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 58void _rtld_bind_secureplt_start(void); 59 60bool 61arch_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 */ 74int 75do_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 */ 139void 140reloc_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 */ 174static int 175reloc_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 */ 329int 330reloc_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; 361done: 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; 370 (const char *)phdr < (const char *)obj->phdr + obj->phsize; 371 phdr++) { 372 if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) { 373 __syncicache(obj->relocbase + phdr->p_vaddr, 374 phdr->p_memsz); 375 } 376 } 377 378 return (r); 379} 380 381/* 382 * Initialise a PLT slot to the resolving trampoline 383 */ 384static int 385reloc_plt_object(Obj_Entry *obj, const Elf_Rela *rela) 386{ 387 Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset); 388 Elf_Addr *pltresolve, *pltlongresolve, *jmptab; 389 Elf_Addr distance; 390 int N = obj->pltrelasize / sizeof(Elf_Rela); 391 int reloff; 392 393 reloff = rela - obj->pltrela; 394 395 if (reloff < 0) 396 return (-1); 397 398 if (obj->gotptr != NULL) { 399 *where += (Elf_Addr)obj->relocbase; 400 return (0); 401 } 402 403 pltlongresolve = obj->pltgot + 5; 404 pltresolve = pltlongresolve + 5; 405 406 distance = (Elf_Addr)pltresolve - (Elf_Addr)(where + 1); 407 408 dbg(" reloc_plt_object: where=%p,pltres=%p,reloff=%x,distance=%x", 409 (void *)where, (void *)pltresolve, reloff, distance); 410 411 if (reloff < PLT_EXTENDED_BEGIN) { 412 /* li r11,reloff */ 413 /* b pltresolve */ 414 where[0] = 0x39600000 | reloff; 415 where[1] = 0x48000000 | (distance & 0x03fffffc); 416 } else { 417 jmptab = obj->pltgot + JMPTAB_BASE(N); 418 jmptab[reloff] = (u_int)pltlongresolve; 419 420 /* lis r11,jmptab[reloff]@ha */ 421 /* lwzu r12,jmptab[reloff]@l(r11) */ 422 /* mtctr r12 */ 423 /* bctr */ 424 where[0] = 0x3d600000 | _ppc_ha(&jmptab[reloff]); 425 where[1] = 0x858b0000 | _ppc_la(&jmptab[reloff]); 426 where[2] = 0x7d8903a6; 427 where[3] = 0x4e800420; 428 } 429 430 431 /* 432 * The icache will be sync'd in reloc_plt, which is called 433 * after all the slots have been updated 434 */ 435 436 return (0); 437} 438 439/* 440 * Process the PLT relocations. 441 */ 442int 443reloc_plt(Obj_Entry *obj, int flags __unused, RtldLockState *lockstate __unused) 444{ 445 const Elf_Rela *relalim; 446 const Elf_Rela *rela; 447 int N = obj->pltrelasize / sizeof(Elf_Rela); 448 449 if (obj->pltrelasize != 0) { 450 451 relalim = (const Elf_Rela *)((const char *)obj->pltrela + 452 obj->pltrelasize); 453 for (rela = obj->pltrela; rela < relalim; rela++) { 454 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 455 dbg("ABI violation - found IRELATIVE in the PLT."); 456 obj->irelative = true; 457 continue; 458 } 459 460 /* 461 * PowerPC(64) .rela.plt is composed of an array of 462 * R_PPC_JMP_SLOT relocations. Unlike other platforms, 463 * this is the ONLY relocation type that is valid here. 464 */ 465 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT); 466 467 if (reloc_plt_object(obj, rela) < 0) { 468 return (-1); 469 } 470 } 471 } 472 473 /* 474 * Sync the icache for the byte range represented by the 475 * trampoline routines and call slots. 476 */ 477 if (obj->pltgot != NULL && obj->gotptr == NULL) 478 __syncicache(obj->pltgot, JMPTAB_BASE(N)*4); 479 480 return (0); 481} 482 483/* 484 * LD_BIND_NOW was set - force relocation for all jump slots 485 */ 486int 487reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate) 488{ 489 const Obj_Entry *defobj; 490 const Elf_Rela *relalim; 491 const Elf_Rela *rela; 492 const Elf_Sym *def; 493 Elf_Addr *where; 494 Elf_Addr target; 495 496 relalim = (const Elf_Rela *)((const char *)obj->pltrela + 497 obj->pltrelasize); 498 for (rela = obj->pltrela; rela < relalim; rela++) { 499 /* This isn't actually a jump slot, ignore it. */ 500 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) 501 continue; 502 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT); 503 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 504 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, 505 SYMLOOK_IN_PLT | flags, NULL, lockstate); 506 if (def == NULL) { 507 dbg("reloc_jmpslots: sym not found"); 508 return (-1); 509 } 510 511 target = (Elf_Addr)(defobj->relocbase + def->st_value); 512 513 if (def == &sym_zero) { 514 /* Zero undefined weak symbols */ 515 *where = 0; 516 } else { 517 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 518 /* LD_BIND_NOW, ifunc in shared lib.*/ 519 obj->gnu_ifunc = true; 520 continue; 521 } 522 reloc_jmpslot(where, target, defobj, obj, 523 (const Elf_Rel *) rela); 524 } 525 } 526 527 obj->jmpslots_done = true; 528 529 return (0); 530} 531 532 533/* 534 * Update the value of a PLT jump slot. 535 */ 536Elf_Addr 537reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target, 538 const Obj_Entry *defobj __unused, const Obj_Entry *obj, const Elf_Rel *rel) 539{ 540 Elf_Addr offset; 541 const Elf_Rela *rela = (const Elf_Rela *) rel; 542 543 dbg(" reloc_jmpslot: where=%p, target=%p", 544 (void *)wherep, (void *)target); 545 546 if (ld_bind_not) 547 goto out; 548 549 550 /* 551 * Process Secure-PLT. 552 */ 553 if (obj->gotptr != NULL) { 554 assert(wherep >= (Elf_Word *)obj->pltgot); 555 assert(wherep < 556 (Elf_Word *)obj->pltgot + obj->pltrelasize); 557 if (*wherep != target) 558 *wherep = target; 559 goto out; 560 } 561 562 /* 563 * BSS-PLT optimization: 564 * Branch directly to the target if it is within +/- 32Mb, 565 * otherwise go indirectly via the pltcall trampoline call and 566 * jump table. 567 */ 568 offset = target - (Elf_Addr)wherep; 569 if (abs((int)offset) < 32*1024*1024) { /* inside 32MB? */ 570 /* 571 * At the PLT entry pointed at by `wherep', construct 572 * a direct transfer to the now fully resolved function 573 * address. 574 */ 575 /* b value # branch directly */ 576 *wherep = 0x48000000 | (offset & 0x03fffffc); 577 __syncicache(wherep, 4); 578 } else { 579 Elf_Addr *pltcall, *jmptab; 580 int distance; 581 int N = obj->pltrelasize / sizeof(Elf_Rela); 582 int reloff = rela - obj->pltrela; 583 584 if (reloff < 0) 585 return (-1); 586 587 pltcall = obj->pltgot; 588 589 dbg(" reloc_jmpslot: indir, reloff=%x, N=%x\n", 590 reloff, N); 591 592 jmptab = obj->pltgot + JMPTAB_BASE(N); 593 jmptab[reloff] = target; 594 mb(); /* Order jmptab update before next changes */ 595 596 if (reloff < PLT_EXTENDED_BEGIN) { 597 /* for extended PLT entries, we keep the old code */ 598 599 distance = (Elf_Addr)pltcall - (Elf_Addr)(wherep + 1); 600 601 /* li r11,reloff */ 602 /* b pltcall # use indirect pltcall routine */ 603 604 /* first instruction same as before */ 605 wherep[1] = 0x48000000 | (distance & 0x03fffffc); 606 __syncicache(wherep, 8); 607 } 608 } 609 610out: 611 return (target); 612} 613 614int 615reloc_iresolve(Obj_Entry *obj, 616 struct Struct_RtldLockState *lockstate) 617{ 618 /* 619 * Since PLT slots on PowerPC are always R_PPC_JMP_SLOT, 620 * R_PPC_IRELATIVE is in RELA. 621 */ 622 const Elf_Rela *relalim; 623 const Elf_Rela *rela; 624 Elf_Addr *where, target, *ptr; 625 626 if (!obj->irelative) 627 return (0); 628 629 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize); 630 for (rela = obj->rela; rela < relalim; rela++) { 631 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 632 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend); 633 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 634 635 lock_release(rtld_bind_lock, lockstate); 636 target = call_ifunc_resolver(ptr); 637 wlock_acquire(rtld_bind_lock, lockstate); 638 639 *where = target; 640 } 641 } 642 /* 643 * XXX Remove me when lld is fixed! 644 * LLD currently makes illegal relocations in the PLT. 645 */ 646 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize); 647 for (rela = obj->pltrela; rela < relalim; rela++) { 648 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) { 649 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend); 650 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 651 652 lock_release(rtld_bind_lock, lockstate); 653 target = call_ifunc_resolver(ptr); 654 wlock_acquire(rtld_bind_lock, lockstate); 655 656 *where = target; 657 } 658 } 659 660 obj->irelative = false; 661 return (0); 662} 663 664int 665reloc_iresolve_nonplt(Obj_Entry *obj __unused, 666 struct Struct_RtldLockState *lockstate __unused) 667{ 668 return (0); 669} 670 671int 672reloc_gnu_ifunc(Obj_Entry *obj __unused, int flags __unused, 673 struct Struct_RtldLockState *lockstate __unused) 674{ 675 const Elf_Rela *relalim; 676 const Elf_Rela *rela; 677 Elf_Addr *where, target; 678 const Elf_Sym *def; 679 const Obj_Entry *defobj; 680 681 if (!obj->gnu_ifunc) 682 return (0); 683 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize); 684 for (rela = obj->pltrela; rela < relalim; rela++) { 685 if (ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT) { 686 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 687 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, 688 SYMLOOK_IN_PLT | flags, NULL, lockstate); 689 if (def == NULL) 690 return (-1); 691 if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC) 692 continue; 693 lock_release(rtld_bind_lock, lockstate); 694 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 695 wlock_acquire(rtld_bind_lock, lockstate); 696 reloc_jmpslot(where, target, defobj, obj, 697 (const Elf_Rel *)rela); 698 } 699 } 700 obj->gnu_ifunc = false; 701 return (0); 702} 703 704/* 705 * Setup the plt glue routines. 706 */ 707#define PLTCALL_SIZE 20 708#define PLTLONGRESOLVE_SIZE 20 709#define PLTRESOLVE_SIZE 24 710 711void 712init_pltgot(Obj_Entry *obj) 713{ 714 Elf_Word *pltcall, *pltresolve, *pltlongresolve; 715 Elf_Word *jmptab; 716 int N = obj->pltrelasize / sizeof(Elf_Rela); 717 718 pltcall = obj->pltgot; 719 720 if (pltcall == NULL) { 721 return; 722 } 723 724 /* Handle Secure-PLT first, if applicable. */ 725 if (obj->gotptr != NULL) { 726 obj->gotptr[1] = (Elf_Addr)_rtld_bind_secureplt_start; 727 obj->gotptr[2] = (Elf_Addr)obj; 728 dbg("obj %s secure-plt gotptr=%p start=%p obj=%p", 729 obj->path, obj->gotptr, 730 (void *)obj->gotptr[1], (void *)obj->gotptr[2]); 731 return; 732 } 733 734 /* 735 * From the SVR4 PPC ABI: 736 * 737 * 'The first 18 words (72 bytes) of the PLT are reserved for 738 * use by the dynamic linker. 739 * ... 740 * 'If the executable or shared object requires N procedure 741 * linkage table entries, the link editor shall reserve 3*N 742 * words (12*N bytes) following the 18 reserved words. The 743 * first 2*N of these words are the procedure linkage table 744 * entries themselves. The static linker directs calls to bytes 745 * (72 + (i-1)*8), for i between 1 and N inclusive. The remaining 746 * N words (4*N bytes) are reserved for use by the dynamic linker.' 747 */ 748 749 /* 750 * Copy the absolute-call assembler stub into the first part of 751 * the reserved PLT area. 752 */ 753 memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE); 754 755 /* 756 * Determine the address of the jumptable, which is the dyn-linker 757 * reserved area after the call cells. Write the absolute address 758 * of the jumptable into the absolute-call assembler code so it 759 * can determine this address. 760 */ 761 jmptab = obj->pltgot + JMPTAB_BASE(N); 762 pltcall[1] |= _ppc_ha(jmptab); /* addis 11,11,jmptab@ha */ 763 pltcall[2] |= _ppc_la(jmptab); /* lwz 11,jmptab@l(11) */ 764 765 /* 766 * Skip down 20 bytes into the initial reserved area and copy 767 * in the standard resolving assembler call. Into this assembler, 768 * insert the absolute address of the _rtld_bind_start routine 769 * and the address of the relocation object. 770 * 771 * We place pltlongresolve first, so it can fix up its arguments 772 * and then fall through to the regular PLT resolver. 773 */ 774 pltlongresolve = obj->pltgot + 5; 775 776 memcpy(pltlongresolve, _rtld_powerpc_pltlongresolve, 777 PLTLONGRESOLVE_SIZE); 778 pltlongresolve[0] |= _ppc_ha(jmptab); /* lis 12,jmptab@ha */ 779 pltlongresolve[1] |= _ppc_la(jmptab); /* addi 12,12,jmptab@l */ 780 781 pltresolve = pltlongresolve + PLTLONGRESOLVE_SIZE/sizeof(uint32_t); 782 memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE); 783 pltresolve[0] |= _ppc_ha(_rtld_bind_start); 784 pltresolve[1] |= _ppc_la(_rtld_bind_start); 785 pltresolve[3] |= _ppc_ha(obj); 786 pltresolve[4] |= _ppc_la(obj); 787 788 /* 789 * The icache will be sync'd in reloc_plt, which is called 790 * after all the slots have been updated 791 */ 792} 793 794/* 795 * 32 bit cpu feature flag fields. 796 */ 797u_long cpu_features; 798u_long cpu_features2; 799 800void 801powerpc_abi_variant_hook(Elf_Auxinfo** aux_info) 802{ 803 /* 804 * Since aux_info[] is easier to work with than aux, go ahead and 805 * initialize cpu_features / cpu_features2. 806 */ 807 cpu_features = -1UL; 808 cpu_features2 = -1UL; 809 if (aux_info[AT_HWCAP] != NULL) 810 cpu_features = aux_info[AT_HWCAP]->a_un.a_val; 811 if (aux_info[AT_HWCAP2] != NULL) 812 cpu_features2 = aux_info[AT_HWCAP2]->a_un.a_val; 813} 814 815void 816ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused) 817{ 818 819} 820 821void 822allocate_initial_tls(Obj_Entry *list) 823{ 824 825 /* 826 * Fix the size of the static TLS block by using the maximum 827 * offset allocated so far and adding a bit for dynamic modules to 828 * use. 829 */ 830 831 tls_static_space = tls_last_offset + tls_last_size + 832 ld_static_tls_extra; 833 834 _tcb_set(allocate_tls(list, NULL, TLS_TCB_SIZE, TLS_TCB_ALIGN)); 835} 836 837void* 838__tls_get_addr(tls_index* ti) 839{ 840 uintptr_t **dtvp; 841 char *p; 842 843 dtvp = &_tcb_get()->tcb_dtv; 844 p = tls_get_addr_common(dtvp, ti->ti_module, ti->ti_offset); 845 846 return (p + TLS_DTV_OFFSET); 847} 848