[apple/ld64.git] / src / rebase.cpp

/* -*- 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 = &sectionsStart[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);
	}
Commit	Line	Data
69a49097 A	1	/* -- mode: C++; c-basic-offset: 4; tab-width: 4 --
	2	*
	3	* Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
	4	*
	5	* @APPLE_LICENSE_HEADER_START@
	6	*
	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
	10	* compliance with the License. Please obtain a copy of the License at
	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
	15	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	16	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	17	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	19	* Please see the License for the specific language governing rights and
	20	* limitations under the License.
	21	*
	22	* @APPLE_LICENSE_HEADER_END@
	23	*/
	24
	25	#include <sys/types.h>
	26	#include <sys/stat.h>
	27	#include <sys/mman.h>
	28	#include <mach/mach.h>
	29	#include <limits.h>
	30	#include <stdarg.h>
	31	#include <stdio.h>
	32	#include <fcntl.h>
	33	#include <errno.h>
	34	#include <unistd.h>
	35	#include <mach-o/loader.h>
	36	#include <mach-o/fat.h>
	37	#include <mach-o/reloc.h>
	38	#include <mach-o/ppc/reloc.h>
	39	#include <mach-o/x86_64/reloc.h>
	40	#include <vector>
	41	#include <set>
	42
	43	#include "MachOFileAbstraction.hpp"
	44	#include "Architectures.hpp"
	45
	46
	47	static bool verbose = false;
	48
	49	__attribute__((noreturn))
	50	void throwf(const char* format, ...)
	51	{
	52	va_list list;
	53	char* p;
	54	va_start(list, format);
	55	vasprintf(&p, format, list);
	56	va_end(list);
	57
	58	const char* t = p;
	59	throw t;
	60	}
	61
	62
	63	class AbstractRebaser
	64	{
65	public:
66	virtual cpu_type_t getArchitecture() const = 0;
67	virtual uint64_t getBaseAddress() const = 0;
68	virtual uint64_t getVMSize() const = 0;
69	virtual void setBaseAddress(uint64_t) = 0;
70	};
71
72
73	template <typename A>
74	class Rebaser : public AbstractRebaser
75	{
76	public:
77	Rebaser(const void* machHeader);
78	virtual ~Rebaser() {}
79
80	virtual cpu_type_t getArchitecture() const;
81	virtual uint64_t getBaseAddress() const;
82	virtual uint64_t getVMSize() const;
83	virtual void setBaseAddress(uint64_t);
84
85	private:
86	typedef typename A::P P;
87	typedef typename A::P::E E;
88	typedef typename A::P::uint_t pint_t;
89
90	struct vmmap { pint_t vmaddr; pint_t vmsize; pint_t fileoff; };
91
92	void setRelocBase();
93	void buildSectionTable();
94	void adjustLoadCommands();
95	void adjustSymbolTable();
96	void adjustDATA();
97	void doLocalRelocation(const macho_relocation_info<P>* reloc);
98	pint_t* mappedAddressForVMAddress(uint32_t vmaddress);
99
100	const macho_header<P>* fHeader;
101	pint_t fOrignalVMRelocBaseAddress;
102	pint_t fSlide;
103	pint_t fRelocBase;
104	std::vector<vmmap> fVMMApping;
105	};
106
107
108
109	class MultiArchRebaser
110	{
111	public:
112	MultiArchRebaser(const char* path, bool writable=false);
113	~MultiArchRebaser();
114
115	const std::vector<AbstractRebaser*>& getArchs() const { return fRebasers; }
116	void commit();
117
118	private:
119	std::vector<AbstractRebaser*> fRebasers;
120	void* fMappingAddress;
121	uint64_t fFileSize;
122	};
123
124
125
126	MultiArchRebaser::MultiArchRebaser(const char* path, bool writable)
127	: fMappingAddress(0), fFileSize(0)
128	{
129	// map in whole file
130	int fd = ::open(path, (writable ? O_RDWR : O_RDONLY), 0);
131	if ( fd == -1 )
132	throwf("can't open file, errno=%d", errno);
133	struct stat stat_buf;
134	if ( fstat(fd, &stat_buf) == -1)
135	throwf("can't stat open file %s, errno=%d", path, errno);
136	if ( stat_buf.st_size < 20 )
137	throwf("file too small %s", path);
138	const int prot = writable ? (PROT_READ \| PROT_WRITE) : PROT_READ;
139	const int flags = writable ? (MAP_FILE \| MAP_SHARED) : (MAP_FILE \| MAP_PRIVATE);
140	uint8_t* p = (uint8_t*)::mmap(NULL, stat_buf.st_size, prot, flags, fd, 0);
141	if ( p == (uint8_t*)(-1) )
142	throwf("can't map file %s, errno=%d", path, errno);
143	::close(fd);
144
145	// if fat file, process each architecture
146	const fat_header* fh = (fat_header*)p;
147	const mach_header* mh = (mach_header*)p;
148	if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
149	// Fat header is always big-endian
150	const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
151	for (unsigned long i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
152	uint32_t fileOffset = OSSwapBigToHostInt32(archs[i].offset);
153	try {
154	switch ( OSSwapBigToHostInt32(archs[i].cputype) ) {
155	case CPU_TYPE_POWERPC:
156	fRebasers.push_back(new Rebaser<ppc>(&p[fileOffset]));
157	break;
158	case CPU_TYPE_POWERPC64:
159	fRebasers.push_back(new Rebaser<ppc64>(&p[fileOffset]));
160	break;
161	case CPU_TYPE_I386:
162	fRebasers.push_back(new Rebaser<x86>(&p[fileOffset]));
163	break;
164	case CPU_TYPE_X86_64:
165	fRebasers.push_back(new Rebaser<x86_64>(&p[fileOffset]));
166	break;
167	default:
168	throw "unknown file format";
169	}
170	}
171	catch (const char* msg) {
172	fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
173	}
174	}
175	}
176	else {
177	try {
178	if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC)) {
179	fRebasers.push_back(new Rebaser<ppc>(mh));
180	}
181	else if ( (OSSwapBigToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapBigToHostInt32(mh->cputype) == CPU_TYPE_POWERPC64)) {
182	fRebasers.push_back(new Rebaser<ppc64>(mh));
183	}
184	else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_I386)) {
185	fRebasers.push_back(new Rebaser<x86>(mh));
186	}
187	else if ( (OSSwapLittleToHostInt32(mh->magic) == MH_MAGIC_64) && (OSSwapLittleToHostInt32(mh->cputype) == CPU_TYPE_X86_64)) {
188	fRebasers.push_back(new Rebaser<x86_64>(mh));
189	}
190	else {
191	throw "unknown file format";
192	}
193	}
194	catch (const char* msg) {
195	fprintf(stderr, "rebase warning: %s for %s\n", msg, path);
196	}
197	}
198
199	fMappingAddress = p;
200	fFileSize = stat_buf.st_size;
201	}
202
203
204	MultiArchRebaser::~MultiArchRebaser()
205	{
206	::munmap(fMappingAddress, fFileSize);
207	}
208
209	void MultiArchRebaser::commit()
210	{
211	::msync(fMappingAddress, fFileSize, MS_ASYNC);
212	}
213
214
215
216	template <typename A>
217	Rebaser<A>::Rebaser(const void* machHeader)
218	: fHeader((const macho_header<P>*)machHeader)
219	{
220	switch ( fHeader->filetype() ) {
221	case MH_DYLIB:
222	if ( (fHeader->flags() & MH_SPLIT_SEGS) != 0 )
223	throw "split-seg dylibs cannot be rebased";
224	break;
225	case MH_BUNDLE:
226	break;
227	default:
228	throw "file is not a dylib or bundle";
229	}
230
231	}
232
233	template <> cpu_type_t Rebaser<ppc>::getArchitecture() const { return CPU_TYPE_POWERPC; }
234	template <> cpu_type_t Rebaser<ppc64>::getArchitecture() const { return CPU_TYPE_POWERPC64; }
235	template <> cpu_type_t Rebaser<x86>::getArchitecture() const { return CPU_TYPE_I386; }
236	template <> cpu_type_t Rebaser<x86_64>::getArchitecture() const { return CPU_TYPE_X86_64; }
237
238
239	template <typename A>
240	uint64_t Rebaser<A>::getBaseAddress() const
241	{
242	uint64_t lowestSegmentAddress = LLONG_MAX;
243	const macho_load_command<P>* const cmds = (macho_load_command<P>)((uint8_t)fHeader + sizeof(macho_header<P>));
244	const uint32_t cmd_count = fHeader->ncmds();
245	const macho_load_command<P>* cmd = cmds;
246	for (uint32_t i = 0; i < cmd_count; ++i) {
247	if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
248	const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
249	if ( segCmd->vmaddr() < lowestSegmentAddress ) {
250	lowestSegmentAddress = segCmd->vmaddr();
251	}
252	}
253	cmd = (const macho_load_command<P>)(((uint8_t)cmd)+cmd->cmdsize());
254	}
255	return lowestSegmentAddress;
256	}
257
258	template <typename A>
259	uint64_t Rebaser<A>::getVMSize() const
260	{
261	const macho_segment_command<P>* highestSegmentCmd = NULL;
262	const macho_load_command<P>* const cmds = (macho_load_command<P>)((uint8_t)fHeader + sizeof(macho_header<P>));
263	const uint32_t cmd_count = fHeader->ncmds();
264	const macho_load_command<P>* cmd = cmds;
265	for (uint32_t i = 0; i < cmd_count; ++i) {
266	if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
267	const macho_segment_command<P>* segCmd = (const macho_segment_command<P>*)cmd;
268	if ( (highestSegmentCmd == NULL) \|\| (segCmd->vmaddr() > highestSegmentCmd->vmaddr()) ) {
269	highestSegmentCmd = segCmd;
270	}
271	}
272	cmd = (const macho_load_command<P>)(((uint8_t)cmd)+cmd->cmdsize());
273	}
274
275	return ((highestSegmentCmd->vmaddr() + highestSegmentCmd->vmsize() - this->getBaseAddress() + 4095) & (-4096));
276	}
277
278
279	template <typename A>
280	void Rebaser<A>::setBaseAddress(uint64_t addr)
281	{
282	// calculate slide
283	fSlide = addr - this->getBaseAddress();
284
285	// compute base address for relocations
286	this->setRelocBase();
287
288	// build cache of section index to section
289	this->buildSectionTable();
290
291	// update load commands
292	this->adjustLoadCommands();
293
294	// update symbol table
295	this->adjustSymbolTable();
296
297	// update writable segments that have internal pointers
298	this->adjustDATA();
299	}
300
301	template <typename A>
302	void Rebaser<A>::adjustLoadCommands()
303	{
304	const macho_segment_command<P>* highestSegmentCmd = NULL;
305	const macho_load_command<P>* const cmds = (macho_load_command<P>)((uint8_t)fHeader + sizeof(macho_header<P>));
306	const uint32_t cmd_count = fHeader->ncmds();
307	const macho_load_command<P>* cmd = cmds;
308	for (uint32_t i = 0; i < cmd_count; ++i) {
309	switch ( cmd->cmd() ) {
310	case LC_ID_DYLIB:
311	if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
312	// clear timestamp so that any prebound clients are invalidated
313	macho_dylib_command<P>* dylib = (macho_dylib_command<P>*)cmd;
314	dylib->set_timestamp(1);
315	}
316	break;
317	case LC_LOAD_DYLIB:
318	case LC_LOAD_WEAK_DYLIB:
319	if ( (fHeader->flags() & MH_PREBOUND) != 0 ) {
320	// clear expected timestamps so that this image will load with invalid prebinding
321	macho_dylib_command<P>* dylib = (macho_dylib_command<P>*)cmd;
322	dylib->set_timestamp(2);
323	}
324	break;
325	case macho_routines_command<P>::CMD:
326	// update -init command
327	{
328	struct macho_routines_command<P>* routines = (struct macho_routines_command<P>*)cmd;
329	routines->set_init_address(routines->init_address() + fSlide);
330	}
331	break;
332	case macho_segment_command<P>::CMD:
333	// update segment commands
334	{
335	macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
336	seg->set_vmaddr(seg->vmaddr() + fSlide);
337	macho_section<P>* const sectionsStart = (macho_section<P>)((char)seg + sizeof(macho_segment_command<P>));
338	macho_section<P>* const sectionsEnd = &sectionsStart[seg->nsects()];
339	for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
340	sect->set_addr(sect->addr() + fSlide);
341	}
342	}
343	break;
344	}
345	cmd = (const macho_load_command<P>)(((uint8_t)cmd)+cmd->cmdsize());
346	}
347	}
348
349
350	template <typename A>
351	void Rebaser<A>::buildSectionTable()
352	{
353	// build vector of sections
354	const macho_load_command<P>* const cmds = (macho_load_command<P>)((uint8_t)fHeader + sizeof(macho_header<P>));
355	const uint32_t cmd_count = fHeader->ncmds();
356	const macho_load_command<P>* cmd = cmds;
357	for (uint32_t i = 0; i < cmd_count; ++i) {
358	if ( cmd->cmd() == macho_segment_command<P>::CMD ) {
359	const macho_segment_command<P>* seg = (macho_segment_command<P>*)cmd;
360	vmmap mapping;
361	mapping.vmaddr = seg->vmaddr();
362	mapping.vmsize = seg->vmsize();
363	mapping.fileoff = seg->fileoff();
364	fVMMApping.push_back(mapping);
365	}
366	cmd = (const macho_load_command<P>)(((uint8_t)cmd)+cmd->cmdsize());
367	}
368	}
369
370
371	template <typename A>
372	void Rebaser<A>::adjustSymbolTable()
373	{
374	const macho_dysymtab_command<P>* dysymtab = NULL;
375	macho_nlist<P>* symbolTable = NULL;
376
377	// get symbol table info
378	const macho_load_command<P>* const cmds = (macho_load_command<P>)((uint8_t)fHeader + sizeof(macho_header<P>));
379	const uint32_t cmd_count = fHeader->ncmds();
380	const macho_load_command<P>* cmd = cmds;
381	for (uint32_t i = 0; i < cmd_count; ++i) {
382	switch (cmd->cmd()) {
383	case LC_SYMTAB:
384	{
385	const macho_symtab_command<P>* symtab = (macho_symtab_command<P>*)cmd;
386	symbolTable = (macho_nlist<P>)(((uint8_t)fHeader) + symtab->symoff());
387	}
388	break;
389	case LC_DYSYMTAB:
390	dysymtab = (macho_dysymtab_command<P>*)cmd;
391	break;
392	}
393	cmd = (const macho_load_command<P>)(((uint8_t)cmd)+cmd->cmdsize());
394	}
395
396	// walk all exports and slide their n_value
397	macho_nlist<P>* lastExport = &symbolTable[dysymtab->iextdefsym()+dysymtab->nextdefsym()];
398	for (macho_nlist<P>* entry = &symbolTable[dysymtab->iextdefsym()]; entry < lastExport; ++entry) {
399	if ( (entry->n_type() & N_TYPE) == N_SECT )
400	entry->set_n_value(entry->n_value() + fSlide);
401	}
402
403	// walk all local symbols and slide their n_value
404	macho_nlist<P>* lastLocal = &symbolTable[dysymtab->ilocalsym()+dysymtab->nlocalsym()];
405	for (macho_nlist<P>* entry = &symbolTable[dysymtab->ilocalsym()]; entry < lastLocal; ++entry) {
406	if ( entry->n_sect() != NO_SECT )
407	entry->set_n_value(entry->n_value() + fSlide);
408	}
74cfe461 A	409
74cfe461 A	410