Пример #1
0
Файл: asm.go Проект: Mokolea/go
func elfreloc1(r *ld.Reloc, sectoff int64) int {
	ld.Thearch.Vput(uint64(sectoff))

	elfsym := r.Xsym.ElfsymForReloc()
	switch r.Type {
	default:
		return -1

	case obj.R_ADDR:
		switch r.Siz {
		case 4:
			ld.Thearch.Vput(ld.R_PPC64_ADDR32 | uint64(elfsym)<<32)
		case 8:
			ld.Thearch.Vput(ld.R_PPC64_ADDR64 | uint64(elfsym)<<32)
		default:
			return -1
		}

	case obj.R_POWER_TLS:
		ld.Thearch.Vput(ld.R_PPC64_TLS | uint64(elfsym)<<32)

	case obj.R_POWER_TLS_LE:
		ld.Thearch.Vput(ld.R_PPC64_TPREL16 | uint64(elfsym)<<32)

	case obj.R_POWER_TLS_IE:
		ld.Thearch.Vput(ld.R_PPC64_GOT_TPREL16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_GOT_TPREL16_LO_DS | uint64(elfsym)<<32)

	case obj.R_ADDRPOWER:
		ld.Thearch.Vput(ld.R_PPC64_ADDR16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_ADDR16_LO | uint64(elfsym)<<32)

	case obj.R_ADDRPOWER_DS:
		ld.Thearch.Vput(ld.R_PPC64_ADDR16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_ADDR16_LO_DS | uint64(elfsym)<<32)

	case obj.R_ADDRPOWER_GOT:
		ld.Thearch.Vput(ld.R_PPC64_GOT16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_GOT16_LO_DS | uint64(elfsym)<<32)

	case obj.R_ADDRPOWER_PCREL:
		ld.Thearch.Vput(ld.R_PPC64_REL16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_REL16_LO | uint64(elfsym)<<32)
		r.Xadd += 4

	case obj.R_ADDRPOWER_TOCREL:
		ld.Thearch.Vput(ld.R_PPC64_TOC16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_TOC16_LO | uint64(elfsym)<<32)

	case obj.R_ADDRPOWER_TOCREL_DS:
		ld.Thearch.Vput(ld.R_PPC64_TOC16_HA | uint64(elfsym)<<32)
		ld.Thearch.Vput(uint64(r.Xadd))
		ld.Thearch.Vput(uint64(sectoff + 4))
		ld.Thearch.Vput(ld.R_PPC64_TOC16_LO_DS | uint64(elfsym)<<32)

	case obj.R_CALLPOWER:
		if r.Siz != 4 {
			return -1
		}
		ld.Thearch.Vput(ld.R_PPC64_REL24 | uint64(elfsym)<<32)

	}
	ld.Thearch.Vput(uint64(r.Xadd))

	return 0
}
Пример #2
0
Файл: asm.go Проект: Mokolea/go
func archreloc(r *ld.Reloc, s *ld.Symbol, 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
}
Пример #3
0
Файл: asm.go Проект: hurkgu/go
func archreloc(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, 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(ctxt, rs) - ld.Symaddr(ctxt, rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ctxt.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(ctxt, r.Sym) + r.Add - ld.Symaddr(ctxt, ld.Linklookup(ctxt, ".got", 0))
		return 0

	case obj.R_ADDRMIPS,
		obj.R_ADDRMIPSU:
		t := ld.Symaddr(ctxt, 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(ctxt, r.Sym) + r.Add - 0x7000
		if t < -32768 || t >= 32678 {
			ctxt.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(ctxt, 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
}
Пример #4
0
func archreloc(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, 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(ctxt, rs) - ld.Symaddr(ctxt, rs.Outer)
				rs = rs.Outer
			}

			if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
				ctxt.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(ctxt, 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(ctxt, r.Sym) + r.Add - ld.Symaddr(ctxt, ld.Linklookup(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(ctxt, ld.Linklookup(ctxt, ".got.plt", 0)) < ld.Symaddr(ctxt, ld.Linklookup(ctxt, ".plt", 0)) {
			ctxt.Diag(".got.plt should be placed after .plt section.")
		}
		*val = 0xe28fc600 + (0xff & (int64(uint32(ld.Symaddr(ctxt, r.Sym)-(ld.Symaddr(ctxt, ld.Linklookup(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(ctxt, r.Sym)-(ld.Symaddr(ctxt, ld.Linklookup(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(ctxt, r.Sym)-(ld.Symaddr(ctxt, ld.Linklookup(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(ctxt, r.Sym)+int64((uint32(r.Add))*4)-(s.Value+int64(r.Off)))/4))))

		return 0
	}

	return -1
}
Пример #5
0
Файл: asm.go Проект: 4ad/go
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.Thearch.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
}
Пример #6
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_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.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.Thearch.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
}
Пример #7
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_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.Sect == nil {
				ld.Diag("missing section for %s", rs.Name)
			}
			r.Xsym = rs

			// the first instruction is always at the lower address, this is endian neutral;
			// but note that o0 and o1 should still use the target endian.
			o0 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off : r.Off+4])
			o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off+4 : r.Off+8])

			// 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 {
				// 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:
			r.Done = 0
			r.Xsym = r.Sym
			*val = int64(0xfc000000 & uint32(r.Add))
			r.Xadd = int64((uint32(r.Add) &^ 0xfc000000) * 4)
			r.Add = 0
			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)
		}

		// the first instruction is always at the lower address, this is endian neutral;
		// but note that o0 and o1 should still use the target endian.
		o0 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off : r.Off+4])
		o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off+4 : r.Off+8])

		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_CALLARM64:
		*val = int64((0xfc000000 & uint32(r.Add)) | uint32((ld.Symaddr(r.Sym)+r.Add*4-(s.Value+int64(r.Off)))/4))
		return 0
	}

	return -1
}