Adding upstream version 1.16.10.upstream/1.16.10upstream

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

3 files changed, 616 insertions, 0 deletions

diff --git a/src/cmd/link/internal/s390x/asm.go b/src/cmd/link/internal/s390x/asm.go
new file mode 100644
index 0000000..78d2cc8
--- /dev/null
+++ b/src/cmd/link/internal/s390x/asm.go
@@ -0,0 +1,455 @@
+// Inferno utils/5l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/5l/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 s390x
+
+import (
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+	"cmd/link/internal/loader"
+	"cmd/link/internal/sym"
+	"debug/elf"
+)
+
+// gentext generates assembly to append the local moduledata to the global
+// moduledata linked list at initialization time. This is only done if the runtime
+// is in a different module.
+//
+// <go.link.addmoduledata>:
+// 	larl  %r2, <local.moduledata>
+// 	jg    <runtime.addmoduledata@plt>
+//	undef
+//
+// The job of appending the moduledata is delegated to runtime.addmoduledata.
+func gentext(ctxt *ld.Link, ldr *loader.Loader) {
+	initfunc, addmoduledata := ld.PrepareAddmoduledata(ctxt)
+	if initfunc == nil {
+		return
+	}
+
+	// larl %r2, <local.moduledata>
+	initfunc.AddUint8(0xc0)
+	initfunc.AddUint8(0x20)
+	initfunc.AddSymRef(ctxt.Arch, ctxt.Moduledata, 6, objabi.R_PCREL, 4)
+	r1 := initfunc.Relocs()
+	ldr.SetRelocVariant(initfunc.Sym(), r1.Count()-1, sym.RV_390_DBL)
+
+	// jg <runtime.addmoduledata[@plt]>
+	initfunc.AddUint8(0xc0)
+	initfunc.AddUint8(0xf4)
+	initfunc.AddSymRef(ctxt.Arch, addmoduledata, 6, objabi.R_CALL, 4)
+	r2 := initfunc.Relocs()
+	ldr.SetRelocVariant(initfunc.Sym(), r2.Count()-1, sym.RV_390_DBL)
+
+	// undef (for debugging)
+	initfunc.AddUint32(ctxt.Arch, 0)
+}
+
+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 r.Type() {
+	default:
+		if r.Type() >= objabi.ElfRelocOffset {
+			ldr.Errorf(s, "unexpected relocation type %d", r.Type())
+			return false
+		}
+
+		// Handle relocations found in ELF object files.
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_12),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT12):
+		ldr.Errorf(s, "s390x 12-bit relocations have not been implemented (relocation type %d)", r.Type()-objabi.ElfRelocOffset)
+		return false
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_8),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_16),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_32),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_390_nn relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_ADDR)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC16),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC32),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC64):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_390_PCnn 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()+int64(r.Siz()))
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT16),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT32),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT64):
+		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT16DBL),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT32DBL):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
+		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			r.SetSym(syms.PLT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
+		}
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT32),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT64):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
+		if targType == sym.SDYNIMPORT {
+			addpltsym(target, ldr, syms, targ)
+			r.SetSym(syms.PLT)
+			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
+		}
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_COPY):
+		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
+		return false
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GLOB_DAT):
+		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
+		return false
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_JMP_SLOT):
+		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
+		return false
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_RELATIVE):
+		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
+		return false
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTOFF):
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_390_GOTOFF relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_GOTOFF)
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTPC):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		r.SetSym(syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC16DBL),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC32DBL):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
+		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
+		if targType == sym.SDYNIMPORT {
+			ldr.Errorf(s, "unexpected R_390_PCnnDBL relocation for dynamic symbol %s", ldr.SymName(targ))
+		}
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTPCDBL):
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
+		r.SetSym(syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
+		return true
+
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTENT):
+		ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_390_GLOB_DAT))
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocType(rIdx, objabi.R_PCREL)
+		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
+		r.SetSym(syms.GOT)
+		su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ))+int64(r.Siz()))
+		return true
+	}
+	// Handle references to ELF symbols from our own object files.
+	if targType != sym.SDYNIMPORT {
+		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_TLS_LE:
+		switch siz {
+		default:
+			return false
+		case 4:
+			// WARNING - silently ignored by linker in ELF64
+			out.Write64(uint64(elf.R_390_TLS_LE32) | uint64(elfsym)<<32)
+		case 8:
+			// WARNING - silently ignored by linker in ELF32
+			out.Write64(uint64(elf.R_390_TLS_LE64) | uint64(elfsym)<<32)
+		}
+	case objabi.R_TLS_IE:
+		switch siz {
+		default:
+			return false
+		case 4:
+			out.Write64(uint64(elf.R_390_TLS_IEENT) | uint64(elfsym)<<32)
+		}
+	case objabi.R_ADDR, objabi.R_DWARFSECREF:
+		switch siz {
+		default:
+			return false
+		case 4:
+			out.Write64(uint64(elf.R_390_32) | uint64(elfsym)<<32)
+		case 8:
+			out.Write64(uint64(elf.R_390_64) | uint64(elfsym)<<32)
+		}
+	case objabi.R_GOTPCREL:
+		if siz == 4 {
+			out.Write64(uint64(elf.R_390_GOTENT) | uint64(elfsym)<<32)
+		} else {
+			return false
+		}
+	case objabi.R_PCREL, objabi.R_PCRELDBL, objabi.R_CALL:
+		elfrel := elf.R_390_NONE
+		rVariant := ldr.RelocVariant(s, ri)
+		isdbl := rVariant&sym.RV_TYPE_MASK == sym.RV_390_DBL
+		// TODO(mundaym): all DBL style relocations should be
+		// signalled using the variant - see issue 14218.
+		switch r.Type {
+		case objabi.R_PCRELDBL, objabi.R_CALL:
+			isdbl = true
+		}
+		if ldr.SymType(r.Xsym) == sym.SDYNIMPORT && (ldr.SymElfType(r.Xsym) == elf.STT_FUNC || r.Type == objabi.R_CALL) {
+			if isdbl {
+				switch siz {
+				case 2:
+					elfrel = elf.R_390_PLT16DBL
+				case 4:
+					elfrel = elf.R_390_PLT32DBL
+				}
+			} else {
+				switch siz {
+				case 4:
+					elfrel = elf.R_390_PLT32
+				case 8:
+					elfrel = elf.R_390_PLT64
+				}
+			}
+		} else {
+			if isdbl {
+				switch siz {
+				case 2:
+					elfrel = elf.R_390_PC16DBL
+				case 4:
+					elfrel = elf.R_390_PC32DBL
+				}
+			} else {
+				switch siz {
+				case 2:
+					elfrel = elf.R_390_PC16
+				case 4:
+					elfrel = elf.R_390_PC32
+				case 8:
+					elfrel = elf.R_390_PC64
+				}
+			}
+		}
+		if elfrel == elf.R_390_NONE {
+			return false // unsupported size/dbl combination
+		}
+		out.Write64(uint64(elfrel) | uint64(elfsym)<<32)
+	}
+
+	out.Write64(uint64(r.Xadd))
+	return true
+}
+
+func elfsetupplt(ctxt *ld.Link, plt, got *loader.SymbolBuilder, dynamic loader.Sym) {
+	if plt.Size() == 0 {
+		// stg     %r1,56(%r15)
+		plt.AddUint8(0xe3)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0xf0)
+		plt.AddUint8(0x38)
+		plt.AddUint8(0x00)
+		plt.AddUint8(0x24)
+		// larl    %r1,_GLOBAL_OFFSET_TABLE_
+		plt.AddUint8(0xc0)
+		plt.AddUint8(0x10)
+		plt.AddSymRef(ctxt.Arch, got.Sym(), 6, objabi.R_PCRELDBL, 4)
+		// mvc     48(8,%r15),8(%r1)
+		plt.AddUint8(0xd2)
+		plt.AddUint8(0x07)
+		plt.AddUint8(0xf0)
+		plt.AddUint8(0x30)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x08)
+		// lg      %r1,16(%r1)
+		plt.AddUint8(0xe3)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x00)
+		plt.AddUint8(0x04)
+		// br      %r1
+		plt.AddUint8(0x07)
+		plt.AddUint8(0xf1)
+		// nopr    %r0
+		plt.AddUint8(0x07)
+		plt.AddUint8(0x00)
+		// nopr    %r0
+		plt.AddUint8(0x07)
+		plt.AddUint8(0x00)
+		// nopr    %r0
+		plt.AddUint8(0x07)
+		plt.AddUint8(0x00)
+
+		// assume got->size == 0 too
+		got.AddAddrPlus(ctxt.Arch, dynamic, 0)
+
+		got.AddUint64(ctxt.Arch, 0)
+		got.AddUint64(ctxt.Arch, 0)
+	}
+}
+
+func machoreloc1(*sys.Arch, *ld.OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int64) bool {
+	return false
+}
+
+func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) {
+	return val, 0, false
+}
+
+func archrelocvariant(target *ld.Target, ldr *loader.Loader, r loader.Reloc, rv sym.RelocVariant, s loader.Sym, t int64) int64 {
+	switch rv & sym.RV_TYPE_MASK {
+	default:
+		ldr.Errorf(s, "unexpected relocation variant %d", rv)
+		return t
+
+	case sym.RV_NONE:
+		return t
+
+	case sym.RV_390_DBL:
+		if t&1 != 0 {
+			ldr.Errorf(s, "%s+%v is not 2-byte aligned", ldr.SymName(r.Sym()), ldr.SymValue(r.Sym()))
+		}
+		return t >> 1
+	}
+}
+
+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.GOT)
+		rela := ldr.MakeSymbolUpdater(syms.RelaPLT)
+		if plt.Size() == 0 {
+			panic("plt is not set up")
+		}
+		// larl    %r1,_GLOBAL_OFFSET_TABLE_+index
+
+		plt.AddUint8(0xc0)
+		plt.AddUint8(0x10)
+		plt.AddPCRelPlus(target.Arch, got.Sym(), got.Size()+6)
+		pltrelocs := plt.Relocs()
+		ldr.SetRelocVariant(plt.Sym(), pltrelocs.Count()-1, sym.RV_390_DBL)
+
+		// add to got: pointer to current pos in plt
+		got.AddAddrPlus(target.Arch, plt.Sym(), plt.Size()+8) // weird but correct
+		// lg      %r1,0(%r1)
+		plt.AddUint8(0xe3)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x00)
+		plt.AddUint8(0x00)
+		plt.AddUint8(0x04)
+		// br      %r1
+		plt.AddUint8(0x07)
+		plt.AddUint8(0xf1)
+		// basr    %r1,%r0
+		plt.AddUint8(0x0d)
+		plt.AddUint8(0x10)
+		// lgf     %r1,12(%r1)
+		plt.AddUint8(0xe3)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x10)
+		plt.AddUint8(0x0c)
+		plt.AddUint8(0x00)
+		plt.AddUint8(0x14)
+		// jg .plt
+		plt.AddUint8(0xc0)
+		plt.AddUint8(0xf4)
+
+		plt.AddUint32(target.Arch, uint32(-((plt.Size() - 2) >> 1))) // roll-your-own relocation
+		//.plt index
+		plt.AddUint32(target.Arch, uint32(rela.Size())) // rela size before current entry
+
+		// 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_390_JMP_SLOT)))
+		rela.AddUint64(target.Arch, 0)
+
+		ldr.SetPlt(s, int32(plt.Size()-32))
+
+	} else {
+		ldr.Errorf(s, "addpltsym: unsupported binary format")
+	}
+}
diff --git a/src/cmd/link/internal/s390x/l.go b/src/cmd/link/internal/s390x/l.go
new file mode 100644
index 0000000..f040587
--- /dev/null
+++ b/src/cmd/link/internal/s390x/l.go
@@ -0,0 +1,74 @@
+// Inferno utils/5l/asm.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/5l/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 s390x
+
+// Writing object files.
+
+// cmd/9l/l.h from Vita Nuova.
+//
+//	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 © 2000-2008 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 © 2000-2008 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.
+
+const (
+	maxAlign  = 32 // max data alignment
+	minAlign  = 2  // min data alignment
+	funcAlign = 16
+)
+
+/* Used by ../internal/ld/dwarf.go */
+const (
+	dwarfRegSP = 15
+	dwarfRegLR = 14
+)
diff --git a/src/cmd/link/internal/s390x/obj.go b/src/cmd/link/internal/s390x/obj.go
new file mode 100644
index 0000000..8acc1d4
--- /dev/null
+++ b/src/cmd/link/internal/s390x/obj.go
@@ -0,0 +1,87 @@
+// Inferno utils/5l/obj.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/5l/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 s390x
+
+import (
+	"cmd/internal/objabi"
+	"cmd/internal/sys"
+	"cmd/link/internal/ld"
+)
+
+func Init() (*sys.Arch, ld.Arch) {
+	arch := sys.ArchS390X
+
+	theArch := ld.Arch{
+		Funcalign:  funcAlign,
+		Maxalign:   maxAlign,
+		Minalign:   minAlign,
+		Dwarfregsp: dwarfRegSP,
+		Dwarfreglr: dwarfRegLR,
+
+		Adddynrel:        adddynrel,
+		Archinit:         archinit,
+		Archreloc:        archreloc,
+		Archrelocvariant: archrelocvariant,
+		Elfreloc1:        elfreloc1,
+		ElfrelocSize:     24,
+		Elfsetupplt:      elfsetupplt,
+		Gentext:          gentext,
+		Machoreloc1:      machoreloc1,
+
+		Linuxdynld: "/lib64/ld64.so.1",
+
+		// not relevant for s390x
+		Freebsddynld:   "XXX",
+		Openbsddynld:   "XXX",
+		Netbsddynld:    "XXX",
+		Dragonflydynld: "XXX",
+		Solarisdynld:   "XXX",
+	}
+
+	return arch, theArch
+}
+
+func archinit(ctxt *ld.Link) {
+	switch ctxt.HeadType {
+	default:
+		ld.Exitf("unknown -H option: %v", ctxt.HeadType)
+
+	case objabi.Hlinux: // s390x ELF
+		ld.Elfinit(ctxt)
+		ld.HEADR = ld.ELFRESERVE
+		if *ld.FlagTextAddr == -1 {
+			*ld.FlagTextAddr = 0x10000 + int64(ld.HEADR)
+		}
+		if *ld.FlagRound == -1 {
+			*ld.FlagRound = 0x10000
+		}
+	}
+}