23 R_SH_GNU_VTENTRY */ 79 _RF_E, /* 24 R_SH_SWITCH8 */ 80 _RF_E, /* 25 R_SH_SWITCH16 */ 81 _RF_E, /* 26 R_SH_SWITCH32 */ 82 _RF_E, /* 27 R_SH_USES */ 83 _RF_E, /* 28 R_SH_COUNT */ 84 _RF_E, /* 29 R_SH_ALIGN */ 85 _RF_E, /* 30 R_SH_CODE */ 86 _RF_E, /* 31 R_SH_DATA */ 87 _RF_E, /* 32 R_SH_LABEL */ 88 _RF_E, /* 33 R_SH_DIR16 */ 89 _RF_E, /* 34 R_SH_DIR8 */ 90 _RF_E, /* 35 R_SH_DIR8UL */ 91 _RF_E, /* 36 R_SH_DIR8UW */ 92 _RF_E, /* 37 R_SH_DIR8U */ 93 _RF_E, /* 38 R_SH_DIR8SW */ 94 _RF_E, /* 39 R_SH_DIR8S */ 95 _RF_E, /* 40 R_SH_DIR4UL */ 96 _RF_E, /* 41 R_SH_DIR4UW */ 97 _RF_E, /* 42 R_SH_DIR4U */ 98 _RF_E, /* 43 R_SH_PSHA */ 99 _RF_E, /* 44 R_SH_PSHL */ 100 _RF_E, /* 45 R_SH_DIR5U */ 101 _RF_E, /* 46 R_SH_DIR6U */ 102 _RF_E, /* 47 R_SH_DIR6S */ 103 _RF_E, /* 48 R_SH_DIR10S */ 104 _RF_E, /* 49 R_SH_DIR10SW */ 105 _RF_E, /* 50 R_SH_DIR10SL */ 106 _RF_E, /* 51 R_SH_DIR10SQ */ 107 _RF_E, /* 52 XXXX */ 108 _RF_E, /* 53 R_SH_DIR16S */ 109 _RF_E, /* 54 Unused */ 110 _RF_E, /* 55 Unused */ 111 _RF_E, /* 56 Unused */ 112 _RF_E, /* 57 Unused */ 113 _RF_E, /* 58 Unused */ 114 _RF_E, /* 59 Unused */ 115 _RF_E, /* 60 Unused */ 116 _RF_E, /* 61 Unused */ 117 _RF_E, /* 62 Unused */ 118 _RF_E, /* 63 Unused */ 119 _RF_E, /* 64 Unused */ 120 _RF_E, /* 65 Unused */ 121 _RF_E, /* 66 Unused */ 122 _RF_E, /* 67 Unused */ 123 _RF_E, /* 68 Unused */ 124 _RF_E, /* 69 Unused */ 125 _RF_E, /* 70 Unused */ 126 _RF_E, /* 71 Unused */ 127 _RF_E, /* 72 Unused */ 128 _RF_E, /* 73 Unused */ 129 _RF_E, /* 74 Unused */ 130 _RF_E, /* 75 Unused */ 131 _RF_E, /* 76 Unused */ 132 _RF_E, /* 77 Unused */ 133 _RF_E, /* 78 Unused */ 134 _RF_E, /* 79 Unused */ 135 _RF_E, /* 80 Unused */ 136 _RF_E, /* 81 Unused */ 137 _RF_E, /* 82 Unused */ 138 _RF_E, /* 83 Unused */ 139 _RF_E, /* 84 Unused */ 140 _RF_E, /* 85 Unused */ 141 _RF_E, /* 86 Unused */ 142 _RF_E, /* 87 Unused */ 143 _RF_E, /* 88 Unused */ 144 _RF_E, /* 89 Unused */ 145 _RF_E, /* 90 Unused */ 146 _RF_E, /* 91 Unused */ 147 _RF_E, /* 92 Unused */ 148 _RF_E, /* 93 Unused */ 149 _RF_E, /* 94 Unused */ 150 _RF_E, /* 95 Unused */ 151 _RF_E, /* 96 Unused */ 152 _RF_E, /* 97 Unused */ 153 _RF_E, /* 98 Unused */ 154 _RF_E, /* 99 Unused */ 155 _RF_E, /* 100 Unused */ 156 _RF_E, /* 101 Unused */ 157 _RF_E, /* 102 Unused */ 158 _RF_E, /* 103 Unused */ 159 _RF_E, /* 104 Unused */ 160 _RF_E, /* 105 Unused */ 161 _RF_E, /* 106 Unused */ 162 _RF_E, /* 107 Unused */ 163 _RF_E, /* 108 Unused */ 164 _RF_E, /* 109 Unused */ 165 _RF_E, /* 110 Unused */ 166 _RF_E, /* 111 Unused */ 167 _RF_E, /* 112 Unused */ 168 _RF_E, /* 113 Unused */ 169 _RF_E, /* 114 Unused */ 170 _RF_E, /* 115 Unused */ 171 _RF_E, /* 116 Unused */ 172 _RF_E, /* 117 Unused */ 173 _RF_E, /* 118 Unused */ 174 _RF_E, /* 119 Unused */ 175 _RF_E, /* 120 Unused */ 176 _RF_E, /* 121 Unused */ 177 _RF_E, /* 122 Unused */ 178 _RF_E, /* 123 Unused */ 179 _RF_E, /* 124 Unused */ 180 _RF_E, /* 125 Unused */ 181 _RF_E, /* 126 Unused */ 182 _RF_E, /* 127 Unused */ 183 _RF_E, /* 128 Unused */ 184 _RF_E, /* 129 Unused */ 185 _RF_E, /* 130 Unused */ 186 _RF_E, /* 131 Unused */ 187 _RF_E, /* 132 Unused */ 188 _RF_E, /* 133 Unused */ 189 _RF_E, /* 134 Unused */ 190 _RF_E, /* 135 Unused */ 191 _RF_E, /* 136 Unused */ 192 _RF_E, /* 137 Unused */ 193 _RF_E, /* 138 Unused */ 194 _RF_E, /* 139 Unused */ 195 _RF_E, /* 140 Unused */ 196 _RF_E, /* 141 Unused */ 197 _RF_E, /* 142 Unused */ 198 _RF_E, /* 143 Unused */ 199 _RF_E, /* 144 R_SH_TLS_GD_32 */ 200 _RF_E, /* 145 R_SH_TLS_LD_32 */ 201 _RF_E, /* 146 R_SH_TLS_LDO_32 */ 202 _RF_E, /* 147 R_SH_TLS_IE_32 */ 203 _RF_E, /* 148 R_SH_TLS_LE_32 */ 204 _RF_E, /* 149 R_SH_TLS_DTPMOD32 */ 205 _RF_E, /* 150 R_SH_TLS_DTPOFF32 */ 206 _RF_E, /* 151 R_SH_TLS_TPOFF32 */ 207 _RF_E, /* 152 Unused */ 208 _RF_E, /* 153 Unused */ 209 _RF_E, /* 154 Unused */ 210 _RF_E, /* 155 Unused */ 211 _RF_E, /* 156 Unused */ 212 _RF_E, /* 157 Unused */ 213 _RF_E, /* 158 Unused */ 214 _RF_E, /* 159 Unused */ 215 _RF_E, /* 160 R_SH_GOT32 */ 216 _RF_E, /* 161 R_SH_PLT32 */ 217 _RF_S| _RF_SZ(32) | _RF_RS(0), /* 162 COPY */ 218 _RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 163 GLOB_DAT */ 219 _RF_S| _RF_SZ(32) | _RF_RS(0), /* 164 JMP_SLOT */ 220 _RF_A| _RF_B| _RF_SZ(32) | _RF_RS(0), /* 165 RELATIVE */ 221 }; 222 223 #define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0) 224 #define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0) 225 #define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0) 226 #define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0) 227 #define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff) 228 #define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff) 229 #define RELOC_ERROR(t) \ 230 ((t) >= nitems(reloc_target_flags) || (reloc_target_flags[t] & _RF_E)) 231 232 static const int reloc_target_bitmask[] = { 233 #define _BM(x) (x == 32? ~0 : ~(-(1UL << (x)))) 234 _BM(0), /* 0 R_SH_NONE */ 235 _BM(32), /* 1 R_SH_DIR32 */ 236 _BM(32), /* 2 R_SH_REL32 */ 237 _BM(8), /* 3 R_SH_DIR8WPN */ 238 _BM(12), /* 4 R_SH_IND12W */ 239 _BM(8), /* 5 R_SH_DIR8WPL */ 240 _BM(8), /* 6 R_SH_DIR8WPZ */ 241 _BM(8), /* 7 R_SH_DIR8BP */ 242 _BM(8), /* 8 R_SH_DIR8W */ 243 _BM(8), /* 9 R_SH_DIR8L */ 244 _BM(0), /* 10 R_SH_LOOP_START */ 245 _BM(0), /* 11 R_SH_LOOP_END */ 246 _BM(0), /* 12 Unused */ 247 _BM(0), /* 13 Unused */ 248 _BM(0), /* 14 Unused */ 249 _BM(0), /* 15 Unused */ 250 _BM(0), /* 16 Unused */ 251 _BM(0), /* 17 Unused */ 252 _BM(0), /* 18 Unused */ 253 _BM(0), /* 19 Unused */ 254 _BM(0), /* 20 Unused */ 255 _BM(0), /* 21 Unused */ 256 _BM(0), /* 22 R_SH_GNU_VTINHERIT */ 257 _BM(0), /* 23 R_SH_GNU_VTENTRY */ 258 _BM(0), /* 24 R_SH_SWITCH8 */ 259 _BM(0), /* 25 R_SH_SWITCH16 */ 260 _BM(0), /* 26 R_SH_SWITCH32 */ 261 _BM(0), /* 27 R_SH_USES */ 262 _BM(0), /* 28 R_SH_COUNT */ 263 _BM(0), /* 29 R_SH_ALIGN */ 264 _BM(0), /* 30 R_SH_CODE */ 265 _BM(0), /* 31 R_SH_DATA */ 266 _BM(0), /* 32 R_SH_LABEL */ 267 _BM(0), /* 33 R_SH_DIR16 */ 268 _BM(0), /* 34 R_SH_DIR8 */ 269 _BM(0), /* 35 R_SH_DIR8UL */ 270 _BM(0), /* 36 R_SH_DIR8UW */ 271 _BM(0), /* 37 R_SH_DIR8U */ 272 _BM(0), /* 38 R_SH_DIR8SW */ 273 _BM(0), /* 39 R_SH_DIR8S */ 274 _BM(0), /* 40 R_SH_DIR4UL */ 275 _BM(0), /* 41 R_SH_DIR4UW */ 276 _BM(0), /* 42 R_SH_DIR4U */ 277 _BM(0), /* 43 R_SH_PSHA */ 278 _BM(0), /* 44 R_SH_PSHL */ 279 _BM(0), /* 45 R_SH_DIR5U */ 280 _BM(0), /* 46 R_SH_DIR6U */ 281 _BM(0), /* 47 R_SH_DIR6S */ 282 _BM(0), /* 48 R_SH_DIR10S */ 283 _BM(0), /* 49 R_SH_DIR10SW */ 284 _BM(0), /* 50 R_SH_DIR10SL */ 285 _BM(0), /* 51 R_SH_DIR10SQ */ 286 _BM(0), /* 52 xxx */ 287 _BM(0), /* 53 R_SH_DIR16S */ 288 _BM(0), /* 54 Unused */ 289 _BM(0), /* 55 Unused */ 290 _BM(0), /* 56 Unused */ 291 _BM(0), /* 57 Unused */ 292 _BM(0), /* 58 Unused */ 293 _BM(0), /* 59 Unused */ 294 _BM(0), /* 60 Unused */ 295 _BM(0), /* 61 Unused */ 296 _BM(0), /* 62 Unused */ 297 _BM(0), /* 63 Unused */ 298 _BM(0), /* 64 Unused */ 299 _BM(0), /* 65 Unused */ 300 _BM(0), /* 66 Unused */ 301 _BM(0), /* 67 Unused */ 302 _BM(0), /* 68 Unused */ 303 _BM(0), /* 69 Unused */ 304 _BM(0), /* 70 Unused */ 305 _BM(0), /* 71 Unused */ 306 _BM(0), /* 72 Unused */ 307 _BM(0), /* 73 Unused */ 308 _BM(0), /* 74 Unused */ 309 _BM(0), /* 75 Unused */ 310 _BM(0), /* 76 Unused */ 311 _BM(0), /* 77 Unused */ 312 _BM(0), /* 78 Unused */ 313 _BM(0), /* 79 Unused */ 314 _BM(0), /* 80 Unused */ 315 _BM(0), /* 81 Unused */ 316 _BM(0), /* 82 Unused */ 317 _BM(0), /* 83 Unused */ 318 _BM(0), /* 84 Unused */ 319 _BM(0), /* 85 Unused */ 320 _BM(0), /* 86 Unused */ 321 _BM(0), /* 87 Unused */ 322 _BM(0), /* 88 Unused */ 323 _BM(0), /* 89 Unused */ 324 _BM(0), /* 90 Unused */ 325 _BM(0), /* 91 Unused */ 326 _BM(0), /* 92 Unused */ 327 _BM(0), /* 93 Unused */ 328 _BM(0), /* 94 Unused */ 329 _BM(0), /* 95 Unused */ 330 _BM(0), /* 96 Unused */ 331 _BM(0), /* 97 Unused */ 332 _BM(0), /* 98 Unused */ 333 _BM(0), /* 99 Unused */ 334 _BM(0), /* 100 Unused */ 335 _BM(0), /* 101 Unused */ 336 _BM(0), /* 102 Unused */ 337 _BM(0), /* 103 Unused */ 338 _BM(0), /* 104 Unused */ 339 _BM(0), /* 105 Unused */ 340 _BM(0), /* 106 Unused */ 341 _BM(0), /* 107 Unused */ 342 _BM(0), /* 108 Unused */ 343 _BM(0), /* 109 Unused */ 344 _BM(0), /* 110 Unused */ 345 _BM(0), /* 111 Unused */ 346 _BM(0), /* 112 Unused */ 347 _BM(0), /* 113 Unused */ 348 _BM(0), /* 114 Unused */ 349 _BM(0), /* 115 Unused */ 350 _BM(0), /* 116 Unused */ 351 _BM(0), /* 117 Unused */ 352 _BM(0), /* 118 Unused */ 353 _BM(0), /* 119 Unused */ 354 _BM(0), /* 120 Unused */ 355 _BM(0), /* 121 Unused */ 356 _BM(0), /* 122 Unused */ 357 _BM(0), /* 123 Unused */ 358 _BM(0), /* 124 Unused */ 359 _BM(0), /* 125 Unused */ 360 _BM(0), /* 126 Unused */ 361 _BM(0), /* 127 Unused */ 362 _BM(0), /* 128 Unused */ 363 _BM(0), /* 129 Unused */ 364 _BM(0), /* 130 Unused */ 365 _BM(0), /* 131 Unused */ 366 _BM(0), /* 132 Unused */ 367 _BM(0), /* 133 Unused */ 368 _BM(0), /* 134 Unused */ 369 _BM(0), /* 135 Unused */ 370 _BM(0), /* 136 Unused */ 371 _BM(0), /* 137 Unused */ 372 _BM(0), /* 138 Unused */ 373 _BM(0), /* 139 Unused */ 374 _BM(0), /* 140 Unused */ 375 _BM(0), /* 141 Unused */ 376 _BM(0), /* 142 Unused */ 377 _BM(0), /* 143 Unused */ 378 _BM(0), /* 144 R_SH_TLS_GD_32 */ 379 _BM(0), /* 145 R_SH_TLS_LD_32 */ 380 _BM(0), /* 146 R_SH_TLS_LDO_32 */ 381 _BM(0), /* 147 R_SH_TLS_IE_32 */ 382 _BM(0), /* 148 R_SH_TLS_LE_32 */ 383 _BM(0), /* 149 R_SH_TLS_DTPMOD32 */ 384 _BM(0), /* 150 R_SH_TLS_DTPOFF32 */ 385 _BM(0), /* 151 R_SH_TLS_TPOFF32 */ 386 _BM(0), /* 152 xxx */ 387 _BM(0), /* 153 xxx */ 388 _BM(0), /* 154 xxx */ 389 _BM(0), /* 155 xxx */ 390 _BM(0), /* 156 xxx */ 391 _BM(0), /* 157 xxx */ 392 _BM(0), /* 158 xxx */ 393 _BM(0), /* 159 xxx */ 394 _BM(0), /* 160 R_SH_GOT32 */ 395 _BM(0), /* 161 R_SH_PLT32 */ 396 _BM(0), /* 162 R_SH_COPY */ 397 _BM(32), /* 163 R_SH_GLOB_DAT */ 398 _BM(0), /* 164 R_SH_JMP_SLOT */ 399 _BM(32), /* 165 R_SH_RELATIVE */ 400 #undef _BM 401 }; 402 #define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t]) 403 404 #define R_TYPE(x) R_SH_ ## x 405 406 void _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rel); 407 408 void 409 _dl_reloc_plt(Elf_Word *where, Elf_Addr value, Elf_RelA *rel) 410 { 411 *where = value + rel->r_addend; 412 } 413 414 int 415 _dl_md_reloc(elf_object_t *object, int rel, int relasz) 416 { 417 long i; 418 long numrela; 419 long relrel; 420 int fails = 0; 421 Elf_Addr loff; 422 Elf_Addr prev_value = 0; 423 const Elf_Sym *prev_sym = NULL; 424 Elf_RelA *rels; 425 426 loff = object->obj_base; 427 numrela = object->Dyn.info[relasz] / sizeof(Elf_RelA); 428 relrel = rel == DT_RELA ? object->relacount : 0; 429 rels = (Elf_RelA *)(object->Dyn.info[rel]); 430 431 if (rels == NULL) 432 return 0; 433 434 if (relrel > numrela) 435 _dl_die("relacount > numrel: %ld > %ld", relrel, numrela); 436 437 /* tight loop for leading RELATIVE relocs */ 438 for (i = 0; i < relrel; i++, rels++) { 439 Elf_Addr *where; 440 441 where = (Elf_Addr *)(rels->r_offset + loff); 442 *where = rels->r_addend + loff; 443 } 444 for (; i < numrela; i++, rels++) { 445 Elf_Addr *where, value, mask; 446 Elf_Word type; 447 const Elf_Sym *sym; 448 const char *symn; 449 450 type = ELF_R_TYPE(rels->r_info); 451 452 if (RELOC_ERROR(type)) 453 _dl_die("bad relocation obj %s %ld %d", 454 object->load_name, i, type); 455 456 if (type == R_TYPE(NONE)) 457 continue; 458 459 if (type == R_TYPE(JMP_SLOT) && rel != DT_JMPREL) 460 continue; 461 462 where = (Elf_Addr *)(rels->r_offset + loff); 463 464 if (RELOC_USE_ADDEND(type)) 465 #ifdef LDSO_ARCH_IS_RELA_ 466 value = rels->r_addend; 467 #else 468 value = *where & RELOC_VALUE_BITMASK(type); 469 #endif 470 else 471 value = 0; 472 473 474 sym = NULL; 475 symn = NULL; 476 if (RELOC_RESOLVE_SYMBOL(type)) { 477 sym = object->dyn.symtab; 478 sym += ELF_R_SYM(rels->r_info); 479 symn = object->dyn.strtab + sym->st_name; 480 481 if (sym->st_shndx != SHN_UNDEF && 482 ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 483 value += loff; 484 } else if (sym == prev_sym) { 485 value += prev_value; 486 } else { 487 struct sym_res sr; 488 489 sr = _dl_find_symbol(symn, 490 SYM_SEARCH_ALL|SYM_WARNNOTFOUND| 491 ((type == R_TYPE(JMP_SLOT)) ? 492 SYM_PLT : SYM_NOTPLT), 493 sym, object); 494 if (sr.sym == NULL) { 495 resolve_failed: 496 if (ELF_ST_BIND(sym->st_info) != 497 STB_WEAK) 498 fails++; 499 continue; 500 } 501 prev_sym = sym; 502 prev_value = (Elf_Addr)(sr.obj->obj_base + 503 sr.sym->st_value); 504 value += prev_value; 505 } 506 } 507 508 if (type == R_TYPE(JMP_SLOT)) { 509 _dl_reloc_plt((Elf_Word *)where, value, rels); 510 continue; 511 } 512 513 if (type == R_TYPE(COPY)) { 514 void *dstaddr = where; 515 const void *srcaddr; 516 const Elf_Sym *dstsym = sym; 517 struct sym_res sr; 518 519 sr = _dl_find_symbol(symn, 520 SYM_SEARCH_OTHER|SYM_WARNNOTFOUND|SYM_NOTPLT, 521 dstsym, object); 522 if (sr.sym == NULL) 523 goto resolve_failed; 524 525 srcaddr = (void *)(sr.obj->obj_base + sr.sym->st_value); 526 _dl_bcopy(srcaddr, dstaddr, dstsym->st_size); 527 continue; 528 } 529 530 if (RELOC_PC_RELATIVE(type)) 531 value -= (Elf_Addr)where; 532 if (RELOC_BASE_RELATIVE(type)) 533 value += loff; 534 535 mask = RELOC_VALUE_BITMASK(type); 536 value >>= RELOC_VALUE_RIGHTSHIFT(type); 537 value &= mask; 538 539 *where &= ~mask; 540 *where |= value; 541 } 542 543 return fails; 544 } 545 546 /* 547 * Relocate the Global Offset Table (GOT). 548 * This is done by calling _dl_md_reloc on DT_JMPREL for DL_BIND_NOW, 549 * otherwise the lazy binding plt initialization is performed. 550 */ 551 int 552 _dl_md_reloc_got(elf_object_t *object, int lazy) 553 { 554 int fails = 0; 555 Elf_Addr *pltgot = (Elf_Addr *)object->Dyn.info[DT_PLTGOT]; 556 int i, num; 557 Elf_RelA *rel; 558 559 if (object->Dyn.info[DT_PLTREL] != DT_RELA) 560 return 0; 561 562 if (!lazy) { 563 fails = _dl_md_reloc(object, DT_JMPREL, DT_PLTRELSZ); 564 } else { 565 rel = (Elf_RelA *)(object->Dyn.info[DT_JMPREL]); 566 num = (object->Dyn.info[DT_PLTRELSZ]) / sizeof(Elf_RelA); 567 568 for (i = 0; i < num; i++, rel++) { 569 Elf_Addr *where, value; 570 Elf_Word type; 571 572 where = (Elf_Addr *)(rel->r_offset + object->obj_base); 573 type = ELF_R_TYPE(rel->r_info); 574 if (RELOC_USE_ADDEND(type)) 575 value = rel->r_addend; 576 else 577 value = 0; 578 *where += object->obj_base + value; 579 } 580 581 pltgot[1] = (Elf_Addr)object; 582 pltgot[2] = (Elf_Addr)_dl_bind_start; 583 } 584 585 return fails; 586 } 587 588 Elf_Addr 589 _dl_bind(elf_object_t *object, int reloff) 590 { 591 Elf_RelA *rel; 592 const Elf_Sym *sym; 593 const char *symn; 594 struct sym_res sr; 595 uint64_t cookie = pcookie; 596 struct { 597 struct __kbind param; 598 Elf_Addr newval; 599 } buf; 600 601 rel = (Elf_RelA *)(object->Dyn.info[DT_JMPREL] + reloff); 602 603 sym = object->dyn.symtab; 604 sym += ELF_R_SYM(rel->r_info); 605 symn = object->dyn.strtab + sym->st_name; 606 607 sr = _dl_find_symbol(symn, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, 608 sym, object); 609 if (sr.sym == NULL) 610 _dl_die("lazy binding failed!"); 611 612 buf.newval = sr.obj->obj_base + sr.sym->st_value; 613 614 if (__predict_false(sr.obj->traced) && _dl_trace_plt(sr.obj, symn)) 615 return buf.newval; 616 617 buf.param.kb_addr = (Elf_Addr *)(object->obj_base + rel->r_offset); 618 buf.param.kb_size = sizeof(Elf_Addr); 619 620 /* directly code the syscall, so that it's actually inline here */ 621 { 622 register long syscall_num __asm("r0") = SYS_kbind; 623 register void *arg1 __asm("r4") = &buf; 624 register long arg2 __asm("r5") = sizeof(buf); 625 register long arg3 __asm("r6") = 0xffffffff & cookie; 626 register long arg4 __asm("r7") = 0xffffffff & (cookie >> 32); 627 628 __asm volatile("trapa #0x80" : "+r" (syscall_num) 629 : "r" (arg1), "r" (arg2), "r" (arg3), "r" (arg4) 630 : "r1", "cc", "memory"); 631 } 632 633 return buf.newval; 634 } 635