1 /* $NetBSD: ppc_reloc.c,v 1.10 2001/09/10 06:09:41 mycroft Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (C) 1998 Tsubai Masanari 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/mman.h> 34 35 #include <errno.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 #include <machine/cpu.h> 41 #include <machine/atomic.h> 42 #include <machine/md_var.h> 43 44 #include "debug.h" 45 #include "rtld.h" 46 47 #define _ppc_ha(x) ((((u_int32_t)(x) & 0x8000) ? \ 48 ((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16) 49 #define _ppc_la(x) ((u_int32_t)(x) & 0xffff) 50 51 #define min(a,b) (((a) < (b)) ? (a) : (b)) 52 #define max(a,b) (((a) > (b)) ? (a) : (b)) 53 54 #define PLT_EXTENDED_BEGIN (1 << 13) 55 #define JMPTAB_BASE(N) (18 + N*2 + ((N > PLT_EXTENDED_BEGIN) ? \ 56 (N - PLT_EXTENDED_BEGIN)*2 : 0)) 57 58 void _rtld_bind_secureplt_start(void); 59 60 bool 61 arch_digest_dynamic(struct Struct_Obj_Entry *obj, const Elf_Dyn *dynp) 62 { 63 if (dynp->d_tag == DT_PPC_GOT) { 64 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 65 return (true); 66 } 67 68 return (false); 69 } 70 71 /* 72 * Process the R_PPC_COPY relocations 73 */ 74 int 75 do_copy_relocations(Obj_Entry *dstobj) 76 { 77 const Elf_Rela *relalim; 78 const Elf_Rela *rela; 79 80 /* 81 * COPY relocs are invalid outside of the main program 82 */ 83 assert(dstobj->mainprog); 84 85 relalim = (const Elf_Rela *)((const char *) dstobj->rela + 86 dstobj->relasize); 87 for (rela = dstobj->rela; rela < relalim; rela++) { 88 void *dstaddr; 89 const Elf_Sym *dstsym; 90 const char *name; 91 size_t size; 92 const void *srcaddr; 93 const Elf_Sym *srcsym = NULL; 94 const Obj_Entry *srcobj, *defobj; 95 SymLook req; 96 int res; 97 98 if (ELF_R_TYPE(rela->r_info) != R_PPC_COPY) { 99 continue; 100 } 101 102 dstaddr = (void *)(dstobj->relocbase + rela->r_offset); 103 dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info); 104 name = dstobj->strtab + dstsym->st_name; 105 size = dstsym->st_size; 106 symlook_init(&req, name); 107 req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info)); 108 req.flags = SYMLOOK_EARLY; 109 110 for (srcobj = globallist_next(dstobj); srcobj != NULL; 111 srcobj = globallist_next(srcobj)) { 112 res = symlook_obj(&req, srcobj); 113 if (res == 0) { 114 srcsym = req.sym_out; 115 defobj = req.defobj_out; 116 break; 117 } 118 } 119 120 if (srcobj == NULL) { 121 _rtld_error("Undefined symbol \"%s\" " 122 " referenced from COPY" 123 " relocation in %s", name, dstobj->path); 124 return (-1); 125 } 126 127 srcaddr = (const void *)(defobj->relocbase+srcsym->st_value); 128 memcpy(dstaddr, srcaddr, size); 129 dbg("copy_reloc: src=%p,dst=%p,size=%d\n",srcaddr,dstaddr,size); 130 } 131 132 return (0); 133 } 134 135 136 /* 137 * Perform early relocation of the run-time linker image 138 */ 139 void 140 reloc_non_plt_self(Elf_Dyn *dynp, Elf_Addr relocbase) 141 { 142 const Elf_Rela *rela = NULL, *relalim; 143 Elf_Addr relasz = 0; 144 Elf_Addr *where; 145 146 /* 147 * Extract the rela/relasz values from the dynamic section 148 */ 149 for (; dynp->d_tag != DT_NULL; dynp++) { 150 switch (dynp->d_tag) { 151 case DT_RELA: 152 rela = (const Elf_Rela *)(relocbase+dynp->d_un.d_ptr); 153 break; 154 case DT_RELASZ: 155 relasz = dynp->d_un.d_val; 156 break; 157 } 158 } 159 160 /* 161 * Relocate these values 162 */ 163 relalim = (const Elf_Rela *)((const char *)rela + relasz); 164 for (; rela < relalim; rela++) { 165 where = (Elf_Addr *)(relocbase + rela->r_offset); 166 *where = (Elf_Addr)(relocbase + rela->r_addend); 167 } 168 } 169 170 171 /* 172 * Relocate a non-PLT object with addend. 173 */ 174 static int 175 reloc_nonplt_object(Obj_Entry *obj_rtld __unused, Obj_Entry *obj, 176 const Elf_Rela *rela, SymCache *cache, int flags, RtldLockState *lockstate) 177 { 178 const Elf_Sym *def = NULL; 179 const Obj_Entry *defobj; 180 Elf_Addr *where, symval = 0; 181 182 /* 183 * First, resolve symbol for relocations which 184 * reference symbols. 185 */ 186 switch (ELF_R_TYPE(rela->r_info)) { 187 188 case R_PPC_UADDR32: /* word32 S + A */ 189 case R_PPC_ADDR32: 190 case R_PPC_GLOB_DAT: /* word32 S + A */ 191 case R_PPC_DTPMOD32: 192 case R_PPC_TPREL32: 193 case R_PPC_DTPREL32: 194 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, 195 flags, cache, lockstate); 196 if (def == NULL) { 197 return (-1); 198 } 199 200 /* 201 * If symbol is IFUNC, only perform relocation 202 * when caller allowed it by passing 203 * SYMLOOK_IFUNC flag. Skip the relocations 204 * otherwise. 205 * 206 * Also error out in case IFUNC relocations 207 * are specified for TLS, which cannot be 208 * usefully interpreted. 209 */ 210 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 211 switch (ELF_R_TYPE(rela->r_info)) { 212 case R_PPC_UADDR32: 213 case R_PPC_ADDR32: 214 case R_PPC_GLOB_DAT: 215 if ((flags & SYMLOOK_IFUNC) == 0) { 216 dbg("Non-PLT reference to IFUNC found!"); 217 obj->non_plt_gnu_ifunc = true; 218 return (0); 219 } 220 symval = (Elf_Addr)rtld_resolve_ifunc( 221 defobj, def); 222 break; 223 default: 224 _rtld_error("%s: IFUNC for TLS reloc", 225 obj->path); 226 return (-1); 227 } 228 } else { 229 if ((flags & SYMLOOK_IFUNC) != 0) 230 return (0); 231 symval = (Elf_Addr)defobj->relocbase + 232 def->st_value; 233 } 234 break; 235 default: 236 if ((flags & SYMLOOK_IFUNC) != 0) 237 return (0); 238 } 239 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 240 241 switch (ELF_R_TYPE(rela->r_info)) { 242 case R_PPC_NONE: 243 break; 244 case R_PPC_UADDR32: 245 case R_PPC_ADDR32: 246 case R_PPC_GLOB_DAT: 247 /* Don't issue write if unnecessary; avoid COW page fault */ 248 if (*where != symval + rela->r_addend) { 249 *where = symval + rela->r_addend; 250 } 251 break; 252 case R_PPC_DTPMOD32: 253 *where = (Elf_Addr) defobj->tlsindex; 254 break; 255 case R_PPC_TPREL32: 256 /* 257 * We lazily allocate offsets for static TLS as we 258 * see the first relocation that references the 259 * TLS block. This allows us to support (small 260 * amounts of) static TLS in dynamically loaded 261 * modules. If we run out of space, we generate an 262 * error. 263 */ 264 if (!defobj->tls_static) { 265 if (!allocate_tls_offset( 266 __DECONST(Obj_Entry *, defobj))) { 267 _rtld_error("%s: No space available for static " 268 "Thread Local Storage", obj->path); 269 return (-1); 270 } 271 } 272 273 *(Elf_Addr **)where = *where * sizeof(Elf_Addr) 274 + (Elf_Addr *)(def->st_value + rela->r_addend 275 + defobj->tlsoffset - TLS_TP_OFFSET - TLS_TCB_SIZE); 276 break; 277 case R_PPC_DTPREL32: 278 *where += (Elf_Addr)(def->st_value + rela->r_addend 279 - TLS_DTV_OFFSET); 280 break; 281 case R_PPC_RELATIVE: /* word32 B + A */ 282 symval = (Elf_Addr)(obj->relocbase + rela->r_addend); 283 284 /* As above, don't issue write unnecessarily */ 285 if (*where != symval) { 286 *where = symval; 287 } 288 break; 289 case R_PPC_COPY: 290 /* 291 * These are deferred until all other relocations 292 * have been done. All we do here is make sure 293 * that the COPY relocation is not in a shared 294 * library. They are allowed only in executable 295 * files. 296 */ 297 if (!obj->mainprog) { 298 _rtld_error("%s: Unexpected R_COPY " 299 " relocation in shared library", 300 obj->path); 301 return (-1); 302 } 303 break; 304 case R_PPC_IRELATIVE: 305 /* 306 * These will be handled by reloc_iresolve(). 307 */ 308 obj->irelative = true; 309 break; 310 case R_PPC_JMP_SLOT: 311 /* 312 * These will be handled by the plt/jmpslot routines 313 */ 314 break; 315 316 default: 317 _rtld_error("%s: Unsupported relocation type %d" 318 " in non-PLT relocations\n", obj->path, 319 ELF_R_TYPE(rela->r_info)); 320 return (-1); 321 } 322 return (0); 323 } 324 325 326 /* 327 * Process non-PLT relocations 328 */ 329 int 330 reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags, 331 RtldLockState *lockstate) 332 { 333 const Elf_Rela *relalim; 334 const Elf_Rela *rela; 335 const Elf_Phdr *phdr; 336 SymCache *cache; 337 int r = -1; 338 339 /* 340 * The dynamic loader may be called from a thread, we have 341 * limited amounts of stack available so we cannot use alloca(). 342 */ 343 if (obj != obj_rtld) { 344 cache = calloc(obj->dynsymcount, sizeof(SymCache)); 345 /* No need to check for NULL here */ 346 } else 347 cache = NULL; 348 349 /* 350 * From the SVR4 PPC ABI: 351 * "The PowerPC family uses only the Elf32_Rela relocation 352 * entries with explicit addends." 353 */ 354 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize); 355 for (rela = obj->rela; rela < relalim; rela++) { 356 if (reloc_nonplt_object(obj_rtld, obj, rela, cache, flags, 357 lockstate) < 0) 358 goto done; 359 } 360 r = 0; 361 done: 362 if (cache != NULL) 363 free(cache); 364 365 /* 366 * Synchronize icache for executable segments in case we made 367 * any changes. 368 */ 369 for (phdr = obj->phdr; phdr < obj->phdr + obj->phnum; phdr++) { 370 if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) { 371 __syncicache(obj->relocbase + phdr->p_vaddr, 372 phdr->p_memsz); 373 } 374 } 375 376 return (r); 377 } 378 379 /* 380 * Initialise a PLT slot to the resolving trampoline 381 */ 382 static int 383 reloc_plt_object(Obj_Entry *obj, const Elf_Rela *rela) 384 { 385 Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset); 386 Elf_Addr *pltresolve, *pltlongresolve, *jmptab; 387 Elf_Addr distance; 388 int N = obj->pltrelasize / sizeof(Elf_Rela); 389 int reloff; 390 391 reloff = rela - obj->pltrela; 392 393 if (reloff < 0) 394 return (-1); 395 396 if (obj->gotptr != NULL) { 397 *where += (Elf_Addr)obj->relocbase; 398 return (0); 399 } 400 401 pltlongresolve = obj->pltgot + 5; 402 pltresolve = pltlongresolve + 5; 403 404 distance = (Elf_Addr)pltresolve - (Elf_Addr)(where + 1); 405 406 dbg(" reloc_plt_object: where=%p,pltres=%p,reloff=%x,distance=%x", 407 (void *)where, (void *)pltresolve, reloff, distance); 408 409 if (reloff < PLT_EXTENDED_BEGIN) { 410 /* li r11,reloff */ 411 /* b pltresolve */ 412 where[0] = 0x39600000 | reloff; 413 where[1] = 0x48000000 | (distance & 0x03fffffc); 414 } else { 415 jmptab = obj->pltgot + JMPTAB_BASE(N); 416 jmptab[reloff] = (u_int)pltlongresolve; 417 418 /* lis r11,jmptab[reloff]@ha */ 419 /* lwzu r12,jmptab[reloff]@l(r11) */ 420 /* mtctr r12 */ 421 /* bctr */ 422 where[0] = 0x3d600000 | _ppc_ha(&jmptab[reloff]); 423 where[1] = 0x858b0000 | _ppc_la(&jmptab[reloff]); 424 where[2] = 0x7d8903a6; 425 where[3] = 0x4e800420; 426 } 427 428 429 /* 430 * The icache will be sync'd in reloc_plt, which is called 431 * after all the slots have been updated 432 */ 433 434 return (0); 435 } 436 437 /* 438 * Process the PLT relocations. 439 */ 440 int 441 reloc_plt(Obj_Entry *obj, int flags __unused, RtldLockState *lockstate __unused) 442 { 443 const Elf_Rela *relalim; 444 const Elf_Rela *rela; 445 int N = obj->pltrelasize / sizeof(Elf_Rela); 446 447 if (obj->pltrelasize != 0) { 448 449 relalim = (const Elf_Rela *)((const char *)obj->pltrela + 450 obj->pltrelasize); 451 for (rela = obj->pltrela; rela < relalim; rela++) { 452 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 453 dbg("ABI violation - found IRELATIVE in the PLT."); 454 obj->irelative = true; 455 continue; 456 } 457 458 /* 459 * PowerPC(64) .rela.plt is composed of an array of 460 * R_PPC_JMP_SLOT relocations. Unlike other platforms, 461 * this is the ONLY relocation type that is valid here. 462 */ 463 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT); 464 465 if (reloc_plt_object(obj, rela) < 0) { 466 return (-1); 467 } 468 } 469 } 470 471 /* 472 * Sync the icache for the byte range represented by the 473 * trampoline routines and call slots. 474 */ 475 if (obj->pltgot != NULL && obj->gotptr == NULL) 476 __syncicache(obj->pltgot, JMPTAB_BASE(N)*4); 477 478 return (0); 479 } 480 481 /* 482 * LD_BIND_NOW was set - force relocation for all jump slots 483 */ 484 int 485 reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate) 486 { 487 const Obj_Entry *defobj; 488 const Elf_Rela *relalim; 489 const Elf_Rela *rela; 490 const Elf_Sym *def; 491 Elf_Addr *where; 492 Elf_Addr target; 493 494 relalim = (const Elf_Rela *)((const char *)obj->pltrela + 495 obj->pltrelasize); 496 for (rela = obj->pltrela; rela < relalim; rela++) { 497 /* This isn't actually a jump slot, ignore it. */ 498 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) 499 continue; 500 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT); 501 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 502 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, 503 SYMLOOK_IN_PLT | flags, NULL, lockstate); 504 if (def == NULL) { 505 dbg("reloc_jmpslots: sym not found"); 506 return (-1); 507 } 508 509 target = (Elf_Addr)(defobj->relocbase + def->st_value); 510 511 if (def == &sym_zero) { 512 /* Zero undefined weak symbols */ 513 *where = 0; 514 } else { 515 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 516 /* LD_BIND_NOW, ifunc in shared lib.*/ 517 obj->gnu_ifunc = true; 518 continue; 519 } 520 reloc_jmpslot(where, target, defobj, obj, 521 (const Elf_Rel *) rela); 522 } 523 } 524 525 obj->jmpslots_done = true; 526 527 return (0); 528 } 529 530 531 /* 532 * Update the value of a PLT jump slot. 533 */ 534 Elf_Addr 535 reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, 536 const Obj_Entry *defobj __unused, const Obj_Entry *obj, const Elf_Rel *rel) 537 { 538 Elf_Addr offset; 539 const Elf_Rela *rela = (const Elf_Rela *) rel; 540 541 dbg(" reloc_jmpslot: where=%p, target=%p", 542 (void *)wherep, (void *)target); 543 544 if (ld_bind_not) 545 goto out; 546 547 548 /* 549 * Process Secure-PLT. 550 */ 551 if (obj->gotptr != NULL) { 552 assert(wherep >= (Elf_Word *)obj->pltgot); 553 assert(wherep < 554 (Elf_Word *)obj->pltgot + obj->pltrelasize); 555 if (*wherep != target) 556 *wherep = target; 557 goto out; 558 } 559 560 /* 561 * BSS-PLT optimization: 562 * Branch directly to the target if it is within +/- 32Mb, 563 * otherwise go indirectly via the pltcall trampoline call and 564 * jump table. 565 */ 566 offset = target - (Elf_Addr)wherep; 567 if (abs((int)offset) < 32*1024*1024) { /* inside 32MB? */ 568 /* 569 * At the PLT entry pointed at by `wherep', construct 570 * a direct transfer to the now fully resolved function 571 * address. 572 */ 573 /* b value # branch directly */ 574 *wherep = 0x48000000 | (offset & 0x03fffffc); 575 __syncicache(wherep, 4); 576 } else { 577 Elf_Addr *pltcall, *jmptab; 578 int distance; 579 int N = obj->pltrelasize / sizeof(Elf_Rela); 580 int reloff = rela - obj->pltrela; 581 582 if (reloff < 0) 583 return (-1); 584 585 pltcall = obj->pltgot; 586 587 dbg(" reloc_jmpslot: indir, reloff=%x, N=%x\n", 588 reloff, N); 589 590 jmptab = obj->pltgot + JMPTAB_BASE(N); 591 jmptab[reloff] = target; 592 mb(); /* Order jmptab update before next changes */ 593 594 if (reloff < PLT_EXTENDED_BEGIN) { 595 /* for extended PLT entries, we keep the old code */ 596 597 distance = (Elf_Addr)pltcall - (Elf_Addr)(wherep + 1); 598 599 /* li r11,reloff */ 600 /* b pltcall # use indirect pltcall routine */ 601 602 /* first instruction same as before */ 603 wherep[1] = 0x48000000 | (distance & 0x03fffffc); 604 __syncicache(wherep, 8); 605 } 606 } 607 608 out: 609 return (target); 610 } 611 612 int 613 reloc_iresolve(Obj_Entry *obj, 614 struct Struct_RtldLockState *lockstate) 615 { 616 /* 617 * Since PLT slots on PowerPC are always R_PPC_JMP_SLOT, 618 * R_PPC_IRELATIVE is in RELA. 619 */ 620 const Elf_Rela *relalim; 621 const Elf_Rela *rela; 622 Elf_Addr *where, target, *ptr; 623 624 if (!obj->irelative) 625 return (0); 626 627 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize); 628 for (rela = obj->rela; rela < relalim; rela++) { 629 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 630 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend); 631 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 632 633 lock_release(rtld_bind_lock, lockstate); 634 target = call_ifunc_resolver(ptr); 635 wlock_acquire(rtld_bind_lock, lockstate); 636 637 *where = target; 638 } 639 } 640 /* 641 * XXX Remove me when lld is fixed! 642 * LLD currently makes illegal relocations in the PLT. 643 */ 644 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize); 645 for (rela = obj->pltrela; rela < relalim; rela++) { 646 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 647 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend); 648 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 649 650 lock_release(rtld_bind_lock, lockstate); 651 target = call_ifunc_resolver(ptr); 652 wlock_acquire(rtld_bind_lock, lockstate); 653 654 *where = target; 655 } 656 } 657 658 obj->irelative = false; 659 return (0); 660 } 661 662 int 663 reloc_iresolve_nonplt(Obj_Entry *obj __unused, 664 struct Struct_RtldLockState *lockstate __unused) 665 { 666 return (0); 667 } 668 669 int 670 reloc_gnu_ifunc(Obj_Entry *obj __unused, int flags __unused, 671 struct Struct_RtldLockState *lockstate __unused) 672 { 673 const Elf_Rela *relalim; 674 const Elf_Rela *rela; 675 Elf_Addr *where, target; 676 const Elf_Sym *def; 677 const Obj_Entry *defobj; 678 679 if (!obj->gnu_ifunc) 680 return (0); 681 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize); 682 for (rela = obj->pltrela; rela < relalim; rela++) { 683 if (ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT) { 684 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 685 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, 686 SYMLOOK_IN_PLT | flags, NULL, lockstate); 687 if (def == NULL) 688 return (-1); 689 if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC) 690 continue; 691 lock_release(rtld_bind_lock, lockstate); 692 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 693 wlock_acquire(rtld_bind_lock, lockstate); 694 reloc_jmpslot(where, target, defobj, obj, 695 (const Elf_Rel *)rela); 696 } 697 } 698 obj->gnu_ifunc = false; 699 return (0); 700 } 701 702 /* 703 * Setup the plt glue routines. 704 */ 705 #define PLTCALL_SIZE 20 706 #define PLTLONGRESOLVE_SIZE 20 707 #define PLTRESOLVE_SIZE 24 708 709 void 710 init_pltgot(Obj_Entry *obj) 711 { 712 Elf_Word *pltcall, *pltresolve, *pltlongresolve; 713 Elf_Word *jmptab; 714 int N = obj->pltrelasize / sizeof(Elf_Rela); 715 716 pltcall = obj->pltgot; 717 718 if (pltcall == NULL) { 719 return; 720 } 721 722 /* Handle Secure-PLT first, if applicable. */ 723 if (obj->gotptr != NULL) { 724 obj->gotptr[1] = (Elf_Addr)_rtld_bind_secureplt_start; 725 obj->gotptr[2] = (Elf_Addr)obj; 726 dbg("obj %s secure-plt gotptr=%p start=%p obj=%p", 727 obj->path, obj->gotptr, 728 (void *)obj->gotptr[1], (void *)obj->gotptr[2]); 729 return; 730 } 731 732 /* 733 * From the SVR4 PPC ABI: 734 * 735 * 'The first 18 words (72 bytes) of the PLT are reserved for 736 * use by the dynamic linker. 737 * ... 738 * 'If the executable or shared object requires N procedure 739 * linkage table entries, the link editor shall reserve 3*N 740 * words (12*N bytes) following the 18 reserved words. The 741 * first 2*N of these words are the procedure linkage table 742 * entries themselves. The static linker directs calls to bytes 743 * (72 + (i-1)*8), for i between 1 and N inclusive. The remaining 744 * N words (4*N bytes) are reserved for use by the dynamic linker.' 745 */ 746 747 /* 748 * Copy the absolute-call assembler stub into the first part of 749 * the reserved PLT area. 750 */ 751 memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE); 752 753 /* 754 * Determine the address of the jumptable, which is the dyn-linker 755 * reserved area after the call cells. Write the absolute address 756 * of the jumptable into the absolute-call assembler code so it 757 * can determine this address. 758 */ 759 jmptab = obj->pltgot + JMPTAB_BASE(N); 760 pltcall[1] |= _ppc_ha(jmptab); /* addis 11,11,jmptab@ha */ 761 pltcall[2] |= _ppc_la(jmptab); /* lwz 11,jmptab@l(11) */ 762 763 /* 764 * Skip down 20 bytes into the initial reserved area and copy 765 * in the standard resolving assembler call. Into this assembler, 766 * insert the absolute address of the _rtld_bind_start routine 767 * and the address of the relocation object. 768 * 769 * We place pltlongresolve first, so it can fix up its arguments 770 * and then fall through to the regular PLT resolver. 771 */ 772 pltlongresolve = obj->pltgot + 5; 773 774 memcpy(pltlongresolve, _rtld_powerpc_pltlongresolve, 775 PLTLONGRESOLVE_SIZE); 776 pltlongresolve[0] |= _ppc_ha(jmptab); /* lis 12,jmptab@ha */ 777 pltlongresolve[1] |= _ppc_la(jmptab); /* addi 12,12,jmptab@l */ 778 779 pltresolve = pltlongresolve + PLTLONGRESOLVE_SIZE/sizeof(uint32_t); 780 memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE); 781 pltresolve[0] |= _ppc_ha(_rtld_bind_start); 782 pltresolve[1] |= _ppc_la(_rtld_bind_start); 783 pltresolve[3] |= _ppc_ha(obj); 784 pltresolve[4] |= _ppc_la(obj); 785 786 /* 787 * The icache will be sync'd in reloc_plt, which is called 788 * after all the slots have been updated 789 */ 790 } 791 792 /* 793 * 32 bit cpu feature flag fields. 794 */ 795 u_long cpu_features; 796 u_long cpu_features2; 797 798 void 799 powerpc_abi_variant_hook(Elf_Auxinfo** aux_info) 800 { 801 /* 802 * Since aux_info[] is easier to work with than aux, go ahead and 803 * initialize cpu_features / cpu_features2. 804 */ 805 cpu_features = -1UL; 806 cpu_features2 = -1UL; 807 if (aux_info[AT_HWCAP] != NULL) 808 cpu_features = aux_info[AT_HWCAP]->a_un.a_val; 809 if (aux_info[AT_HWCAP2] != NULL) 810 cpu_features2 = aux_info[AT_HWCAP2]->a_un.a_val; 811 } 812 813 void 814 ifunc_init(Elf_Auxinfo *aux_info[__min_size(AT_COUNT)] __unused) 815 { 816 817 } 818 819 void 820 allocate_initial_tls(Obj_Entry *list) 821 { 822 823 /* 824 * Fix the size of the static TLS block by using the maximum 825 * offset allocated so far and adding a bit for dynamic modules to 826 * use. 827 */ 828 829 tls_static_space = tls_last_offset + tls_last_size + 830 ld_static_tls_extra; 831 832 _tcb_set(allocate_tls(list, NULL, TLS_TCB_SIZE, TLS_TCB_ALIGN)); 833 } 834 835 void* 836 __tls_get_addr(tls_index* ti) 837 { 838 return (tls_get_addr_common(_tcb_get(), ti->ti_module, ti->ti_offset + 839 TLS_DTV_OFFSET)); 840 } 841 842 void 843 arch_fix_auxv(Elf_Auxinfo *aux, Elf_Auxinfo *aux_info[]) 844 { 845 Elf_Auxinfo *auxp; 846 847 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 848 if (auxp->a_type == 23) /* AT_STACKPROT */ 849 return; 850 } 851 852 /* Remap from old-style auxv numbers. */ 853 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 854 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 855 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 856 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 857 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 858 aux_info[13] = NULL; /* AT_GID */ 859 860 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 861 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 862 aux_info[16] = aux_info[14]; /* AT_CANARY */ 863 aux_info[14] = NULL; /* AT_EGID */ 864 } 865