Source file src/pkg/cmd/link/internal/arm64/asm.go

     1	// Inferno utils/5l/asm.c
     2	// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5l/asm.c
     3	//
     4	//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
     5	//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
     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 (forsyth@terzarima.net)
    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	
    31	package arm64
    32	
    33	import (
    34		"cmd/internal/objabi"
    35		"cmd/internal/sys"
    36		"cmd/link/internal/ld"
    37		"cmd/link/internal/sym"
    38		"debug/elf"
    39		"encoding/binary"
    40		"fmt"
    41		"log"
    42	)
    43	
    44	func gentext(ctxt *ld.Link) {
    45		if !ctxt.DynlinkingGo() {
    46			return
    47		}
    48		addmoduledata := ctxt.Syms.Lookup("runtime.addmoduledata", 0)
    49		if addmoduledata.Type == sym.STEXT && ctxt.BuildMode != ld.BuildModePlugin {
    50			// we're linking a module containing the runtime -> no need for
    51			// an init function
    52			return
    53		}
    54		addmoduledata.Attr |= sym.AttrReachable
    55		initfunc := ctxt.Syms.Lookup("go.link.addmoduledata", 0)
    56		initfunc.Type = sym.STEXT
    57		initfunc.Attr |= sym.AttrLocal
    58		initfunc.Attr |= sym.AttrReachable
    59		o := func(op uint32) {
    60			initfunc.AddUint32(ctxt.Arch, op)
    61		}
    62		// 0000000000000000 <local.dso_init>:
    63		// 0:	90000000 	adrp	x0, 0 <runtime.firstmoduledata>
    64		// 	0: R_AARCH64_ADR_PREL_PG_HI21	local.moduledata
    65		// 4:	91000000 	add	x0, x0, #0x0
    66		// 	4: R_AARCH64_ADD_ABS_LO12_NC	local.moduledata
    67		o(0x90000000)
    68		o(0x91000000)
    69		rel := initfunc.AddRel()
    70		rel.Off = 0
    71		rel.Siz = 8
    72		rel.Sym = ctxt.Moduledata
    73		rel.Type = objabi.R_ADDRARM64
    74	
    75		// 8:	14000000 	b	0 <runtime.addmoduledata>
    76		// 	8: R_AARCH64_CALL26	runtime.addmoduledata
    77		o(0x14000000)
    78		rel = initfunc.AddRel()
    79		rel.Off = 8
    80		rel.Siz = 4
    81		rel.Sym = ctxt.Syms.Lookup("runtime.addmoduledata", 0)
    82		rel.Type = objabi.R_CALLARM64 // Really should be R_AARCH64_JUMP26 but doesn't seem to make any difference
    83	
    84		if ctxt.BuildMode == ld.BuildModePlugin {
    85			ctxt.Textp = append(ctxt.Textp, addmoduledata)
    86		}
    87		ctxt.Textp = append(ctxt.Textp, initfunc)
    88		initarray_entry := ctxt.Syms.Lookup("go.link.addmoduledatainit", 0)
    89		initarray_entry.Attr |= sym.AttrReachable
    90		initarray_entry.Attr |= sym.AttrLocal
    91		initarray_entry.Type = sym.SINITARR
    92		initarray_entry.AddAddr(ctxt.Arch, initfunc)
    93	}
    94	
    95	func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
    96		targ := r.Sym
    97	
    98		switch r.Type {
    99		default:
   100			if r.Type >= objabi.ElfRelocOffset {
   101				ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type))
   102				return false
   103			}
   104	
   105		// Handle relocations found in ELF object files.
   106		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL32):
   107			if targ.Type == sym.SDYNIMPORT {
   108				ld.Errorf(s, "unexpected R_AARCH64_PREL32 relocation for dynamic symbol %s", targ.Name)
   109			}
   110			// TODO(mwhudson): the test of VisibilityHidden here probably doesn't make
   111			// sense and should be removed when someone has thought about it properly.
   112			if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() {
   113				ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name)
   114			}
   115			r.Type = objabi.R_PCREL
   116			r.Add += 4
   117			return true
   118	
   119		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL64):
   120			if targ.Type == sym.SDYNIMPORT {
   121				ld.Errorf(s, "unexpected R_AARCH64_PREL64 relocation for dynamic symbol %s", targ.Name)
   122			}
   123			if targ.Type == 0 || targ.Type == sym.SXREF {
   124				ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name)
   125			}
   126			r.Type = objabi.R_PCREL
   127			r.Add += 8
   128			return true
   129	
   130		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_CALL26),
   131			objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_JUMP26):
   132			if targ.Type == sym.SDYNIMPORT {
   133				addpltsym(ctxt, targ)
   134				r.Sym = ctxt.Syms.Lookup(".plt", 0)
   135				r.Add += int64(targ.Plt())
   136			}
   137			if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() {
   138				ld.Errorf(s, "unknown symbol %s in callarm64", targ.Name)
   139			}
   140			r.Type = objabi.R_CALLARM64
   141			return true
   142	
   143		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_GOT_PAGE),
   144			objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LD64_GOT_LO12_NC):
   145			if targ.Type != sym.SDYNIMPORT {
   146				// have symbol
   147				// TODO: turn LDR of GOT entry into ADR of symbol itself
   148			}
   149	
   150			// fall back to using GOT
   151			// TODO: just needs relocation, no need to put in .dynsym
   152			addgotsym(ctxt, targ)
   153	
   154			r.Type = objabi.R_ARM64_GOT
   155			r.Sym = ctxt.Syms.Lookup(".got", 0)
   156			r.Add += int64(targ.Got())
   157			return true
   158	
   159		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_PREL_PG_HI21),
   160			objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADD_ABS_LO12_NC):
   161			if targ.Type == sym.SDYNIMPORT {
   162				ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   163			}
   164			if targ.Type == 0 || targ.Type == sym.SXREF {
   165				ld.Errorf(s, "unknown symbol %s", targ.Name)
   166			}
   167			r.Type = objabi.R_ARM64_PCREL
   168			return true
   169	
   170		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ABS64):
   171			if targ.Type == sym.SDYNIMPORT {
   172				ld.Errorf(s, "unexpected R_AARCH64_ABS64 relocation for dynamic symbol %s", targ.Name)
   173			}
   174			r.Type = objabi.R_ADDR
   175			return true
   176	
   177		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST8_ABS_LO12_NC):
   178			if targ.Type == sym.SDYNIMPORT {
   179				ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   180			}
   181			r.Type = objabi.R_ARM64_LDST8
   182			return true
   183	
   184		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST32_ABS_LO12_NC):
   185			if targ.Type == sym.SDYNIMPORT {
   186				ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   187			}
   188			r.Type = objabi.R_ARM64_LDST32
   189			return true
   190	
   191		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST64_ABS_LO12_NC):
   192			if targ.Type == sym.SDYNIMPORT {
   193				ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   194			}
   195			r.Type = objabi.R_ARM64_LDST64
   196			return true
   197	
   198		case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST128_ABS_LO12_NC):
   199			if targ.Type == sym.SDYNIMPORT {
   200				ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   201			}
   202			r.Type = objabi.R_ARM64_LDST128
   203			return true
   204		}
   205	
   206		switch r.Type {
   207		case objabi.R_CALL,
   208			objabi.R_PCREL,
   209			objabi.R_CALLARM64:
   210			if targ.Type != sym.SDYNIMPORT {
   211				// nothing to do, the relocation will be laid out in reloc
   212				return true
   213			}
   214			if ctxt.LinkMode == ld.LinkExternal {
   215				// External linker will do this relocation.
   216				return true
   217			}
   218	
   219		case objabi.R_ADDR:
   220			if s.Type == sym.STEXT && ctxt.IsELF {
   221				// The code is asking for the address of an external
   222				// function. We provide it with the address of the
   223				// correspondent GOT symbol.
   224				addgotsym(ctxt, targ)
   225	
   226				r.Sym = ctxt.Syms.Lookup(".got", 0)
   227				r.Add += int64(targ.Got())
   228				return true
   229			}
   230	
   231			// Process dynamic relocations for the data sections.
   232			if ctxt.BuildMode == ld.BuildModePIE && ctxt.LinkMode == ld.LinkInternal {
   233				// When internally linking, generate dynamic relocations
   234				// for all typical R_ADDR relocations. The exception
   235				// are those R_ADDR that are created as part of generating
   236				// the dynamic relocations and must be resolved statically.
   237				//
   238				// There are three phases relevant to understanding this:
   239				//
   240				//	dodata()  // we are here
   241				//	address() // symbol address assignment
   242				//	reloc()   // resolution of static R_ADDR relocs
   243				//
   244				// At this point symbol addresses have not been
   245				// assigned yet (as the final size of the .rela section
   246				// will affect the addresses), and so we cannot write
   247				// the Elf64_Rela.r_offset now. Instead we delay it
   248				// until after the 'address' phase of the linker is
   249				// complete. We do this via Addaddrplus, which creates
   250				// a new R_ADDR relocation which will be resolved in
   251				// the 'reloc' phase.
   252				//
   253				// These synthetic static R_ADDR relocs must be skipped
   254				// now, or else we will be caught in an infinite loop
   255				// of generating synthetic relocs for our synthetic
   256				// relocs.
   257				//
   258				// Furthermore, the rela sections contain dynamic
   259				// relocations with R_ADDR relocations on
   260				// Elf64_Rela.r_offset. This field should contain the
   261				// symbol offset as determined by reloc(), not the
   262				// final dynamically linked address as a dynamic
   263				// relocation would provide.
   264				switch s.Name {
   265				case ".dynsym", ".rela", ".rela.plt", ".got.plt", ".dynamic":
   266					return false
   267				}
   268			} else {
   269				// Either internally linking a static executable,
   270				// in which case we can resolve these relocations
   271				// statically in the 'reloc' phase, or externally
   272				// linking, in which case the relocation will be
   273				// prepared in the 'reloc' phase and passed to the
   274				// external linker in the 'asmb' phase.
   275				if s.Type != sym.SDATA && s.Type != sym.SRODATA {
   276					break
   277				}
   278			}
   279	
   280			if ctxt.IsELF {
   281				// TODO: We generate a R_AARCH64_ABS64 relocation for every R_ADDR, even
   282				// though it would be more efficient (for the dynamic linker) if we
   283				// generated R_AARCH64_RELATIVE instead.
   284				ld.Adddynsym(ctxt, targ)
   285				rela := ctxt.Syms.Lookup(".rela", 0)
   286				rela.AddAddrPlus(ctxt.Arch, s, int64(r.Off))
   287				if r.Siz == 8 {
   288					rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(targ.Dynid), uint32(elf.R_AARCH64_ABS64)))
   289				} else {
   290					ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
   291				}
   292				rela.AddUint64(ctxt.Arch, uint64(r.Add))
   293				r.Type = objabi.ElfRelocOffset // ignore during relocsym
   294				return true
   295			}
   296		}
   297		return false
   298	}
   299	
   300	func elfreloc1(ctxt *ld.Link, r *sym.Reloc, sectoff int64) bool {
   301		ctxt.Out.Write64(uint64(sectoff))
   302	
   303		elfsym := r.Xsym.ElfsymForReloc()
   304		switch r.Type {
   305		default:
   306			return false
   307		case objabi.R_ADDR:
   308			switch r.Siz {
   309			case 4:
   310				ctxt.Out.Write64(uint64(elf.R_AARCH64_ABS32) | uint64(elfsym)<<32)
   311			case 8:
   312				ctxt.Out.Write64(uint64(elf.R_AARCH64_ABS64) | uint64(elfsym)<<32)
   313			default:
   314				return false
   315			}
   316		case objabi.R_ADDRARM64:
   317			// two relocations: R_AARCH64_ADR_PREL_PG_HI21 and R_AARCH64_ADD_ABS_LO12_NC
   318			ctxt.Out.Write64(uint64(elf.R_AARCH64_ADR_PREL_PG_HI21) | uint64(elfsym)<<32)
   319			ctxt.Out.Write64(uint64(r.Xadd))
   320			ctxt.Out.Write64(uint64(sectoff + 4))
   321			ctxt.Out.Write64(uint64(elf.R_AARCH64_ADD_ABS_LO12_NC) | uint64(elfsym)<<32)
   322		case objabi.R_ARM64_TLS_LE:
   323			ctxt.Out.Write64(uint64(elf.R_AARCH64_TLSLE_MOVW_TPREL_G0) | uint64(elfsym)<<32)
   324		case objabi.R_ARM64_TLS_IE:
   325			ctxt.Out.Write64(uint64(elf.R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21) | uint64(elfsym)<<32)
   326			ctxt.Out.Write64(uint64(r.Xadd))
   327			ctxt.Out.Write64(uint64(sectoff + 4))
   328			ctxt.Out.Write64(uint64(elf.R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC) | uint64(elfsym)<<32)
   329		case objabi.R_ARM64_GOTPCREL:
   330			ctxt.Out.Write64(uint64(elf.R_AARCH64_ADR_GOT_PAGE) | uint64(elfsym)<<32)
   331			ctxt.Out.Write64(uint64(r.Xadd))
   332			ctxt.Out.Write64(uint64(sectoff + 4))
   333			ctxt.Out.Write64(uint64(elf.R_AARCH64_LD64_GOT_LO12_NC) | uint64(elfsym)<<32)
   334		case objabi.R_CALLARM64:
   335			if r.Siz != 4 {
   336				return false
   337			}
   338			ctxt.Out.Write64(uint64(elf.R_AARCH64_CALL26) | uint64(elfsym)<<32)
   339	
   340		}
   341		ctxt.Out.Write64(uint64(r.Xadd))
   342	
   343		return true
   344	}
   345	
   346	func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool {
   347		var v uint32
   348	
   349		rs := r.Xsym
   350	
   351		if rs.Type == sym.SHOSTOBJ || r.Type == objabi.R_CALLARM64 || r.Type == objabi.R_ADDRARM64 {
   352			if rs.Dynid < 0 {
   353				ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Type, rs.Type)
   354				return false
   355			}
   356	
   357			v = uint32(rs.Dynid)
   358			v |= 1 << 27 // external relocation
   359		} else {
   360			v = uint32(rs.Sect.Extnum)
   361			if v == 0 {
   362				ld.Errorf(s, "reloc %d (%s) to symbol %s in non-macho section %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Sect.Name, rs.Type, rs.Type)
   363				return false
   364			}
   365		}
   366	
   367		switch r.Type {
   368		default:
   369			return false
   370		case objabi.R_ADDR:
   371			v |= ld.MACHO_ARM64_RELOC_UNSIGNED << 28
   372		case objabi.R_CALLARM64:
   373			if r.Xadd != 0 {
   374				ld.Errorf(s, "ld64 doesn't allow BR26 reloc with non-zero addend: %s+%d", rs.Name, r.Xadd)
   375			}
   376	
   377			v |= 1 << 24 // pc-relative bit
   378			v |= ld.MACHO_ARM64_RELOC_BRANCH26 << 28
   379		case objabi.R_ADDRARM64:
   380			r.Siz = 4
   381			// Two relocation entries: MACHO_ARM64_RELOC_PAGEOFF12 MACHO_ARM64_RELOC_PAGE21
   382			// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
   383			if r.Xadd != 0 {
   384				out.Write32(uint32(sectoff + 4))
   385				out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
   386			}
   387			out.Write32(uint32(sectoff + 4))
   388			out.Write32(v | (ld.MACHO_ARM64_RELOC_PAGEOFF12 << 28) | (2 << 25))
   389			if r.Xadd != 0 {
   390				out.Write32(uint32(sectoff))
   391				out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
   392			}
   393			v |= 1 << 24 // pc-relative bit
   394			v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28
   395		}
   396	
   397		switch r.Siz {
   398		default:
   399			return false
   400		case 1:
   401			v |= 0 << 25
   402		case 2:
   403			v |= 1 << 25
   404		case 4:
   405			v |= 2 << 25
   406		case 8:
   407			v |= 3 << 25
   408		}
   409	
   410		out.Write32(uint32(sectoff))
   411		out.Write32(v)
   412		return true
   413	}
   414	
   415	func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bool) {
   416		if ctxt.LinkMode == ld.LinkExternal {
   417			switch r.Type {
   418			default:
   419				return val, false
   420			case objabi.R_ARM64_GOTPCREL:
   421				var o1, o2 uint32
   422				if ctxt.Arch.ByteOrder == binary.BigEndian {
   423					o1 = uint32(val >> 32)
   424					o2 = uint32(val)
   425				} else {
   426					o1 = uint32(val)
   427					o2 = uint32(val >> 32)
   428				}
   429				// Any relocation against a function symbol is redirected to
   430				// be against a local symbol instead (see putelfsym in
   431				// symtab.go) but unfortunately the system linker was buggy
   432				// when confronted with a R_AARCH64_ADR_GOT_PAGE relocation
   433				// against a local symbol until May 2015
   434				// (https://sourceware.org/bugzilla/show_bug.cgi?id=18270). So
   435				// we convert the adrp; ld64 + R_ARM64_GOTPCREL into adrp;
   436				// add + R_ADDRARM64.
   437				if !(r.Sym.IsFileLocal() || r.Sym.Attr.VisibilityHidden() || r.Sym.Attr.Local()) && r.Sym.Type == sym.STEXT && ctxt.DynlinkingGo() {
   438					if o2&0xffc00000 != 0xf9400000 {
   439						ld.Errorf(s, "R_ARM64_GOTPCREL against unexpected instruction %x", o2)
   440					}
   441					o2 = 0x91000000 | (o2 & 0x000003ff)
   442					r.Type = objabi.R_ADDRARM64
   443				}
   444				if ctxt.Arch.ByteOrder == binary.BigEndian {
   445					val = int64(o1)<<32 | int64(o2)
   446				} else {
   447					val = int64(o2)<<32 | int64(o1)
   448				}
   449				fallthrough
   450			case objabi.R_ADDRARM64:
   451				r.Done = false
   452	
   453				// set up addend for eventual relocation via outer symbol.
   454				rs := r.Sym
   455				r.Xadd = r.Add
   456				for rs.Outer != nil {
   457					r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
   458					rs = rs.Outer
   459				}
   460	
   461				if rs.Type != sym.SHOSTOBJ && rs.Type != sym.SDYNIMPORT && rs.Sect == nil {
   462					ld.Errorf(s, "missing section for %s", rs.Name)
   463				}
   464				r.Xsym = rs
   465	
   466				// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
   467				// will make the linking fail because it thinks the code is not PIC even though
   468				// the BR26 relocation should be fully resolved at link time.
   469				// That is the reason why the next if block is disabled. When the bug in ld64
   470				// is fixed, we can enable this block and also enable duff's device in cmd/7g.
   471				if false && ctxt.HeadType == objabi.Hdarwin {
   472					var o0, o1 uint32
   473	
   474					if ctxt.Arch.ByteOrder == binary.BigEndian {
   475						o0 = uint32(val >> 32)
   476						o1 = uint32(val)
   477					} else {
   478						o0 = uint32(val)
   479						o1 = uint32(val >> 32)
   480					}
   481					// Mach-O wants the addend to be encoded in the instruction
   482					// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
   483					// can only encode 24-bit of signed addend, but the instructions
   484					// supports 33-bit of signed addend, so we always encode the
   485					// addend in place.
   486					o0 |= (uint32((r.Xadd>>12)&3) << 29) | (uint32((r.Xadd>>12>>2)&0x7ffff) << 5)
   487					o1 |= uint32(r.Xadd&0xfff) << 10
   488					r.Xadd = 0
   489	
   490					// when laid out, the instruction order must always be o1, o2.
   491					if ctxt.Arch.ByteOrder == binary.BigEndian {
   492						val = int64(o0)<<32 | int64(o1)
   493					} else {
   494						val = int64(o1)<<32 | int64(o0)
   495					}
   496				}
   497	
   498				return val, true
   499			case objabi.R_CALLARM64,
   500				objabi.R_ARM64_TLS_LE,
   501				objabi.R_ARM64_TLS_IE:
   502				r.Done = false
   503				r.Xsym = r.Sym
   504				r.Xadd = r.Add
   505				return val, true
   506			}
   507		}
   508	
   509		switch r.Type {
   510		case objabi.R_CONST:
   511			return r.Add, true
   512	
   513		case objabi.R_GOTOFF:
   514			return ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ctxt.Syms.Lookup(".got", 0)), true
   515	
   516		case objabi.R_ADDRARM64:
   517			t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   518			if t >= 1<<32 || t < -1<<32 {
   519				ld.Errorf(s, "program too large, address relocation distance = %d", t)
   520			}
   521	
   522			var o0, o1 uint32
   523	
   524			if ctxt.Arch.ByteOrder == binary.BigEndian {
   525				o0 = uint32(val >> 32)
   526				o1 = uint32(val)
   527			} else {
   528				o0 = uint32(val)
   529				o1 = uint32(val >> 32)
   530			}
   531	
   532			o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
   533			o1 |= uint32(t&0xfff) << 10
   534	
   535			// when laid out, the instruction order must always be o1, o2.
   536			if ctxt.Arch.ByteOrder == binary.BigEndian {
   537				return int64(o0)<<32 | int64(o1), true
   538			}
   539			return int64(o1)<<32 | int64(o0), true
   540	
   541		case objabi.R_ARM64_TLS_LE:
   542			r.Done = false
   543			if ctxt.HeadType == objabi.Hdarwin {
   544				ld.Errorf(s, "TLS reloc on unsupported OS %v", ctxt.HeadType)
   545			}
   546			// The TCB is two pointers. This is not documented anywhere, but is
   547			// de facto part of the ABI.
   548			v := r.Sym.Value + int64(2*ctxt.Arch.PtrSize)
   549			if v < 0 || v >= 32678 {
   550				ld.Errorf(s, "TLS offset out of range %d", v)
   551			}
   552			return val | (v << 5), true
   553	
   554		case objabi.R_ARM64_TLS_IE:
   555			if ctxt.BuildMode == ld.BuildModePIE && ctxt.IsELF {
   556				// We are linking the final executable, so we
   557				// can optimize any TLS IE relocation to LE.
   558				r.Done = false
   559				if ctxt.HeadType != objabi.Hlinux {
   560					ld.Errorf(s, "TLS reloc on unsupported OS %v", ctxt.HeadType)
   561				}
   562	
   563				// The TCB is two pointers. This is not documented anywhere, but is
   564				// de facto part of the ABI.
   565				v := ld.Symaddr(r.Sym) + int64(2*ctxt.Arch.PtrSize) + r.Add
   566				if v < 0 || v >= 32678 {
   567					ld.Errorf(s, "TLS offset out of range %d", v)
   568				}
   569	
   570				var o0, o1 uint32
   571				if ctxt.Arch.ByteOrder == binary.BigEndian {
   572					o0 = uint32(val >> 32)
   573					o1 = uint32(val)
   574				} else {
   575					o0 = uint32(val)
   576					o1 = uint32(val >> 32)
   577				}
   578	
   579				// R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21
   580				// turn ADRP to MOVZ
   581				o0 = 0xd2a00000 | uint32(o0&0x1f) | (uint32((v>>16)&0xffff) << 5)
   582				// R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC
   583				// turn LD64 to MOVK
   584				if v&3 != 0 {
   585					ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC", v)
   586				}
   587				o1 = 0xf2800000 | uint32(o1&0x1f) | (uint32(v&0xffff) << 5)
   588	
   589				// when laid out, the instruction order must always be o0, o1.
   590				if ctxt.Arch.ByteOrder == binary.BigEndian {
   591					return int64(o0)<<32 | int64(o1), true
   592				}
   593				return int64(o1)<<32 | int64(o0), true
   594			} else {
   595				log.Fatalf("cannot handle R_ARM64_TLS_IE (sym %s) when linking internally", s.Name)
   596			}
   597	
   598		case objabi.R_CALLARM64:
   599			var t int64
   600			if r.Sym.Type == sym.SDYNIMPORT {
   601				t = (ld.Symaddr(ctxt.Syms.Lookup(".plt", 0)) + r.Add) - (s.Value + int64(r.Off))
   602			} else {
   603				t = (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
   604			}
   605			if t >= 1<<27 || t < -1<<27 {
   606				ld.Errorf(s, "program too large, call relocation distance = %d", t)
   607			}
   608			return val | ((t >> 2) & 0x03ffffff), true
   609	
   610		case objabi.R_ARM64_GOT:
   611			if s.P[r.Off+3]&0x9f == 0x90 {
   612				// R_AARCH64_ADR_GOT_PAGE
   613				// patch instruction: adrp
   614				t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   615				if t >= 1<<32 || t < -1<<32 {
   616					ld.Errorf(s, "program too large, address relocation distance = %d", t)
   617				}
   618				var o0 uint32
   619				o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
   620				return val | int64(o0), true
   621			} else if s.P[r.Off+3] == 0xf9 {
   622				// R_AARCH64_LD64_GOT_LO12_NC
   623				// patch instruction: ldr
   624				t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   625				if t&7 != 0 {
   626					ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LD64_GOT_LO12_NC", t)
   627				}
   628				var o1 uint32
   629				o1 |= uint32(t&0xfff) << (10 - 3)
   630				return val | int64(uint64(o1)), true
   631			} else {
   632				ld.Errorf(s, "unsupported instruction for %v R_GOTARM64", s.P[r.Off:r.Off+4])
   633			}
   634	
   635		case objabi.R_ARM64_PCREL:
   636			if s.P[r.Off+3]&0x9f == 0x90 {
   637				// R_AARCH64_ADR_PREL_PG_HI21
   638				// patch instruction: adrp
   639				t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   640				if t >= 1<<32 || t < -1<<32 {
   641					ld.Errorf(s, "program too large, address relocation distance = %d", t)
   642				}
   643				o0 := (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
   644				return val | int64(o0), true
   645			} else if s.P[r.Off+3]&0x91 == 0x91 {
   646				// R_AARCH64_ADD_ABS_LO12_NC
   647				// patch instruction: add
   648				t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   649				o1 := uint32(t&0xfff) << 10
   650				return val | int64(o1), true
   651			} else {
   652				ld.Errorf(s, "unsupported instruction for %v R_PCRELARM64", s.P[r.Off:r.Off+4])
   653			}
   654	
   655		case objabi.R_ARM64_LDST8:
   656			t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   657			o0 := uint32(t&0xfff) << 10
   658			return val | int64(o0), true
   659	
   660		case objabi.R_ARM64_LDST32:
   661			t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   662			if t&3 != 0 {
   663				ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST32_ABS_LO12_NC", t)
   664			}
   665			o0 := (uint32(t&0xfff) >> 2) << 10
   666			return val | int64(o0), true
   667	
   668		case objabi.R_ARM64_LDST64:
   669			t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   670			if t&7 != 0 {
   671				ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST64_ABS_LO12_NC", t)
   672			}
   673			o0 := (uint32(t&0xfff) >> 3) << 10
   674			return val | int64(o0), true
   675	
   676		case objabi.R_ARM64_LDST128:
   677			t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
   678			if t&15 != 0 {
   679				ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST128_ABS_LO12_NC", t)
   680			}
   681			o0 := (uint32(t&0xfff) >> 4) << 10
   682			return val | int64(o0), true
   683		}
   684	
   685		return val, false
   686	}
   687	
   688	func archrelocvariant(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, t int64) int64 {
   689		log.Fatalf("unexpected relocation variant")
   690		return -1
   691	}
   692	
   693	func elfsetupplt(ctxt *ld.Link) {
   694		plt := ctxt.Syms.Lookup(".plt", 0)
   695		gotplt := ctxt.Syms.Lookup(".got.plt", 0)
   696		if plt.Size == 0 {
   697			// stp     x16, x30, [sp, #-16]!
   698			// identifying information
   699			plt.AddUint32(ctxt.Arch, 0xa9bf7bf0)
   700	
   701			// the following two instructions (adrp + ldr) load *got[2] into x17
   702			// adrp    x16, &got[0]
   703			plt.AddAddrPlus4(gotplt, 16)
   704			plt.SetUint32(ctxt.Arch, plt.Size-4, 0x90000010)
   705			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
   706	
   707			// <imm> is the offset value of &got[2] to &got[0], the same below
   708			// ldr     x17, [x16, <imm>]
   709			plt.AddAddrPlus4(gotplt, 16)
   710			plt.SetUint32(ctxt.Arch, plt.Size-4, 0xf9400211)
   711			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
   712	
   713			// add     x16, x16, <imm>
   714			plt.AddAddrPlus4(gotplt, 16)
   715			plt.SetUint32(ctxt.Arch, plt.Size-4, 0x91000210)
   716			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_PCREL
   717	
   718			// br      x17
   719			plt.AddUint32(ctxt.Arch, 0xd61f0220)
   720	
   721			// 3 nop for place holder
   722			plt.AddUint32(ctxt.Arch, 0xd503201f)
   723			plt.AddUint32(ctxt.Arch, 0xd503201f)
   724			plt.AddUint32(ctxt.Arch, 0xd503201f)
   725	
   726			// check gotplt.size == 0
   727			if gotplt.Size != 0 {
   728				ld.Errorf(gotplt, "got.plt is not empty at the very beginning")
   729			}
   730			gotplt.AddAddrPlus(ctxt.Arch, ctxt.Syms.Lookup(".dynamic", 0), 0)
   731	
   732			gotplt.AddUint64(ctxt.Arch, 0)
   733			gotplt.AddUint64(ctxt.Arch, 0)
   734		}
   735	}
   736	
   737	func addpltsym(ctxt *ld.Link, s *sym.Symbol) {
   738		if s.Plt() >= 0 {
   739			return
   740		}
   741	
   742		ld.Adddynsym(ctxt, s)
   743	
   744		if ctxt.IsELF {
   745			plt := ctxt.Syms.Lookup(".plt", 0)
   746			gotplt := ctxt.Syms.Lookup(".got.plt", 0)
   747			rela := ctxt.Syms.Lookup(".rela.plt", 0)
   748			if plt.Size == 0 {
   749				elfsetupplt(ctxt)
   750			}
   751	
   752			// adrp    x16, &got.plt[0]
   753			plt.AddAddrPlus4(gotplt, gotplt.Size)
   754			plt.SetUint32(ctxt.Arch, plt.Size-4, 0x90000010)
   755			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
   756	
   757			// <offset> is the offset value of &got.plt[n] to &got.plt[0]
   758			// ldr     x17, [x16, <offset>]
   759			plt.AddAddrPlus4(gotplt, gotplt.Size)
   760			plt.SetUint32(ctxt.Arch, plt.Size-4, 0xf9400211)
   761			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
   762	
   763			// add     x16, x16, <offset>
   764			plt.AddAddrPlus4(gotplt, gotplt.Size)
   765			plt.SetUint32(ctxt.Arch, plt.Size-4, 0x91000210)
   766			plt.R[len(plt.R)-1].Type = objabi.R_ARM64_PCREL
   767	
   768			// br      x17
   769			plt.AddUint32(ctxt.Arch, 0xd61f0220)
   770	
   771			// add to got.plt: pointer to plt[0]
   772			gotplt.AddAddrPlus(ctxt.Arch, plt, 0)
   773	
   774			// rela
   775			rela.AddAddrPlus(ctxt.Arch, gotplt, gotplt.Size-8)
   776			rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_AARCH64_JUMP_SLOT)))
   777			rela.AddUint64(ctxt.Arch, 0)
   778	
   779			s.SetPlt(int32(plt.Size - 16))
   780		} else {
   781			ld.Errorf(s, "addpltsym: unsupported binary format")
   782		}
   783	}
   784	
   785	func addgotsym(ctxt *ld.Link, s *sym.Symbol) {
   786		if s.Got() >= 0 {
   787			return
   788		}
   789	
   790		ld.Adddynsym(ctxt, s)
   791		got := ctxt.Syms.Lookup(".got", 0)
   792		s.SetGot(int32(got.Size))
   793		got.AddUint64(ctxt.Arch, 0)
   794	
   795		if ctxt.IsELF {
   796			rela := ctxt.Syms.Lookup(".rela", 0)
   797			rela.AddAddrPlus(ctxt.Arch, got, int64(s.Got()))
   798			rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_AARCH64_GLOB_DAT)))
   799			rela.AddUint64(ctxt.Arch, 0)
   800		} else {
   801			ld.Errorf(s, "addgotsym: unsupported binary format")
   802		}
   803	}
   804	
   805	func asmb(ctxt *ld.Link) {
   806		if ctxt.Debugvlog != 0 {
   807			ctxt.Logf("%5.2f asmb\n", ld.Cputime())
   808		}
   809	
   810		if ctxt.IsELF {
   811			ld.Asmbelfsetup()
   812		}
   813	
   814		sect := ld.Segtext.Sections[0]
   815		ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
   816		ld.Codeblk(ctxt, int64(sect.Vaddr), int64(sect.Length))
   817		for _, sect = range ld.Segtext.Sections[1:] {
   818			ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
   819			ld.Datblk(ctxt, int64(sect.Vaddr), int64(sect.Length))
   820		}
   821	
   822		if ld.Segrodata.Filelen > 0 {
   823			if ctxt.Debugvlog != 0 {
   824				ctxt.Logf("%5.2f rodatblk\n", ld.Cputime())
   825			}
   826			ctxt.Out.SeekSet(int64(ld.Segrodata.Fileoff))
   827			ld.Datblk(ctxt, int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
   828		}
   829		if ld.Segrelrodata.Filelen > 0 {
   830			if ctxt.Debugvlog != 0 {
   831				ctxt.Logf("%5.2f relrodatblk\n", ld.Cputime())
   832			}
   833			ctxt.Out.SeekSet(int64(ld.Segrelrodata.Fileoff))
   834			ld.Datblk(ctxt, int64(ld.Segrelrodata.Vaddr), int64(ld.Segrelrodata.Filelen))
   835		}
   836	
   837		if ctxt.Debugvlog != 0 {
   838			ctxt.Logf("%5.2f datblk\n", ld.Cputime())
   839		}
   840	
   841		ctxt.Out.SeekSet(int64(ld.Segdata.Fileoff))
   842		ld.Datblk(ctxt, int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))
   843	
   844		ctxt.Out.SeekSet(int64(ld.Segdwarf.Fileoff))
   845		ld.Dwarfblk(ctxt, int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen))
   846	}
   847	
   848	func asmb2(ctxt *ld.Link) {
   849		machlink := uint32(0)
   850		if ctxt.HeadType == objabi.Hdarwin {
   851			machlink = uint32(ld.Domacholink(ctxt))
   852		}
   853	
   854		/* output symbol table */
   855		ld.Symsize = 0
   856	
   857		ld.Lcsize = 0
   858		symo := uint32(0)
   859		if !*ld.FlagS {
   860			// TODO: rationalize
   861			if ctxt.Debugvlog != 0 {
   862				ctxt.Logf("%5.2f sym\n", ld.Cputime())
   863			}
   864			switch ctxt.HeadType {
   865			default:
   866				if ctxt.IsELF {
   867					symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen)
   868					symo = uint32(ld.Rnd(int64(symo), int64(*ld.FlagRound)))
   869				}
   870	
   871			case objabi.Hplan9:
   872				symo = uint32(ld.Segdata.Fileoff + ld.Segdata.Filelen)
   873	
   874			case objabi.Hdarwin:
   875				symo = uint32(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(*ld.FlagRound))) + uint64(machlink))
   876			}
   877	
   878			ctxt.Out.SeekSet(int64(symo))
   879			switch ctxt.HeadType {
   880			default:
   881				if ctxt.IsELF {
   882					if ctxt.Debugvlog != 0 {
   883						ctxt.Logf("%5.2f elfsym\n", ld.Cputime())
   884					}
   885					ld.Asmelfsym(ctxt)
   886					ctxt.Out.Flush()
   887					ctxt.Out.Write(ld.Elfstrdat)
   888	
   889					if ctxt.LinkMode == ld.LinkExternal {
   890						ld.Elfemitreloc(ctxt)
   891					}
   892				}
   893	
   894			case objabi.Hplan9:
   895				ld.Asmplan9sym(ctxt)
   896				ctxt.Out.Flush()
   897	
   898				sym := ctxt.Syms.Lookup("pclntab", 0)
   899				if sym != nil {
   900					ld.Lcsize = int32(len(sym.P))
   901					ctxt.Out.Write(sym.P)
   902					ctxt.Out.Flush()
   903				}
   904	
   905			case objabi.Hdarwin:
   906				if ctxt.LinkMode == ld.LinkExternal {
   907					ld.Machoemitreloc(ctxt)
   908				}
   909			}
   910		}
   911	
   912		if ctxt.Debugvlog != 0 {
   913			ctxt.Logf("%5.2f header\n", ld.Cputime())
   914		}
   915		ctxt.Out.SeekSet(0)
   916		switch ctxt.HeadType {
   917		default:
   918		case objabi.Hplan9: /* plan 9 */
   919			ctxt.Out.Write32(0x647)                      /* magic */
   920			ctxt.Out.Write32(uint32(ld.Segtext.Filelen)) /* sizes */
   921			ctxt.Out.Write32(uint32(ld.Segdata.Filelen))
   922			ctxt.Out.Write32(uint32(ld.Segdata.Length - ld.Segdata.Filelen))
   923			ctxt.Out.Write32(uint32(ld.Symsize))          /* nsyms */
   924			ctxt.Out.Write32(uint32(ld.Entryvalue(ctxt))) /* va of entry */
   925			ctxt.Out.Write32(0)
   926			ctxt.Out.Write32(uint32(ld.Lcsize))
   927	
   928		case objabi.Hlinux,
   929			objabi.Hfreebsd,
   930			objabi.Hnetbsd,
   931			objabi.Hopenbsd,
   932			objabi.Hnacl:
   933			ld.Asmbelf(ctxt, int64(symo))
   934	
   935		case objabi.Hdarwin:
   936			ld.Asmbmacho(ctxt)
   937		}
   938	
   939		ctxt.Out.Flush()
   940		if *ld.FlagC {
   941			fmt.Printf("textsize=%d\n", ld.Segtext.Filelen)
   942			fmt.Printf("datsize=%d\n", ld.Segdata.Filelen)
   943			fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen)
   944			fmt.Printf("symsize=%d\n", ld.Symsize)
   945			fmt.Printf("lcsize=%d\n", ld.Lcsize)
   946			fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize))
   947		}
   948	}
   949	

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