Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 841 insertions, 0 deletions

diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go
new file mode 100644
index 0000000..2d09a61
--- /dev/null
+++ b/src/cmd/link/internal/amd64/asm.go
@@ -0,0 +1,676 @@
+// Inferno utils/6l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/asm.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package amd64
+
+import (
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+	"cmd/link/internal/loader"
+	"cmd/link/internal/sym"
+	"debug/elf"
+	"log"
+)
+
+func PADDR(x uint32) uint32 {
+	return x &^ 0x80000000
+}
+
+func gentext(ctxt *ld.Link, ldr *loader.Loader) {
+	initfunc, addmoduledata := ld.PrepareAddmoduledata(ctxt)
+	if initfunc == nil {
+		return
+	}
+
+	o := func(op ...uint8) {
+		for _, op1 := range op {
+			initfunc.AddUint8(op1)
+		}
+	}
+
+	// 0000000000000000 <local.dso_init>:
+	//    0:	48 8d 3d 00 00 00 00 	lea    0x0(%rip),%rdi        # 7 <local.dso_init+0x7>
+	// 			3: R_X86_64_PC32	runtime.firstmoduledata-0x4
+	o(0x48, 0x8d, 0x3d)
+	initfunc.AddPCRelPlus(ctxt.Arch, ctxt.Moduledata, 0)
+	//    7:	e8 00 00 00 00       	callq  c <local.dso_init+0xc>
+	// 			8: R_X86_64_PLT32	runtime.addmoduledata-0x4
+	o(0xe8)
+	initfunc.AddSymRef(ctxt.Arch, addmoduledata, 0, objabi.R_CALL, 4)
+	//    c:	c3                   	retq
+	o(0xc3)
+}
+
+func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc, rIdx int) bool {
+	targ := r.Sym()
+	var targType sym.SymKind
+	if targ != 0 {
+		targType = ldr.SymType(targ)
+	}
+
+	switch rt := r.Type(); rt {
+	default:
+		if rt >= objabi.ElfRelocOffset {
+			ldr.Errorf(s, "unexpected relocation type %d (%s)", r.Type(), sym.RelocName(target.Arch, r.Type()))
+			return false
+		}
+
+		// Handle relocations found in ELF object files.
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PC32):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_X86_64_PC32 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		// TODO(mwhudson): the test of VisibilityHidden here probably doesn't make
+		// sense and should be removed when someone has thought about it properly.
+		if (targType == 0 || targType == sym.SXREF) && !ldr.AttrVisibilityHidden(targ) {
+			ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+4)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PC64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_X86_64_PC64 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		if targType == 0 || targType == sym.SXREF {
+			ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+8)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PLT32):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+4)
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			su.SetRelocSym(rIdx, syms.PLT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
+		}
+
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_GOTPCREL),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_GOTPCRELX),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_REX_GOTPCRELX):
+		su := ldr.MakeSymbolUpdater(s)
+		if targType != sym.SDYNIMPORT {
+			// have symbol
+			sData := ldr.Data(s)
+			if r.Off() >= 2 && sData[r.Off()-2] == 0x8b {
+				su.MakeWritable()
+				// turn MOVQ of GOT entry into LEAQ of symbol itself
+				writeableData := su.Data()
+				writeableData[r.Off()-2] = 0x8d
+				su.SetRelocType(rIdx, objabi.R_PCREL)
+				su.SetRelocAdd(rIdx, r.Add()+4)
+				return true
+			}
+		}
+
+		// fall back to using GOT and hope for the best (CMOV*)
+		// TODO: just needs relocation, no need to put in .dynsym
+		ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_X86_64_GLOB_DAT))
+
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocSym(rIdx, syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+4+int64(ldr.SymGot(targ)))
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_X86_64_64 relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ADDR)
+		if target.IsPIE() && target.IsInternal() {
+			// For internal linking PIE, this R_ADDR relocation cannot
+			// be resolved statically. We need to generate a dynamic
+			// relocation. Let the code below handle it.
+			break
+		}
+		return true
+
+	// Handle relocations found in Mach-O object files.
+	case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0:
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ADDR)
+
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected reloc for dynamic symbol %s", ldr.SymName(targ))
+		}
+		if target.IsPIE() && target.IsInternal() {
+			// For internal linking PIE, this R_ADDR relocation cannot
+			// be resolved statically. We need to generate a dynamic
+			// relocation. Let the code below handle it.
+			if rt == objabi.MachoRelocOffset+ld.MACHO_X86_64_RELOC_UNSIGNED*2 {
+				break
+			} else {
+				// MACHO_X86_64_RELOC_SIGNED or MACHO_X86_64_RELOC_BRANCH
+				// Can this happen? The object is expected to be PIC.
+				ldr.Errorf(s, "unsupported relocation for PIE: %v", rt)
+			}
+		}
+		return true
+
+	case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1:
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			su := ldr.MakeSymbolUpdater(s)
+			su.SetRelocSym(rIdx, syms.PLT)
+			su.SetRelocType(rIdx, objabi.R_PCREL)
+			su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
+			return true
+		}
+		fallthrough
+
+	case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1,
+		objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected pc-relative reloc for dynamic symbol %s", ldr.SymName(targ))
+		}
+		return true
+
+	case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
+		if targType != sym.SDYNIMPORT {
+			// have symbol
+			// turn MOVQ of GOT entry into LEAQ of symbol itself
+			sdata := ldr.Data(s)
+			if r.Off() < 2 || sdata[r.Off()-2] != 0x8b {
+				ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ))
+				return false
+			}
+
+			su := ldr.MakeSymbolUpdater(s)
+			su.MakeWritable()
+			sdata = su.Data()
+			sdata[r.Off()-2] = 0x8d
+			su.SetRelocType(rIdx, objabi.R_PCREL)
+			return true
+		}
+		fallthrough
+
+	case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_GOT*2 + 1:
+		if targType != sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected GOT reloc for non-dynamic symbol %s", ldr.SymName(targ))
+		}
+		ld.AddGotSym(target, ldr, syms, targ, 0)
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocSym(rIdx, syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ)))
+		return true
+	}
+
+	// Reread the reloc to incorporate any changes in type above.
+	relocs := ldr.Relocs(s)
+	r = relocs.At(rIdx)
+
+	switch r.Type() {
+	case objabi.R_CALL,
+		objabi.R_PCREL:
+		if targType != sym.SDYNIMPORT {
+			// nothing to do, the relocation will be laid out in reloc
+			return true
+		}
+		if target.IsExternal() {
+			// External linker will do this relocation.
+			return true
+		}
+		// Internal linking, for both ELF and Mach-O.
+		// Build a PLT entry and change the relocation target to that entry.
+		addpltsym(target, ldr, syms, targ)
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocSym(rIdx, syms.PLT)
+		su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
+		return true
+
+	case objabi.R_ADDR:
+		if ldr.SymType(s) == sym.STEXT && target.IsElf() {
+			su := ldr.MakeSymbolUpdater(s)
+			if target.IsSolaris() {
+				addpltsym(target, ldr, syms, targ)
+				su.SetRelocSym(rIdx, syms.PLT)
+				su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
+				return true
+			}
+			// The code is asking for the address of an external
+			// function. We provide it with the address of the
+			// correspondent GOT symbol.
+			ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_X86_64_GLOB_DAT))
+
+			su.SetRelocSym(rIdx, syms.GOT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ)))
+			return true
+		}
+
+		// Process dynamic relocations for the data sections.
+		if target.IsPIE() && target.IsInternal() {
+			// When internally linking, generate dynamic relocations
+			// for all typical R_ADDR relocations. The exception
+			// are those R_ADDR that are created as part of generating
+			// the dynamic relocations and must be resolved statically.
+			//
+			// There are three phases relevant to understanding this:
+			//
+			//	dodata()  // we are here
+			//	address() // symbol address assignment
+			//	reloc()   // resolution of static R_ADDR relocs
+			//
+			// At this point symbol addresses have not been
+			// assigned yet (as the final size of the .rela section
+			// will affect the addresses), and so we cannot write
+			// the Elf64_Rela.r_offset now. Instead we delay it
+			// until after the 'address' phase of the linker is
+			// complete. We do this via Addaddrplus, which creates
+			// a new R_ADDR relocation which will be resolved in
+			// the 'reloc' phase.
+			//
+			// These synthetic static R_ADDR relocs must be skipped
+			// now, or else we will be caught in an infinite loop
+			// of generating synthetic relocs for our synthetic
+			// relocs.
+			//
+			// Furthermore, the rela sections contain dynamic
+			// relocations with R_ADDR relocations on
+			// Elf64_Rela.r_offset. This field should contain the
+			// symbol offset as determined by reloc(), not the
+			// final dynamically linked address as a dynamic
+			// relocation would provide.
+			switch ldr.SymName(s) {
+			case ".dynsym", ".rela", ".rela.plt", ".got.plt", ".dynamic":
+				return false
+			}
+		} else {
+			// Either internally linking a static executable,
+			// in which case we can resolve these relocations
+			// statically in the 'reloc' phase, or externally
+			// linking, in which case the relocation will be
+			// prepared in the 'reloc' phase and passed to the
+			// external linker in the 'asmb' phase.
+			if ldr.SymType(s) != sym.SDATA && ldr.SymType(s) != sym.SRODATA {
+				break
+			}
+		}
+
+		if target.IsElf() {
+			// Generate R_X86_64_RELATIVE relocations for best
+			// efficiency in the dynamic linker.
+			//
+			// As noted above, symbol addresses have not been
+			// assigned yet, so we can't generate the final reloc
+			// entry yet. We ultimately want:
+			//
+			// r_offset = s + r.Off
+			// r_info = R_X86_64_RELATIVE
+			// r_addend = targ + r.Add
+			//
+			// The dynamic linker will set *offset = base address +
+			// addend.
+			//
+			// AddAddrPlus is used for r_offset and r_addend to
+			// generate new R_ADDR relocations that will update
+			// these fields in the 'reloc' phase.
+			rela := ldr.MakeSymbolUpdater(syms.Rela)
+			rela.AddAddrPlus(target.Arch, s, int64(r.Off()))
+			if r.Siz() == 8 {
+				rela.AddUint64(target.Arch, elf.R_INFO(0, uint32(elf.R_X86_64_RELATIVE)))
+			} else {
+				ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ))
+			}
+			rela.AddAddrPlus(target.Arch, targ, int64(r.Add()))
+			// Not mark r done here. So we still apply it statically,
+			// so in the file content we'll also have the right offset
+			// to the relocation target. So it can be examined statically
+			// (e.g. go version).
+			return true
+		}
+
+		if target.IsDarwin() {
+			// Mach-O relocations are a royal pain to lay out.
+			// They use a compact stateful bytecode representation.
+			// Here we record what are needed and encode them later.
+			ld.MachoAddRebase(s, int64(r.Off()))
+			// Not mark r done here. So we still apply it statically,
+			// so in the file content we'll also have the right offset
+			// to the relocation target. So it can be examined statically
+			// (e.g. go version).
+			return true
+		}
+	}
+
+	return false
+}
+
+func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, ri int, sectoff int64) bool {
+	out.Write64(uint64(sectoff))
+
+	elfsym := ld.ElfSymForReloc(ctxt, r.Xsym)
+	siz := r.Size
+	switch r.Type {
+	default:
+		return false
+	case objabi.R_ADDR, objabi.R_DWARFSECREF:
+		if siz == 4 {
+			out.Write64(uint64(elf.R_X86_64_32) | uint64(elfsym)<<32)
+		} else if siz == 8 {
+			out.Write64(uint64(elf.R_X86_64_64) | uint64(elfsym)<<32)
+		} else {
+			return false
+		}
+	case objabi.R_TLS_LE:
+		if siz == 4 {
+			out.Write64(uint64(elf.R_X86_64_TPOFF32) | uint64(elfsym)<<32)
+		} else {
+			return false
+		}
+	case objabi.R_TLS_IE:
+		if siz == 4 {
+			out.Write64(uint64(elf.R_X86_64_GOTTPOFF) | uint64(elfsym)<<32)
+		} else {
+			return false
+		}
+	case objabi.R_CALL:
+		if siz == 4 {
+			if ldr.SymType(r.Xsym) == sym.SDYNIMPORT {
+				out.Write64(uint64(elf.R_X86_64_PLT32) | uint64(elfsym)<<32)
+			} else {
+				out.Write64(uint64(elf.R_X86_64_PC32) | uint64(elfsym)<<32)
+			}
+		} else {
+			return false
+		}
+	case objabi.R_PCREL:
+		if siz == 4 {
+			if ldr.SymType(r.Xsym) == sym.SDYNIMPORT && ldr.SymElfType(r.Xsym) == elf.STT_FUNC {
+				out.Write64(uint64(elf.R_X86_64_PLT32) | uint64(elfsym)<<32)
+			} else {
+				out.Write64(uint64(elf.R_X86_64_PC32) | uint64(elfsym)<<32)
+			}
+		} else {
+			return false
+		}
+	case objabi.R_GOTPCREL:
+		if siz == 4 {
+			out.Write64(uint64(elf.R_X86_64_GOTPCREL) | uint64(elfsym)<<32)
+		} else {
+			return false
+		}
+	}
+
+	out.Write64(uint64(r.Xadd))
+	return true
+}
+
+func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, sectoff int64) bool {
+	var v uint32
+
+	rs := r.Xsym
+	rt := r.Type
+
+	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_PCREL || rt == objabi.R_GOTPCREL || rt == objabi.R_CALL {
+		if ldr.SymDynid(rs) < 0 {
+			ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
+			return false
+		}
+
+		v = uint32(ldr.SymDynid(rs))
+		v |= 1 << 27 // external relocation
+	} else {
+		v = uint32(ldr.SymSect(rs).Extnum)
+		if v == 0 {
+			ldr.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymSect(rs).Name, ldr.SymType(rs), ldr.SymType(rs))
+			return false
+		}
+	}
+
+	switch rt {
+	default:
+		return false
+
+	case objabi.R_ADDR:
+		v |= ld.MACHO_X86_64_RELOC_UNSIGNED << 28
+
+	case objabi.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 objabi.R_PCREL:
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_X86_64_RELOC_SIGNED << 28
+	case objabi.R_GOTPCREL:
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_X86_64_RELOC_GOT_LOAD << 28
+	}
+
+	switch r.Size {
+	default:
+		return false
+
+	case 1:
+		v |= 0 << 25
+
+	case 2:
+		v |= 1 << 25
+
+	case 4:
+		v |= 2 << 25
+
+	case 8:
+		v |= 3 << 25
+	}
+
+	out.Write32(uint32(sectoff))
+	out.Write32(v)
+	return true
+}
+
+func pereloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, sectoff int64) bool {
+	var v uint32
+
+	rs := r.Xsym
+	rt := r.Type
+
+	if ldr.SymDynid(rs) < 0 {
+		ldr.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
+		return false
+	}
+
+	out.Write32(uint32(sectoff))
+	out.Write32(uint32(ldr.SymDynid(rs)))
+
+	switch rt {
+	default:
+		return false
+
+	case objabi.R_DWARFSECREF:
+		v = ld.IMAGE_REL_AMD64_SECREL
+
+	case objabi.R_ADDR:
+		if r.Size == 8 {
+			v = ld.IMAGE_REL_AMD64_ADDR64
+		} else {
+			v = ld.IMAGE_REL_AMD64_ADDR32
+		}
+
+	case objabi.R_CALL,
+		objabi.R_PCREL:
+		v = ld.IMAGE_REL_AMD64_REL32
+	}
+
+	out.Write16(uint16(v))
+
+	return true
+}
+
+func archreloc(*ld.Target, *loader.Loader, *ld.ArchSyms, loader.Reloc, loader.Sym, int64) (int64, int, bool) {
+	return -1, 0, false
+}
+
+func archrelocvariant(*ld.Target, *loader.Loader, loader.Reloc, sym.RelocVariant, loader.Sym, int64) int64 {
+	log.Fatalf("unexpected relocation variant")
+	return -1
+}
+
+func elfsetupplt(ctxt *ld.Link, plt, got *loader.SymbolBuilder, dynamic loader.Sym) {
+	if plt.Size() == 0 {
+		// pushq got+8(IP)
+		plt.AddUint8(0xff)
+
+		plt.AddUint8(0x35)
+		plt.AddPCRelPlus(ctxt.Arch, got.Sym(), 8)
+
+		// jmpq got+16(IP)
+		plt.AddUint8(0xff)
+
+		plt.AddUint8(0x25)
+		plt.AddPCRelPlus(ctxt.Arch, got.Sym(), 16)
+
+		// nopl 0(AX)
+		plt.AddUint32(ctxt.Arch, 0x00401f0f)
+
+		// assume got->size == 0 too
+		got.AddAddrPlus(ctxt.Arch, dynamic, 0)
+
+		got.AddUint64(ctxt.Arch, 0)
+		got.AddUint64(ctxt.Arch, 0)
+	}
+}
+
+func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) {
+	if ldr.SymPlt(s) >= 0 {
+		return
+	}
+
+	ld.Adddynsym(ldr, target, syms, s)
+
+	if target.IsElf() {
+		plt := ldr.MakeSymbolUpdater(syms.PLT)
+		got := ldr.MakeSymbolUpdater(syms.GOTPLT)
+		rela := ldr.MakeSymbolUpdater(syms.RelaPLT)
+		if plt.Size() == 0 {
+			panic("plt is not set up")
+		}
+
+		// jmpq *got+size(IP)
+		plt.AddUint8(0xff)
+
+		plt.AddUint8(0x25)
+		plt.AddPCRelPlus(target.Arch, got.Sym(), got.Size())
+
+		// add to got: pointer to current pos in plt
+		got.AddAddrPlus(target.Arch, plt.Sym(), plt.Size())
+
+		// pushq $x
+		plt.AddUint8(0x68)
+
+		plt.AddUint32(target.Arch, uint32((got.Size()-24-8)/8))
+
+		// jmpq .plt
+		plt.AddUint8(0xe9)
+
+		plt.AddUint32(target.Arch, uint32(-(plt.Size() + 4)))
+
+		// rela
+		rela.AddAddrPlus(target.Arch, got.Sym(), got.Size()-8)
+
+		sDynid := ldr.SymDynid(s)
+		rela.AddUint64(target.Arch, elf.R_INFO(uint32(sDynid), uint32(elf.R_X86_64_JMP_SLOT)))
+		rela.AddUint64(target.Arch, 0)
+
+		ldr.SetPlt(s, int32(plt.Size()-16))
+	} else if target.IsDarwin() {
+		ld.AddGotSym(target, ldr, syms, s, 0)
+
+		sDynid := ldr.SymDynid(s)
+		lep := ldr.MakeSymbolUpdater(syms.LinkEditPLT)
+		lep.AddUint32(target.Arch, uint32(sDynid))
+
+		plt := ldr.MakeSymbolUpdater(syms.PLT)
+		ldr.SetPlt(s, int32(plt.Size()))
+
+		// jmpq *got+size(IP)
+		plt.AddUint8(0xff)
+		plt.AddUint8(0x25)
+		plt.AddPCRelPlus(target.Arch, syms.GOT, int64(ldr.SymGot(s)))
+	} else {
+		ldr.Errorf(s, "addpltsym: unsupported binary format")
+	}
+}
+
+func tlsIEtoLE(P []byte, off, size int) {
+	// Transform the PC-relative instruction into a constant load.
+	// That is,
+	//
+	//	MOVQ X(IP), REG  ->  MOVQ $Y, REG
+	//
+	// To determine the instruction and register, we study the op codes.
+	// Consult an AMD64 instruction encoding guide to decipher this.
+	if off < 3 {
+		log.Fatal("R_X86_64_GOTTPOFF reloc not preceded by MOVQ or ADDQ instruction")
+	}
+	op := P[off-3 : off]
+	reg := op[2] >> 3
+
+	if op[1] == 0x8b || reg == 4 {
+		// MOVQ
+		if op[0] == 0x4c {
+			op[0] = 0x49
+		} else if size == 4 && op[0] == 0x44 {
+			op[0] = 0x41
+		}
+		if op[1] == 0x8b {
+			op[1] = 0xc7
+		} else {
+			op[1] = 0x81 // special case for SP
+		}
+		op[2] = 0xc0 | reg
+	} else {
+		// An alternate op is ADDQ. This is handled by GNU gold,
+		// but right now is not generated by the Go compiler:
+		//	ADDQ X(IP), REG  ->  ADDQ $Y, REG
+		// Consider adding support for it here.
+		log.Fatalf("expected TLS IE op to be MOVQ, got %v", op)
+	}
+}
diff --git a/src/cmd/link/internal/amd64/l.go b/src/cmd/link/internal/amd64/l.go
new file mode 100644
index 0000000..c9ea90a
--- /dev/null
+++ b/src/cmd/link/internal/amd64/l.go
@@ -0,0 +1,43 @@
+// Inferno utils/6l/l.h
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/l.h
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package amd64
+
+const (
+	maxAlign  = 32 // max data alignment
+	minAlign  = 1  // min data alignment
+	funcAlign = 32
+)
+
+/* Used by ../internal/ld/dwarf.go */
+const (
+	dwarfRegSP = 7
+	dwarfRegLR = 16
+)
diff --git a/src/cmd/link/internal/amd64/obj.go b/src/cmd/link/internal/amd64/obj.go
new file mode 100644
index 0000000..d09c90e
--- /dev/null
+++ b/src/cmd/link/internal/amd64/obj.go
@@ -0,0 +1,122 @@
+// Inferno utils/6l/obj.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/obj.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package amd64
+
+import (
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+)
+
+func Init() (*sys.Arch, ld.Arch) {
+	arch := sys.ArchAMD64
+
+	theArch := ld.Arch{
+		Funcalign:  funcAlign,
+		Maxalign:   maxAlign,
+		Minalign:   minAlign,
+		Dwarfregsp: dwarfRegSP,
+		Dwarfreglr: dwarfRegLR,
+		// 0xCC is INT $3 - breakpoint instruction
+		CodePad: []byte{0xCC},
+
+		Plan9Magic:  uint32(4*26*26 + 7),
+		Plan9_64Bit: true,
+
+		Adddynrel:        adddynrel,
+		Archinit:         archinit,
+		Archreloc:        archreloc,
+		Archrelocvariant: archrelocvariant,
+		Elfreloc1:        elfreloc1,
+		ElfrelocSize:     24,
+		Elfsetupplt:      elfsetupplt,
+		Gentext:          gentext,
+		Machoreloc1:      machoreloc1,
+		MachorelocSize:   8,
+		PEreloc1:         pereloc1,
+		TLSIEtoLE:        tlsIEtoLE,
+
+		Linuxdynld:     "/lib64/ld-linux-x86-64.so.2",
+		Freebsddynld:   "/libexec/ld-elf.so.1",
+		Openbsddynld:   "/usr/libexec/ld.so",
+		Netbsddynld:    "/libexec/ld.elf_so",
+		Dragonflydynld: "/usr/libexec/ld-elf.so.2",
+		Solarisdynld:   "/lib/amd64/ld.so.1",
+	}
+
+	return arch, theArch
+}
+
+func archinit(ctxt *ld.Link) {
+	switch ctxt.HeadType {
+	default:
+		ld.Exitf("unknown -H option: %v", ctxt.HeadType)
+
+	case objabi.Hplan9: /* plan 9 */
+		ld.HEADR = 32 + 8
+
+		if *ld.FlagTextAddr == -1 {
+			*ld.FlagTextAddr = 0x200000 + int64(ld.HEADR)
+		}
+		if *ld.FlagRound == -1 {
+			*ld.FlagRound = 0x200000
+		}
+
+	case objabi.Hdarwin: /* apple MACH */
+		ld.HEADR = ld.INITIAL_MACHO_HEADR
+		if *ld.FlagRound == -1 {
+			*ld.FlagRound = 4096
+		}
+		if *ld.FlagTextAddr == -1 {
+			*ld.FlagTextAddr = 0x1000000 + int64(ld.HEADR)
+		}
+
+	case objabi.Hlinux, /* elf64 executable */
+		objabi.Hfreebsd,   /* freebsd */
+		objabi.Hnetbsd,    /* netbsd */
+		objabi.Hopenbsd,   /* openbsd */
+		objabi.Hdragonfly, /* dragonfly */
+		objabi.Hsolaris:   /* solaris */
+		ld.Elfinit(ctxt)
+
+		ld.HEADR = ld.ELFRESERVE
+		if *ld.FlagTextAddr == -1 {
+			*ld.FlagTextAddr = (1 << 22) + int64(ld.HEADR)
+		}
+		if *ld.FlagRound == -1 {
+			*ld.FlagRound = 4096
+		}
+
+	case objabi.Hwindows: /* PE executable */
+		// ld.HEADR, ld.FlagTextAddr, ld.FlagRound are set in ld.Peinit
+		return
+	}
+}