1// Inferno utils/5l/asm.c
2// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/5l/asm.c
3//
4//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
5//	Portions Copyright © 1995-1997 C H Forsyth ([email protected])
6//	Portions Copyright © 1997-1999 Vita Nuova Limited
7//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
8//	Portions Copyright © 2004,2006 Bruce Ellis
9//	Portions Copyright © 2005-2007 C H Forsyth ([email protected])
10//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
11//	Portions Copyright © 2009 The Go Authors. All rights reserved.
12//
13// Permission is hereby granted, free of charge, to any person obtaining a copy
14// of this software and associated documentation files (the "Software"), to deal
15// in the Software without restriction, including without limitation the rights
16// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17// copies of the Software, and to permit persons to whom the Software is
18// furnished to do so, subject to the following conditions:
19//
20// The above copyright notice and this permission notice shall be included in
21// all copies or substantial portions of the Software.
22//
23// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
26// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
28// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29// THE SOFTWARE.
30
31package s390x
32
33import (
34	"cmd/internal/objabi"
35	"cmd/internal/sys"
36	"cmd/link/internal/ld"
37	"cmd/link/internal/loader"
38	"cmd/link/internal/sym"
39	"debug/elf"
40)
41
42// gentext generates assembly to append the local moduledata to the global
43// moduledata linked list at initialization time. This is only done if the runtime
44// is in a different module.
45//
46//	<go.link.addmoduledata>:
47//		larl  %r2, <local.moduledata>
48//		jg    <runtime.addmoduledata@plt>
49//		undef
50//
51// The job of appending the moduledata is delegated to runtime.addmoduledata.
52func gentext(ctxt *ld.Link, ldr *loader.Loader) {
53	initfunc, addmoduledata := ld.PrepareAddmoduledata(ctxt)
54	if initfunc == nil {
55		return
56	}
57
58	// larl %r2, <local.moduledata>
59	initfunc.AddUint8(0xc0)
60	initfunc.AddUint8(0x20)
61	initfunc.AddSymRef(ctxt.Arch, ctxt.Moduledata, 6, objabi.R_PCREL, 4)
62	r1 := initfunc.Relocs()
63	ldr.SetRelocVariant(initfunc.Sym(), r1.Count()-1, sym.RV_390_DBL)
64
65	// jg <runtime.addmoduledata[@plt]>
66	initfunc.AddUint8(0xc0)
67	initfunc.AddUint8(0xf4)
68	initfunc.AddSymRef(ctxt.Arch, addmoduledata, 6, objabi.R_CALL, 4)
69	r2 := initfunc.Relocs()
70	ldr.SetRelocVariant(initfunc.Sym(), r2.Count()-1, sym.RV_390_DBL)
71
72	// undef (for debugging)
73	initfunc.AddUint32(ctxt.Arch, 0)
74}
75
76func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc, rIdx int) bool {
77	targ := r.Sym()
78	var targType sym.SymKind
79	if targ != 0 {
80		targType = ldr.SymType(targ)
81	}
82
83	switch r.Type() {
84	default:
85		if r.Type() >= objabi.ElfRelocOffset {
86			ldr.Errorf(s, "unexpected relocation type %d", r.Type())
87			return false
88		}
89
90		// Handle relocations found in ELF object files.
91	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_12),
92		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT12):
93		ldr.Errorf(s, "s390x 12-bit relocations have not been implemented (relocation type %d)", r.Type()-objabi.ElfRelocOffset)
94		return false
95
96	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_8),
97		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_16),
98		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_32),
99		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_64):
100		if targType == sym.SDYNIMPORT {
101			ldr.Errorf(s, "unexpected R_390_nn relocation for dynamic symbol %s", ldr.SymName(targ))
102		}
103
104		su := ldr.MakeSymbolUpdater(s)
105		su.SetRelocType(rIdx, objabi.R_ADDR)
106		return true
107
108	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC16),
109		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC32),
110		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC64):
111		if targType == sym.SDYNIMPORT {
112			ldr.Errorf(s, "unexpected R_390_PCnn relocation for dynamic symbol %s", ldr.SymName(targ))
113		}
114		if targType == 0 || targType == sym.SXREF {
115			ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ))
116		}
117		su := ldr.MakeSymbolUpdater(s)
118		su.SetRelocType(rIdx, objabi.R_PCREL)
119		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
120		return true
121
122	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT16),
123		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT32),
124		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOT64):
125		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
126		return true
127
128	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT16DBL),
129		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT32DBL):
130		su := ldr.MakeSymbolUpdater(s)
131		su.SetRelocType(rIdx, objabi.R_PCREL)
132		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
133		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
134		if targType == sym.SDYNIMPORT {
135			addpltsym(target, ldr, syms, targ)
136			r.SetSym(syms.PLT)
137			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
138		}
139		return true
140
141	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT32),
142		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PLT64):
143		su := ldr.MakeSymbolUpdater(s)
144		su.SetRelocType(rIdx, objabi.R_PCREL)
145		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
146		if targType == sym.SDYNIMPORT {
147			addpltsym(target, ldr, syms, targ)
148			r.SetSym(syms.PLT)
149			su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ)))
150		}
151		return true
152
153	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_COPY):
154		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
155		return false
156
157	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GLOB_DAT):
158		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
159		return false
160
161	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_JMP_SLOT):
162		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
163		return false
164
165	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_RELATIVE):
166		ldr.Errorf(s, "unimplemented S390x relocation: %v", r.Type()-objabi.ElfRelocOffset)
167		return false
168
169	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTOFF):
170		if targType == sym.SDYNIMPORT {
171			ldr.Errorf(s, "unexpected R_390_GOTOFF relocation for dynamic symbol %s", ldr.SymName(targ))
172		}
173		su := ldr.MakeSymbolUpdater(s)
174		su.SetRelocType(rIdx, objabi.R_GOTOFF)
175		return true
176
177	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTPC):
178		su := ldr.MakeSymbolUpdater(s)
179		su.SetRelocType(rIdx, objabi.R_PCREL)
180		r.SetSym(syms.GOT)
181		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
182		return true
183
184	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC16DBL),
185		objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_PC32DBL):
186		su := ldr.MakeSymbolUpdater(s)
187		su.SetRelocType(rIdx, objabi.R_PCREL)
188		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
189		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
190		if targType == sym.SDYNIMPORT {
191			ldr.Errorf(s, "unexpected R_390_PCnnDBL relocation for dynamic symbol %s", ldr.SymName(targ))
192		}
193		return true
194
195	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTPCDBL):
196		su := ldr.MakeSymbolUpdater(s)
197		su.SetRelocType(rIdx, objabi.R_PCREL)
198		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
199		r.SetSym(syms.GOT)
200		su.SetRelocAdd(rIdx, r.Add()+int64(r.Siz()))
201		return true
202
203	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_390_GOTENT):
204		ld.AddGotSym(target, ldr, syms, targ, uint32(elf.R_390_GLOB_DAT))
205		su := ldr.MakeSymbolUpdater(s)
206		su.SetRelocType(rIdx, objabi.R_PCREL)
207		ldr.SetRelocVariant(s, rIdx, sym.RV_390_DBL)
208		r.SetSym(syms.GOT)
209		su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ))+int64(r.Siz()))
210		return true
211	}
212	// Handle references to ELF symbols from our own object files.
213	return targType != sym.SDYNIMPORT
214}
215
216func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, ri int, sectoff int64) bool {
217	out.Write64(uint64(sectoff))
218
219	elfsym := ld.ElfSymForReloc(ctxt, r.Xsym)
220	siz := r.Size
221	switch r.Type {
222	default:
223		return false
224	case objabi.R_TLS_LE:
225		switch siz {
226		default:
227			return false
228		case 4:
229			// WARNING - silently ignored by linker in ELF64
230			out.Write64(uint64(elf.R_390_TLS_LE32) | uint64(elfsym)<<32)
231		case 8:
232			// WARNING - silently ignored by linker in ELF32
233			out.Write64(uint64(elf.R_390_TLS_LE64) | uint64(elfsym)<<32)
234		}
235	case objabi.R_TLS_IE:
236		switch siz {
237		default:
238			return false
239		case 4:
240			out.Write64(uint64(elf.R_390_TLS_IEENT) | uint64(elfsym)<<32)
241		}
242	case objabi.R_ADDR, objabi.R_DWARFSECREF:
243		switch siz {
244		default:
245			return false
246		case 4:
247			out.Write64(uint64(elf.R_390_32) | uint64(elfsym)<<32)
248		case 8:
249			out.Write64(uint64(elf.R_390_64) | uint64(elfsym)<<32)
250		}
251	case objabi.R_GOTPCREL:
252		if siz == 4 {
253			out.Write64(uint64(elf.R_390_GOTENT) | uint64(elfsym)<<32)
254		} else {
255			return false
256		}
257	case objabi.R_PCREL, objabi.R_PCRELDBL, objabi.R_CALL:
258		elfrel := elf.R_390_NONE
259		rVariant := ldr.RelocVariant(s, ri)
260		isdbl := rVariant&sym.RV_TYPE_MASK == sym.RV_390_DBL
261		// TODO(mundaym): all DBL style relocations should be
262		// signalled using the variant - see issue 14218.
263		switch r.Type {
264		case objabi.R_PCRELDBL, objabi.R_CALL:
265			isdbl = true
266		}
267		if ldr.SymType(r.Xsym) == sym.SDYNIMPORT && (ldr.SymElfType(r.Xsym) == elf.STT_FUNC || r.Type == objabi.R_CALL) {
268			if isdbl {
269				switch siz {
270				case 2:
271					elfrel = elf.R_390_PLT16DBL
272				case 4:
273					elfrel = elf.R_390_PLT32DBL
274				}
275			} else {
276				switch siz {
277				case 4:
278					elfrel = elf.R_390_PLT32
279				case 8:
280					elfrel = elf.R_390_PLT64
281				}
282			}
283		} else {
284			if isdbl {
285				switch siz {
286				case 2:
287					elfrel = elf.R_390_PC16DBL
288				case 4:
289					elfrel = elf.R_390_PC32DBL
290				}
291			} else {
292				switch siz {
293				case 2:
294					elfrel = elf.R_390_PC16
295				case 4:
296					elfrel = elf.R_390_PC32
297				case 8:
298					elfrel = elf.R_390_PC64
299				}
300			}
301		}
302		if elfrel == elf.R_390_NONE {
303			return false // unsupported size/dbl combination
304		}
305		out.Write64(uint64(elfrel) | uint64(elfsym)<<32)
306	}
307
308	out.Write64(uint64(r.Xadd))
309	return true
310}
311
312func elfsetupplt(ctxt *ld.Link, ldr *loader.Loader, plt, got *loader.SymbolBuilder, dynamic loader.Sym) {
313	if plt.Size() == 0 {
314		// stg     %r1,56(%r15)
315		plt.AddUint8(0xe3)
316		plt.AddUint8(0x10)
317		plt.AddUint8(0xf0)
318		plt.AddUint8(0x38)
319		plt.AddUint8(0x00)
320		plt.AddUint8(0x24)
321		// larl    %r1,_GLOBAL_OFFSET_TABLE_
322		plt.AddUint8(0xc0)
323		plt.AddUint8(0x10)
324		plt.AddSymRef(ctxt.Arch, got.Sym(), 6, objabi.R_PCRELDBL, 4)
325		// mvc     48(8,%r15),8(%r1)
326		plt.AddUint8(0xd2)
327		plt.AddUint8(0x07)
328		plt.AddUint8(0xf0)
329		plt.AddUint8(0x30)
330		plt.AddUint8(0x10)
331		plt.AddUint8(0x08)
332		// lg      %r1,16(%r1)
333		plt.AddUint8(0xe3)
334		plt.AddUint8(0x10)
335		plt.AddUint8(0x10)
336		plt.AddUint8(0x10)
337		plt.AddUint8(0x00)
338		plt.AddUint8(0x04)
339		// br      %r1
340		plt.AddUint8(0x07)
341		plt.AddUint8(0xf1)
342		// nopr    %r0
343		plt.AddUint8(0x07)
344		plt.AddUint8(0x00)
345		// nopr    %r0
346		plt.AddUint8(0x07)
347		plt.AddUint8(0x00)
348		// nopr    %r0
349		plt.AddUint8(0x07)
350		plt.AddUint8(0x00)
351
352		// assume got->size == 0 too
353		got.AddAddrPlus(ctxt.Arch, dynamic, 0)
354
355		got.AddUint64(ctxt.Arch, 0)
356		got.AddUint64(ctxt.Arch, 0)
357	}
358}
359
360func machoreloc1(*sys.Arch, *ld.OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int64) bool {
361	return false
362}
363
364func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) {
365	return val, 0, false
366}
367
368func archrelocvariant(target *ld.Target, ldr *loader.Loader, r loader.Reloc, rv sym.RelocVariant, s loader.Sym, t int64, p []byte) int64 {
369	switch rv & sym.RV_TYPE_MASK {
370	default:
371		ldr.Errorf(s, "unexpected relocation variant %d", rv)
372		return t
373
374	case sym.RV_NONE:
375		return t
376
377	case sym.RV_390_DBL:
378		if t&1 != 0 {
379			ldr.Errorf(s, "%s+%v is not 2-byte aligned", ldr.SymName(r.Sym()), ldr.SymValue(r.Sym()))
380		}
381		return t >> 1
382	}
383}
384
385func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) {
386	if ldr.SymPlt(s) >= 0 {
387		return
388	}
389
390	ld.Adddynsym(ldr, target, syms, s)
391
392	if target.IsElf() {
393		plt := ldr.MakeSymbolUpdater(syms.PLT)
394		got := ldr.MakeSymbolUpdater(syms.GOT)
395		rela := ldr.MakeSymbolUpdater(syms.RelaPLT)
396		if plt.Size() == 0 {
397			panic("plt is not set up")
398		}
399		// larl    %r1,_GLOBAL_OFFSET_TABLE_+index
400
401		plt.AddUint8(0xc0)
402		plt.AddUint8(0x10)
403		plt.AddPCRelPlus(target.Arch, got.Sym(), got.Size()+6)
404		pltrelocs := plt.Relocs()
405		ldr.SetRelocVariant(plt.Sym(), pltrelocs.Count()-1, sym.RV_390_DBL)
406
407		// add to got: pointer to current pos in plt
408		got.AddAddrPlus(target.Arch, plt.Sym(), plt.Size()+8) // weird but correct
409		// lg      %r1,0(%r1)
410		plt.AddUint8(0xe3)
411		plt.AddUint8(0x10)
412		plt.AddUint8(0x10)
413		plt.AddUint8(0x00)
414		plt.AddUint8(0x00)
415		plt.AddUint8(0x04)
416		// br      %r1
417		plt.AddUint8(0x07)
418		plt.AddUint8(0xf1)
419		// basr    %r1,%r0
420		plt.AddUint8(0x0d)
421		plt.AddUint8(0x10)
422		// lgf     %r1,12(%r1)
423		plt.AddUint8(0xe3)
424		plt.AddUint8(0x10)
425		plt.AddUint8(0x10)
426		plt.AddUint8(0x0c)
427		plt.AddUint8(0x00)
428		plt.AddUint8(0x14)
429		// jg .plt
430		plt.AddUint8(0xc0)
431		plt.AddUint8(0xf4)
432
433		plt.AddUint32(target.Arch, uint32(-((plt.Size() - 2) >> 1))) // roll-your-own relocation
434		//.plt index
435		plt.AddUint32(target.Arch, uint32(rela.Size())) // rela size before current entry
436
437		// rela
438		rela.AddAddrPlus(target.Arch, got.Sym(), got.Size()-8)
439
440		sDynid := ldr.SymDynid(s)
441		rela.AddUint64(target.Arch, elf.R_INFO(uint32(sDynid), uint32(elf.R_390_JMP_SLOT)))
442		rela.AddUint64(target.Arch, 0)
443
444		ldr.SetPlt(s, int32(plt.Size()-32))
445
446	} else {
447		ldr.Errorf(s, "addpltsym: unsupported binary format")
448	}
449}
450