Ejemplo n.º 1
0
func machoreloc1(r *ld.Reloc, sectoff int64) int {
	var v uint32

	rs := r.Xsym

	if rs.Type == obj.SHOSTOBJ || r.Type == obj.R_PCREL {
		if rs.Dynid < 0 {
			ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
			return -1
		}

		v = uint32(rs.Dynid)
		v |= 1 << 27 // external relocation
	} else {
		v = uint32(rs.Sect.Extnum)
		if v == 0 {
			ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
			return -1
		}
	}

	switch r.Type {
	default:
		return -1

	case obj.R_ADDR:
		v |= ld.MACHO_X86_64_RELOC_UNSIGNED << 28

	case obj.R_CALL:
		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_X86_64_RELOC_BRANCH << 28

		// NOTE: Only works with 'external' relocation. Forced above.
	case obj.R_PCREL:
		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_X86_64_RELOC_SIGNED << 28
	}

	switch r.Siz {
	default:
		return -1

	case 1:
		v |= 0 << 25

	case 2:
		v |= 1 << 25

	case 4:
		v |= 2 << 25

	case 8:
		v |= 3 << 25
	}

	ld.Thearch.Lput(uint32(sectoff))
	ld.Thearch.Lput(v)
	return 0
}
Ejemplo n.º 2
0
func machoreloc1(r *ld.Reloc, sectoff int64) int {
	var v uint32

	rs := r.Xsym

	if rs.Type == obj.SHOSTOBJ {
		if rs.Dynid < 0 {
			ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
			return -1
		}

		v = uint32(rs.Dynid)
		v |= 1 << 27 // external relocation
	} else {
		v = uint32(rs.Sect.Extnum)
		if v == 0 {
			ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
			return -1
		}
	}

	switch r.Type {
	default:
		return -1

	case obj.R_ADDR:
		v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28

	case obj.R_CALL,
		obj.R_PCREL:
		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28
	}

	switch r.Siz {
	default:
		return -1

	case 1:
		v |= 0 << 25

	case 2:
		v |= 1 << 25

	case 4:
		v |= 2 << 25

	case 8:
		v |= 3 << 25
	}

	ld.Thearch.Lput(uint32(sectoff))
	ld.Thearch.Lput(v)
	return 0
}
Ejemplo n.º 3
0
func pereloc1(r *ld.Reloc, sectoff int64) bool {
	var v uint32

	rs := r.Xsym

	if rs.Dynid < 0 {
		ld.Diag("reloc %d to non-coff symbol %s type=%d", r.Type, rs.Name, rs.Type)
		return false
	}

	ld.Thearch.Lput(uint32(sectoff))
	ld.Thearch.Lput(uint32(rs.Dynid))

	switch r.Type {
	default:
		return false

	case obj.R_ADDR:
		if r.Siz == 8 {
			v = ld.IMAGE_REL_AMD64_ADDR64
		} else {
			v = ld.IMAGE_REL_AMD64_ADDR32
		}

	case obj.R_CALL,
		obj.R_PCREL:
		v = ld.IMAGE_REL_AMD64_REL32
	}

	ld.Thearch.Wput(uint16(v))

	return true
}
Ejemplo n.º 4
0
func archrelocvariant(r *ld.Reloc, s *ld.LSym, t int64) int64 {
	switch r.Variant & ld.RV_TYPE_MASK {
	default:
		ld.Diag("unexpected relocation variant %d", r.Variant)
		return t

	case ld.RV_NONE:
		return t

	case ld.RV_390_DBL:
		if (t & 1) != 0 {
			ld.Diag("%s+%v is not 2-byte aligned", r.Sym.Name, r.Sym.Value)
		}
		return t >> 1
	}
}
Ejemplo n.º 5
0
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
	if s.Plt >= 0 {
		return
	}

	ld.Adddynsym(ctxt, s)

	if ld.Iself {
		plt := ld.Linklookup(ctxt, ".plt", 0)
		got := ld.Linklookup(ctxt, ".got.plt", 0)
		rel := ld.Linklookup(ctxt, ".rel.plt", 0)
		if plt.Size == 0 {
			elfsetupplt()
		}

		// jmpq *got+size
		ld.Adduint8(ctxt, plt, 0xff)

		ld.Adduint8(ctxt, plt, 0x25)
		ld.Addaddrplus(ctxt, plt, got, got.Size)

		// add to got: pointer to current pos in plt
		ld.Addaddrplus(ctxt, got, plt, plt.Size)

		// pushl $x
		ld.Adduint8(ctxt, plt, 0x68)

		ld.Adduint32(ctxt, plt, uint32(rel.Size))

		// jmp .plt
		ld.Adduint8(ctxt, plt, 0xe9)

		ld.Adduint32(ctxt, plt, uint32(-(plt.Size + 4)))

		// rel
		ld.Addaddrplus(ctxt, rel, got, got.Size-4)

		ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_386_JMP_SLOT))

		s.Plt = int32(plt.Size - 16)
	} else if ld.HEADTYPE == obj.Hdarwin {
		// Same laziness as in 6l.

		plt := ld.Linklookup(ctxt, ".plt", 0)

		addgotsym(ctxt, s)

		ld.Adduint32(ctxt, ld.Linklookup(ctxt, ".linkedit.plt", 0), uint32(s.Dynid))

		// jmpq *got+size(IP)
		s.Plt = int32(plt.Size)

		ld.Adduint8(ctxt, plt, 0xff)
		ld.Adduint8(ctxt, plt, 0x25)
		ld.Addaddrplus(ctxt, plt, ld.Linklookup(ctxt, ".got", 0), int64(s.Got))
	} else {
		ld.Diag("addpltsym: unsupported binary format")
	}
}
Ejemplo n.º 6
0
func addgotsyminternal(ctxt *ld.Link, s *ld.LSym) {
	if s.Got >= 0 {
		return
	}

	got := ld.Linklookup(ctxt, ".got", 0)
	s.Got = int32(got.Size)

	ld.Addaddrplus(ctxt, got, s, 0)

	if ld.Iself {
	} else {
		ld.Diag("addgotsyminternal: unsupported binary format")
	}
}
Ejemplo n.º 7
0
// Return the value of .TOC. for symbol s
func symtoc(s *ld.LSym) int64 {
	var toc *ld.LSym

	if s.Outer != nil {
		toc = ld.Linkrlookup(ld.Ctxt, ".TOC.", int(s.Outer.Version))
	} else {
		toc = ld.Linkrlookup(ld.Ctxt, ".TOC.", int(s.Version))
	}

	if toc == nil {
		ld.Diag("TOC-relative relocation in object without .TOC.")
		return 0
	}

	return toc.Value
}
Ejemplo n.º 8
0
func addgotsym(ctxt *ld.Link, s *ld.LSym) {
	if s.Got >= 0 {
		return
	}

	ld.Adddynsym(ctxt, s)
	got := ld.Linklookup(ctxt, ".got", 0)
	s.Got = int32(got.Size)
	ld.Adduint32(ctxt, got, 0)

	if ld.Iself {
		rel := ld.Linklookup(ctxt, ".rel", 0)
		ld.Addaddrplus(ctxt, rel, got, int64(s.Got))
		ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_ARM_GLOB_DAT))
	} else {
		ld.Diag("addgotsym: unsupported binary format")
	}
}
Ejemplo n.º 9
0
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
	if s.Plt >= 0 {
		return
	}

	ld.Adddynsym(ctxt, s)

	if ld.Iself {
		plt := ld.Linklookup(ctxt, ".plt", 0)
		rela := ld.Linklookup(ctxt, ".rela.plt", 0)
		if plt.Size == 0 {
			elfsetupplt()
		}

		// Create the glink resolver if necessary
		glink := ensureglinkresolver()

		// Write symbol resolver stub (just a branch to the
		// glink resolver stub)
		r := ld.Addrel(glink)

		r.Sym = glink
		r.Off = int32(glink.Size)
		r.Siz = 4
		r.Type = obj.R_CALLPOWER
		ld.Adduint32(ctxt, glink, 0x48000000) // b .glink

		// In the ppc64 ABI, the dynamic linker is responsible
		// for writing the entire PLT.  We just need to
		// reserve 8 bytes for each PLT entry and generate a
		// JMP_SLOT dynamic relocation for it.
		//
		// TODO(austin): ABI v1 is different
		s.Plt = int32(plt.Size)

		plt.Size += 8

		ld.Addaddrplus(ctxt, rela, plt, int64(s.Plt))
		ld.Adduint64(ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_PPC64_JMP_SLOT))
		ld.Adduint64(ctxt, rela, 0)
	} else {
		ld.Diag("addpltsym: unsupported binary format")
	}
}
Ejemplo n.º 10
0
func addgotsym(s *ld.LSym) {
	if s.Got >= 0 {
		return
	}

	ld.Adddynsym(ld.Ctxt, s)
	got := ld.Linklookup(ld.Ctxt, ".got", 0)
	s.Got = int32(got.Size)
	ld.Adduint64(ld.Ctxt, got, 0)

	if ld.Iself {
		rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
		ld.Addaddrplus(ld.Ctxt, rela, got, int64(s.Got))
		ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_390_GLOB_DAT))
		ld.Adduint64(ld.Ctxt, rela, 0)
	} else {
		ld.Diag("addgotsym: unsupported binary format")
	}
}
Ejemplo n.º 11
0
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
	if s.Plt >= 0 {
		return
	}

	ld.Adddynsym(ctxt, s)

	if ld.Iself {
		plt := ld.Linklookup(ctxt, ".plt", 0)
		got := ld.Linklookup(ctxt, ".got.plt", 0)
		rel := ld.Linklookup(ctxt, ".rel.plt", 0)
		if plt.Size == 0 {
			elfsetupplt()
		}

		// .got entry
		s.Got = int32(got.Size)

		// In theory, all GOT should point to the first PLT entry,
		// Linux/ARM's dynamic linker will do that for us, but FreeBSD/ARM's
		// dynamic linker won't, so we'd better do it ourselves.
		ld.Addaddrplus(ctxt, got, plt, 0)

		// .plt entry, this depends on the .got entry
		s.Plt = int32(plt.Size)

		addpltreloc(ctxt, plt, got, s, obj.R_PLT0) // add lr, pc, #0xXX00000
		addpltreloc(ctxt, plt, got, s, obj.R_PLT1) // add lr, lr, #0xYY000
		addpltreloc(ctxt, plt, got, s, obj.R_PLT2) // ldr pc, [lr, #0xZZZ]!

		// rel
		ld.Addaddrplus(ctxt, rel, got, int64(s.Got))

		ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_ARM_JUMP_SLOT))
	} else {
		ld.Diag("addpltsym: unsupported binary format")
	}
}
Ejemplo n.º 12
0
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
	if s.Plt >= 0 {
		return
	}

	ld.Adddynsym(ctxt, s)

	if ld.Iself {
		plt := ld.Linklookup(ctxt, ".plt", 0)
		got := ld.Linklookup(ctxt, ".got", 0)
		rela := ld.Linklookup(ctxt, ".rela.plt", 0)
		if plt.Size == 0 {
			elfsetupplt()
		}
		// larl    %r1,_GLOBAL_OFFSET_TABLE_+index

		ld.Adduint8(ctxt, plt, 0xc0)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Addpcrelplus(ctxt, plt, got, got.Size+6) // need variant?

		// add to got: pointer to current pos in plt
		ld.Addaddrplus(ctxt, got, plt, plt.Size+8) // weird but correct
		// lg      %r1,0(%r1)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x04)
		// br      %r1
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0xf1)
		// basr    %r1,%r0
		ld.Adduint8(ctxt, plt, 0x0d)
		ld.Adduint8(ctxt, plt, 0x10)
		// lgf     %r1,12(%r1)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x0c)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x14)
		// jg .plt
		ld.Adduint8(ctxt, plt, 0xc0)
		ld.Adduint8(ctxt, plt, 0xf4)

		ld.Adduint32(ctxt, plt, uint32(-((plt.Size - 2) >> 1))) // roll-your-own relocation
		//.plt index
		ld.Adduint32(ctxt, plt, uint32(rela.Size)) // rela size before current entry

		// rela
		ld.Addaddrplus(ctxt, rela, got, got.Size-8)

		ld.Adduint64(ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_390_JMP_SLOT))
		ld.Adduint64(ctxt, rela, 0)

		s.Plt = int32(plt.Size - 32)

	} else {
		ld.Diag("addpltsym: unsupported binary format")
	}
}
Ejemplo n.º 13
0
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
	if ld.Linkmode == ld.LinkExternal {
		switch r.Type {
		default:
			return -1

		case obj.R_ADDRMIPS,
			obj.R_ADDRMIPSU:
			r.Done = 0

			// set up addend for eventual relocation via outer symbol.
			rs := r.Sym
			r.Xadd = r.Add
			for rs.Outer != nil {
				r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ld.Diag("missing section for %s", rs.Name)
			}
			r.Xsym = rs

			return 0

		case obj.R_ADDRMIPSTLS,
			obj.R_CALLMIPS,
			obj.R_JMPMIPS:
			r.Done = 0
			r.Xsym = r.Sym
			r.Xadd = r.Add
			return 0
		}
	}

	switch r.Type {
	case obj.R_CONST:
		*val = r.Add
		return 0

	case obj.R_GOTOFF:
		*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
		return 0

	case obj.R_ADDRMIPS,
		obj.R_ADDRMIPSU:
		t := ld.Symaddr(r.Sym) + r.Add
		o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
		if r.Type == obj.R_ADDRMIPS {
			*val = int64(o1&0xffff0000 | uint32(t)&0xffff)
		} else {
			*val = int64(o1&0xffff0000 | uint32((t+1<<15)>>16)&0xffff)
		}
		return 0

	case obj.R_ADDRMIPSTLS:
		// thread pointer is at 0x7000 offset from the start of TLS data area
		t := ld.Symaddr(r.Sym) + r.Add - 0x7000
		if t < -32768 || t >= 32678 {
			ld.Diag("TLS offset out of range %d", t)
		}
		o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
		*val = int64(o1&0xffff0000 | uint32(t)&0xffff)
		return 0

	case obj.R_CALLMIPS,
		obj.R_JMPMIPS:
		// Low 26 bits = (S + A) >> 2
		t := ld.Symaddr(r.Sym) + r.Add
		o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
		*val = int64(o1&0xfc000000 | uint32(t>>2)&^0xfc000000)
		return 0
	}

	return -1
}
Ejemplo n.º 14
0
func adddynrel(s *ld.LSym, r *ld.Reloc) {
	targ := r.Sym
	ld.Ctxt.Cursym = s

	switch r.Type {
	default:
		if r.Type >= 256 {
			ld.Diag("unexpected relocation type %d", r.Type)
			return
		}

		// Handle relocations found in ELF object files.
	case 256 + ld.R_ARM_PLT32:
		r.Type = obj.R_CALLARM

		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
		}

		return

	case 256 + ld.R_ARM_THM_PC22: // R_ARM_THM_CALL
		ld.Exitf("R_ARM_THM_CALL, are you using -marm?")
		return

	case 256 + ld.R_ARM_GOT32: // R_ARM_GOT_BREL
		if targ.Type != obj.SDYNIMPORT {
			addgotsyminternal(ld.Ctxt, targ)
		} else {
			addgotsym(ld.Ctxt, targ)
		}

		r.Type = obj.R_CONST // write r->add during relocsym
		r.Sym = nil
		r.Add += int64(targ.Got)
		return

	case 256 + ld.R_ARM_GOT_PREL: // GOT(nil) + A - nil
		if targ.Type != obj.SDYNIMPORT {
			addgotsyminternal(ld.Ctxt, targ)
		} else {
			addgotsym(ld.Ctxt, targ)
		}

		r.Type = obj.R_PCREL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(targ.Got) + 4
		return

	case 256 + ld.R_ARM_GOTOFF: // R_ARM_GOTOFF32
		r.Type = obj.R_GOTOFF

		return

	case 256 + ld.R_ARM_GOTPC: // R_ARM_BASE_PREL
		r.Type = obj.R_PCREL

		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += 4
		return

	case 256 + ld.R_ARM_CALL:
		r.Type = obj.R_CALLARM
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
		}

		return

	case 256 + ld.R_ARM_REL32: // R_ARM_REL32
		r.Type = obj.R_PCREL

		r.Add += 4
		return

	case 256 + ld.R_ARM_ABS32:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_ARM_ABS32 relocation for dynamic symbol %s", targ.Name)
		}
		r.Type = obj.R_ADDR
		return

		// we can just ignore this, because we are targeting ARM V5+ anyway
	case 256 + ld.R_ARM_V4BX:
		if r.Sym != nil {
			// R_ARM_V4BX is ABS relocation, so this symbol is a dummy symbol, ignore it
			r.Sym.Type = 0
		}

		r.Sym = nil
		return

	case 256 + ld.R_ARM_PC24,
		256 + ld.R_ARM_JUMP24:
		r.Type = obj.R_CALLARM
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
		}

		return
	}

	// Handle references to ELF symbols from our own object files.
	if targ.Type != obj.SDYNIMPORT {
		return
	}

	switch r.Type {
	case obj.R_CALLARM:
		addpltsym(ld.Ctxt, targ)
		r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
		r.Add = int64(targ.Plt)
		return

	case obj.R_ADDR:
		if s.Type != obj.SDATA {
			break
		}
		if ld.Iself {
			ld.Adddynsym(ld.Ctxt, targ)
			rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
			ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
			ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_ARM_GLOB_DAT)) // we need a nil + A dynamic reloc
			r.Type = obj.R_CONST                                                               // write r->add during relocsym
			r.Sym = nil
			return
		}
	}

	ld.Ctxt.Cursym = s
	ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
Ejemplo n.º 15
0
func adddynrel(s *ld.LSym, r *ld.Reloc) {
	targ := r.Sym
	ld.Ctxt.Cursym = s

	switch r.Type {
	default:
		if r.Type >= 256 {
			ld.Diag("unexpected relocation type %d", r.Type)
			return
		}

		// Handle relocations found in ELF object files.
	case 256 + ld.R_386_PC32:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_386_PC32 relocation for dynamic symbol %s", targ.Name)
		}
		if targ.Type == 0 || targ.Type == obj.SXREF {
			ld.Diag("unknown symbol %s in pcrel", targ.Name)
		}
		r.Type = obj.R_PCREL
		r.Add += 4
		return

	case 256 + ld.R_386_PLT32:
		r.Type = obj.R_PCREL
		r.Add += 4
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add += int64(targ.Plt)
		}

		return

	case 256 + ld.R_386_GOT32, 256 + ld.R_386_GOT32X:
		if targ.Type != obj.SDYNIMPORT {
			// have symbol
			if r.Off >= 2 && s.P[r.Off-2] == 0x8b {
				// turn MOVL of GOT entry into LEAL of symbol address, relative to GOT.
				s.P[r.Off-2] = 0x8d

				r.Type = obj.R_GOTOFF
				return
			}

			if r.Off >= 2 && s.P[r.Off-2] == 0xff && s.P[r.Off-1] == 0xb3 {
				// turn PUSHL of GOT entry into PUSHL of symbol itself.
				// use unnecessary SS prefix to keep instruction same length.
				s.P[r.Off-2] = 0x36

				s.P[r.Off-1] = 0x68
				r.Type = obj.R_ADDR
				return
			}

			ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
			return
		}

		addgotsym(ld.Ctxt, targ)
		r.Type = obj.R_CONST // write r->add during relocsym
		r.Sym = nil
		r.Add += int64(targ.Got)
		return

	case 256 + ld.R_386_GOTOFF:
		r.Type = obj.R_GOTOFF
		return

	case 256 + ld.R_386_GOTPC:
		r.Type = obj.R_PCREL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += 4
		return

	case 256 + ld.R_386_32:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_386_32 relocation for dynamic symbol %s", targ.Name)
		}
		r.Type = obj.R_ADDR
		return

	case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 0:
		r.Type = obj.R_ADDR
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
		}
		return

	case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 1:
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(targ.Plt)
			r.Type = obj.R_PCREL
			return
		}

		r.Type = obj.R_PCREL
		return

	case 512 + ld.MACHO_FAKE_GOTPCREL:
		if targ.Type != obj.SDYNIMPORT {
			// have symbol
			// turn MOVL of GOT entry into LEAL of symbol itself
			if r.Off < 2 || s.P[r.Off-2] != 0x8b {
				ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
				return
			}

			s.P[r.Off-2] = 0x8d
			r.Type = obj.R_PCREL
			return
		}

		addgotsym(ld.Ctxt, targ)
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(targ.Got)
		r.Type = obj.R_PCREL
		return
	}

	// Handle references to ELF symbols from our own object files.
	if targ.Type != obj.SDYNIMPORT {
		return
	}

	switch r.Type {
	case obj.R_CALL,
		obj.R_PCREL:
		addpltsym(ld.Ctxt, targ)
		r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
		r.Add = int64(targ.Plt)
		return

	case obj.R_ADDR:
		if s.Type != obj.SDATA {
			break
		}
		if ld.Iself {
			ld.Adddynsym(ld.Ctxt, targ)
			rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
			ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
			ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_386_32))
			r.Type = obj.R_CONST // write r->add during relocsym
			r.Sym = nil
			return
		}

		if ld.HEADTYPE == obj.Hdarwin && s.Size == int64(ld.SysArch.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.
			ld.Adddynsym(ld.Ctxt, targ)

			got := ld.Linklookup(ld.Ctxt, ".got", 0)
			s.Type = got.Type | obj.SSUB
			s.Outer = got
			s.Sub = got.Sub
			got.Sub = s
			s.Value = got.Size
			ld.Adduint32(ld.Ctxt, got, 0)
			ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
			r.Type = 256 // ignore during relocsym
			return
		}

		if ld.HEADTYPE == obj.Hwindows && s.Size == int64(ld.SysArch.PtrSize) {
			// nothing to do, the relocation will be laid out in pereloc1
			return
		}
	}

	ld.Ctxt.Cursym = s
	ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
Ejemplo n.º 16
0
func machoreloc1(r *ld.Reloc, sectoff int64) int {
	var v uint32

	rs := r.Xsym

	if r.Type == obj.R_PCREL {
		if rs.Type == obj.SHOSTOBJ {
			ld.Diag("pc-relative relocation of external symbol is not supported")
			return -1
		}
		if r.Siz != 4 {
			return -1
		}

		// emit a pair of "scattered" relocations that
		// resolve to the difference of section addresses of
		// the symbol and the instruction
		// this value is added to the field being relocated
		o1 := uint32(sectoff)
		o1 |= 1 << 31 // scattered bit
		o1 |= ld.MACHO_ARM_RELOC_SECTDIFF << 24
		o1 |= 2 << 28 // size = 4

		o2 := uint32(0)
		o2 |= 1 << 31 // scattered bit
		o2 |= ld.MACHO_ARM_RELOC_PAIR << 24
		o2 |= 2 << 28 // size = 4

		ld.Thearch.Lput(o1)
		ld.Thearch.Lput(uint32(ld.Symaddr(rs)))
		ld.Thearch.Lput(o2)
		ld.Thearch.Lput(uint32(ld.Ctxt.Cursym.Value + int64(r.Off)))
		return 0
	}

	if rs.Type == obj.SHOSTOBJ || r.Type == obj.R_CALLARM {
		if rs.Dynid < 0 {
			ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
			return -1
		}

		v = uint32(rs.Dynid)
		v |= 1 << 27 // external relocation
	} else {
		v = uint32(rs.Sect.Extnum)
		if v == 0 {
			ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
			return -1
		}
	}

	switch r.Type {
	default:
		return -1

	case obj.R_ADDR:
		v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28

	case obj.R_CALLARM:
		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_ARM_RELOC_BR24 << 28
	}

	switch r.Siz {
	default:
		return -1

	case 1:
		v |= 0 << 25

	case 2:
		v |= 1 << 25

	case 4:
		v |= 2 << 25

	case 8:
		v |= 3 << 25
	}

	ld.Thearch.Lput(uint32(sectoff))
	ld.Thearch.Lput(v)
	return 0
}
Ejemplo n.º 17
0
func archrelocvariant(r *ld.Reloc, s *ld.LSym, t int64) int64 {
	switch r.Variant & ld.RV_TYPE_MASK {
	default:
		ld.Diag("unexpected relocation variant %d", r.Variant)
		fallthrough

	case ld.RV_NONE:
		return t

	case ld.RV_POWER_LO:
		if r.Variant&ld.RV_CHECK_OVERFLOW != 0 {
			// Whether to check for signed or unsigned
			// overflow depends on the instruction
			var o1 uint32
			if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
				o1 = ld.Be32(s.P[r.Off-2:])
			} else {
				o1 = ld.Le32(s.P[r.Off:])
			}
			switch o1 >> 26 {
			case 24, // ori
				26, // xori
				28: // andi
				if t>>16 != 0 {
					goto overflow
				}

			default:
				if int64(int16(t)) != t {
					goto overflow
				}
			}
		}

		return int64(int16(t))

	case ld.RV_POWER_HA:
		t += 0x8000
		fallthrough

		// Fallthrough
	case ld.RV_POWER_HI:
		t >>= 16

		if r.Variant&ld.RV_CHECK_OVERFLOW != 0 {
			// Whether to check for signed or unsigned
			// overflow depends on the instruction
			var o1 uint32
			if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
				o1 = ld.Be32(s.P[r.Off-2:])
			} else {
				o1 = ld.Le32(s.P[r.Off:])
			}
			switch o1 >> 26 {
			case 25, // oris
				27, // xoris
				29: // andis
				if t>>16 != 0 {
					goto overflow
				}

			default:
				if int64(int16(t)) != t {
					goto overflow
				}
			}
		}

		return int64(int16(t))

	case ld.RV_POWER_DS:
		var o1 uint32
		if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
			o1 = uint32(ld.Be16(s.P[r.Off:]))
		} else {
			o1 = uint32(ld.Le16(s.P[r.Off:]))
		}
		if t&3 != 0 {
			ld.Diag("relocation for %s+%d is not aligned: %d", r.Sym.Name, r.Off, t)
		}
		if (r.Variant&ld.RV_CHECK_OVERFLOW != 0) && int64(int16(t)) != t {
			goto overflow
		}
		return int64(o1)&0x3 | int64(int16(t))
	}

overflow:
	ld.Diag("relocation for %s+%d is too big: %d", r.Sym.Name, r.Off, t)
	return t
}
Ejemplo n.º 18
0
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
	if ld.Linkmode == ld.LinkExternal {
		switch r.Type {
		default:
			return -1

		case obj.R_POWER_TLS, obj.R_POWER_TLS_LE, obj.R_POWER_TLS_IE:
			r.Done = 0
			// check Outer is nil, Type is TLSBSS?
			r.Xadd = r.Add
			r.Xsym = r.Sym
			return 0

		case obj.R_ADDRPOWER,
			obj.R_ADDRPOWER_DS,
			obj.R_ADDRPOWER_TOCREL,
			obj.R_ADDRPOWER_TOCREL_DS,
			obj.R_ADDRPOWER_GOT,
			obj.R_ADDRPOWER_PCREL:
			r.Done = 0

			// set up addend for eventual relocation via outer symbol.
			rs := r.Sym
			r.Xadd = r.Add
			for rs.Outer != nil {
				r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ld.Diag("missing section for %s", rs.Name)
			}
			r.Xsym = rs

			return 0

		case obj.R_CALLPOWER:
			r.Done = 0
			r.Xsym = r.Sym
			r.Xadd = r.Add
			return 0
		}
	}

	switch r.Type {
	case obj.R_CONST:
		*val = r.Add
		return 0

	case obj.R_GOTOFF:
		*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
		return 0

	case obj.R_ADDRPOWER, obj.R_ADDRPOWER_DS:
		return archrelocaddr(r, s, val)

	case obj.R_CALLPOWER:
		// Bits 6 through 29 = (S + A - P) >> 2

		t := ld.Symaddr(r.Sym) + r.Add - (s.Value + int64(r.Off))
		if t&3 != 0 {
			ld.Ctxt.Diag("relocation for %s+%d is not aligned: %d", r.Sym.Name, r.Off, t)
		}
		if int64(int32(t<<6)>>6) != t {
			// TODO(austin) This can happen if text > 32M.
			// Add a call trampoline to .text in that case.
			ld.Ctxt.Diag("relocation for %s+%d is too big: %d", r.Sym.Name, r.Off, t)
		}

		*val |= int64(uint32(t) &^ 0xfc000003)
		return 0

	case obj.R_POWER_TOC: // S + A - .TOC.
		*val = ld.Symaddr(r.Sym) + r.Add - symtoc(s)

		return 0

	case obj.R_POWER_TLS_LE:
		// The thread pointer points 0x7000 bytes after the start of the the
		// thread local storage area as documented in section "3.7.2 TLS
		// Runtime Handling" of "Power Architecture 64-Bit ELF V2 ABI
		// Specification".
		v := r.Sym.Value - 0x7000
		if int64(int16(v)) != v {
			ld.Diag("TLS offset out of range %d", v)
		}
		*val = (*val &^ 0xffff) | (v & 0xffff)
		return 0
	}

	return -1
}
Ejemplo n.º 19
0
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
	if ld.Linkmode == ld.LinkExternal {
		switch r.Type {
		case obj.R_CALLARM:
			r.Done = 0

			// set up addend for eventual relocation via outer symbol.
			rs := r.Sym

			r.Xadd = r.Add
			if r.Xadd&0x800000 != 0 {
				r.Xadd |= ^0xffffff
			}
			r.Xadd *= 4
			for rs.Outer != nil {
				r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ld.Diag("missing section for %s", rs.Name)
			}
			r.Xsym = rs

			// ld64 for arm seems to want the symbol table to contain offset
			// into the section rather than pseudo virtual address that contains
			// the section load address.
			// we need to compensate that by removing the instruction's address
			// from addend.
			if ld.HEADTYPE == obj.Hdarwin {
				r.Xadd -= ld.Symaddr(s) + int64(r.Off)
			}

			*val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&uint32(r.Xadd/4))))
			return 0
		}

		return -1
	}

	switch r.Type {
	case obj.R_CONST:
		*val = r.Add
		return 0

	case obj.R_GOTOFF:
		*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
		return 0

		// The following three arch specific relocations are only for generation of
	// Linux/ARM ELF's PLT entry (3 assembler instruction)
	case obj.R_PLT0: // add ip, pc, #0xXX00000
		if ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got.plt", 0)) < ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0)) {
			ld.Diag(".got.plt should be placed after .plt section.")
		}
		*val = 0xe28fc600 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add)) >> 20))
		return 0

	case obj.R_PLT1: // add ip, ip, #0xYY000
		*val = 0xe28cca00 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add+4)) >> 12))

		return 0

	case obj.R_PLT2: // ldr pc, [ip, #0xZZZ]!
		*val = 0xe5bcf000 + (0xfff & int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add+8)))

		return 0

	case obj.R_CALLARM: // bl XXXXXX or b YYYYYY
		*val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&uint32((ld.Symaddr(r.Sym)+int64((uint32(r.Add))*4)-(s.Value+int64(r.Off)))/4))))

		return 0
	}

	return -1
}
Ejemplo n.º 20
0
func adddynrel(s *ld.LSym, r *ld.Reloc) {
	targ := r.Sym
	ld.Ctxt.Cursym = s

	switch r.Type {
	default:
		if r.Type >= 256 {
			ld.Diag("unexpected relocation type %d", r.Type)
			return
		}

		// Handle relocations found in ELF object files.
	case 256 + ld.R_PPC64_REL24:
		r.Type = obj.R_CALLPOWER

		// This is a local call, so the caller isn't setting
		// up r12 and r2 is the same for the caller and
		// callee. Hence, we need to go to the local entry
		// point.  (If we don't do this, the callee will try
		// to use r12 to compute r2.)
		r.Add += int64(r.Sym.Localentry) * 4

		if targ.Type == obj.SDYNIMPORT {
			// Should have been handled in elfsetupplt
			ld.Diag("unexpected R_PPC64_REL24 for dyn import")
		}

		return

	case 256 + ld.R_PPC_REL32:
		r.Type = obj.R_PCREL
		r.Add += 4

		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_PPC_REL32 for dyn import")
		}

		return

	case 256 + ld.R_PPC64_ADDR64:
		r.Type = obj.R_ADDR
		if targ.Type == obj.SDYNIMPORT {
			// These happen in .toc sections
			ld.Adddynsym(ld.Ctxt, targ)

			rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
			ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
			ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_PPC64_ADDR64))
			ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
			r.Type = 256 // ignore during relocsym
		}

		return

	case 256 + ld.R_PPC64_TOC16:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_LO | ld.RV_CHECK_OVERFLOW
		return

	case 256 + ld.R_PPC64_TOC16_LO:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_LO
		return

	case 256 + ld.R_PPC64_TOC16_HA:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
		return

	case 256 + ld.R_PPC64_TOC16_HI:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
		return

	case 256 + ld.R_PPC64_TOC16_DS:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_DS | ld.RV_CHECK_OVERFLOW
		return

	case 256 + ld.R_PPC64_TOC16_LO_DS:
		r.Type = obj.R_POWER_TOC
		r.Variant = ld.RV_POWER_DS
		return

	case 256 + ld.R_PPC64_REL16_LO:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_POWER_LO
		r.Add += 2 // Compensate for relocation size of 2
		return

	case 256 + ld.R_PPC64_REL16_HI:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
		r.Add += 2
		return

	case 256 + ld.R_PPC64_REL16_HA:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
		r.Add += 2
		return
	}

	// Handle references to ELF symbols from our own object files.
	if targ.Type != obj.SDYNIMPORT {
		return
	}

	// TODO(austin): Translate our relocations to ELF

	ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
Ejemplo n.º 21
0
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
	if ld.Linkmode == ld.LinkExternal {
		switch r.Type {
		default:
			return -1

		case obj.R_ARM64_GOTPCREL:
			var o1, o2 uint32
			if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
				o1 = uint32(*val >> 32)
				o2 = uint32(*val)
			} else {
				o1 = uint32(*val)
				o2 = uint32(*val >> 32)
			}
			// Any relocation against a function symbol is redirected to
			// be against a local symbol instead (see putelfsym in
			// symtab.go) but unfortunately the system linker was buggy
			// when confronted with a R_AARCH64_ADR_GOT_PAGE relocation
			// against a local symbol until May 2015
			// (https://sourceware.org/bugzilla/show_bug.cgi?id=18270). So
			// we convert the adrp; ld64 + R_ARM64_GOTPCREL into adrp;
			// add + R_ADDRARM64.
			if !(r.Sym.Version != 0 || (r.Sym.Type&obj.SHIDDEN != 0) || r.Sym.Attr.Local()) && r.Sym.Type == obj.STEXT && ld.DynlinkingGo() {
				if o2&0xffc00000 != 0xf9400000 {
					ld.Ctxt.Diag("R_ARM64_GOTPCREL against unexpected instruction %x", o2)
				}
				o2 = 0x91000000 | (o2 & 0x000003ff)
				r.Type = obj.R_ADDRARM64
			}
			if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
				*val = int64(o1)<<32 | int64(o2)
			} else {
				*val = int64(o2)<<32 | int64(o1)
			}
			fallthrough

		case obj.R_ADDRARM64:
			r.Done = 0

			// set up addend for eventual relocation via outer symbol.
			rs := r.Sym
			r.Xadd = r.Add
			for rs.Outer != nil {
				r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ld.Diag("missing section for %s", rs.Name)
			}
			r.Xsym = rs

			// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
			// will make the linking fail because it thinks the code is not PIC even though
			// the BR26 relocation should be fully resolved at link time.
			// That is the reason why the next if block is disabled. When the bug in ld64
			// is fixed, we can enable this block and also enable duff's device in cmd/7g.
			if false && ld.HEADTYPE == obj.Hdarwin {
				var o0, o1 uint32

				if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
					o0 = uint32(*val >> 32)
					o1 = uint32(*val)
				} else {
					o0 = uint32(*val)
					o1 = uint32(*val >> 32)
				}
				// Mach-O wants the addend to be encoded in the instruction
				// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
				// can only encode 24-bit of signed addend, but the instructions
				// supports 33-bit of signed addend, so we always encode the
				// addend in place.
				o0 |= (uint32((r.Xadd>>12)&3) << 29) | (uint32((r.Xadd>>12>>2)&0x7ffff) << 5)
				o1 |= uint32(r.Xadd&0xfff) << 10
				r.Xadd = 0

				// when laid out, the instruction order must always be o1, o2.
				if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
					*val = int64(o0)<<32 | int64(o1)
				} else {
					*val = int64(o1)<<32 | int64(o0)
				}
			}

			return 0

		case obj.R_CALLARM64,
			obj.R_ARM64_TLS_LE,
			obj.R_ARM64_TLS_IE:
			r.Done = 0
			r.Xsym = r.Sym
			r.Xadd = r.Add
			return 0
		}
	}

	switch r.Type {
	case obj.R_CONST:
		*val = r.Add
		return 0

	case obj.R_GOTOFF:
		*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
		return 0

	case obj.R_ADDRARM64:
		t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
		if t >= 1<<32 || t < -1<<32 {
			ld.Diag("program too large, address relocation distance = %d", t)
		}

		var o0, o1 uint32

		if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
			o0 = uint32(*val >> 32)
			o1 = uint32(*val)
		} else {
			o0 = uint32(*val)
			o1 = uint32(*val >> 32)
		}

		o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
		o1 |= uint32(t&0xfff) << 10

		// when laid out, the instruction order must always be o1, o2.
		if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
			*val = int64(o0)<<32 | int64(o1)
		} else {
			*val = int64(o1)<<32 | int64(o0)
		}
		return 0

	case obj.R_ARM64_TLS_LE:
		r.Done = 0
		if ld.HEADTYPE != obj.Hlinux {
			ld.Diag("TLS reloc on unsupported OS %s", ld.Headstr(int(ld.HEADTYPE)))
		}
		// The TCB is two pointers. This is not documented anywhere, but is
		// de facto part of the ABI.
		v := r.Sym.Value + int64(2*ld.SysArch.PtrSize)
		if v < 0 || v >= 32678 {
			ld.Diag("TLS offset out of range %d", v)
		}
		*val |= v << 5
		return 0

	case obj.R_CALLARM64:
		t := (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
		if t >= 1<<27 || t < -1<<27 {
			ld.Diag("program too large, call relocation distance = %d", t)
		}
		*val |= (t >> 2) & 0x03ffffff
		return 0
	}

	return -1
}
Ejemplo n.º 22
0
func asmb() {
	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime())
	}
	ld.Bso.Flush()

	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f codeblk\n", obj.Cputime())
	}
	ld.Bso.Flush()

	if ld.Iself {
		ld.Asmbelfsetup()
	}

	sect := ld.Segtext.Sect
	ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
	// 0xCC is INT $3 - breakpoint instruction
	ld.CodeblkPad(int64(sect.Vaddr), int64(sect.Length), []byte{0xCC})
	for sect = sect.Next; sect != nil; sect = sect.Next {
		ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
		ld.Datblk(int64(sect.Vaddr), int64(sect.Length))
	}

	if ld.Segrodata.Filelen > 0 {
		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime())
		}
		ld.Bso.Flush()

		ld.Cseek(int64(ld.Segrodata.Fileoff))
		ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
	}

	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime())
	}
	ld.Bso.Flush()

	ld.Cseek(int64(ld.Segdata.Fileoff))
	ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))

	ld.Cseek(int64(ld.Segdwarf.Fileoff))
	ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen))

	machlink := int64(0)
	if ld.HEADTYPE == obj.Hdarwin {
		machlink = ld.Domacholink()
	}

	switch ld.HEADTYPE {
	default:
		ld.Diag("unknown header type %d", ld.HEADTYPE)
		fallthrough

	case obj.Hplan9:
		break

	case obj.Hdarwin:
		ld.Debug['8'] = 1 /* 64-bit addresses */

	case obj.Hlinux,
		obj.Hfreebsd,
		obj.Hnetbsd,
		obj.Hopenbsd,
		obj.Hdragonfly,
		obj.Hsolaris:
		ld.Debug['8'] = 1 /* 64-bit addresses */

	case obj.Hnacl,
		obj.Hwindows:
		break
	}

	ld.Symsize = 0
	ld.Spsize = 0
	ld.Lcsize = 0
	symo := int64(0)
	if ld.Debug['s'] == 0 {
		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime())
		}
		ld.Bso.Flush()
		switch ld.HEADTYPE {
		default:
		case obj.Hplan9:
			ld.Debug['s'] = 1
			symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen)

		case obj.Hdarwin:
			symo = int64(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(ld.INITRND))) + uint64(machlink))

		case obj.Hlinux,
			obj.Hfreebsd,
			obj.Hnetbsd,
			obj.Hopenbsd,
			obj.Hdragonfly,
			obj.Hsolaris,
			obj.Hnacl:
			symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
			symo = ld.Rnd(symo, int64(ld.INITRND))

		case obj.Hwindows:
			symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
			symo = ld.Rnd(symo, ld.PEFILEALIGN)
		}

		ld.Cseek(symo)
		switch ld.HEADTYPE {
		default:
			if ld.Iself {
				ld.Cseek(symo)
				ld.Asmelfsym()
				ld.Cflush()
				ld.Cwrite(ld.Elfstrdat)

				if ld.Debug['v'] != 0 {
					fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime())
				}

				if ld.Linkmode == ld.LinkExternal {
					ld.Elfemitreloc()
				}
			}

		case obj.Hplan9:
			ld.Asmplan9sym()
			ld.Cflush()

			sym := ld.Linklookup(ld.Ctxt, "pclntab", 0)
			if sym != nil {
				ld.Lcsize = int32(len(sym.P))
				for i := 0; int32(i) < ld.Lcsize; i++ {
					ld.Cput(sym.P[i])
				}

				ld.Cflush()
			}

		case obj.Hwindows:
			if ld.Debug['v'] != 0 {
				fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime())
			}

		case obj.Hdarwin:
			if ld.Linkmode == ld.LinkExternal {
				ld.Machoemitreloc()
			}
		}
	}

	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f headr\n", obj.Cputime())
	}
	ld.Bso.Flush()
	ld.Cseek(0)
	switch ld.HEADTYPE {
	default:
	case obj.Hplan9: /* plan9 */
		magic := int32(4*26*26 + 7)

		magic |= 0x00008000                  /* fat header */
		ld.Lputb(uint32(magic))              /* magic */
		ld.Lputb(uint32(ld.Segtext.Filelen)) /* sizes */
		ld.Lputb(uint32(ld.Segdata.Filelen))
		ld.Lputb(uint32(ld.Segdata.Length - ld.Segdata.Filelen))
		ld.Lputb(uint32(ld.Symsize)) /* nsyms */
		vl := ld.Entryvalue()
		ld.Lputb(PADDR(uint32(vl))) /* va of entry */
		ld.Lputb(uint32(ld.Spsize)) /* sp offsets */
		ld.Lputb(uint32(ld.Lcsize)) /* line offsets */
		ld.Vputb(uint64(vl))        /* va of entry */

	case obj.Hdarwin:
		ld.Asmbmacho()

	case obj.Hlinux,
		obj.Hfreebsd,
		obj.Hnetbsd,
		obj.Hopenbsd,
		obj.Hdragonfly,
		obj.Hsolaris,
		obj.Hnacl:
		ld.Asmbelf(symo)

	case obj.Hwindows:
		ld.Asmbpe()
	}

	ld.Cflush()
}
Ejemplo n.º 23
0
func adddynrel(s *ld.LSym, r *ld.Reloc) {
	targ := r.Sym
	ld.Ctxt.Cursym = s

	switch r.Type {
	default:
		if r.Type >= 256 {
			ld.Diag("unexpected relocation type %d", r.Type)
			return
		}

		// Handle relocations found in ELF object files.
	case 256 + ld.R_390_12,
		256 + ld.R_390_GOT12:
		ld.Diag("s390x 12-bit relocations have not been implemented (relocation type %d)", r.Type-256)
		return

	case 256 + ld.R_390_8,
		256 + ld.R_390_16,
		256 + ld.R_390_32,
		256 + ld.R_390_64:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_390_nn relocation for dynamic symbol %s", targ.Name)
		}
		r.Type = obj.R_ADDR
		return

	case 256 + ld.R_390_PC16,
		256 + ld.R_390_PC32,
		256 + ld.R_390_PC64:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_390_PCnn relocation for dynamic symbol %s", targ.Name)
		}
		if targ.Type == 0 || targ.Type == obj.SXREF {
			ld.Diag("unknown symbol %s in pcrel", targ.Name)
		}
		r.Type = obj.R_PCREL
		r.Add += int64(r.Siz)
		return

	case 256 + ld.R_390_GOT16,
		256 + ld.R_390_GOT32,
		256 + ld.R_390_GOT64:
		ld.Diag("unimplemented S390x relocation: %v", r.Type-256)
		return

	case 256 + ld.R_390_PLT16DBL,
		256 + ld.R_390_PLT32DBL:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_390_DBL
		r.Add += int64(r.Siz)
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add += int64(targ.Plt)
		}
		return

	case 256 + ld.R_390_PLT32,
		256 + ld.R_390_PLT64:
		r.Type = obj.R_PCREL
		r.Add += int64(r.Siz)
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(ld.Ctxt, targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add += int64(targ.Plt)
		}
		return

	case 256 + ld.R_390_COPY:
		ld.Diag("unimplemented S390x relocation: %v", r.Type-256)

	case 256 + ld.R_390_GLOB_DAT:
		ld.Diag("unimplemented S390x relocation: %v", r.Type-256)

	case 256 + ld.R_390_JMP_SLOT:
		ld.Diag("unimplemented S390x relocation: %v", r.Type-256)

	case 256 + ld.R_390_RELATIVE:
		ld.Diag("unimplemented S390x relocation: %v", r.Type-256)

	case 256 + ld.R_390_GOTOFF:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_390_GOTOFF relocation for dynamic symbol %s", targ.Name)
		}
		r.Type = obj.R_GOTOFF
		return

	case 256 + ld.R_390_GOTPC:
		r.Type = obj.R_PCREL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(r.Siz)
		return

	case 256 + ld.R_390_PC16DBL,
		256 + ld.R_390_PC32DBL:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_390_DBL
		r.Add += int64(r.Siz)
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_390_PCnnDBL relocation for dynamic symbol %s", targ.Name)
		}
		return

	case 256 + ld.R_390_GOTPCDBL:
		r.Type = obj.R_PCREL
		r.Variant = ld.RV_390_DBL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(r.Siz)
		return

	case 256 + ld.R_390_GOTENT:
		addgotsym(targ)

		r.Type = obj.R_PCREL
		r.Variant = ld.RV_390_DBL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(targ.Got)
		r.Add += int64(r.Siz)
		return
	}
	// Handle references to ELF symbols from our own object files.
	if targ.Type != obj.SDYNIMPORT {
		return
	}

	ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
Ejemplo n.º 24
0
func addpltsym(s *ld.LSym) {
	if s.Plt >= 0 {
		return
	}

	ld.Adddynsym(ld.Ctxt, s)

	if ld.Iself {
		plt := ld.Linklookup(ld.Ctxt, ".plt", 0)
		got := ld.Linklookup(ld.Ctxt, ".got.plt", 0)
		rela := ld.Linklookup(ld.Ctxt, ".rela.plt", 0)
		if plt.Size == 0 {
			elfsetupplt()
		}

		// jmpq *got+size(IP)
		ld.Adduint8(ld.Ctxt, plt, 0xff)

		ld.Adduint8(ld.Ctxt, plt, 0x25)
		ld.Addpcrelplus(ld.Ctxt, plt, got, got.Size)

		// add to got: pointer to current pos in plt
		ld.Addaddrplus(ld.Ctxt, got, plt, plt.Size)

		// pushq $x
		ld.Adduint8(ld.Ctxt, plt, 0x68)

		ld.Adduint32(ld.Ctxt, plt, uint32((got.Size-24-8)/8))

		// jmpq .plt
		ld.Adduint8(ld.Ctxt, plt, 0xe9)

		ld.Adduint32(ld.Ctxt, plt, uint32(-(plt.Size + 4)))

		// rela
		ld.Addaddrplus(ld.Ctxt, rela, got, got.Size-8)

		ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_X86_64_JMP_SLOT))
		ld.Adduint64(ld.Ctxt, rela, 0)

		s.Plt = int32(plt.Size - 16)
	} else if ld.HEADTYPE == obj.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.

		addgotsym(s)
		plt := ld.Linklookup(ld.Ctxt, ".plt", 0)

		ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.plt", 0), uint32(s.Dynid))

		// jmpq *got+size(IP)
		s.Plt = int32(plt.Size)

		ld.Adduint8(ld.Ctxt, plt, 0xff)
		ld.Adduint8(ld.Ctxt, plt, 0x25)
		ld.Addpcrelplus(ld.Ctxt, plt, ld.Linklookup(ld.Ctxt, ".got", 0), int64(s.Got))
	} else {
		ld.Diag("addpltsym: unsupported binary format")
	}
}
Ejemplo n.º 25
0
func asmb() {
	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime())
	}
	ld.Bso.Flush()

	if ld.Iself {
		ld.Asmbelfsetup()
	}

	sect := ld.Segtext.Sect
	ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
	ld.Codeblk(int64(sect.Vaddr), int64(sect.Length))
	for sect = sect.Next; sect != nil; sect = sect.Next {
		ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
		ld.Datblk(int64(sect.Vaddr), int64(sect.Length))
	}

	if ld.Segrodata.Filelen > 0 {
		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime())
		}
		ld.Bso.Flush()

		ld.Cseek(int64(ld.Segrodata.Fileoff))
		ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
	}

	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime())
	}
	ld.Bso.Flush()

	ld.Cseek(int64(ld.Segdata.Fileoff))
	ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))

	ld.Cseek(int64(ld.Segdwarf.Fileoff))
	ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen))

	/* output symbol table */
	ld.Symsize = 0

	ld.Lcsize = 0
	symo := uint32(0)
	if ld.Debug['s'] == 0 {
		if !ld.Iself {
			ld.Diag("unsupported executable format")
		}
		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime())
		}
		ld.Bso.Flush()
		symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
		symo = uint32(ld.Rnd(int64(symo), int64(ld.INITRND)))

		ld.Cseek(int64(symo))
		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f elfsym\n", obj.Cputime())
		}
		ld.Asmelfsym()
		ld.Cflush()
		ld.Cwrite(ld.Elfstrdat)

		if ld.Debug['v'] != 0 {
			fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime())
		}

		if ld.Linkmode == ld.LinkExternal {
			ld.Elfemitreloc()
		}
	}

	ld.Ctxt.Cursym = nil
	if ld.Debug['v'] != 0 {
		fmt.Fprintf(ld.Bso, "%5.2f header\n", obj.Cputime())
	}
	ld.Bso.Flush()
	ld.Cseek(0)
	switch ld.HEADTYPE {
	default:
		ld.Diag("unsupported operating system")
	case obj.Hlinux:
		ld.Asmbelf(int64(symo))
	}

	ld.Cflush()
	if ld.Debug['c'] != 0 {
		fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
		fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
		fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen)
		fmt.Printf("symsize=%d\n", ld.Symsize)
		fmt.Printf("lcsize=%d\n", ld.Lcsize)
		fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize))
	}
}
Ejemplo n.º 26
0
func adddynrel(s *ld.LSym, r *ld.Reloc) {
	targ := r.Sym
	ld.Ctxt.Cursym = s

	switch r.Type {
	default:
		if r.Type >= 256 {
			ld.Diag("unexpected relocation type %d", r.Type)
			return
		}

		// Handle relocations found in ELF object files.
	case 256 + ld.R_X86_64_PC32:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ.Name)
		}
		if targ.Type == 0 || targ.Type == obj.SXREF {
			ld.Diag("unknown symbol %s in pcrel", targ.Name)
		}
		r.Type = obj.R_PCREL
		r.Add += 4
		return

	case 256 + ld.R_X86_64_PLT32:
		r.Type = obj.R_PCREL
		r.Add += 4
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add += int64(targ.Plt)
		}

		return

	case 256 + ld.R_X86_64_GOTPCREL, 256 + ld.R_X86_64_GOTPCRELX, 256 + ld.R_X86_64_REX_GOTPCRELX:
		if targ.Type != obj.SDYNIMPORT {
			// 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 = obj.R_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
		addgotsym(targ)

		r.Type = obj.R_PCREL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += 4
		r.Add += int64(targ.Got)
		return

	case 256 + ld.R_X86_64_64:
		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected R_X86_64_64 relocation for dynamic symbol %s", targ.Name)
		}
		r.Type = obj.R_ADDR
		return

	// Handle relocations found in Mach-O object files.
	case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0,
		512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0,
		512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0:
		// TODO: What is the difference between all these?
		r.Type = obj.R_ADDR

		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
		}
		return

	case 512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1:
		if targ.Type == obj.SDYNIMPORT {
			addpltsym(targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(targ.Plt)
			r.Type = obj.R_PCREL
			return
		}
		fallthrough

		// fall through
	case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1,
		512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1,
		512 + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1,
		512 + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1,
		512 + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
		r.Type = obj.R_PCREL

		if targ.Type == obj.SDYNIMPORT {
			ld.Diag("unexpected pc-relative reloc for dynamic symbol %s", targ.Name)
		}
		return

	case 512 + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
		if targ.Type != obj.SDYNIMPORT {
			// have symbol
			// turn MOVQ of GOT entry into LEAQ of symbol itself
			if r.Off < 2 || s.P[r.Off-2] != 0x8b {
				ld.Diag("unexpected GOT_LOAD reloc for non-dynamic symbol %s", targ.Name)
				return
			}

			s.P[r.Off-2] = 0x8d
			r.Type = obj.R_PCREL
			return
		}
		fallthrough

		// fall through
	case 512 + ld.MACHO_X86_64_RELOC_GOT*2 + 1:
		if targ.Type != obj.SDYNIMPORT {
			ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
		}
		addgotsym(targ)
		r.Type = obj.R_PCREL
		r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
		r.Add += int64(targ.Got)
		return
	}

	// Handle references to ELF symbols from our own object files.
	if targ.Type != obj.SDYNIMPORT {
		return
	}

	switch r.Type {
	case obj.R_CALL,
		obj.R_PCREL:
		if ld.HEADTYPE == obj.Hwindows {
			// nothing to do, the relocation will be laid out in pereloc1
			return
		} else {
			// for both ELF and Mach-O
			addpltsym(targ)
			r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
			r.Add = int64(targ.Plt)
			return
		}

	case obj.R_ADDR:
		if s.Type == obj.STEXT && ld.Iself {
			if ld.HEADTYPE == obj.Hsolaris {
				addpltsym(targ)
				r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
				r.Add += int64(targ.Plt)
				return
			}
			// The code is asking for the address of an external
			// function. We provide it with the address of the
			// correspondent GOT symbol.
			addgotsym(targ)

			r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
			r.Add += int64(targ.Got)
			return
		}

		if s.Type != obj.SDATA {
			break
		}
		if ld.Iself {
			ld.Adddynsym(ld.Ctxt, targ)
			rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
			ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
			if r.Siz == 8 {
				ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_64))
			} else {
				ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_32))
			}
			ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
			r.Type = 256 // ignore during relocsym
			return
		}

		if ld.HEADTYPE == obj.Hdarwin && s.Size == int64(ld.SysArch.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.
			ld.Adddynsym(ld.Ctxt, targ)

			got := ld.Linklookup(ld.Ctxt, ".got", 0)
			s.Type = got.Type | obj.SSUB
			s.Outer = got
			s.Sub = got.Sub
			got.Sub = s
			s.Value = got.Size
			ld.Adduint64(ld.Ctxt, got, 0)
			ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
			r.Type = 256 // ignore during relocsym
			return
		}

		if ld.HEADTYPE == obj.Hwindows {
			// nothing to do, the relocation will be laid out in pereloc1
			return
		}
	}

	ld.Ctxt.Cursym = s
	ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
Ejemplo n.º 27
0
func machoreloc1(r *ld.Reloc, sectoff int64) int {
	var v uint32

	rs := r.Xsym

	// ld64 has a bug handling MACHO_ARM64_RELOC_UNSIGNED with !extern relocation.
	// see cmd/avail/ld/data.go for details. The workaround is that don't use !extern
	// UNSIGNED relocation at all.
	if rs.Type == obj.SHOSTOBJ || r.Type == obj.R_CALLARM64 || r.Type == obj.R_ADDRARM64 || r.Type == obj.R_ADDR {
		if rs.Dynid < 0 {
			ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
			return -1
		}

		v = uint32(rs.Dynid)
		v |= 1 << 27 // external relocation
	} else {
		v = uint32(rs.Sect.Extnum)
		if v == 0 {
			ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
			return -1
		}
	}

	switch r.Type {
	default:
		return -1

	case obj.R_ADDR:
		v |= ld.MACHO_ARM64_RELOC_UNSIGNED << 28

	case obj.R_CALLARM64:
		if r.Xadd != 0 {
			ld.Diag("ld64 doesn't allow BR26 reloc with non-zero addend: %s+%d", rs.Name, r.Xadd)
		}

		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_ARM64_RELOC_BRANCH26 << 28

	case obj.R_ADDRARM64:
		r.Siz = 4
		// Two relocation entries: MACHO_ARM64_RELOC_PAGEOFF12 MACHO_ARM64_RELOC_PAGE21
		// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
		if r.Xadd != 0 {
			ld.Thearch.Lput(uint32(sectoff + 4))
			ld.Thearch.Lput((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
		}
		ld.Thearch.Lput(uint32(sectoff + 4))
		ld.Thearch.Lput(v | (ld.MACHO_ARM64_RELOC_PAGEOFF12 << 28) | (2 << 25))
		if r.Xadd != 0 {
			ld.Thearch.Lput(uint32(sectoff))
			ld.Thearch.Lput((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
		}
		v |= 1 << 24 // pc-relative bit
		v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28
	}

	switch r.Siz {
	default:
		return -1

	case 1:
		v |= 0 << 25

	case 2:
		v |= 1 << 25

	case 4:
		v |= 2 << 25

	case 8:
		v |= 3 << 25
	}

	ld.Thearch.Lput(uint32(sectoff))
	ld.Thearch.Lput(v)
	return 0
}