stub_x86_64.hpp   [plain text]


/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
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// already in ld::passes::stubs namespace
namespace x86_64 {



class FastBindingPointerAtom : public ld::Atom {
public:
											FastBindingPointerAtom(ld::passes::stubs::Pass& pass)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeNonLazyPointer, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(3)), 
				_fixup(0, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressLittleEndian64, 
												pass.internal()->compressedFastBinderProxy)
					{ pass.addAtom(*this); }

	virtual const ld::File*					file() const					{ return NULL; }
	virtual bool							translationUnitSource(const char** dir, const char** nm) const 
																			{ return false; }
	virtual const char*						name() const					{ return "fast binder pointer"; }
	virtual uint64_t						size() const					{ return 8; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const { }
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup; }
	virtual ld::Fixup::iterator				fixupsEnd()	const 				{ return &((ld::Fixup*)&_fixup)[1]; }

private:
	mutable ld::Fixup						_fixup;

	static ld::Section						_s_section;
};

ld::Section FastBindingPointerAtom::_s_section("__DATA", "__nl_symbol_ptr", ld::Section::typeNonLazyPointer);


class ImageCachePointerAtom : public ld::Atom {
public:
											ImageCachePointerAtom(ld::passes::stubs::Pass& pass)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeNonLazyPointer, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(3)) { pass.addAtom(*this); }

	virtual const ld::File*					file() const					{ return NULL; }
	virtual bool							translationUnitSource(const char** dir, const char** nm) const 
																			{ return false; }
	virtual const char*						name() const					{ return "image cache pointer"; }
	virtual uint64_t						size() const					{ return 8; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const { }
	virtual void							setScope(Scope)					{ }

private:
	
	static ld::Section						_s_section;
};

ld::Section ImageCachePointerAtom::_s_section("__DATA", "__nl_symbol_ptr", ld::Section::typeNonLazyPointer);





//
//  The stub-helper-helper is the common code factored out of each helper function.
//  It is in the same section as the stub-helpers.  
//  Similar to the PLT0 entry in ELF. 
//
class StubHelperHelperAtom : public ld::Atom {
public:
											StubHelperHelperAtom(ld::passes::stubs::Pass& pass)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeStubHelper, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(2)), 
				_fixup1(3,  ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86PCRel32, compressedImageCache(pass)),
				_fixup2(11, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86PCRel32, compressedFastBinder(pass)) 
					{ pass.addAtom(*this); }

	virtual ld::File*						file() const					{ return NULL; }
	virtual bool							translationUnitSource(const char** dir, const char** nm) const 
																			{ return false; }
	virtual const char*						name() const					{ return "helper helper"; }
	virtual uint64_t						size() const					{ return 16; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const {
		buffer[0]  = 0x4C;		// leaq dyld_mageLoaderCache(%rip),%r11
		buffer[1]  = 0x8D;
		buffer[2]  = 0x1D;
		buffer[3]  = 0x00;
		buffer[4]  = 0x00;
		buffer[5]  = 0x00;
		buffer[6]  = 0x00;
		buffer[7]  = 0x41;		// pushq %r11
		buffer[8]  = 0x53;
		buffer[9]  = 0xFF;		// jmp *_fast_lazy_bind(%rip)
		buffer[10] = 0x25;
		buffer[11] = 0x00;
		buffer[12] = 0x00;
		buffer[13] = 0x00;
		buffer[14] = 0x00;
		buffer[15] = 0x90;		// nop
	}
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup1; }
	virtual ld::Fixup::iterator				fixupsEnd()	const				{ return &((ld::Fixup*)&_fixup2)[1]; }

private:
	static ld::Atom* compressedImageCache(ld::passes::stubs::Pass& pass) {
		if ( pass.compressedImageCache == NULL ) 
			pass.compressedImageCache = new ImageCachePointerAtom(pass);
		return pass.compressedImageCache;		
	}
	static ld::Atom* compressedFastBinder(ld::passes::stubs::Pass& pass) {
		if ( pass.compressedFastBinderPointer == NULL ) 
			pass.compressedFastBinderPointer = new FastBindingPointerAtom(pass);
		return pass.compressedFastBinderPointer;		
	}
	
	mutable ld::Fixup						_fixup1;
	ld::Fixup								_fixup2;
	
	static ld::Section						_s_section;
};

ld::Section StubHelperHelperAtom::_s_section("__TEXT", "__stub_helper", ld::Section::typeStubHelper);



class StubHelperAtom : public ld::Atom {
public:
											StubHelperAtom(ld::passes::stubs::Pass& pass, const ld::Atom* lazyPointer,
																							const ld::Atom& stubTo)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeStubHelper, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(1)), 
				_stubTo(stubTo),
				_fixup1(1, ld::Fixup::k1of2, ld::Fixup::kindSetLazyOffset, lazyPointer),
				_fixup2(1, ld::Fixup::k2of2, ld::Fixup::kindStoreLittleEndian32),
				_fixup3(6, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86BranchPCRel32, helperHelper(pass)) { }
				
	virtual const ld::File*					file() const					{ return _stubTo.file(); }
	virtual bool							translationUnitSource(const char** dir, const char** nm) const 
																			{ return false; }
	virtual const char*						name() const					{ return _stubTo.name(); }
	virtual uint64_t						size() const					{ return 10; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const {
			buffer[0]  = 0x68;		// pushq $lazy-info-offset
			buffer[1]  = 0x00;
			buffer[2]  = 0x00;
			buffer[3]  = 0x00;
			buffer[4]  = 0x00;
			buffer[5]  = 0xE9;		// jmp helperhelper
			buffer[6]  = 0x00;
			buffer[7]  = 0x00;
			buffer[8]  = 0x00;
			buffer[9]  = 0x00;
	}
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup1; }
	virtual ld::Fixup::iterator				fixupsEnd() const				{ return &((ld::Fixup*)&_fixup3)[1]; }

private:
	static ld::Atom* helperHelper(ld::passes::stubs::Pass& pass) {
		if ( pass.compressedHelperHelper == NULL ) 
			pass.compressedHelperHelper = new StubHelperHelperAtom(pass);
		return pass.compressedHelperHelper;
	}

	const ld::Atom&							_stubTo;
	mutable ld::Fixup						_fixup1;
			ld::Fixup						_fixup2;
			ld::Fixup						_fixup3;
	
	static ld::Section						_s_section;
};

ld::Section						StubHelperAtom::_s_section("__TEXT", "__stub_helper", ld::Section::typeStubHelper);


class ResolverHelperAtom : public ld::Atom {
public:
											ResolverHelperAtom(ld::passes::stubs::Pass& pass, const ld::Atom* lazyPointer,
																							const ld::Atom& stubTo)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeStubHelper, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(1)), 
				_stubTo(stubTo),
				_fixup1(10, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86BranchPCRel32, &stubTo),
				_fixup2(17, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86PCRel32, lazyPointer),
				_fixup3(32, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86PCRel32, lazyPointer) { }
				
	virtual const ld::File*					file() const					{ return _stubTo.file(); }
	virtual bool							translationUnitSource(const char** dir, const char** nm) const 
																			{ return false; }
	virtual const char*						name() const					{ return _stubTo.name(); }
	virtual uint64_t						size() const					{ return 36; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const {
			buffer[ 0]  = 0x50;		// push %rax
			buffer[ 1]  = 0x57;		// push %rdi
			buffer[ 2]  = 0x56;		// push %rsi
			buffer[ 3]  = 0x52;		// push %rdx
			buffer[ 4]  = 0x51;		// push %rcx
			buffer[ 5]  = 0x41;		// push %r8
			buffer[ 6]  = 0x50;
			buffer[ 7]  = 0x41;		// push %r9
			buffer[ 8]  = 0x51;
			buffer[ 9]  = 0xE8;		// call foo
			buffer[10]  = 0x00;
			buffer[11]  = 0x00;
			buffer[12]  = 0x00;		
			buffer[13]  = 0x00;
			buffer[14]  = 0x48;		// movq %rax,foo$lazy_pointer(%rip)
			buffer[15]  = 0x89;
			buffer[16]  = 0x05;
			buffer[17]  = 0x00;
			buffer[18]  = 0x00;
			buffer[19]  = 0x00;
			buffer[20]  = 0x00;
			buffer[21]  = 0x41;		// pop %r9
			buffer[22]  = 0x59;	
			buffer[23]  = 0x41;		// pop %r8
			buffer[24]  = 0x58;
			buffer[25]  = 0x59;		// pop %rcx
			buffer[26]  = 0x5A;		// pop %rdx
			buffer[27]  = 0x5E;		// pop %rsi
			buffer[28]  = 0x5F;		// pop %rdi
			buffer[29]  = 0x58;		// pop %rax
			buffer[30]  = 0xFF;		// jmp *foo$lazy_ptr(%rip)
			buffer[31]  = 0x25;
			buffer[32]  = 0x00;
			buffer[33]  = 0x00;
			buffer[34]  = 0x00;
			buffer[35]  = 0x00;
	}
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup1; }
	virtual ld::Fixup::iterator				fixupsEnd() const				{ return &((ld::Fixup*)&_fixup3)[1]; }

private:

	const ld::Atom&							_stubTo;
	mutable ld::Fixup						_fixup1;
			ld::Fixup						_fixup2;
			ld::Fixup						_fixup3;
	
	static ld::Section						_s_section;
};

ld::Section						ResolverHelperAtom::_s_section("__TEXT", "__stub_helper", ld::Section::typeStubHelper);



class LazyPointerAtom : public ld::Atom {
public:
											LazyPointerAtom(ld::passes::stubs::Pass& pass, const ld::Atom& stubTo,
															bool stubToGlobalWeakDef, bool stubToResolver, bool weakImport)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeTranslationUnit, ld::Atom::typeLazyPointer, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(3)), 
				_stubTo(stubTo),
				_helper(pass, this, stubTo),
				_resolverHelper(pass, this, stubTo),
				_fixup1(0, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressLittleEndian64, 
													stubToResolver ? &_resolverHelper : 
														(stubToGlobalWeakDef ?  &stubTo : &_helper)),
				_fixup2(0, ld::Fixup::k1of1, ld::Fixup::kindLazyTarget, &stubTo) { 
						_fixup2.weakImport = weakImport; pass.addAtom(*this); 
						if ( stubToResolver )
							pass.addAtom(_resolverHelper);
						else if ( !stubToGlobalWeakDef ) 
							pass.addAtom(_helper); 
					}

	virtual const ld::File*					file() const					{ return _stubTo.file(); }
	virtual bool							translationUnitSource(const char** dir, const char** ) const 
																			{ return false; }
	virtual const char*						name() const					{ return _stubTo.name(); }
	virtual uint64_t						size() const					{ return 8; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const { }
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup1; }
	virtual ld::Fixup::iterator				fixupsEnd()	const 				{ return &((ld::Fixup*)&_fixup2)[1]; }

private:
	const ld::Atom&							_stubTo;
	StubHelperAtom							_helper;
	ResolverHelperAtom						_resolverHelper;
	mutable ld::Fixup						_fixup1;
	ld::Fixup								_fixup2;
	
	static ld::Section						_s_section;
};

ld::Section LazyPointerAtom::_s_section("__DATA", "__la_symbol_ptr", ld::Section::typeLazyPointer);


class StubAtom : public ld::Atom {
public:
											StubAtom(ld::passes::stubs::Pass& pass, const ld::Atom& stubTo,
													bool stubToGlobalWeakDef, bool stubToResolver, bool weakImport)
				: ld::Atom(_s_section, ld::Atom::definitionRegular, ld::Atom::combineNever,
							ld::Atom::scopeLinkageUnit, ld::Atom::typeStub, 
							symbolTableNotIn, false, false, false, ld::Atom::Alignment(1)), 
				_stubTo(stubTo), 
				_lazyPointer(pass, stubTo, stubToGlobalWeakDef, stubToResolver, weakImport),
				_fixup(2, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressX86PCRel32, &_lazyPointer) { pass.addAtom(*this); }

	virtual const ld::File*					file() const					{ return _stubTo.file(); }
	virtual bool							translationUnitSource(const char** dir, const char** ) const 
																			{ return false; }
	virtual const char*						name() const					{ return _stubTo.name(); }
	virtual uint64_t						size() const					{ return 6; }
	virtual uint64_t						objectAddress() const			{ return 0; }
	virtual void							copyRawContent(uint8_t buffer[]) const {
			buffer[0] = 0xFF;		// jmp *foo$lazy_pointer(%rip)
			buffer[1] = 0x25;
			buffer[2] = 0x00;
			buffer[3] = 0x00;
			buffer[4] = 0x00;
			buffer[5] = 0x00;
	}
	virtual void							setScope(Scope)					{ }
	virtual ld::Fixup::iterator				fixupsBegin() const				{ return &_fixup; }
	virtual ld::Fixup::iterator				fixupsEnd()	const 				{ return &((ld::Fixup*)&_fixup)[1]; }

private:
	const ld::Atom&							_stubTo;
	LazyPointerAtom							_lazyPointer;
	mutable ld::Fixup						_fixup;
	
	static ld::Section						_s_section;
};

ld::Section StubAtom::_s_section("__TEXT", "__stubs", ld::Section::typeStub);



} // namespace x86_64