+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <mach/mach.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <mach-o/loader.h>
+#include <mach-o/fat.h>
+#include <mach-o/reloc.h>
+#include <mach-o/ppc/reloc.h>
+#include <mach-o/x86_64/reloc.h>
+#include <vector>
+#include <set>
+
+#include "MachOFileAbstraction.hpp"
+#include "Architectures.hpp"
+
+
+static bool verbose = false;
+
+__attribute__((noreturn))
+void throwf(const char* format, ...)
+{
+ va_list list;
+ char* p;
+ va_start(list, format);
+ vasprintf(&p, format, list);
+ va_end(list);
+
+ const char* t = p;
+ throw t;
+}
+
+
+class AbstractRebaser
+{
+public:
+ virtual cpu_type_t getArchitecture() const = 0;
+ virtual uint64_t getBaseAddress() const = 0;
+ virtual uint64_t getVMSize() const = 0;
+ virtual void setBaseAddress(uint64_t) = 0;
+};
+
+
+template <typename A>
+class Rebaser : public AbstractRebaser
+{
+public:
+ Rebaser(const void* machHeader);
+ virtual ~Rebaser() {}
+
+ virtual cpu_type_t getArchitecture() const;
+ virtual uint64_t getBaseAddress() const;
+ virtual uint64_t getVMSize() const;
+ virtual void setBaseAddress(uint64_t);
+
+private:
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+ struct vmmap { pint_t vmaddr; pint_t vmsize; pint_t fileoff; };
+
+ void setRelocBase();
+ void buildSectionTable();
+ void adjustLoadCommands();
+ void adjustSymbolTable();
+ void adjustDATA();
+ void doLocalRelocation(const macho_relocation_info<P>* reloc);
+ pint_t* mappedAddressForVMAddress(uint32_t vmaddress);
+
+ const macho_header<P>* fHeader;
+ pint_t fOrignalVMRelocBaseAddress;
+ pint_t fSlide;
+ pint_t fRelocBase;
+ std::vector<vmmap> fVMMApping;
+};
+
+
+
+class MultiArchRebaser
+{
+public:
+ MultiArchRebaser(const char* path, bool writable=false);
+ ~MultiArchRebaser();
+
+ const std::vector<AbstractRebaser*>& getArchs() const { return fRebasers; }
+ void commit();
+
+private:
+ std::vector<AbstractRebaser*> fRebasers;
+ void* fMappingAddress;
+ uint64_t fFileSize;
+};
+
+
+
+MultiArchRebaser::MultiArchRebaser(const char* path, bool writable)
+ : fMappingAddress(0), fFileSize(0)
+{
+ // map in whole file
+ int fd = ::open(path, (writable ? O_RDWR : O_RDONLY), 0);
+ if ( fd == -1 )
+ throwf("can't open file, errno=%d", errno);
+ struct stat stat_buf;
+ if ( fstat(fd, &stat_buf) == -1)
+ throwf("can't stat open file %s, errno=%d", path, errno);
+ if ( stat_buf.st_size < 20 )
+ throwf("file too small %s", path);
+ const int prot = writable ? (PROT_READ | PROT_WRITE) : PROT_READ;
+ const int flags = writable ? (MAP_FILE | MAP_SHARED) : (MAP_FILE | MAP_PRIVATE);
+ uint8_t* p = (uint8_t*)::mmap(NULL, stat_buf.st_size, prot, flags, fd, 0);
+ if ( p == (uint8_t*)(-1) )
+ throwf("can't map file %s, errno=%d", path, errno);
+ ::close(fd);
+
+ // if fat file, process each architecture
+ const fat_header* fh = (fat_header*)p;
+ const mach_header* mh = (mach_header*)p;
+ if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+ // Fat header is always big-endian
+ const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
+ for (unsigned long i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
+ uint32_t fileOffset = OSSwapBigToHostInt32(archs[i].offset);
+ try {
+ switch ( OSSwapBigToHostInt32(archs[i].cputype) ) {
+ case CPU_TYPE_POWERPC:
+ fRebasers.push_back(new Rebaser<ppc>(&p[fileOffset]));
+ break;
+ case CPU_TYPE_POWERPC64:
+ fRebasers.push_back(new Rebaser<ppc64>(&p[fileOffset]));
+ break;
+ case CPU_TYPE_I386:
+ fRebasers.push_back(new Rebaser<x86>(&p[fileOffset]));
+ break;
+ case CPU_TYPE_X86_64:
+ fRebasers.push_back(new Rebaser<x86_64>(&p[fileOffset]));
+ break;
+ default:
+ throw "unknown file format";
+ }
+ }
+ catch (const char* msg) {
+ fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
+ }
+ }
+ }
+ else {
+ try {
+ if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC)) {
+ fRebasers.push_back(new Rebaser<ppc>(mh));
+ }
+ else if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC64)) {
+ fRebasers.push_back(new Rebaser<ppc64>(mh));
+ }
+ else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_I386)) {
+ fRebasers.push_back(new Rebaser<x86>(mh));
+ }
+ else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_X86_64)) {
+ fRebasers.push_back(new Rebaser<x86_64>(mh));
+ }
+ else {
+ throw "unknown file format";
+ }
+ }
+ catch (const char* msg) {
+ fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
+ }
+ }
+
+ fMappingAddress = p;
+ fFileSize = stat_buf.st_size;
+}
+
+
+MultiArchRebaser::~MultiArchRebaser()
+{
+ ::munmap(fMappingAddress, fFileSize);
+}
+
+void MultiArchRebaser::commit()
+{
+ ::msync(fMappingAddress, fFileSize, MS_ASYNC);
+}
+
+
+
+template <typename A>
+Rebaser<A>::Rebaser(const void* machHeader)
+ : fHeader((const macho_header<P>*)machHeader)
+{
+ switch ( fHeader->filetype() ) {
+ case MH_DYLIB:
+ if ( (fHeader->flags() & MH_SPLIT_SEGS) != 0 )
+ throw "split-seg dylibs cannot be rebased";
+ break;
+ case MH_BUNDLE:
+ break;
+ default:
+ throw "file is not a dylib or bundle";
+ }
+
+}
+
+template <> cpu_type_t Rebaser<ppc>::getArchitecture() const { return CPU_TYPE_POWERPC; }
+template <> cpu_type_t Rebaser<ppc64>::getArchitecture() const { return CPU_TYPE_POWERPC64; }
+template <> cpu_type_t Rebaser<x86>::getArchitecture() const { return CPU_TYPE_I386; }
+template <> cpu_type_t Rebaser<x86_64>::getArchitecture() const { return CPU_TYPE_X86_64; }
+
+
+template <typename A>
+uint64_t Rebaser<A>::getBaseAddress() const
+{
+ uint64_t lowestSegmentAddress = LLONG_MAX;
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
+ if ( segCmd->vmaddr() < lowestSegmentAddress ) {
+ lowestSegmentAddress = segCmd->vmaddr();
+ }
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+ return lowestSegmentAddress;
+}
+
+template <typename A>
+uint64_t Rebaser<A>::getVMSize() const
+{
+ const macho_segment_command<P>* highestSegmentCmd = NULL;
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
+ if ( (highestSegmentCmd == NULL) || (segCmd->vmaddr() > highestSegmentCmd->vmaddr()) ) {
+ highestSegmentCmd = segCmd;
+ }
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+
+ return ((highestSegmentCmd->vmaddr() + highestSegmentCmd->vmsize() - this->getBaseAddress() + 4095) & (-4096));
+}
+
+
+template <typename A>
+void Rebaser<A>::setBaseAddress(uint64_t addr)
+{
+ // calculate slide
+ fSlide = addr - this->getBaseAddress();
+
+ // compute base address for relocations
+ this->setRelocBase();
+
+ // build cache of section index to section
+ this->buildSectionTable();
+
+ // update load commands
+ this->adjustLoadCommands();
+
+ // update symbol table
+ this->adjustSymbolTable();
+
+ // update writable segments that have internal pointers
+ this->adjustDATA();
+}
+
+template <typename A>
+void Rebaser<A>::adjustLoadCommands()
+{
+ const macho_segment_command<P>* highestSegmentCmd = NULL;
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch ( cmd->cmd() ) {
+ case LC_ID_DYLIB:
+ if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
+ // clear timestamp so that any prebound clients are invalidated
+ macho_dylib_command<P>* dylib = (macho_dylib_command<P>*)cmd;
+ dylib->set_timestamp(1);
+ }
+ break;
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
+ // clear expected timestamps so that this image will load with invalid prebinding
+ macho_dylib_command<P>* dylib = (macho_dylib_command<P>*)cmd;
+ dylib->set_timestamp(2);
+ }
+ break;
+ case macho_routines_command<P>::CMD:
+ // update -init command
+ {
+ struct macho_routines_command<P>* routines = (struct macho_routines_command<P>*)cmd;
+ routines->set_init_address(routines->init_address() + fSlide);
+ }
+ break;
+ case macho_segment_command<P>::CMD:
+ // update segment commands
+ {
+ macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
+ seg->set_vmaddr(seg->vmaddr() + fSlide);
+ macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
+ macho_section<P>* const sectionsEnd = §ionsStart[seg->nsects()];
+ for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
+ sect->set_addr(sect->addr() + fSlide);
+ }
+ }
+ break;
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+}
+
+
+template <typename A>
+void Rebaser<A>::buildSectionTable()
+{
+ // build vector of sections
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
+ vmmap mapping;
+ mapping.vmaddr = seg->vmaddr();
+ mapping.vmsize = seg->vmsize();
+ mapping.fileoff = seg->fileoff();
+ fVMMApping.push_back(mapping);
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+}
+
+
+template <typename A>
+void Rebaser<A>::adjustSymbolTable()
+{
+ const macho_dysymtab_command<P>* dysymtab = NULL;
+ macho_nlist<P>* symbolTable = NULL;
+
+ // get symbol table info
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd()) {
+ case LC_SYMTAB:
+ {
+ const macho_symtab_command<P>* symtab = (macho_symtab_command<P>*)cmd;
+ symbolTable = (macho_nlist<P>*)(((uint8_t*)fHeader) + symtab->symoff());
+ }
+ break;
+ case LC_DYSYMTAB:
+ dysymtab = (macho_dysymtab_command<P>*)cmd;
+ break;
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+
+ // walk all exports and slide their n_value
+ macho_nlist<P>* lastExport = &symbolTable[dysymtab->iextdefsym()+dysymtab->nextdefsym()];
+ for (macho_nlist<P>* entry = &symbolTable[dysymtab->iextdefsym()]; entry < lastExport; ++entry) {
+ if ( (entry->n_type() & N_TYPE) == N_SECT )
+ entry->set_n_value(entry->n_value() + fSlide);
+ }
+
+ // walk all local symbols and slide their n_value
+ macho_nlist<P>* lastLocal = &symbolTable[dysymtab->ilocalsym()+dysymtab->nlocalsym()];
+ for (macho_nlist<P>* entry = &symbolTable[dysymtab->ilocalsym()]; entry < lastLocal; ++entry) {
+ if ( entry->n_sect() != NO_SECT )
+ entry->set_n_value(entry->n_value() + fSlide);
+ }
+}
+
+template <typename A>
+void Rebaser<A>::adjustDATA()
+{
+ const macho_dysymtab_command<P>* dysymtab = NULL;
+
+ // get symbol table info
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd()) {
+ case LC_DYSYMTAB:
+ dysymtab = (macho_dysymtab_command<P>*)cmd;
+ break;
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+
+ // walk all local relocations and slide every pointer
+ const macho_relocation_info<P>* const relocsStart = (macho_relocation_info<P>*)(((uint8_t*)fHeader) + dysymtab->locreloff());
+ const macho_relocation_info<P>* const relocsEnd = &relocsStart[dysymtab->nlocrel()];
+ for (const macho_relocation_info<P>* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ this->doLocalRelocation(reloc);
+ }
+
+ // walk non-lazy-pointers and slide the ones that are LOCAL
+ cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
+ const macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)seg + sizeof(macho_segment_command<P>));
+ const macho_section<P>* const sectionsEnd = §ionsStart[seg->nsects()];
+ const uint32_t* const indirectTable = (uint32_t*)(((uint8_t*)fHeader) + dysymtab->indirectsymoff());
+ for(const macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags() & SECTION_TYPE) == S_NON_LAZY_SYMBOL_POINTERS ) {
+ const uint32_t indirectTableOffset = sect->reserved1();
+ uint32_t pointerCount = sect->size() / sizeof(pint_t);
+ pint_t* nonLazyPointer = (pint_t*)(((uint8_t*)fHeader) + sect->offset());
+ for (uint32_t i=0; i < pointerCount; ++i, ++nonLazyPointer) {
+ if ( E::get32(indirectTable[indirectTableOffset + i]) == INDIRECT_SYMBOL_LOCAL ) {
+ P::setP(*nonLazyPointer, A::P::getP(*nonLazyPointer) + fSlide);
+ }
+ }
+ }
+ }
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+
+}
+
+
+template <typename A>
+typename A::P::uint_t* Rebaser<A>::mappedAddressForVMAddress(uint32_t vmaddress)
+{
+ for(typename std::vector<vmmap>::iterator it = fVMMApping.begin(); it != fVMMApping.end(); ++it) {
+ //fprintf(stderr, "vmaddr=0x%08lX, vmsize=0x%08lX\n", it->vmaddr, it->vmsize);
+ if ( (vmaddress >= it->vmaddr) && (vmaddress < (it->vmaddr+it->vmsize)) ) {
+ return (pint_t*)((vmaddress - it->vmaddr) + it->fileoff + (uint8_t*)fHeader);
+ }
+ }
+ throwf("reloc address 0x%08X not found", vmaddress);
+}
+
+
+template <>
+void Rebaser<x86_64>::doLocalRelocation(const macho_relocation_info<x86_64::P>* reloc)
+{
+ if ( reloc->r_type() == X86_64_RELOC_UNSIGNED ) {
+ pint_t* addr = mappedAddressForVMAddress(reloc->r_address() + fOrignalVMRelocBaseAddress);
+ P::setP(*addr, P::getP(*addr) + fSlide);
+ }
+ else {
+ throw "invalid relocation type";
+ }
+}
+
+template <>
+void Rebaser<ppc>::doLocalRelocation(const macho_relocation_info<P>* reloc)
+{
+ if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
+ if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
+ pint_t* addr = mappedAddressForVMAddress(reloc->r_address() + fOrignalVMRelocBaseAddress);
+ P::setP(*addr, P::getP(*addr) + fSlide);
+ }
+ }
+ else {
+ macho_scattered_relocation_info<P>* sreloc = (macho_scattered_relocation_info<P>*)reloc;
+ if ( sreloc->r_type() == PPC_RELOC_PB_LA_PTR ) {
+ sreloc->set_r_value( sreloc->r_value() + fSlide );
+ }
+ else {
+ throw "cannot rebase final linked image with scattered relocations";
+ }
+ }
+}
+
+template <>
+void Rebaser<x86>::doLocalRelocation(const macho_relocation_info<P>* reloc)
+{
+ if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
+ if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
+ pint_t* addr = mappedAddressForVMAddress(reloc->r_address() + fOrignalVMRelocBaseAddress);
+ P::setP(*addr, P::getP(*addr) + fSlide);
+ }
+ }
+ else {
+ macho_scattered_relocation_info<P>* sreloc = (macho_scattered_relocation_info<P>*)reloc;
+ if ( sreloc->r_type() == GENERIC_RELOC_PB_LA_PTR ) {
+ sreloc->set_r_value( sreloc->r_value() + fSlide );
+ }
+ else {
+ throw "cannot rebase final linked image with scattered relocations";
+ }
+ }
+}
+
+template <typename A>
+void Rebaser<A>::doLocalRelocation(const macho_relocation_info<P>* reloc)
+{
+ if ( (reloc->r_address() & R_SCATTERED) == 0 ) {
+ if ( reloc->r_type() == GENERIC_RELOC_VANILLA ) {
+ pint_t* addr = mappedAddressForVMAddress(reloc->r_address() + fOrignalVMRelocBaseAddress);
+ P::setP(*addr, P::getP(*addr) + fSlide);
+ }
+ }
+ else {
+ throw "cannot rebase final linked image with scattered relocations";
+ }
+}
+
+
+template <typename A>
+void Rebaser<A>::setRelocBase()
+{
+ // reloc addresses are from the start of the mapped file (base address)
+ fRelocBase = (pint_t)fHeader;
+ fOrignalVMRelocBaseAddress = this->getBaseAddress();
+ //fprintf(stderr, "fOrignalVMRelocBaseAddress=0x%08X\n", fOrignalVMRelocBaseAddress);
+}
+
+template <>
+void Rebaser<ppc64>::setRelocBase()
+{
+ // reloc addresses either:
+ // 1) from the base address if no writable segment is > 4GB from base address
+ // 2) from start of first writable segment
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
+ if ( segCmd->initprot() & VM_PROT_WRITE ) {
+ if ( (segCmd->vmaddr() + segCmd->vmsize() - this->getBaseAddress()) > 0x100000000ULL ) {
+ // found writable segment with address > 4GB past base address
+ fRelocBase = segCmd->fileoff() + (pint_t)fHeader;
+ fOrignalVMRelocBaseAddress = segCmd->vmaddr();
+ return;
+ }
+ }
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+ // just use base address
+ fRelocBase = (pint_t)fHeader;
+ fOrignalVMRelocBaseAddress = this->getBaseAddress();
+}
+
+template <>
+void Rebaser<x86_64>::setRelocBase()
+{
+ // reloc addresses are always based from the start of the first writable segment
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)fHeader + sizeof(macho_header<P>));
+ const uint32_t cmd_count = fHeader->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
+ const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
+ if ( segCmd->initprot() & VM_PROT_WRITE ) {
+ fRelocBase = segCmd->fileoff() + (pint_t)fHeader;
+ fOrignalVMRelocBaseAddress = segCmd->vmaddr();
+ return;
+ }
+ }
+ cmd = (const macho_load_command<P>*)(((uint8_t*)cmd)+cmd->cmdsize());
+ }
+ throw "no writable segment";
+}
+
+
+static void copyFile(const char* srcFile, const char* dstFile)
+{
+ // open files
+ int src = open(srcFile, O_RDONLY);
+ if ( src == -1 )
+ throwf("can't open file %s, errno=%d", srcFile, errno);
+ struct stat stat_buf;
+ if ( fstat(src, &stat_buf) == -1)
+ throwf("can't stat open file %s, errno=%d", srcFile, errno);
+
+ // create new file with all same permissions to hold copy of dylib
+ ::unlink(dstFile);
+ int dst = open(dstFile, O_CREAT | O_RDWR | O_TRUNC, stat_buf.st_mode);
+ if ( dst == -1 )
+ throwf("can't create temp file %s, errnor=%d", dstFile, errno);
+
+ // mark source as "don't cache"
+ (void)fcntl(src, F_NOCACHE, 1);
+ // we want to cache the dst because we are about to map it in and modify it
+
+ // copy permission bits
+ if ( chmod(dstFile, stat_buf.st_mode & 07777) == -1 )
+ throwf("can't chmod temp file %s, errno=%d", dstFile, errno);
+ if ( chown(dstFile, stat_buf.st_uid, stat_buf.st_gid) == -1)
+ throwf("can't chown temp file %s, errno=%d", dstFile, errno);
+
+ // copy contents
+ ssize_t len;
+ const uint32_t kBufferSize = 128*1024;
+ static uint8_t* buffer = NULL;
+ if ( buffer == NULL ) {
+ vm_address_t addr = 0;
+ if ( vm_allocate(mach_task_self(), &addr, kBufferSize, true /*find range*/) == KERN_SUCCESS )
+ buffer = (uint8_t*)addr;
+ else
+ throw "can't allcoate copy buffer";
+ }
+ while ( (len = read(src, buffer, kBufferSize)) > 0 ) {
+ if ( write(dst, buffer, len) == -1 )
+ throwf("write failure copying feil %s, errno=%d", dstFile, errno);
+ }
+
+ // close files
+ int result1 = close(dst);
+ int result2 = close(src);
+ if ( (result1 != 0) || (result2 != 0) )
+ throw "can't close file";
+}
+
+
+// scan dylibs and collect size info
+// calculate new base address for each dylib
+// rebase each file
+// copy to temp and mmap
+// update content
+// unmap/flush
+// rename
+
+struct archInfo {
+ cpu_type_t arch;
+ uint64_t vmSize;
+ uint64_t orgBase;
+ uint64_t newBase;
+};
+
+struct fileInfo
+{
+ fileInfo(const char* p) : path(p) {}
+
+ const char* path;
+ std::vector<archInfo> archs;
+};
+
+//
+// add archInfos to fileInfo for every slice of a fat file
+// for ppc, there may be duplicate architectures (with different sub-types)
+//
+static void setSizes(fileInfo& info, const std::set<cpu_type_t>& onlyArchs)
+{
+ const MultiArchRebaser mar(info.path);
+ const std::vector<AbstractRebaser*>& rebasers = mar.getArchs();
+ for(std::set<cpu_type_t>::iterator ait=onlyArchs.begin(); ait != onlyArchs.end(); ++ait) {
+ for(std::vector<AbstractRebaser*>::const_iterator rit=rebasers.begin(); rit != rebasers.end(); ++rit) {
+ AbstractRebaser* rebaser = *rit;
+ if ( rebaser->getArchitecture() == *ait ) {
+ archInfo ai;
+ ai.arch = *ait;
+ ai.vmSize = rebaser->getVMSize();
+ ai.orgBase = rebaser->getBaseAddress();
+ ai.newBase = 0;
+ //fprintf(stderr, "base=0x%llX, size=0x%llX\n", ai.orgBase, ai.vmSize);
+ info.archs.push_back(ai);
+ }
+ }
+ }
+}
+
+static const char* nameForArch(cpu_type_t arch)
+{
+ switch( arch ) {
+ case CPU_TYPE_POWERPC:
+ return "ppc";
+ case CPU_TYPE_POWERPC64:
+ return "ppca64";
+ case CPU_TYPE_I386:
+ return "i386";
+ case CPU_TYPE_X86_64:
+ return "x86_64";
+ }
+ return "unknown";
+}
+
+static void rebase(const fileInfo& info)
+{
+ // generate temp file name
+ char realFilePath[PATH_MAX];
+ if ( realpath(info.path, realFilePath) == NULL ) {
+ throwf("realpath() failed on %s, errno=%d", info.path, errno);
+ }
+ const char* tempPath;
+ asprintf((char**)&tempPath, "%s_rebase", realFilePath);
+
+ // copy whole file to temp file
+ copyFile(info.path, tempPath);
+
+ try {
+ // rebase temp file
+ MultiArchRebaser mar(tempPath, true);
+ const std::vector<AbstractRebaser*>& rebasers = mar.getArchs();
+ for(std::vector<archInfo>::const_iterator fait=info.archs.begin(); fait != info.archs.end(); ++fait) {
+ for(std::vector<AbstractRebaser*>::const_iterator rit=rebasers.begin(); rit != rebasers.end(); ++rit) {
+ if ( (*rit)->getArchitecture() == fait->arch ) {
+ (*rit)->setBaseAddress(fait->newBase);
+ if ( verbose )
+ printf("%8s 0x%0llX -> 0x%0llX %s\n", nameForArch(fait->arch), fait->orgBase, fait->newBase, info.path);
+ }
+ }
+ }
+
+ // flush temp file out to disk
+ mar.commit();
+
+ // rename
+ int result = rename(tempPath, info.path);
+ if ( result != 0 ) {
+ throwf("can't swap temporary rebased file: rename(%s,%s) returned errno=%d", tempPath, info.path, errno);
+ }
+
+ // make sure every really gets out to disk
+ ::sync();
+ }
+ catch (const char* msg) {
+ // delete temp file
+ ::unlink(tempPath);
+
+ // throw exception with file name added
+ const char* newMsg;
+ asprintf((char**)&newMsg, "%s for file %s", msg, info.path);
+ throw newMsg;
+ }
+}
+
+static uint64_t totalVMSize(cpu_type_t arch, std::vector<fileInfo>& files)
+{
+ uint64_t totalSize = 0;
+ for(std::vector<fileInfo>::iterator fit=files.begin(); fit != files.end(); ++fit) {
+ fileInfo& fi = *fit;
+ for(std::vector<archInfo>::iterator fait=fi.archs.begin(); fait != fi.archs.end(); ++fait) {
+ if ( fait->arch == arch )
+ totalSize += fait->vmSize;
+ }
+ }
+ return totalSize;
+}
+
+static uint64_t startAddress(cpu_type_t arch, std::vector<fileInfo>& files, uint64_t lowAddress, uint64_t highAddress)
+{
+ if ( lowAddress != 0 )
+ return lowAddress;
+ else if ( highAddress != 0 ) {
+ uint64_t totalSize = totalVMSize(arch, files);
+ if ( highAddress < totalSize )
+ throwf("cannot use -high_address 0x%X because total size of images is greater: 0x%X", highAddress, totalSize);
+ return highAddress - totalSize;
+ }
+ else {
+ if ( (arch == CPU_TYPE_I386) || (arch == CPU_TYPE_POWERPC) ) {
+ // place dylibs below dyld
+ uint64_t topAddr = 0x8FE00000;
+ uint64_t totalSize = totalVMSize(arch, files);
+ if ( totalSize > topAddr )
+ throwf("total size of images (0x%X) does not fit below 0x8FE00000", totalSize);
+ return topAddr - totalSize;
+ }
+ else if ( arch == CPU_TYPE_POWERPC64 ) {
+ return 0x200000000ULL;
+ }
+ else if ( arch == CPU_TYPE_X86_64 ) {
+ return 0x200000000ULL;
+ }
+ else
+ throw "unknown architecture";
+ }
+}
+
+static void usage()
+{
+ fprintf(stderr, "rebase [-low_address] [-high_address] [-v] [-arch <arch>] files...\n");
+}
+
+
+int main(int argc, const char* argv[])
+{
+ std::vector<fileInfo> files;
+ std::set<cpu_type_t> onlyArchs;
+ uint64_t lowAddress = 0;
+ uint64_t highAddress = 0;
+
+ try {
+ // parse command line options
+ char* endptr;
+ for(int i=1; i < argc; ++i) {
+ const char* arg = argv[i];
+ if ( arg[0] == '-' ) {
+ if ( strcmp(arg, "-v") == 0 ) {
+ verbose = true;
+ }
+ else if ( strcmp(arg, "-low_address") == 0 ) {
+ lowAddress = strtoull(argv[++i], &endptr, 16);
+ }
+ else if ( strcmp(arg, "-high_address") == 0 ) {
+ highAddress = strtoull(argv[++i], &endptr, 16);
+ }
+ else if ( strcmp(arg, "-arch") == 0 ) {
+ const char* arch = argv[++i];
+ if ( strcmp(arch, "ppc") == 0 )
+ onlyArchs.insert(CPU_TYPE_POWERPC);
+ else if ( strcmp(arch, "ppc64") == 0 )
+ onlyArchs.insert(CPU_TYPE_POWERPC64);
+ else if ( strcmp(arch, "i386") == 0 )
+ onlyArchs.insert(CPU_TYPE_I386);
+ else if ( strcmp(arch, "x86_64") == 0 )
+ onlyArchs.insert(CPU_TYPE_X86_64);
+ else
+ throwf("unknown architecture %s", arch);
+ }
+ else {
+ usage();
+ throwf("unknown option: %s\n", arg);
+ }
+ }
+ else {
+ files.push_back(fileInfo(arg));
+ }
+ }
+
+ if ( files.size() == 0 )
+ throw "no files specified";
+
+ // use all architectures if no restrictions specified
+ if ( onlyArchs.size() == 0 ) {
+ onlyArchs.insert(CPU_TYPE_POWERPC);
+ onlyArchs.insert(CPU_TYPE_POWERPC64);
+ onlyArchs.insert(CPU_TYPE_I386);
+ onlyArchs.insert(CPU_TYPE_X86_64);
+ }
+
+ // scan files and collect sizes
+ for(std::vector<fileInfo>::iterator it=files.begin(); it != files.end(); ++it) {
+ setSizes(*it, onlyArchs);
+ }
+
+ // assign new base address for each arch
+ for(std::set<cpu_type_t>::iterator ait=onlyArchs.begin(); ait != onlyArchs.end(); ++ait) {
+ cpu_type_t arch = *ait;
+ uint64_t baseAddress = startAddress(arch, files, lowAddress, highAddress);
+ for(std::vector<fileInfo>::iterator fit=files.begin(); fit != files.end(); ++fit) {
+ fileInfo& fi = *fit;
+ for(std::vector<archInfo>::iterator fait=fi.archs.begin(); fait != fi.archs.end(); ++fait) {
+ if ( fait->arch == arch ) {
+ fait->newBase = baseAddress;
+ baseAddress += fait->vmSize;
+ baseAddress = (baseAddress + 4095) & (-4096); // page align
+ }
+ }
+ }
+ }
+
+ // rebase each file if it contains something rebaseable
+ for(std::vector<fileInfo>::iterator it=files.begin(); it != files.end(); ++it) {
+ fileInfo& fi = *it;
+ if ( fi.archs.size() > 0 )
+ rebase(fi);
+ }
+
+ }
+ catch (const char* msg) {
+ fprintf(stderr, "rebase failed: %s\n", msg);
+ return 1;
+ }
+
+ return 0;
+}
+
+
+
projects / apple / ld64.git / commitdiff
