launch-cache/MachORebaser.hpp

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
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   7  * This file contains Original Code and/or Modifications of Original Code
   8  * as defined in and that are subject to the Apple Public Source License
   9  * Version 2.0 (the 'License'). You may not use this file except in
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  11  * http://www.opensource.apple.com/apsl/ and read it before using this
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  13  *
  14  * The Original Code and all software distributed under the License are
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  24
  25 #ifndef __MACHO_REBASER__
  26 #define __MACHO_REBASER__
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <sys/mman.h>
  31 #include <mach/mach.h>
  32 #include <limits.h>
  33 #include <stdarg.h>
  34 #include <stdio.h>
  35 #include <fcntl.h>
  36 #include <errno.h>
  37 #include <unistd.h>
  38 #include <mach-o/loader.h>
  39 #include <mach-o/fat.h>
  40 #include <mach-o/reloc.h>
  41 #include <mach-o/ppc/reloc.h>
  42 #include <mach-o/x86_64/reloc.h>
  43 #include <vector>
  44 #include <set>
  45
  46 #include "MachOFileAbstraction.hpp"
  47 #include "Architectures.hpp"
  48 #include "MachOLayout.hpp"
  49
  50
  51
  52 class AbstractRebaser
  53 {
  54 public:
  55         virtual cpu_type_t                                                      getArchitecture() const = 0;
  56         virtual uint64_t                                                        getBaseAddress() const = 0;
  57         virtual uint64_t                                                        getVMSize() const = 0;
  58         virtual void                                                            rebase() = 0;
  59 };
  60
  61
  62 template <typename A>
  63 class Rebaser : public AbstractRebaser
  64 {
  65 public:
  66                                                                                                 Rebaser(const MachOLayoutAbstraction&);
  67         virtual                                                                         ~Rebaser() {}
  68
  69         virtual cpu_type_t                                                      getArchitecture() const;
  70         virtual uint64_t                                                        getBaseAddress() const;
  71         virtual uint64_t                                                        getVMSize() const;
  72         virtual void                                                            rebase();
  73
  74 protected:
  75         typedef typename A::P                                   P;
  76         typedef typename A::P::E                                E;
  77         typedef typename A::P::uint_t                   pint_t;
  78
  79         pint_t*                                                                         mappedAddressForNewAddress(pint_t vmaddress);
  80         pint_t                                                                          getSlideForNewAddress(pint_t newAddress);
  81
  82 private:
  83         pint_t                                                                          calculateRelocBase();
  84         void                                                                            adjustLoadCommands();
  85         void                                                                            adjustSymbolTable();
  86         void                                                                            adjustDATA();
  87         void                                                                            adjustCode();
  88         void                                                                            adjustSegmentLoadCommand(macho_segment_command<P>* seg);
  89         pint_t                                                                          getSlideForVMAddress(pint_t vmaddress);
  90         pint_t*                                                                         mappedAddressForVMAddress(pint_t vmaddress);
  91         pint_t*                                                                         mappedAddressForRelocAddress(pint_t r_address);
  92         void                                                                            adjustRelocBaseAddresses();
  93         const uint8_t*                                                          doCodeUpdateForEachULEB128Address(const uint8_t* p, uint8_t kind, uint64_t orgBaseAddress, int64_t codeToDataDelta, int64_t codeToImportDelta);
  94         void                                                                            doCodeUpdate(uint8_t kind, uint64_t address, int64_t codeToDataDelta, int64_t codeToImportDelta);
  95         void                                                                            doLocalRelocation(const macho_relocation_info<P>* reloc);
  96         bool                                                                            unequalSlides() const;
  97
  98 protected:
  99         const macho_header<P>*                                          fHeader;
 100         uint8_t*                                                                        fLinkEditBase;                          // add file offset to this to get linkedit content
 101         const MachOLayoutAbstraction&                           fLayout;
 102 private:
 103         pint_t                                                                          fOrignalVMRelocBaseAddress; // add reloc address to this to get original address reloc referred to
 104         bool                                                                            fSplittingSegments;
 105 };
 106
 107
 108
 109 template <typename A>
 110 Rebaser<A>::Rebaser(const MachOLayoutAbstraction& layout)
 111  :      fLayout(layout), fOrignalVMRelocBaseAddress(NULL), fLinkEditBase(NULL), fSplittingSegments(false)
 112 {
 113         fHeader = (const macho_header<P>*)fLayout.getSegments()[0].mappedAddress();
 114         switch ( fHeader->filetype() ) {
 115                 case MH_DYLIB:
 116                 case MH_BUNDLE:
 117                         break;
 118                 default:
 119                         throw "file is not a dylib or bundle";
 120         }
 121
 122         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 123         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 124                 const MachOLayoutAbstraction::Segment& seg = *it;
 125                 if ( strcmp(seg.name(), "__LINKEDIT") == 0 ) {
 126                         fLinkEditBase = (uint8_t*)seg.mappedAddress() - seg.fileOffset();
 127                         break;
 128                 }
 129         }
 130         if ( fLinkEditBase == NULL )
 131                 throw "no __LINKEDIT segment";
 132
 133         fOrignalVMRelocBaseAddress = calculateRelocBase();
 134
 135         fSplittingSegments = layout.hasSplitSegInfo() && this->unequalSlides();
 136 }
 137
 138 template <> cpu_type_t Rebaser<ppc>::getArchitecture()    const { return CPU_TYPE_POWERPC; }
 139 template <> cpu_type_t Rebaser<ppc64>::getArchitecture()  const { return CPU_TYPE_POWERPC64; }
 140 template <> cpu_type_t Rebaser<x86>::getArchitecture()    const { return CPU_TYPE_I386; }
 141 template <> cpu_type_t Rebaser<x86_64>::getArchitecture() const { return CPU_TYPE_X86_64; }
 142
 143 template <typename A>
 144 bool Rebaser<A>::unequalSlides() const
 145 {
 146         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 147         uint64_t slide = segments[0].newAddress() - segments[0].address();
 148         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 149                 const MachOLayoutAbstraction::Segment& seg = *it;
 150                 if ( (seg.newAddress() - seg.address()) != slide )
 151                         return true;
 152         }
 153         return false;
 154 }
 155
 156 template <typename A>
 157 uint64_t Rebaser<A>::getBaseAddress() const
 158 {
 159         return fLayout.getSegments()[0].address();
 160 }
 161
 162 template <typename A>
 163 uint64_t Rebaser<A>::getVMSize() const
 164 {
 165         uint64_t highestVMAddress = 0;
 166         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 167         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 168                 const MachOLayoutAbstraction::Segment& seg = *it;
 169                 if ( seg.address() > highestVMAddress )
 170                         highestVMAddress = seg.address();
 171         }
 172         return (((highestVMAddress - getBaseAddress()) + 4095) & (-4096));
 173 }
 174
 175
 176
 177 template <typename A>
 178 void Rebaser<A>::rebase()
 179 {
 180         // update writable segments that have internal pointers
 181         this->adjustDATA();
 182
 183         // if splitting segments, update code-to-data references
 184         this->adjustCode();
 185
 186         // change address on relocs now that segments are split
 187         this->adjustRelocBaseAddresses();
 188
 189         // update load commands
 190         this->adjustLoadCommands();
 191
 192         // update symbol table
 193         this->adjustSymbolTable();
 194 }
 195
 196 template <>
 197 void Rebaser<x86>::adjustSegmentLoadCommand(macho_segment_command<P>* seg)
 198 {
 199         // __IMPORT segments are not-writable in shared cache
 200         if ( strcmp(seg->segname(), "__IMPORT") == 0 )
 201                 seg->set_initprot(VM_PROT_READ|VM_PROT_EXECUTE);
 202 }
 203
 204 template <typename A>
 205 void Rebaser<A>::adjustSegmentLoadCommand(macho_segment_command<P>* seg)
 206 {
 207 }
 208
 209
 210 template <typename A>
 211 void Rebaser<A>::adjustLoadCommands()
 212 {
 213         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 214         const uint32_t cmd_count = fHeader->ncmds();
 215         const macho_load_command<P>* cmd = cmds;
 216         for (uint32_t i = 0; i < cmd_count; ++i) {
 217                 switch ( cmd->cmd() ) {
 218                         case LC_ID_DYLIB:
 219                                 if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
 220                                         // clear timestamp so that any prebound clients are invalidated
 221                                         macho_dylib_command<P>* dylib  = (macho_dylib_command<P>*)cmd;
 222                                         dylib->set_timestamp(1);
 223                                 }
 224                                 break;
 225                         case LC_LOAD_DYLIB:
 226                         case LC_LOAD_WEAK_DYLIB:
 227                         case LC_REEXPORT_DYLIB:
 228                                 if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
 229                                         // clear expected timestamps so that this image will load with invalid prebinding
 230                                         macho_dylib_command<P>* dylib  = (macho_dylib_command<P>*)cmd;
 231                                         dylib->set_timestamp(2);
 232                                 }
 233                                 break;
 234                         case macho_routines_command<P>::CMD:
 235                                 // update -init command
 236                                 {
 237                                         struct macho_routines_command<P>* routines = (struct macho_routines_command<P>*)cmd;
 238                                         routines->set_init_address(routines->init_address() + this->getSlideForVMAddress(routines->init_address()));
 239                                 }
 240                                 break;
 241                         case macho_segment_command<P>::CMD:
 242                                 // update segment commands
 243                                 {
 244                                         macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
 245                                         this->adjustSegmentLoadCommand(seg);
 246                                         pint_t slide = this->getSlideForVMAddress(seg->vmaddr());
 247                                         seg->set_vmaddr(seg->vmaddr() + slide);
 248                                         macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 249                                         macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 250                                         for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 251                                                 sect->set_addr(sect->addr() + slide);
 252                                         }
 253                                 }
 254                                 break;
 255                 }
 256                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 257         }
 258 }
 259
 260
 261
 262 template <typename A>
 263 typename A::P::uint_t Rebaser<A>::getSlideForVMAddress(pint_t vmaddress)
 264 {
 265         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 266         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 267                 const MachOLayoutAbstraction::Segment& seg = *it;
 268                 if ( (seg.address() <= vmaddress) && (seg.size() != 0) && ((vmaddress < (seg.address()+seg.size())) || (seg.address() == vmaddress)) ) {
 269                         return seg.newAddress() - seg.address();
 270                 }
 271         }
 272         throwf("vm address 0x%08llX not found", (uint64_t)vmaddress);
 273 }
 274
 275
 276 template <typename A>
 277 typename A::P::uint_t* Rebaser<A>::mappedAddressForVMAddress(pint_t vmaddress)
 278 {
 279         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 280         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 281                 const MachOLayoutAbstraction::Segment& seg = *it;
 282                 if ( (seg.address() <= vmaddress) && (vmaddress < (seg.address()+seg.size())) ) {
 283                         return (pint_t*)((vmaddress - seg.address()) + (uint8_t*)seg.mappedAddress());
 284                 }
 285         }
 286         throwf("mappedAddressForVMAddress(0x%08llX) not found", (uint64_t)vmaddress);
 287 }
 288
 289 template <typename A>
 290 typename A::P::uint_t* Rebaser<A>::mappedAddressForNewAddress(pint_t vmaddress)
 291 {
 292         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 293         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 294                 const MachOLayoutAbstraction::Segment& seg = *it;
 295                 if ( (seg.newAddress() <= vmaddress) && (vmaddress < (seg.newAddress()+seg.size())) ) {
 296                         return (pint_t*)((vmaddress - seg.newAddress()) + (uint8_t*)seg.mappedAddress());
 297                 }
 298         }
 299         throwf("mappedAddressForNewAddress(0x%08llX) not found", (uint64_t)vmaddress);
 300 }
 301
 302 template <typename A>
 303 typename A::P::uint_t Rebaser<A>::getSlideForNewAddress(pint_t newAddress)
 304 {
 305         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 306         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 307                 const MachOLayoutAbstraction::Segment& seg = *it;
 308                 if ( (seg.newAddress() <= newAddress) && (newAddress < (seg.newAddress()+seg.size())) ) {
 309                         return seg.newAddress() - seg.address();
 310                 }
 311         }
 312         throwf("new address 0x%08llX not found", (uint64_t)newAddress);
 313 }
 314
 315 template <typename A>
 316 typename A::P::uint_t* Rebaser<A>::mappedAddressForRelocAddress(pint_t r_address)
 317 {
 318         return this->mappedAddressForVMAddress(r_address + fOrignalVMRelocBaseAddress);
 319 }
 320
 321
 322 template <typename A>
 323 void Rebaser<A>::adjustSymbolTable()
 324 {
 325         const macho_dysymtab_command<P>* dysymtab = NULL;
 326         macho_nlist<P>* symbolTable = NULL;
 327
 328         // get symbol table info
 329         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 330         const uint32_t cmd_count = fHeader->ncmds();
 331         const macho_load_command<P>* cmd = cmds;
 332         for (uint32_t i = 0; i < cmd_count; ++i) {
 333                 switch (cmd->cmd()) {
 334                         case LC_SYMTAB:
 335                                 {
 336                                         const macho_symtab_command<P>* symtab = (macho_symtab_command<P>*)cmd;
 337                                         symbolTable = (macho_nlist<P>*)(&fLinkEditBase[symtab->symoff()]);
 338                                 }
 339                                 break;
 340                         case LC_DYSYMTAB:
 341                                 dysymtab = (macho_dysymtab_command<P>*)cmd;
 342                                 break;
 343                 }
 344                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 345         }
 346
 347         // walk all exports and slide their n_value
 348         macho_nlist<P>* lastExport = &symbolTable[dysymtab->iextdefsym()+dysymtab->nextdefsym()];
 349         for (macho_nlist<P>* entry = &symbolTable[dysymtab->iextdefsym()]; entry < lastExport; ++entry) {
 350                 if ( (entry->n_type() & N_TYPE) == N_SECT )
 351                         entry->set_n_value(entry->n_value() + this->getSlideForVMAddress(entry->n_value()));
 352         }
 353
 354         // walk all local symbols and slide their n_value (don't adjust and stabs)
 355         macho_nlist<P>*  lastLocal = &symbolTable[dysymtab->ilocalsym()+dysymtab->nlocalsym()];
 356         for (macho_nlist<P>* entry = &symbolTable[dysymtab->ilocalsym()]; entry < lastLocal; ++entry) {
 357                 if ( (entry->n_sect() != NO_SECT) && ((entry->n_type() & N_STAB) == 0) )
 358                         entry->set_n_value(entry->n_value() + this->getSlideForVMAddress(entry->n_value()));
 359         }
 360 }
 361
 362
 363
 364
 365 template <typename A>
 366 void Rebaser<A>::doCodeUpdate(uint8_t kind, uint64_t address, int64_t codeToDataDelta, int64_t codeToImportDelta)
 367 {
 368         //fprintf(stderr, "doCodeUpdate(kind=%d, address=0x%0llX, dataDelta=0x%08llX, importDelta=0x%08llX)\n", kind, address, codeToDataDelta, codeToImportDelta);
 369         uint32_t* p;
 370         uint32_t instruction;
 371         uint32_t value;
 372         uint64_t value64;
 373         switch (kind) {
 374                 case 1: // 32-bit pointer
 375                         p = (uint32_t*)mappedAddressForVMAddress(address);
 376                         value = A::P::E::get32(*p);
 377                         value += codeToDataDelta;
 378                          A::P::E::set32(*p, value);
 379                         break;
 380                 case 2: // 64-bit pointer
 381                         p = (uint32_t*)mappedAddressForVMAddress(address);
 382                         value64 =  A::P::E::get64(*(uint64_t*)p);
 383                         value64 += codeToDataDelta;
 384                          A::P::E::set64(*(uint64_t*)p, value64);
 385                         break;
 386                 case 3: // used only for ppc/ppc64, an instruction that sets the hi16 of a register
 387                         // adjust low 16 bits of instruction which contain hi16 of distance to something in DATA
 388                         if ( (codeToDataDelta & 0xFFFF) != 0 )
 389                                 throwf("codeToDataDelta=0x%0llX is not a multiple of 64K", codeToDataDelta);
 390                         p = (uint32_t*)mappedAddressForVMAddress(address);
 391                         instruction = BigEndian::get32(*p);
 392                         uint16_t originalLo16 = instruction & 0x0000FFFF;
 393                         uint16_t delta64Ks = codeToDataDelta >> 16;
 394                         instruction = (instruction & 0xFFFF0000) | ((originalLo16+delta64Ks) & 0x0000FFFF);
 395                         BigEndian::set32(*p, instruction);
 396                         break;
 397                 case 4: // only used for i386, a reference to something in the IMPORT segment
 398                         p = (uint32_t*)mappedAddressForVMAddress(address);
 399                         value = A::P::E::get32(*p);
 400                         value += codeToImportDelta;
 401                          A::P::E::set32(*p, value);
 402                         break;
 403                 default:
 404                         throwf("invalid kind=%d in split seg info", kind);
 405         }
 406 }
 407
 408 template <typename A>
 409 const uint8_t* Rebaser<A>::doCodeUpdateForEachULEB128Address(const uint8_t* p, uint8_t kind, uint64_t orgBaseAddress, int64_t codeToDataDelta, int64_t codeToImportDelta)
 410 {
 411         uint64_t address = 0;
 412         uint64_t delta = 0;
 413         uint32_t shift = 0;
 414         bool more = true;
 415         do {
 416                 uint8_t byte = *p++;
 417                 delta |= ((byte & 0x7F) << shift);
 418                 shift += 7;
 419                 if ( byte < 0x80 ) {
 420                         if ( delta != 0 ) {
 421                                 address += delta;
 422                                 doCodeUpdate(kind, address+orgBaseAddress, codeToDataDelta, codeToImportDelta);
 423                                 delta = 0;
 424                                 shift = 0;
 425                         }
 426                         else {
 427                                 more = false;
 428                         }
 429                 }
 430         } while (more);
 431         return p;
 432 }
 433
 434 template <typename A>
 435 void Rebaser<A>::adjustCode()
 436 {
 437         if ( fSplittingSegments ) {
 438                 // get uleb128 compressed runs of code addresses to update
 439                 const uint8_t* infoStart = NULL;
 440                 const uint8_t* infoEnd = NULL;
 441                 const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 442                 const uint32_t cmd_count = fHeader->ncmds();
 443                 const macho_load_command<P>* cmd = cmds;
 444                 for (uint32_t i = 0; i < cmd_count; ++i) {
 445                         switch (cmd->cmd()) {
 446                                 case LC_SEGMENT_SPLIT_INFO:
 447                                         {
 448                                                 const macho_linkedit_data_command<P>* segInfo = (macho_linkedit_data_command<P>*)cmd;
 449                                                 infoStart = &fLinkEditBase[segInfo->dataoff()];
 450                                                 infoEnd = &infoStart[segInfo->datasize()];
 451                                         }
 452                                         break;
 453                         }
 454                         cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 455                 }
 456                 // calculate how much we need to slide writable segments
 457                 const uint64_t orgBaseAddress = this->getBaseAddress();
 458                 int64_t codeToDataDelta = 0;
 459                 int64_t codeToImportDelta = 0;
 460                 const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 461                 const MachOLayoutAbstraction::Segment& codeSeg = segments[0];
 462                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 463                         const MachOLayoutAbstraction::Segment& dataSeg = *it;
 464                         if ( strcmp(dataSeg.name(), "__IMPORT") == 0 )
 465                                 codeToImportDelta = (dataSeg.newAddress() - codeSeg.newAddress()) - (dataSeg.address() - codeSeg.address());
 466                         else if ( dataSeg.writable() )
 467                                 codeToDataDelta = (dataSeg.newAddress() - codeSeg.newAddress()) - (dataSeg.address() - codeSeg.address());
 468                 }
 469                 // decompress and call doCodeUpdate() on each address
 470                 for(const uint8_t* p = infoStart; *p != 0;) {
 471                         uint8_t kind = *p++;
 472                         p = this->doCodeUpdateForEachULEB128Address(p, kind, orgBaseAddress, codeToDataDelta, codeToImportDelta);
 473                 }
 474         }
 475 }
 476
 477
 478 template <typename A>
 479 void Rebaser<A>::adjustDATA()
 480 {
 481         const macho_dysymtab_command<P>* dysymtab = NULL;
 482
 483         // get symbol table info
 484         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 485         const uint32_t cmd_count = fHeader->ncmds();
 486         const macho_load_command<P>* cmd = cmds;
 487         for (uint32_t i = 0; i < cmd_count; ++i) {
 488                 switch (cmd->cmd()) {
 489                         case LC_DYSYMTAB:
 490                                 dysymtab = (macho_dysymtab_command<P>*)cmd;
 491                                 break;
 492                 }
 493                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 494         }
 495
 496
 497         // walk all local relocations and slide every pointer
 498         const macho_relocation_info<P>* const relocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[dysymtab->locreloff()]);
 499         const macho_relocation_info<P>* const relocsEnd = &relocsStart[dysymtab->nlocrel()];
 500         for (const macho_relocation_info<P>* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
 501                 this->doLocalRelocation(reloc);
 502         }
 503
 504         // walk non-lazy-pointers and slide the ones that are LOCAL
 505         cmd = cmds;
 506         for (uint32_t i = 0; i < cmd_count; ++i) {
 507                 if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
 508                         const macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
 509                         const macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 510                         const macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 511                         const uint32_t* const indirectTable = (uint32_t*)(&fLinkEditBase[dysymtab->indirectsymoff()]);
 512                         for(const macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 513                                 if ( (sect->flags() & SECTION_TYPE) == S_NON_LAZY_SYMBOL_POINTERS ) {
 514                                         const uint32_t indirectTableOffset = sect->reserved1();
 515                                         uint32_t pointerCount = sect->size() / sizeof(pint_t);
 516                                         pint_t* nonLazyPointerAddr = this->mappedAddressForVMAddress(sect->addr());
 517                                         for (uint32_t j=0; j < pointerCount; ++j, ++nonLazyPointerAddr) {
 518                                                 if ( E::get32(indirectTable[indirectTableOffset + j]) == INDIRECT_SYMBOL_LOCAL ) {
 519                                                         pint_t value = A::P::getP(*nonLazyPointerAddr);
 520                                                         P::setP(*nonLazyPointerAddr, value + this->getSlideForVMAddress(value));
 521                                                 }
 522                                         }
 523                                 }
 524                         }
 525                 }
 526                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 527         }
 528 }
 529
 530
 531 template <typename A>
 532 void Rebaser<A>::adjustRelocBaseAddresses()
 533 {
 534         // split seg file alreday have reloc base of first writable segment
 535         // only non-split-segs that are being split need this adjusted
 536         if ( (fHeader->flags() & MH_SPLIT_SEGS) == 0  ) {
 537
 538                 // get symbol table to find relocation records
 539                 const macho_dysymtab_command<P>* dysymtab = NULL;
 540                 const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 541                 const uint32_t cmd_count = fHeader->ncmds();
 542                 const macho_load_command<P>* cmd = cmds;
 543                 for (uint32_t i = 0; i < cmd_count; ++i) {
 544                         switch (cmd->cmd()) {
 545                                 case LC_DYSYMTAB:
 546                                         dysymtab = (macho_dysymtab_command<P>*)cmd;
 547                                         break;
 548                         }
 549                         cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 550                 }
 551
 552                 // get amount to adjust reloc address
 553                 int32_t relocAddressAdjust = 0;
 554                 const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 555                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 556                         const MachOLayoutAbstraction::Segment& seg = *it;
 557                         if ( seg.writable() ) {
 558                                 relocAddressAdjust = seg.address() - segments[0].address();
 559                                 break;
 560                         }
 561                 }
 562
 563                 // walk all local relocations and adjust every address
 564                 macho_relocation_info<P>* const relocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[dysymtab->locreloff()]);
 565                 macho_relocation_info<P>* const relocsEnd = &relocsStart[dysymtab->nlocrel()];
 566                 for (macho_relocation_info<P>* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
 567                         reloc->set_r_address(reloc->r_address()-relocAddressAdjust);
 568                 }
 569
 570                 // walk all external relocations and adjust every address
 571                 macho_relocation_info<P>* const externRelocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[dysymtab->extreloff()]);
 572                 macho_relocation_info<P>* const externRelocsEnd = &externRelocsStart[dysymtab->nextrel()];
 573                 for (macho_relocation_info<P>* reloc=externRelocsStart; reloc < externRelocsEnd; ++reloc) {
 574                         reloc->set_r_address(reloc->r_address()-relocAddressAdjust);
 575                 }
 576         }
 577 }
 578
 579 template <>
 580 void Rebaser<x86_64>::adjustRelocBaseAddresses()
 581 {
 582         // x86_64 already have reloc base of first writable segment
 583 }
 584
 585
 586 template <>
 587 void Rebaser<x86_64>::doLocalRelocation(const macho_relocation_info<x86_64::P>* reloc)
 588 {
 589         if ( reloc->r_type() == X86_64_RELOC_UNSIGNED ) {
 590                 pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 591                 pint_t value = P::getP(*addr);
 592                 P::setP(*addr, value + this->getSlideForVMAddress(value));
 593         }
 594         else {
 595                 throw "invalid relocation type";
 596         }
 597 }
 598
 599 template <>
 600 void Rebaser<ppc>::doLocalRelocation(const macho_relocation_info<P>* reloc)
 601 {
 602         if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
 603                 if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
 604                         pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 605                         pint_t value = P::getP(*addr);
 606                         P::setP(*addr, value + this->getSlideForVMAddress(value));
 607                 }
 608         }
 609         else {
 610                 macho_scattered_relocation_info<P>* sreloc = (macho_scattered_relocation_info<P>*)reloc;
 611                 if ( sreloc->r_type() == PPC_RELOC_PB_LA_PTR ) {
 612                         sreloc->set_r_value( sreloc->r_value() + this->getSlideForVMAddress(sreloc->r_value()) );
 613                 }
 614                 else {
 615                         throw "cannot rebase final linked image with scattered relocations";
 616                 }
 617         }
 618 }
 619
 620 template <>
 621 void Rebaser<x86>::doLocalRelocation(const macho_relocation_info<P>* reloc)
 622 {
 623         if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
 624                 if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
 625                         pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 626                         pint_t value = P::getP(*addr);
 627                         P::setP(*addr, value + this->getSlideForVMAddress(value));
 628                 }
 629         }
 630         else {
 631                 macho_scattered_relocation_info<P>* sreloc = (macho_scattered_relocation_info<P>*)reloc;
 632                 if ( sreloc->r_type() == GENERIC_RELOC_PB_LA_PTR ) {
 633                         sreloc->set_r_value( sreloc->r_value() + this->getSlideForVMAddress(sreloc->r_value()) );
 634                 }
 635                 else {
 636                         throw "cannot rebase final linked image with scattered relocations";
 637                 }
 638         }
 639 }
 640
 641 template <typename A>
 642 void Rebaser<A>::doLocalRelocation(const macho_relocation_info<P>* reloc)
 643 {
 644         if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
 645                 if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
 646                         pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 647                         pint_t value = P::getP(*addr);
 648                         P::setP(*addr, value + this->getSlideForVMAddress(value));
 649                 }
 650         }
 651         else {
 652                 throw "cannot rebase final linked image with scattered relocations";
 653         }
 654 }
 655
 656
 657 template <typename A>
 658 typename A::P::uint_t Rebaser<A>::calculateRelocBase()
 659 {
 660         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 661         if ( fHeader->flags() & MH_SPLIT_SEGS ) {
 662                 // reloc addresses are from the start of the first writable segment
 663                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 664                         const MachOLayoutAbstraction::Segment& seg = *it;
 665                         if ( seg.writable() ) {
 666                                 // found first writable segment
 667                                 return seg.address();
 668                         }
 669                 }
 670                 throw "no writable segment";
 671         }
 672         else {
 673                 // reloc addresses are from the start of the mapped file (base address)
 674                 return segments[0].address();
 675         }
 676 }
 677
 678 template <>
 679 ppc64::P::uint_t Rebaser<ppc64>::calculateRelocBase()
 680 {
 681         // reloc addresses either:
 682         // 1) from the first segment vmaddr if no writable segment is > 4GB from first segment vmaddr
 683         // 2) from start of first writable segment
 684         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 685         uint64_t threshold = segments[0].address() + 0x100000000ULL;
 686         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 687                 const MachOLayoutAbstraction::Segment& seg = *it;
 688                 if ( seg.writable() && (seg.address()+seg.size()) > threshold ) {
 689                         // found writable segment with address > 4GB past base address
 690                         return seg.address();
 691                 }
 692         }
 693         // just use base address
 694         return segments[0].address();
 695 }
 696
 697 template <>
 698 x86_64::P::uint_t Rebaser<x86_64>::calculateRelocBase()
 699 {
 700         // reloc addresses are always based from the start of the first writable segment
 701         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 702         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 703                 const MachOLayoutAbstraction::Segment& seg = *it;
 704                 if ( seg.writable() ) {
 705                         // found first writable segment
 706                         return seg.address();
 707                 }
 708         }
 709         throw "no writable segment";
 710 }
 711
 712
 713 #if 0
 714 class MultiArchRebaser
 715 {
 716 public:
 717                 MultiArchRebaser::MultiArchRebaser(const char* path, bool writable=false)
 718                  : fMappingAddress(0), fFileSize(0)
 719                 {
 720                         // map in whole file
 721                         int fd = ::open(path, (writable ? O_RDWR : O_RDONLY), 0);
 722                         if ( fd == -1 )
 723                                 throwf("can't open file, errno=%d", errno);
 724                         struct stat stat_buf;
 725                         if ( fstat(fd, &stat_buf) == -1)
 726                                 throwf("can't stat open file %s, errno=%d", path, errno);
 727                         if ( stat_buf.st_size < 20 )
 728                                 throwf("file too small %s", path);
 729                         const int prot = writable ? (PROT_READ | PROT_WRITE) : PROT_READ;
 730                         const int flags = writable ? (MAP_FILE | MAP_SHARED) : (MAP_FILE | MAP_PRIVATE);
 731                         uint8_t* p = (uint8_t*)::mmap(NULL, stat_buf.st_size, prot, flags, fd, 0);
 732                         if ( p == (uint8_t*)(-1) )
 733                                 throwf("can't map file %s, errno=%d", path, errno);
 734                         ::close(fd);
 735
 736                         // if fat file, process each architecture
 737                         const fat_header* fh = (fat_header*)p;
 738                         const mach_header* mh = (mach_header*)p;
 739                         if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
 740                                 // Fat header is always big-endian
 741                                 const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
 742                                 for (unsigned long i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
 743                                         uint32_t fileOffset = OSSwapBigToHostInt32(archs[i].offset);
 744                                         try {
 745                                                 switch ( OSSwapBigToHostInt32(archs[i].cputype) ) {
 746                                                         case CPU_TYPE_POWERPC:
 747                                                                 fRebasers.push_back(new Rebaser<ppc>(&p[fileOffset]));
 748                                                                 break;
 749                                                         case CPU_TYPE_POWERPC64:
 750                                                                 fRebasers.push_back(new Rebaser<ppc64>(&p[fileOffset]));
 751                                                                 break;
 752                                                         case CPU_TYPE_I386:
 753                                                                 fRebasers.push_back(new Rebaser<x86>(&p[fileOffset]));
 754                                                                 break;
 755                                                         case CPU_TYPE_X86_64:
 756                                                                 fRebasers.push_back(new Rebaser<x86_64>(&p[fileOffset]));
 757                                                                 break;
 758                                                         default:
 759                                                                 throw "unknown file format";
 760                                                 }
 761                                         }
 762                                         catch (const char* msg) {
 763                                                 fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
 764                                         }
 765                                 }
 766                         }
 767                         else {
 768                                 try {
 769                                         if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC)) {
 770                                                 fRebasers.push_back(new Rebaser<ppc>(mh));
 771                                         }
 772                                         else if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC64)) {
 773                                                 fRebasers.push_back(new Rebaser<ppc64>(mh));
 774                                         }
 775                                         else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_I386)) {
 776                                                 fRebasers.push_back(new Rebaser<x86>(mh));
 777                                         }
 778                                         else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_X86_64)) {
 779                                                 fRebasers.push_back(new Rebaser<x86_64>(mh));
 780                                         }
 781                                         else {
 782                                                 throw "unknown file format";
 783                                         }
 784                                 }
 785                                 catch (const char* msg) {
 786                                         fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
 787                                 }
 788                         }
 789
 790                         fMappingAddress = p;
 791                         fFileSize = stat_buf.st_size;
 792                 }
 793
 794
 795                 ~MultiArchRebaser()     {::munmap(fMappingAddress, fFileSize); }
 796
 797         const std::vector<AbstractRebaser*>&            getArchs() const { return fRebasers; }
 798         void                                                                            commit()                { ::msync(fMappingAddress, fFileSize, MS_ASYNC);  }
 799
 800 private:
 801         std::vector<AbstractRebaser*>                           fRebasers;
 802         void*                                                                           fMappingAddress;
 803         uint64_t                                                                        fFileSize;
 804 };
 805 #endif
 806
 807
 808 #endif // __MACHO_REBASER__
 809
 810
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