dyld/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
  12  * file.
  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/x86_64/reloc.h>
  42 #include <mach-o/arm/reloc.h>
  43 #include <vector>
  44 #include <set>
  45
  46 #include "MachOFileAbstraction.hpp"
  47 #include "Architectures.hpp"
  48 #include "MachOLayout.hpp"
  49 #include "MachOTrie.hpp"
  50
  51
  52
  53 class AbstractRebaser
  54 {
  55 public:
  56         virtual cpu_type_t                                                      getArchitecture() const = 0;
  57         virtual uint64_t                                                        getBaseAddress() const = 0;
  58         virtual uint64_t                                                        getVMSize() const = 0;
  59         virtual void                                                            rebase(std::vector<void*>&) = 0;
  60 };
  61
  62
  63 template <typename A>
  64 class Rebaser : public AbstractRebaser
  65 {
  66 public:
  67                                                                                                 Rebaser(const MachOLayoutAbstraction&);
  68         virtual                                                                         ~Rebaser() {}
  69
  70         virtual cpu_type_t                                                      getArchitecture() const;
  71         virtual uint64_t                                                        getBaseAddress() const;
  72         virtual uint64_t                                                        getVMSize() const;
  73         virtual void                                                            rebase(std::vector<void*>&);
  74
  75 protected:
  76         typedef typename A::P                                   P;
  77         typedef typename A::P::E                                E;
  78         typedef typename A::P::uint_t                   pint_t;
  79
  80         pint_t*                                                                         mappedAddressForNewAddress(pint_t vmaddress);
  81         pint_t                                                                          getSlideForNewAddress(pint_t newAddress);
  82
  83 private:
  84         void                                                                            calculateRelocBase();
  85         void                                                                            adjustLoadCommands();
  86         void                                                                            adjustSymbolTable();
  87         void                                                                            optimzeStubs();
  88         void                                                                            makeNoPicStub(uint8_t* stub, pint_t logicalAddress);
  89         void                                                                            adjustDATA();
  90         void                                                                            adjustCode();
  91         void                                                                            applyRebaseInfo(std::vector<void*>& pointersInData);
  92         void                                                                            adjustExportInfo();
  93         void                                                                            doRebase(int segIndex, uint64_t segOffset, uint8_t type, std::vector<void*>& pointersInData);
  94         void                                                                            adjustSegmentLoadCommand(macho_segment_command<P>* seg);
  95         pint_t                                                                          getSlideForVMAddress(pint_t vmaddress);
  96         pint_t                                                                          maskedVMAddress(pint_t vmaddress);
  97         pint_t*                                                                         mappedAddressForVMAddress(pint_t vmaddress);
  98         pint_t*                                                                         mappedAddressForRelocAddress(pint_t r_address);
  99         void                                                                            adjustRelocBaseAddresses();
 100         const uint8_t*                                                          doCodeUpdateForEachULEB128Address(const uint8_t* p, uint8_t kind, uint64_t orgBaseAddress, int64_t codeToDataDelta, int64_t codeToImportDelta);
 101         void                                                                            doCodeUpdate(uint8_t kind, uint64_t address, int64_t codeToDataDelta, int64_t codeToImportDelta);
 102         void                                                                            doLocalRelocation(const macho_relocation_info<P>* reloc);
 103         bool                                                                            unequalSlides() const;
 104
 105 protected:
 106         const macho_header<P>*                                          fHeader;
 107         uint8_t*                                                                        fLinkEditBase;                          // add file offset to this to get linkedit content
 108         const MachOLayoutAbstraction&                           fLayout;
 109 private:
 110         pint_t                                                                          fOrignalVMRelocBaseAddress; // add reloc address to this to get original address reloc referred to
 111         const macho_symtab_command<P>*                          fSymbolTable;
 112         const macho_dysymtab_command<P>*                        fDynamicSymbolTable;
 113         const macho_dyld_info_command<P>*                       fDyldInfo;
 114         bool                                                                            fSplittingSegments;
 115         bool                                                                            fOrignalVMRelocBaseAddressValid;
 116         pint_t                                                                          fSkipSplitSegInfoStart;
 117         pint_t                                                                          fSkipSplitSegInfoEnd;
 118 };
 119
 120
 121
 122 template <typename A>
 123 Rebaser<A>::Rebaser(const MachOLayoutAbstraction& layout)
 124  :      fLayout(layout), fOrignalVMRelocBaseAddress(0), fLinkEditBase(0),
 125         fSymbolTable(NULL), fDynamicSymbolTable(NULL), fDyldInfo(NULL), fSplittingSegments(false),
 126         fOrignalVMRelocBaseAddressValid(false), fSkipSplitSegInfoStart(0), fSkipSplitSegInfoEnd(0)
 127 {
 128         fHeader = (const macho_header<P>*)fLayout.getSegments()[0].mappedAddress();
 129         switch ( fHeader->filetype() ) {
 130                 case MH_DYLIB:
 131                 case MH_BUNDLE:
 132                         break;
 133                 default:
 134                         throw "file is not a dylib or bundle";
 135         }
 136
 137         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 138         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 139                 const MachOLayoutAbstraction::Segment& seg = *it;
 140                 if ( strcmp(seg.name(), "__LINKEDIT") == 0 ) {
 141                         fLinkEditBase = (uint8_t*)seg.mappedAddress() - seg.fileOffset();
 142                         break;
 143                 }
 144         }
 145         if ( fLinkEditBase == NULL )
 146                 throw "no __LINKEDIT segment";
 147
 148         // get symbol table info
 149         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 150         const uint32_t cmd_count = fHeader->ncmds();
 151         const macho_load_command<P>* cmd = cmds;
 152         for (uint32_t i = 0; i < cmd_count; ++i) {
 153                 switch (cmd->cmd()) {
 154                         case LC_SYMTAB:
 155                                 fSymbolTable = (macho_symtab_command<P>*)cmd;
 156                                 break;
 157                         case LC_DYSYMTAB:
 158                                 fDynamicSymbolTable = (macho_dysymtab_command<P>*)cmd;
 159                                 break;
 160                         case LC_DYLD_INFO:
 161                         case LC_DYLD_INFO_ONLY:
 162                                 fDyldInfo = (macho_dyld_info_command<P>*)cmd;
 163                                 break;
 164                 }
 165                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 166         }
 167
 168         calculateRelocBase();
 169
 170         fSplittingSegments = layout.hasSplitSegInfo() && this->unequalSlides();
 171 }
 172
 173 template <> cpu_type_t Rebaser<x86>::getArchitecture()    const { return CPU_TYPE_I386; }
 174 template <> cpu_type_t Rebaser<x86_64>::getArchitecture() const { return CPU_TYPE_X86_64; }
 175 template <> cpu_type_t Rebaser<arm>::getArchitecture() const { return CPU_TYPE_ARM; }
 176 template <> cpu_type_t Rebaser<arm64>::getArchitecture() const { return CPU_TYPE_ARM64; }
 177
 178 template <typename A>
 179 bool Rebaser<A>::unequalSlides() const
 180 {
 181         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 182         uint64_t slide = segments[0].newAddress() - segments[0].address();
 183         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 184                 const MachOLayoutAbstraction::Segment& seg = *it;
 185                 if ( (seg.newAddress() - seg.address()) != slide )
 186                         return true;
 187         }
 188         return false;
 189 }
 190
 191 template <typename A>
 192 uint64_t Rebaser<A>::getBaseAddress() const
 193 {
 194         return fLayout.getSegments()[0].address();
 195 }
 196
 197 template <typename A>
 198 uint64_t Rebaser<A>::getVMSize() const
 199 {
 200         uint64_t highestVMAddress = 0;
 201         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 202         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 203                 const MachOLayoutAbstraction::Segment& seg = *it;
 204                 if ( seg.address() > highestVMAddress )
 205                         highestVMAddress = seg.address();
 206         }
 207         return (((highestVMAddress - getBaseAddress()) + 4095) & (-4096));
 208 }
 209
 210
 211
 212 template <typename A>
 213 void Rebaser<A>::rebase(std::vector<void*>& pointersInData)
 214 {
 215         // update writable segments that have internal pointers
 216         if ( fDyldInfo != NULL )
 217                 this->applyRebaseInfo(pointersInData);
 218         else
 219                 this->adjustDATA();
 220
 221         // if splitting segments, update code-to-data references
 222         this->adjustCode();
 223
 224         // change address on relocs now that segments are split
 225         this->adjustRelocBaseAddresses();
 226
 227         // update load commands
 228         this->adjustLoadCommands();
 229
 230         // update symbol table
 231         this->adjustSymbolTable();
 232
 233         // optimize stubs
 234         this->optimzeStubs();
 235
 236         // update export info
 237         if ( fDyldInfo != NULL )
 238                 this->adjustExportInfo();
 239 }
 240
 241 template <>
 242 void Rebaser<x86>::adjustSegmentLoadCommand(macho_segment_command<P>* seg)
 243 {
 244         // __IMPORT segments are not-writable in shared cache
 245         if ( strcmp(seg->segname(), "__IMPORT") == 0 )
 246                 seg->set_initprot(VM_PROT_READ|VM_PROT_EXECUTE);
 247 }
 248
 249 template <typename A>
 250 void Rebaser<A>::adjustSegmentLoadCommand(macho_segment_command<P>* seg)
 251 {
 252 }
 253
 254
 255 template <typename A>
 256 void Rebaser<A>::adjustLoadCommands()
 257 {
 258         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 259         const uint32_t cmd_count = fHeader->ncmds();
 260         const macho_load_command<P>* cmd = cmds;
 261         for (uint32_t i = 0; i < cmd_count; ++i) {
 262                 switch ( cmd->cmd() ) {
 263                         case LC_ID_DYLIB:
 264                                 if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
 265                                         // clear timestamp so that any prebound clients are invalidated
 266                                         macho_dylib_command<P>* dylib  = (macho_dylib_command<P>*)cmd;
 267                                         dylib->set_timestamp(1);
 268                                 }
 269                                 break;
 270                         case LC_LOAD_DYLIB:
 271                         case LC_LOAD_WEAK_DYLIB:
 272                         case LC_REEXPORT_DYLIB:
 273                         case LC_LOAD_UPWARD_DYLIB:
 274                                 if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
 275                                         // clear expected timestamps so that this image will load with invalid prebinding
 276                                         macho_dylib_command<P>* dylib  = (macho_dylib_command<P>*)cmd;
 277                                         dylib->set_timestamp(2);
 278                                 }
 279                                 break;
 280                         case macho_routines_command<P>::CMD:
 281                                 // update -init command
 282                                 {
 283                                         struct macho_routines_command<P>* routines = (struct macho_routines_command<P>*)cmd;
 284                                         routines->set_init_address(routines->init_address() + this->getSlideForVMAddress(routines->init_address()));
 285                                 }
 286                                 break;
 287                         case macho_segment_command<P>::CMD:
 288                                 // update segment commands
 289                                 {
 290                                         macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
 291                                         this->adjustSegmentLoadCommand(seg);
 292                                         pint_t slide = this->getSlideForVMAddress(seg->vmaddr());
 293                                         seg->set_vmaddr(seg->vmaddr() + slide);
 294                                         macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 295                                         macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 296                                         for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 297                                                 sect->set_addr(sect->addr() + slide);
 298                                         }
 299                                 }
 300                                 break;
 301                 }
 302                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 303         }
 304 }
 305
 306 template <>
 307 uint64_t Rebaser<arm64>::maskedVMAddress(pint_t vmaddress)
 308 {
 309         return (vmaddress & 0x0FFFFFFFFFFFFFFF);
 310 }
 311
 312 template <typename A>
 313 typename A::P::uint_t Rebaser<A>::maskedVMAddress(pint_t vmaddress)
 314 {
 315         return vmaddress;
 316 }
 317
 318
 319 template <typename A>
 320 typename A::P::uint_t Rebaser<A>::getSlideForVMAddress(pint_t vmaddress)
 321 {
 322         pint_t vmaddr = this->maskedVMAddress(vmaddress);
 323         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 324         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 325                 const MachOLayoutAbstraction::Segment& seg = *it;
 326                 if ( (seg.address() <= vmaddr) && (seg.size() != 0) && ((vmaddr < (seg.address()+seg.size())) || (seg.address() == vmaddr)) ) {
 327                         return seg.newAddress() - seg.address();
 328                 }
 329         }
 330         throwf("vm address 0x%08llX not found", (uint64_t)vmaddr);
 331 }
 332
 333
 334 template <typename A>
 335 typename A::P::uint_t* Rebaser<A>::mappedAddressForVMAddress(pint_t vmaddress)
 336 {
 337         pint_t vmaddr = this->maskedVMAddress(vmaddress);
 338         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 339         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 340                 const MachOLayoutAbstraction::Segment& seg = *it;
 341                 if ( (seg.address() <= vmaddr) && (vmaddr < (seg.address()+seg.size())) ) {
 342                         return (pint_t*)((vmaddr - seg.address()) + (uint8_t*)seg.mappedAddress());
 343                 }
 344         }
 345         throwf("mappedAddressForVMAddress(0x%08llX) not found", (uint64_t)vmaddr);
 346 }
 347
 348 template <typename A>
 349 typename A::P::uint_t* Rebaser<A>::mappedAddressForNewAddress(pint_t vmaddress)
 350 {
 351         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 352         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 353                 const MachOLayoutAbstraction::Segment& seg = *it;
 354                 if ( (seg.newAddress() <= vmaddress) && (vmaddress < (seg.newAddress()+seg.size())) ) {
 355                         return (pint_t*)((vmaddress - seg.newAddress()) + (uint8_t*)seg.mappedAddress());
 356                 }
 357         }
 358         throwf("mappedAddressForNewAddress(0x%08llX) not found", (uint64_t)vmaddress);
 359 }
 360
 361 template <typename A>
 362 typename A::P::uint_t Rebaser<A>::getSlideForNewAddress(pint_t newAddress)
 363 {
 364         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 365         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 366                 const MachOLayoutAbstraction::Segment& seg = *it;
 367                 if ( (seg.newAddress() <= newAddress) && (newAddress < (seg.newAddress()+seg.size())) ) {
 368                         return seg.newAddress() - seg.address();
 369                 }
 370         }
 371         throwf("new address 0x%08llX not found", (uint64_t)newAddress);
 372 }
 373
 374 template <typename A>
 375 typename A::P::uint_t* Rebaser<A>::mappedAddressForRelocAddress(pint_t r_address)
 376 {
 377         if ( fOrignalVMRelocBaseAddressValid )
 378                 return this->mappedAddressForVMAddress(r_address + fOrignalVMRelocBaseAddress);
 379         else
 380                 throw "can't apply relocation.  Relocation base not known";
 381 }
 382
 383
 384 template <>
 385 void Rebaser<arm>::makeNoPicStub(uint8_t* stub, pint_t logicalAddress)
 386 {
 387         uint32_t* instructions = (uint32_t*)stub;
 388         if ( (LittleEndian::get32(instructions[0]) == 0xE59FC004) &&
 389                 (LittleEndian::get32(instructions[1]) == 0xE08FC00C) &&
 390                 (LittleEndian::get32(instructions[2]) == 0xE59CF000) ) {
 391                         uint32_t lazyPtrAddress = instructions[3] + logicalAddress + 12;
 392                         LittleEndian::set32(instructions[0], 0xE59FC000);               //      ldr ip, [pc, #0]
 393                         LittleEndian::set32(instructions[1], 0xE59CF000);               //      ldr pc, [ip]
 394                         LittleEndian::set32(instructions[2], lazyPtrAddress);   //      .long   L_foo$lazy_ptr
 395                         LittleEndian::set32(instructions[3], 0xE1A00000);               //      nop
 396         }
 397         else
 398                 fprintf(stderr, "unoptimized stub in %s at 0x%08X\n", fLayout.getFilePath(), logicalAddress);
 399 }
 400
 401
 402 #if 0
 403 // disable this optimization do allow cache to slide
 404 template <>
 405 void Rebaser<arm>::optimzeStubs()
 406 {
 407         // convert pic stubs to no-pic stubs in dyld shared cache
 408         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 409         const uint32_t cmd_count = fHeader->ncmds();
 410         const macho_load_command<P>* cmd = cmds;
 411         for (uint32_t i = 0; i < cmd_count; ++i) {
 412                 if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
 413                         macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
 414                         macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 415                         macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 416                         for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 417                                 if ( (sect->flags() & SECTION_TYPE) == S_SYMBOL_STUBS ) {
 418                                         const uint32_t stubSize = sect->reserved2();
 419                                         // ARM PIC stubs are 4 32-bit instructions long
 420                                         if ( stubSize == 16 ) {
 421                                                 uint32_t stubCount = sect->size() / 16;
 422                                                 pint_t stubLogicalAddress = sect->addr();
 423                                                 uint8_t* stubMappedAddress = (uint8_t*)mappedAddressForNewAddress(stubLogicalAddress);
 424                                                 for(uint32_t s=0; s < stubCount; ++s) {
 425                                                         makeNoPicStub(stubMappedAddress, stubLogicalAddress);
 426                                                         stubLogicalAddress += 16;
 427                                                         stubMappedAddress += 16;
 428                                                 }
 429                                         }
 430                                 }
 431                         }
 432                 }
 433                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 434         }
 435 }
 436 #endif
 437
 438 template <typename A>
 439 void Rebaser<A>::optimzeStubs()
 440 {
 441         // other architectures don't need stubs changed in shared cache
 442 }
 443
 444 template <typename A>
 445 void Rebaser<A>::adjustSymbolTable()
 446 {
 447         macho_nlist<P>* symbolTable = (macho_nlist<P>*)(&fLinkEditBase[fSymbolTable->symoff()]);
 448
 449         // walk all exports and slide their n_value
 450         macho_nlist<P>* lastExport = &symbolTable[fDynamicSymbolTable->iextdefsym()+fDynamicSymbolTable->nextdefsym()];
 451         for (macho_nlist<P>* entry = &symbolTable[fDynamicSymbolTable->iextdefsym()]; entry < lastExport; ++entry) {
 452                 if ( (entry->n_type() & N_TYPE) == N_SECT )
 453                         entry->set_n_value(entry->n_value() + this->getSlideForVMAddress(entry->n_value()));
 454         }
 455
 456         // walk all local symbols and slide their n_value (don't adjust any stabs)
 457         macho_nlist<P>*  lastLocal = &symbolTable[fDynamicSymbolTable->ilocalsym()+fDynamicSymbolTable->nlocalsym()];
 458         for (macho_nlist<P>* entry = &symbolTable[fDynamicSymbolTable->ilocalsym()]; entry < lastLocal; ++entry) {
 459                 if ( (entry->n_sect() != NO_SECT) && ((entry->n_type() & N_STAB) == 0) )
 460                         entry->set_n_value(entry->n_value() + this->getSlideForVMAddress(entry->n_value()));
 461         }
 462 }
 463
 464 template <typename A>
 465 void Rebaser<A>::adjustExportInfo()
 466 {
 467         // if no export info, nothing to adjust
 468         if ( fDyldInfo->export_size() == 0 )
 469                 return;
 470
 471         // since export info addresses are offsets from mach_header, everything in __TEXT is fine
 472         // only __DATA addresses need to be updated
 473         const uint8_t* start = fLayout.getDyldInfoExports();
 474         const uint8_t* end = &start[fDyldInfo->export_size()];
 475         std::vector<mach_o::trie::Entry> originalExports;
 476         try {
 477                 parseTrie(start, end, originalExports);
 478         }
 479         catch (const char* msg) {
 480                 throwf("%s in %s", msg, fLayout.getFilePath());
 481         }
 482
 483         std::vector<mach_o::trie::Entry> newExports;
 484         newExports.reserve(originalExports.size());
 485         pint_t baseAddress = this->getBaseAddress();
 486         pint_t baseAddressSlide = this->getSlideForVMAddress(baseAddress);
 487         for (std::vector<mach_o::trie::Entry>::iterator it=originalExports.begin(); it != originalExports.end(); ++it) {
 488                 // remove symbols used by the static linker only
 489                 if (       (strncmp(it->name, "$ld$", 4) == 0)
 490                                 || (strncmp(it->name, ".objc_class_name",16) == 0)
 491                                 || (strncmp(it->name, ".objc_category_name",19) == 0) ) {
 492                         //fprintf(stderr, "ignoring symbol %s\n", it->name);
 493                         continue;
 494                 }
 495                 // adjust symbols in slid segments
 496                 //uint32_t oldOffset = it->address;
 497                 it->address += (this->getSlideForVMAddress(it->address + baseAddress) - baseAddressSlide);
 498                 //fprintf(stderr, "orig=0x%08X, new=0x%08llX, sym=%s\n", oldOffset, it->address, it->name);
 499                 newExports.push_back(*it);
 500         }
 501
 502         // rebuild export trie
 503         std::vector<uint8_t> newExportTrieBytes;
 504         newExportTrieBytes.reserve(fDyldInfo->export_size());
 505         mach_o::trie::makeTrie(newExports, newExportTrieBytes);
 506         // align
 507         while ( (newExportTrieBytes.size() % sizeof(pint_t)) != 0 )
 508                 newExportTrieBytes.push_back(0);
 509
 510         // allocate new buffer and set export_off to use new buffer instead
 511         uint32_t newExportsSize = newExportTrieBytes.size();
 512         uint8_t* sideTrie = new uint8_t[newExportsSize];
 513         memcpy(sideTrie, &newExportTrieBytes[0], newExportsSize);
 514         fLayout.setDyldInfoExports(sideTrie);
 515         ((macho_dyld_info_command<P>*)fDyldInfo)->set_export_off(0); // invalidate old trie
 516         ((macho_dyld_info_command<P>*)fDyldInfo)->set_export_size(newExportsSize);
 517 }
 518
 519
 520
 521 template <typename A>
 522 void Rebaser<A>::doCodeUpdate(uint8_t kind, uint64_t address, int64_t codeToDataDelta, int64_t codeToImportDelta)
 523 {
 524         // begin hack for <rdar://problem/8253549> split seg info wrong for x86_64 stub helpers
 525         if ( (fSkipSplitSegInfoStart <= address) && (address < fSkipSplitSegInfoEnd) ) {
 526                 uint8_t* p = (uint8_t*)mappedAddressForVMAddress(address);
 527                 // only ignore split seg info for "push" instructions
 528                 if ( p[-1] == 0x68 )
 529                         return;
 530         }
 531         // end hack for <rdar://problem/8253549>
 532
 533         //fprintf(stderr, "doCodeUpdate(kind=%d, address=0x%0llX, dataDelta=0x%08llX, importDelta=0x%08llX, path=%s)\n",
 534         //                              kind, address, codeToDataDelta, codeToImportDelta, fLayout.getFilePath());
 535         uint32_t* p;
 536         uint32_t instruction;
 537         uint32_t value;
 538         uint64_t value64;
 539         switch (kind) {
 540                 case 1: // 32-bit pointer
 541                         p = (uint32_t*)mappedAddressForVMAddress(address);
 542                         value = A::P::E::get32(*p);
 543                         value += codeToDataDelta;
 544                          A::P::E::set32(*p, value);
 545                         break;
 546                 case 2: // 64-bit pointer
 547                         p = (uint32_t*)mappedAddressForVMAddress(address);
 548                         value64 =  A::P::E::get64(*(uint64_t*)p);
 549                         value64 += codeToDataDelta;
 550                          A::P::E::set64(*(uint64_t*)p, value64);
 551                         break;
 552                 case 4: // only used for i386, a reference to something in the IMPORT segment
 553                         p = (uint32_t*)mappedAddressForVMAddress(address);
 554                         value = A::P::E::get32(*p);
 555                         value += codeToImportDelta;
 556                          A::P::E::set32(*p, value);
 557                         break;
 558         case 5: // used by thumb2 movw
 559                         p = (uint32_t*)mappedAddressForVMAddress(address);
 560                         instruction = A::P::E::get32(*p);
 561                         // codeToDataDelta is always a multiple of 4096, so only top 4 bits of lo16 will ever need adjusting
 562                         value = (instruction & 0x0000000F) + (codeToDataDelta >> 12);
 563                         instruction = (instruction & 0xFFFFFFF0) | (value & 0x0000000F);
 564                         A::P::E::set32(*p, instruction);
 565                         break;
 566         case 6: // used by ARM movw
 567                         p = (uint32_t*)mappedAddressForVMAddress(address);
 568                         instruction = A::P::E::get32(*p);
 569                         // codeToDataDelta is always a multiple of 4096, so only top 4 bits of lo16 will ever need adjusting
 570                         value = ((instruction & 0x000F0000) >> 16) + (codeToDataDelta >> 12);
 571                         instruction = (instruction & 0xFFF0FFFF) | ((value <<16) & 0x000F0000);
 572                         A::P::E::set32(*p, instruction);
 573                         break;
 574                 case 0x10:
 575                 case 0x11:
 576                 case 0x12:
 577                 case 0x13:
 578                 case 0x14:
 579                 case 0x15:
 580                 case 0x16:
 581                 case 0x17:
 582                 case 0x18:
 583                 case 0x19:
 584                 case 0x1A:
 585                 case 0x1B:
 586                 case 0x1C:
 587                 case 0x1D:
 588                 case 0x1E:
 589                 case 0x1F:
 590                         // used by thumb2 movt (low nibble of kind is high 4-bits of paired movw)
 591                         {
 592                                 p = (uint32_t*)mappedAddressForVMAddress(address);
 593                                 instruction = A::P::E::get32(*p);
 594                                 // extract 16-bit value from instruction
 595                                 uint32_t i =    ((instruction & 0x00000400) >> 10);
 596                                 uint32_t imm4 =  (instruction & 0x0000000F);
 597                                 uint32_t imm3 = ((instruction & 0x70000000) >> 28);
 598                                 uint32_t imm8 = ((instruction & 0x00FF0000) >> 16);
 599                                 uint32_t imm16 = (imm4 << 12) | (i << 11) | (imm3 << 8) | imm8;
 600                                 // combine with codeToDataDelta and kind nibble
 601                                 uint32_t targetValue = (imm16 << 16) | ((kind & 0xF) << 12);
 602                                 uint32_t newTargetValue = targetValue + codeToDataDelta;
 603                                 // construct new bits slices
 604                                 uint32_t imm4_  = (newTargetValue & 0xF0000000) >> 28;
 605                                 uint32_t i_             = (newTargetValue & 0x08000000) >> 27;
 606                                 uint32_t imm3_  = (newTargetValue & 0x07000000) >> 24;
 607                                 uint32_t imm8_  = (newTargetValue & 0x00FF0000) >> 16;
 608                                 // update instruction to match codeToDataDelta
 609                                 uint32_t newInstruction = (instruction & 0x8F00FBF0) | imm4_ | (i_ << 10) | (imm3_ << 28) | (imm8_ << 16);
 610                                 A::P::E::set32(*p, newInstruction);
 611                         }
 612                         break;
 613                 case 0x20:
 614                 case 0x21:
 615                 case 0x22:
 616                 case 0x23:
 617                 case 0x24:
 618                 case 0x25:
 619                 case 0x26:
 620                 case 0x27:
 621                 case 0x28:
 622                 case 0x29:
 623                 case 0x2A:
 624                 case 0x2B:
 625                 case 0x2C:
 626                 case 0x2D:
 627                 case 0x2E:
 628                 case 0x2F:
 629                         // used by arm movt (low nibble of kind is high 4-bits of paired movw)
 630                         {
 631                                 p = (uint32_t*)mappedAddressForVMAddress(address);
 632                                 instruction = A::P::E::get32(*p);
 633                                 // extract 16-bit value from instruction
 634                                 uint32_t imm4 = ((instruction & 0x000F0000) >> 16);
 635                                 uint32_t imm12 = (instruction & 0x00000FFF);
 636                                 uint32_t imm16 = (imm4 << 12) | imm12;
 637                                 // combine with codeToDataDelta and kind nibble
 638                                 uint32_t targetValue = (imm16 << 16) | ((kind & 0xF) << 12);
 639                                 uint32_t newTargetValue = targetValue + codeToDataDelta;
 640                                 // construct new bits slices
 641                                 uint32_t imm4_  = (newTargetValue & 0xF0000000) >> 28;
 642                                 uint32_t imm12_ = (newTargetValue & 0x0FFF0000) >> 16;
 643                                 // update instruction to match codeToDataDelta
 644                                 uint32_t newInstruction = (instruction & 0xFFF0F000) | (imm4_ << 16) | imm12_;
 645                                 A::P::E::set32(*p, newInstruction);
 646                         }
 647                         break;
 648                 case 3: // used for arm64 ADRP
 649                         p = (uint32_t*)mappedAddressForVMAddress(address);
 650                         instruction = A::P::E::get32(*p);
 651                         if ( (instruction & 0x9F000000) == 0x90000000 ) {
 652                                 // codeToDataDelta is always a multiple of 4096, so only top 4 bits of lo16 will ever need adjusting
 653                                 value64 = ((instruction & 0x60000000) >> 17) | ((instruction & 0x00FFFFE0) << 9);
 654                                 value64 += codeToDataDelta;
 655                                 instruction = (instruction & 0x9F00001F) | ((value64 << 17) & 0x60000000) | ((value64 >> 9) & 0x00FFFFE0);
 656                                 A::P::E::set32(*p, instruction);
 657                         }
 658                         break;
 659                 default:
 660                         throwf("invalid kind=%d in split seg info", kind);
 661         }
 662 }
 663
 664 template <typename A>
 665 const uint8_t* Rebaser<A>::doCodeUpdateForEachULEB128Address(const uint8_t* p, uint8_t kind, uint64_t orgBaseAddress, int64_t codeToDataDelta, int64_t codeToImportDelta)
 666 {
 667         uint64_t address = 0;
 668         uint64_t delta = 0;
 669         uint32_t shift = 0;
 670         bool more = true;
 671         do {
 672                 uint8_t byte = *p++;
 673                 delta |= ((byte & 0x7F) << shift);
 674                 shift += 7;
 675                 if ( byte < 0x80 ) {
 676                         if ( delta != 0 ) {
 677                                 address += delta;
 678                                 doCodeUpdate(kind, address+orgBaseAddress, codeToDataDelta, codeToImportDelta);
 679                                 delta = 0;
 680                                 shift = 0;
 681                         }
 682                         else {
 683                                 more = false;
 684                         }
 685                 }
 686         } while (more);
 687         return p;
 688 }
 689
 690 template <typename A>
 691 void Rebaser<A>::adjustCode()
 692 {
 693         if ( fSplittingSegments ) {
 694                 // get uleb128 compressed runs of code addresses to update
 695                 const uint8_t* infoStart = NULL;
 696                 const uint8_t* infoEnd = NULL;
 697                 const macho_segment_command<P>* seg;
 698                 const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 699                 const uint32_t cmd_count = fHeader->ncmds();
 700                 const macho_load_command<P>* cmd = cmds;
 701                 for (uint32_t i = 0; i < cmd_count; ++i) {
 702                         switch (cmd->cmd()) {
 703                                 case LC_SEGMENT_SPLIT_INFO:
 704                                         {
 705                                                 const macho_linkedit_data_command<P>* segInfo = (macho_linkedit_data_command<P>*)cmd;
 706                                                 infoStart = &fLinkEditBase[segInfo->dataoff()];
 707                                                 infoEnd = &infoStart[segInfo->datasize()];
 708                                         }
 709                                         break;
 710                                 // begin hack for <rdar://problem/8253549> split seg info wrong for x86_64 stub helpers
 711                                 case macho_segment_command<P>::CMD:
 712                                         seg = (macho_segment_command<P>*)cmd;
 713                                         if ( (getArchitecture() == CPU_TYPE_X86_64) && (strcmp(seg->segname(), "__TEXT") == 0) ) {
 714                                                 const macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 715                                                 const macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 716                                                 for(const macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 717                                                         if ( strcmp(sect->sectname(), "__stub_helper") == 0 ) {
 718                                                                 fSkipSplitSegInfoStart = sect->addr();
 719                                                                 fSkipSplitSegInfoEnd = sect->addr() + sect->size() - 16;
 720                                                         }
 721                                                 }
 722                                         }
 723                                         break;
 724                                 // end hack for <rdar://problem/8253549> split seg info wrong for x86_64 stub helpers
 725                         }
 726                         cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 727                 }
 728                 // calculate how much we need to slide writable segments
 729                 const uint64_t orgBaseAddress = this->getBaseAddress();
 730                 int64_t codeToDataDelta = 0;
 731                 int64_t codeToImportDelta = 0;
 732                 const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 733                 const MachOLayoutAbstraction::Segment& codeSeg = segments[0];
 734                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 735                         const MachOLayoutAbstraction::Segment& dataSeg = *it;
 736                         if ( strcmp(dataSeg.name(), "__IMPORT") == 0 )
 737                                 codeToImportDelta = (dataSeg.newAddress() - codeSeg.newAddress()) - (dataSeg.address() - codeSeg.address());
 738                         else if ( dataSeg.writable() ) {
 739                                 if ( (strcmp(dataSeg.name(), "__DATA") != 0) && (strcmp(dataSeg.name(), "__OBJC") != 0) )
 740                                         throwf("only one rw segment named '__DATA' can be used in dylibs placed in the dyld shared cache (%s)", fLayout.getFilePath());
 741                                 codeToDataDelta = (dataSeg.newAddress() - codeSeg.newAddress()) - (dataSeg.address() - codeSeg.address());
 742                         }
 743                 }
 744                 // decompress and call doCodeUpdate() on each address
 745                 for(const uint8_t* p = infoStart; (*p != 0) && (p < infoEnd);) {
 746                         uint8_t kind = *p++;
 747                         p = this->doCodeUpdateForEachULEB128Address(p, kind, orgBaseAddress, codeToDataDelta, codeToImportDelta);
 748                 }
 749         }
 750 }
 751
 752 template <typename A>
 753 void Rebaser<A>::doRebase(int segIndex, uint64_t segOffset, uint8_t type, std::vector<void*>& pointersInData)
 754 {
 755         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 756         if ( segIndex > segments.size() )
 757                 throw "bad segment index in rebase info";
 758         const MachOLayoutAbstraction::Segment& seg = segments[segIndex];
 759         uint8_t*  mappedAddr = (uint8_t*)seg.mappedAddress() + segOffset;
 760         pint_t*   mappedAddrP = (pint_t*)mappedAddr;
 761         uint32_t* mappedAddr32 = (uint32_t*)mappedAddr;
 762         pint_t valueP;
 763         pint_t valuePnew;
 764         uint32_t value32;
 765         int32_t svalue32;
 766         int32_t svalue32new;
 767         switch ( type ) {
 768                 case REBASE_TYPE_POINTER:
 769                         valueP= P::getP(*mappedAddrP);
 770                         try {
 771                                 P::setP(*mappedAddrP, valueP + this->getSlideForVMAddress(valueP));
 772                         }
 773                         catch (const char* msg) {
 774                                 throwf("at offset=0x%08llX in seg=%s, pointer cannot be rebased because it does not point to __TEXT or __DATA. %s\n",
 775                                                 segOffset, seg.name(), msg);
 776                         }
 777                         break;
 778
 779                 case REBASE_TYPE_TEXT_ABSOLUTE32:
 780                         value32 = E::get32(*mappedAddr32);
 781                         E::set32(*mappedAddr32, value32 + this->getSlideForVMAddress(value32));
 782                         break;
 783
 784                 case REBASE_TYPE_TEXT_PCREL32:
 785                         svalue32 = E::get32(*mappedAddr32);
 786                         valueP = seg.address() + segOffset + 4 + svalue32;
 787                         valuePnew = valueP + this->getSlideForVMAddress(valueP);
 788                         svalue32new = seg.address() + segOffset + 4 - valuePnew;
 789                         E::set32(*mappedAddr32, svalue32new);
 790                         break;
 791
 792                 default:
 793                         throw "bad rebase type";
 794         }
 795         pointersInData.push_back(mappedAddr);
 796 }
 797
 798
 799 template <typename A>
 800 void Rebaser<A>::applyRebaseInfo(std::vector<void*>& pointersInData)
 801 {
 802         const uint8_t* p = &fLinkEditBase[fDyldInfo->rebase_off()];
 803         const uint8_t* end = &p[fDyldInfo->rebase_size()];
 804
 805         uint8_t type = 0;
 806         int segIndex;
 807         uint64_t segOffset = 0;
 808         uint32_t count;
 809         uint32_t skip;
 810         bool done = false;
 811         while ( !done && (p < end) ) {
 812                 uint8_t immediate = *p & REBASE_IMMEDIATE_MASK;
 813                 uint8_t opcode = *p & REBASE_OPCODE_MASK;
 814                 ++p;
 815                 switch (opcode) {
 816                         case REBASE_OPCODE_DONE:
 817                                 done = true;
 818                                 break;
 819                         case REBASE_OPCODE_SET_TYPE_IMM:
 820                                 type = immediate;
 821                                 break;
 822                         case REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
 823                                 segIndex = immediate;
 824                                 segOffset = read_uleb128(p, end);
 825                                 break;
 826                         case REBASE_OPCODE_ADD_ADDR_ULEB:
 827                                 segOffset += read_uleb128(p, end);
 828                                 break;
 829                         case REBASE_OPCODE_ADD_ADDR_IMM_SCALED:
 830                                 segOffset += immediate*sizeof(pint_t);
 831                                 break;
 832                         case REBASE_OPCODE_DO_REBASE_IMM_TIMES:
 833                                 for (int i=0; i < immediate; ++i) {
 834                                         doRebase(segIndex, segOffset, type, pointersInData);
 835                                         segOffset += sizeof(pint_t);
 836                                 }
 837                                 break;
 838                         case REBASE_OPCODE_DO_REBASE_ULEB_TIMES:
 839                                 count = read_uleb128(p, end);
 840                                 for (uint32_t i=0; i < count; ++i) {
 841                                         doRebase(segIndex, segOffset, type, pointersInData);
 842                                         segOffset += sizeof(pint_t);
 843                                 }
 844                                 break;
 845                         case REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB:
 846                                 doRebase(segIndex, segOffset, type, pointersInData);
 847                                 segOffset += read_uleb128(p, end) + sizeof(pint_t);
 848                                 break;
 849                         case REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB:
 850                                 count = read_uleb128(p, end);
 851                                 skip = read_uleb128(p, end);
 852                                 for (uint32_t i=0; i < count; ++i) {
 853                                         doRebase(segIndex, segOffset, type, pointersInData);
 854                                         segOffset += skip + sizeof(pint_t);
 855                                 }
 856                                 break;
 857                         default:
 858                                 throwf("bad rebase opcode %d", *p);
 859                 }
 860         }
 861 }
 862
 863 template <typename A>
 864 void Rebaser<A>::adjustDATA()
 865 {
 866         // walk all local relocations and slide every pointer
 867         const macho_relocation_info<P>* const relocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[fDynamicSymbolTable->locreloff()]);
 868         const macho_relocation_info<P>* const relocsEnd = &relocsStart[fDynamicSymbolTable->nlocrel()];
 869         for (const macho_relocation_info<P>* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
 870                 this->doLocalRelocation(reloc);
 871         }
 872
 873         // walk non-lazy-pointers and slide the ones that are LOCAL
 874         const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
 875         const uint32_t cmd_count = fHeader->ncmds();
 876         const macho_load_command<P>* cmd = cmds;
 877         for (uint32_t i = 0; i < cmd_count; ++i) {
 878                 if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
 879                         const macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
 880                         const macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
 881                         const macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
 882                         const uint32_t* const indirectTable = (uint32_t*)(&fLinkEditBase[fDynamicSymbolTable->indirectsymoff()]);
 883                         for(const macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
 884                                 if ( (sect->flags() & SECTION_TYPE) == S_NON_LAZY_SYMBOL_POINTERS ) {
 885                                         const uint32_t indirectTableOffset = sect->reserved1();
 886                                         uint32_t pointerCount = sect->size() / sizeof(pint_t);
 887                                         pint_t* nonLazyPointerAddr = this->mappedAddressForVMAddress(sect->addr());
 888                                         for (uint32_t j=0; j < pointerCount; ++j, ++nonLazyPointerAddr) {
 889                                                 if ( E::get32(indirectTable[indirectTableOffset + j]) == INDIRECT_SYMBOL_LOCAL ) {
 890                                                         pint_t value = A::P::getP(*nonLazyPointerAddr);
 891                                                         P::setP(*nonLazyPointerAddr, value + this->getSlideForVMAddress(value));
 892                                                 }
 893                                         }
 894                                 }
 895                         }
 896                 }
 897                 cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
 898         }
 899 }
 900
 901
 902 template <typename A>
 903 void Rebaser<A>::adjustRelocBaseAddresses()
 904 {
 905         // split seg file need reloc base to be first writable segment
 906         if ( fSplittingSegments && ((fHeader->flags() & MH_SPLIT_SEGS) == 0) ) {
 907
 908                 // get amount to adjust reloc address
 909                 int32_t relocAddressAdjust = 0;
 910                 const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 911                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 912                         const MachOLayoutAbstraction::Segment& seg = *it;
 913                         if ( seg.writable() ) {
 914                                 relocAddressAdjust = seg.address() - segments[0].address();
 915                                 break;
 916                         }
 917                 }
 918
 919                 // walk all local relocations and adjust every address
 920                 macho_relocation_info<P>* const relocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[fDynamicSymbolTable->locreloff()]);
 921                 macho_relocation_info<P>* const relocsEnd = &relocsStart[fDynamicSymbolTable->nlocrel()];
 922                 for (macho_relocation_info<P>* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
 923                         reloc->set_r_address(reloc->r_address()-relocAddressAdjust);
 924                 }
 925
 926                 // walk all external relocations and adjust every address
 927                 macho_relocation_info<P>* const externRelocsStart = (macho_relocation_info<P>*)(&fLinkEditBase[fDynamicSymbolTable->extreloff()]);
 928                 macho_relocation_info<P>* const externRelocsEnd = &externRelocsStart[fDynamicSymbolTable->nextrel()];
 929                 for (macho_relocation_info<P>* reloc=externRelocsStart; reloc < externRelocsEnd; ++reloc) {
 930                         reloc->set_r_address(reloc->r_address()-relocAddressAdjust);
 931                 }
 932         }
 933 }
 934
 935 template <>
 936 void Rebaser<x86_64>::adjustRelocBaseAddresses()
 937 {
 938         // x86_64 already have reloc base of first writable segment
 939 }
 940
 941
 942 template <>
 943 void Rebaser<x86_64>::doLocalRelocation(const macho_relocation_info<x86_64::P>* reloc)
 944 {
 945         if ( reloc->r_type() == X86_64_RELOC_UNSIGNED ) {
 946                 pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 947                 pint_t value = P::getP(*addr);
 948                 P::setP(*addr, value + this->getSlideForVMAddress(value));
 949         }
 950         else {
 951                 throw "invalid relocation type";
 952         }
 953 }
 954
 955 template <>
 956 void Rebaser<x86>::doLocalRelocation(const macho_relocation_info<P>* reloc)
 957 {
 958         if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
 959                 if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
 960                         pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 961                         pint_t value = P::getP(*addr);
 962                         P::setP(*addr, value + this->getSlideForVMAddress(value));
 963                 }
 964         }
 965         else {
 966                 macho_scattered_relocation_info<P>* sreloc = (macho_scattered_relocation_info<P>*)reloc;
 967                 if ( sreloc->r_type() == GENERIC_RELOC_PB_LA_PTR ) {
 968                         sreloc->set_r_value( sreloc->r_value() + this->getSlideForVMAddress(sreloc->r_value()) );
 969                 }
 970                 else {
 971                         throw "cannot rebase final linked image with scattered relocations";
 972                 }
 973         }
 974 }
 975
 976 template <typename A>
 977 void Rebaser<A>::doLocalRelocation(const macho_relocation_info<P>* reloc)
 978 {
 979         if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
 980                 if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
 981                         pint_t* addr = this->mappedAddressForRelocAddress(reloc->r_address());
 982                         pint_t value = P::getP(*addr);
 983                         P::setP(*addr, value + this->getSlideForVMAddress(value));
 984                 }
 985         }
 986         else {
 987                 throw "cannot rebase final linked image with scattered relocations";
 988         }
 989 }
 990
 991
 992 template <typename A>
 993 void Rebaser<A>::calculateRelocBase()
 994 {
 995         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
 996         if ( fHeader->flags() & MH_SPLIT_SEGS ) {
 997                 // reloc addresses are from the start of the first writable segment
 998                 for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
 999                         const MachOLayoutAbstraction::Segment& seg = *it;
1000                         if ( seg.writable() ) {
1001                                 // found first writable segment
1002                                 fOrignalVMRelocBaseAddress = seg.address();
1003                                 fOrignalVMRelocBaseAddressValid = true;
1004                         }
1005                 }
1006         }
1007         else {
1008                 // reloc addresses are from the start of the mapped file (base address)
1009                 fOrignalVMRelocBaseAddress = segments[0].address();
1010                 fOrignalVMRelocBaseAddressValid = true;
1011         }
1012 }
1013
1014
1015 template <>
1016 void Rebaser<x86_64>::calculateRelocBase()
1017 {
1018         // reloc addresses are always based from the start of the first writable segment
1019         const std::vector<MachOLayoutAbstraction::Segment>& segments = fLayout.getSegments();
1020         for(std::vector<MachOLayoutAbstraction::Segment>::const_iterator it = segments.begin(); it != segments.end(); ++it) {
1021                 const MachOLayoutAbstraction::Segment& seg = *it;
1022                 if ( seg.writable() ) {
1023                         // found first writable segment
1024                         fOrignalVMRelocBaseAddress = seg.address();
1025                         fOrignalVMRelocBaseAddressValid = true;
1026                 }
1027         }
1028 }
1029
1030
1031 #if 0
1032 class MultiArchRebaser
1033 {
1034 public:
1035                 MultiArchRebaser::MultiArchRebaser(const char* path, bool writable=false)
1036                  : fMappingAddress(0), fFileSize(0)
1037                 {
1038                         // map in whole file
1039                         int fd = ::open(path, (writable ? O_RDWR : O_RDONLY), 0);
1040                         if ( fd == -1 )
1041                                 throwf("can't open file, errno=%d", errno);
1042                         struct stat stat_buf;
1043                         if ( fstat(fd, &stat_buf) == -1)
1044                                 throwf("can't stat open file %s, errno=%d", path, errno);
1045                         if ( stat_buf.st_size < 20 )
1046                                 throwf("file too small %s", path);
1047                         const int prot = writable ? (PROT_READ | PROT_WRITE) : PROT_READ;
1048                         const int flags = writable ? (MAP_FILE | MAP_SHARED) : (MAP_FILE | MAP_PRIVATE);
1049                         uint8_t* p = (uint8_t*)::mmap(NULL, stat_buf.st_size, prot, flags, fd, 0);
1050                         if ( p == (uint8_t*)(-1) )
1051                                 throwf("can't map file %s, errno=%d", path, errno);
1052                         ::close(fd);
1053
1054                         // if fat file, process each architecture
1055                         const fat_header* fh = (fat_header*)p;
1056                         const mach_header* mh = (mach_header*)p;
1057                         if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
1058                                 // Fat header is always big-endian
1059                                 const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
1060                                 for (unsigned long i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
1061                                         uint32_t fileOffset = OSSwapBigToHostInt32(archs[i].offset);
1062                                         try {
1063                                                 switch ( OSSwapBigToHostInt32(archs[i].cputype) ) {
1064                                                         case CPU_TYPE_I386:
1065                                                                 fRebasers.push_back(new Rebaser<x86>(&p[fileOffset]));
1066                                                                 break;
1067                                                         case CPU_TYPE_X86_64:
1068                                                                 fRebasers.push_back(new Rebaser<x86_64>(&p[fileOffset]));
1069                                                                 break;
1070                                                         case CPU_TYPE_ARM:
1071                                                                 fRebasers.push_back(new Rebaser<arm>(&p[fileOffset]));
1072                                                                 break;
1073                                                         default:
1074                                                                 throw "unknown file format";
1075                                                 }
1076                                         }
1077                                         catch (const char* msg) {
1078                                                 fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
1079                                         }
1080                                 }
1081                         }
1082                         else {
1083                                 try {
1084                                         if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_I386)) {
1085                                                 fRebasers.push_back(new Rebaser<x86>(mh));
1086                                         }
1087                                         else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_X86_64)) {
1088                                                 fRebasers.push_back(new Rebaser<x86_64>(mh));
1089                                         }
1090                                         else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_ARM)) {
1091                                                 fRebasers.push_back(new Rebaser<arm>(mh));
1092                                         }
1093                                         else {
1094                                                 throw "unknown file format";
1095                                         }
1096                                 }
1097                                 catch (const char* msg) {
1098                                         fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
1099                                 }
1100                         }
1101
1102                         fMappingAddress = p;
1103                         fFileSize = stat_buf.st_size;
1104                 }
1105
1106
1107                 ~MultiArchRebaser()     {::munmap(fMappingAddress, fFileSize); }
1108
1109         const std::vector<AbstractRebaser*>&            getArchs() const { return fRebasers; }
1110         void                                                                            commit()                { ::msync(fMappingAddress, fFileSize, MS_ASYNC);  }
1111
1112 private:
1113         std::vector<AbstractRebaser*>                           fRebasers;
1114         void*                                                                           fMappingAddress;
1115         uint64_t                                                                        fFileSize;
1116 };
1117 #endif
1118
1119
1120 #endif // __MACHO_REBASER__
1121
1122
1123
1124