예제 #1
0
파일: asm.c 프로젝트: zhuowei/go-1-2-haiku
static void
addpltsym(Sym *s)
{
	Sym *plt, *got, *rel;
	
	if(s->plt >= 0)
		return;

	adddynsym(s);
	
	if(iself) {
		plt = lookup(".plt", 0);
		got = lookup(".got.plt", 0);
		rel = lookup(".rel.plt", 0);
		if(plt->size == 0)
			elfsetupplt();
		
		// jmpq *got+size
		adduint8(plt, 0xff);
		adduint8(plt, 0x25);
		addaddrplus(plt, got, got->size);
		
		// add to got: pointer to current pos in plt
		addaddrplus(got, plt, plt->size);
		
		// pushl $x
		adduint8(plt, 0x68);
		adduint32(plt, rel->size);
		
		// jmp .plt
		adduint8(plt, 0xe9);
		adduint32(plt, -(plt->size+4));
		
		// rel
		addaddrplus(rel, got, got->size-4);
		adduint32(rel, ELF32_R_INFO(s->dynid, R_386_JMP_SLOT));
		
		s->plt = plt->size - 16;
	} else if(HEADTYPE == Hdarwin) {
		// Same laziness as in 6l.
		
		Sym *plt;

		plt = lookup(".plt", 0);

		addgotsym(s);

		adduint32(lookup(".linkedit.plt", 0), s->dynid);

		// jmpq *got+size(IP)
		s->plt = plt->size;

		adduint8(plt, 0xff);
		adduint8(plt, 0x25);
		addaddrplus(plt, lookup(".got", 0), s->got);
	} else {
		diag("addpltsym: unsupported binary format");
	}
}
예제 #2
0
파일: go.c 프로젝트: Ahmah2009/golang
void
addexport(void)
{
	int i;
	
	for(i=0; i<ndynexp; i++)
		adddynsym(dynexp[i]);
}
예제 #3
0
파일: go.c 프로젝트: 29decibel/golang
void
addexport(void)
{
	int i;
	
	if(HEADTYPE == Hdarwin)
		return;

	for(i=0; i<ndynexp; i++)
		adddynsym(dynexp[i]);
}
예제 #4
0
파일: asm.c 프로젝트: zhuowei/go-1-2-haiku
static void
addgotsym(Sym *s)
{
	Sym *got, *rel;
	
	if(s->got >= 0)
		return;
	
	adddynsym(s);
	got = lookup(".got", 0);
	s->got = got->size;
	adduint32(got, 0);
	
	if(iself) {
		rel = lookup(".rel", 0);
		addaddrplus(rel, got, s->got);
		adduint32(rel, ELF32_R_INFO(s->dynid, R_386_GLOB_DAT));
	} else if(HEADTYPE == Hdarwin) {
		adduint32(lookup(".linkedit.got", 0), s->dynid);
	} else {
		diag("addgotsym: unsupported binary format");
	}
}
예제 #5
0
static void
addgotsym(LSym *s)
{
	LSym *got, *rela;

	if(s->got >= 0)
		return;

	adddynsym(ctxt, s);
	got = linklookup(ctxt, ".got", 0);
	s->got = got->size;
	adduint64(ctxt, got, 0);

	if(iself) {
		rela = linklookup(ctxt, ".rela", 0);
		addaddrplus(ctxt, rela, got, s->got);
		adduint64(ctxt, rela, ELF64_R_INFO(s->dynid, R_X86_64_GLOB_DAT));
		adduint64(ctxt, rela, 0);
	} else if(HEADTYPE == Hdarwin) {
		adduint32(ctxt, linklookup(ctxt, ".linkedit.got", 0), s->dynid);
	} else {
		diag("addgotsym: unsupported binary format");
	}
}
예제 #6
0
파일: asm.c 프로젝트: zhuowei/go-1-2-haiku
void
adddynrel(Sym *s, Reloc *r)
{
	Sym *targ, *rel, *got;

	targ = r->sym;
	cursym = s;

	switch(r->type) {
	default:
		if(r->type >= 256) {
			diag("unexpected relocation type %d", r->type);
			return;
		}
		break;

	// Handle relocations found in ELF object files.
	case 256 + R_386_PC32:
		if(targ->type == SDYNIMPORT)
			diag("unexpected R_386_PC32 relocation for dynamic symbol %s", targ->name);
		if(targ->type == 0 || targ->type == SXREF)
			diag("unknown symbol %s in pcrel", targ->name);
		r->type = D_PCREL;
		r->add += 4;
		return;

	case 256 + R_386_PLT32:
		r->type = D_PCREL;
		r->add += 4;
		if(targ->type == SDYNIMPORT) {
			addpltsym(targ);
			r->sym = lookup(".plt", 0);
			r->add += targ->plt;
		}
		return;		
	
	case 256 + R_386_GOT32:
		if(targ->type != SDYNIMPORT) {
			// have symbol
			// turn MOVL of GOT entry into LEAL of symbol itself
			if(r->off < 2 || s->p[r->off-2] != 0x8b) {
				diag("unexpected GOT reloc for non-dynamic symbol %s", targ->name);
				return;
			}
			s->p[r->off-2] = 0x8d;
			r->type = D_GOTOFF;
			return;
		}
		addgotsym(targ);
		r->type = D_CONST;	// write r->add during relocsym
		r->sym = S;
		r->add += targ->got;
		return;
	
	case 256 + R_386_GOTOFF:
		r->type = D_GOTOFF;
		return;
	
	case 256 + R_386_GOTPC:
		r->type = D_PCREL;
		r->sym = lookup(".got", 0);
		r->add += 4;
		return;

	case 256 + R_386_32:
		if(targ->type == SDYNIMPORT)
			diag("unexpected R_386_32 relocation for dynamic symbol %s", targ->name);
		r->type = D_ADDR;
		return;
	
	case 512 + MACHO_GENERIC_RELOC_VANILLA*2 + 0:
		r->type = D_ADDR;
		if(targ->type == SDYNIMPORT)
			diag("unexpected reloc for dynamic symbol %s", targ->name);
		return;
	
	case 512 + MACHO_GENERIC_RELOC_VANILLA*2 + 1:
		if(targ->type == SDYNIMPORT) {
			addpltsym(targ);
			r->sym = lookup(".plt", 0);
			r->add = targ->plt;
			r->type = D_PCREL;
			return;
		}
		r->type = D_PCREL;
		return;
	
	case 512 + MACHO_FAKE_GOTPCREL:
		if(targ->type != SDYNIMPORT) {
			// have symbol
			// turn MOVL of GOT entry into LEAL of symbol itself
			if(r->off < 2 || s->p[r->off-2] != 0x8b) {
				diag("unexpected GOT reloc for non-dynamic symbol %s", targ->name);
				return;
			}
			s->p[r->off-2] = 0x8d;
			r->type = D_PCREL;
			return;
		}
		addgotsym(targ);
		r->sym = lookup(".got", 0);
		r->add += targ->got;
		r->type = D_PCREL;
		return;
	}
	
	// Handle references to ELF symbols from our own object files.
	if(targ->type != SDYNIMPORT)
		return;

	switch(r->type) {
	case D_PCREL:
		addpltsym(targ);
		r->sym = lookup(".plt", 0);
		r->add = targ->plt;
		return;
	
	case D_ADDR:
		if(s->type != SDATA)
			break;
		if(iself) {
			adddynsym(targ);
			rel = lookup(".rel", 0);
			addaddrplus(rel, s, r->off);
			adduint32(rel, ELF32_R_INFO(targ->dynid, R_386_32));
			r->type = D_CONST;	// write r->add during relocsym
			r->sym = S;
			return;
		}
		if(HEADTYPE == Hdarwin && s->size == PtrSize && r->off == 0) {
			// Mach-O relocations are a royal pain to lay out.
			// They use a compact stateful bytecode representation
			// that is too much bother to deal with.
			// Instead, interpret the C declaration
			//	void *_Cvar_stderr = &stderr;
			// as making _Cvar_stderr the name of a GOT entry
			// for stderr.  This is separate from the usual GOT entry,
			// just in case the C code assigns to the variable,
			// and of course it only works for single pointers,
			// but we only need to support cgo and that's all it needs.
			adddynsym(targ);
			got = lookup(".got", 0);
			s->type = got->type | SSUB;
			s->outer = got;
			s->sub = got->sub;
			got->sub = s;
			s->value = got->size;
			adduint32(got, 0);
			adduint32(lookup(".linkedit.got", 0), targ->dynid);
			r->type = 256;	// ignore during relocsym
			return;
		}
		break;
	}
	
	cursym = s;
	diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ->name, r->type, targ->type);
}
예제 #7
0
파일: asm.c 프로젝트: serge-hulne/golang
static void
addpltsym(Sym *s)
{
	if(s->plt >= 0)
		return;
	
	adddynsym(s);
	
	if(iself) {
		Sym *plt, *got, *rela;

		plt = lookup(".plt", 0);
		got = lookup(".got.plt", 0);
		rela = lookup(".rela.plt", 0);
		if(plt->size == 0)
			elfsetupplt();
		
		// jmpq *got+size(IP)
		adduint8(plt, 0xff);
		adduint8(plt, 0x25);
		addpcrelplus(plt, got, got->size);
	
		// add to got: pointer to current pos in plt
		addaddrplus(got, plt, plt->size);
		
		// pushq $x
		adduint8(plt, 0x68);
		adduint32(plt, (got->size-24-8)/8);
		
		// jmpq .plt
		adduint8(plt, 0xe9);
		adduint32(plt, -(plt->size+4));
		
		// rela
		addaddrplus(rela, got, got->size-8);
		adduint64(rela, ELF64_R_INFO(s->dynid, R_X86_64_JMP_SLOT));
		adduint64(rela, 0);
		
		s->plt = plt->size - 16;
	} else if(HEADTYPE == Hdarwin) {
		// To do lazy symbol lookup right, we're supposed
		// to tell the dynamic loader which library each 
		// symbol comes from and format the link info
		// section just so.  I'm too lazy (ha!) to do that
		// so for now we'll just use non-lazy pointers,
		// which don't need to be told which library to use.
		//
		// http://networkpx.blogspot.com/2009/09/about-lcdyldinfoonly-command.html
		// has details about what we're avoiding.

		Sym *plt;
		
		addgotsym(s);
		plt = lookup(".plt", 0);

		adduint32(lookup(".linkedit.plt", 0), s->dynid);

		// jmpq *got+size(IP)
		s->plt = plt->size;

		adduint8(plt, 0xff);
		adduint8(plt, 0x25);
		addpcrelplus(plt, lookup(".got", 0), s->got);
	} else {
		diag("addpltsym: unsupported binary format");
	}
}
예제 #8
0
파일: asm.c 프로젝트: serge-hulne/golang
void
adddynrel(Sym *s, Reloc *r)
{
	Sym *targ, *rela, *got;
	
	targ = r->sym;
	cursym = s;

	switch(r->type) {
	default:
		if(r->type >= 256) {
			diag("unexpected relocation type %d", r->type);
			return;
		}
		break;

	// Handle relocations found in ELF object files.
	case 256 + R_X86_64_PC32:
		if(targ->dynimpname != nil && !targ->dynexport)
			diag("unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ->name);
		if(targ->type == 0 || targ->type == SXREF)
			diag("unknown symbol %s in pcrel", targ->name);
		r->type = D_PCREL;
		r->add += 4;
		return;
	
	case 256 + R_X86_64_PLT32:
		r->type = D_PCREL;
		r->add += 4;
		if(targ->dynimpname != nil && !targ->dynexport) {
			addpltsym(targ);
			r->sym = lookup(".plt", 0);
			r->add += targ->plt;
		}
		return;
	
	case 256 + R_X86_64_GOTPCREL:
		if(targ->dynimpname == nil || targ->dynexport) {
			// have symbol
			if(r->off >= 2 && s->p[r->off-2] == 0x8b) {
				// turn MOVQ of GOT entry into LEAQ of symbol itself
				s->p[r->off-2] = 0x8d;
				r->type = D_PCREL;
				r->add += 4;
				return;
			}
			// fall back to using GOT and hope for the best (CMOV*)
			// TODO: just needs relocation, no need to put in .dynsym
			targ->dynimpname = targ->name;
		}
		addgotsym(targ);
		r->type = D_PCREL;
		r->sym = lookup(".got", 0);
		r->add += 4;
		r->add += targ->got;
		return;
	
	case 256 + R_X86_64_64:
		if(targ->dynimpname != nil && !targ->dynexport)
			diag("unexpected R_X86_64_64 relocation for dynamic symbol %s", targ->name);
		r->type = D_ADDR;
		return;
	
	// Handle relocations found in Mach-O object files.
	case 512 + MACHO_X86_64_RELOC_UNSIGNED*2 + 0:
	case 512 + MACHO_X86_64_RELOC_SIGNED*2 + 0:
	case 512 + MACHO_X86_64_RELOC_BRANCH*2 + 0:
		// TODO: What is the difference between all these?
		r->type = D_ADDR;
		if(targ->dynimpname != nil && !targ->dynexport)
			diag("unexpected reloc for dynamic symbol %s", targ->name);
		return;

	case 512 + MACHO_X86_64_RELOC_BRANCH*2 + 1:
		if(targ->dynimpname != nil && !targ->dynexport) {
			addpltsym(targ);
			r->sym = lookup(".plt", 0);
			r->add = targ->plt;
			r->type = D_PCREL;
			return;
		}
		// fall through
	case 512 + MACHO_X86_64_RELOC_UNSIGNED*2 + 1:
	case 512 + MACHO_X86_64_RELOC_SIGNED*2 + 1:
	case 512 + MACHO_X86_64_RELOC_SIGNED_1*2 + 1:
	case 512 + MACHO_X86_64_RELOC_SIGNED_2*2 + 1:
	case 512 + MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
		r->type = D_PCREL;
		if(targ->dynimpname != nil && !targ->dynexport)
			diag("unexpected pc-relative reloc for dynamic symbol %s", targ->name);
		return;

	case 512 + MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
		if(targ->dynimpname == nil || targ->dynexport) {
			// have symbol
			// turn MOVQ of GOT entry into LEAQ of symbol itself
			if(r->off < 2 || s->p[r->off-2] != 0x8b) {
				diag("unexpected GOT_LOAD reloc for non-dynamic symbol %s", targ->name);
				return;
			}
			s->p[r->off-2] = 0x8d;
			r->type = D_PCREL;
			return;
		}
		// fall through
	case 512 + MACHO_X86_64_RELOC_GOT*2 + 1:
		if(targ->dynimpname == nil || targ->dynexport)
			diag("unexpected GOT reloc for non-dynamic symbol %s", targ->name);
		addgotsym(targ);
		r->type = D_PCREL;
		r->sym = lookup(".got", 0);
		r->add += targ->got;
		return;
	}
	
	// Handle references to ELF symbols from our own object files.
	if(targ->dynimpname == nil || targ->dynexport)
		return;

	switch(r->type) {
	case D_PCREL:
		addpltsym(targ);
		r->sym = lookup(".plt", 0);
		r->add = targ->plt;
		return;
	
	case D_ADDR:
		if(s->type != SDATA)
			break;
		if(iself) {
			adddynsym(targ);
			rela = lookup(".rela", 0);
			addaddrplus(rela, s, r->off);
			if(r->siz == 8)
				adduint64(rela, ELF64_R_INFO(targ->dynid, R_X86_64_64));
			else
				adduint64(rela, ELF64_R_INFO(targ->dynid, R_X86_64_32));
			adduint64(rela, r->add);
			r->type = 256;	// ignore during relocsym
			return;
		}
		if(HEADTYPE == Hdarwin && s->size == PtrSize && r->off == 0) {
			// Mach-O relocations are a royal pain to lay out.
			// They use a compact stateful bytecode representation
			// that is too much bother to deal with.
			// Instead, interpret the C declaration
			//	void *_Cvar_stderr = &stderr;
			// as making _Cvar_stderr the name of a GOT entry
			// for stderr.  This is separate from the usual GOT entry,
			// just in case the C code assigns to the variable,
			// and of course it only works for single pointers,
			// but we only need to support cgo and that's all it needs.
			adddynsym(targ);
			got = lookup(".got", 0);
			s->type = got->type | SSUB;
			s->outer = got;
			s->sub = got->sub;
			got->sub = s;
			s->value = got->size;
			adduint64(got, 0);
			adduint32(lookup(".linkedit.got", 0), targ->dynid);
			r->type = 256;	// ignore during relocsym
			return;
		}
		break;
	}
	
	cursym = s;
	diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ->name, r->type, targ->type);
}