| // Inferno utils/6l/asm.c | |
| // https://bitbucket.org/inferno-os/inferno-os/src/default/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/sym" | |
| "debug/elf" | |
| "log" | |
| ) | |
| func PADDR(x uint32) uint32 { | |
| return x &^ 0x80000000 | |
| } | |
| func Addcall(ctxt *ld.Link, s *sym.Symbol, t *sym.Symbol) int64 { | |
| s.Attr |= sym.AttrReachable | |
| i := s.Size | |
| s.Size += 4 | |
| s.Grow(s.Size) | |
| r := s.AddRel() | |
| r.Sym = t | |
| r.Off = int32(i) | |
| r.Type = objabi.R_CALL | |
| r.Siz = 4 | |
| return i + int64(r.Siz) | |
| } | |
| func gentext(ctxt *ld.Link) { | |
| if !ctxt.DynlinkingGo() { | |
| return | |
| } | |
| addmoduledata := ctxt.Syms.Lookup("runtime.addmoduledata", 0) | |
| if addmoduledata.Type == sym.STEXT && ctxt.BuildMode != ld.BuildModePlugin { | |
| // we're linking a module containing the runtime -> no need for | |
| // an init function | |
| return | |
| } | |
| addmoduledata.Attr |= sym.AttrReachable | |
| initfunc := ctxt.Syms.Lookup("go.link.addmoduledata", 0) | |
| initfunc.Type = sym.STEXT | |
| initfunc.Attr |= sym.AttrLocal | |
| initfunc.Attr |= sym.AttrReachable | |
| 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) | |
| Addcall(ctxt, initfunc, addmoduledata) | |
| // c: c3 retq | |
| o(0xc3) | |
| if ctxt.BuildMode == ld.BuildModePlugin { | |
| ctxt.Textp = append(ctxt.Textp, addmoduledata) | |
| } | |
| ctxt.Textp = append(ctxt.Textp, initfunc) | |
| initarray_entry := ctxt.Syms.Lookup("go.link.addmoduledatainit", 0) | |
| initarray_entry.Attr |= sym.AttrReachable | |
| initarray_entry.Attr |= sym.AttrLocal | |
| initarray_entry.Type = sym.SINITARR | |
| initarray_entry.AddAddr(ctxt.Arch, initfunc) | |
| } | |
| func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool { | |
| targ := r.Sym | |
| switch r.Type { | |
| default: | |
| if r.Type >= 256 { | |
| ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type)) | |
| return false | |
| } | |
| // Handle relocations found in ELF object files. | |
| case 256 + objabi.RelocType(elf.R_X86_64_PC32): | |
| if targ.Type == sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ.Name) | |
| } | |
| // TODO(mwhudson): the test of VisibilityHidden here probably doesn't make | |
| // sense and should be removed when someone has thought about it properly. | |
| if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() { | |
| ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name) | |
| } | |
| r.Type = objabi.R_PCREL | |
| r.Add += 4 | |
| return true | |
| case 256 + objabi.RelocType(elf.R_X86_64_PC64): | |
| if targ.Type == sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected R_X86_64_PC64 relocation for dynamic symbol %s", targ.Name) | |
| } | |
| if targ.Type == 0 || targ.Type == sym.SXREF { | |
| ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name) | |
| } | |
| r.Type = objabi.R_PCREL | |
| r.Add += 8 | |
| return true | |
| case 256 + objabi.RelocType(elf.R_X86_64_PLT32): | |
| r.Type = objabi.R_PCREL | |
| r.Add += 4 | |
| if targ.Type == sym.SDYNIMPORT { | |
| addpltsym(ctxt, targ) | |
| r.Sym = ctxt.Syms.Lookup(".plt", 0) | |
| r.Add += int64(targ.Plt()) | |
| } | |
| return true | |
| case 256 + objabi.RelocType(elf.R_X86_64_GOTPCREL), 256 + objabi.RelocType(elf.R_X86_64_GOTPCRELX), 256 + objabi.RelocType(elf.R_X86_64_REX_GOTPCRELX): | |
| if targ.Type != sym.SDYNIMPORT { | |
| // have symbol | |
| if r.Off >= 2 && s.P[r.Off-2] == 0x8b { | |
| // turn MOVQ of GOT entry into LEAQ of symbol itself | |
| s.P[r.Off-2] = 0x8d | |
| r.Type = objabi.R_PCREL | |
| 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 | |
| addgotsym(ctxt, targ) | |
| r.Type = objabi.R_PCREL | |
| r.Sym = ctxt.Syms.Lookup(".got", 0) | |
| r.Add += 4 | |
| r.Add += int64(targ.Got()) | |
| return true | |
| case 256 + objabi.RelocType(elf.R_X86_64_64): | |
| if targ.Type == sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected R_X86_64_64 relocation for dynamic symbol %s", targ.Name) | |
| } | |
| r.Type = objabi.R_ADDR | |
| return true | |
| // Handle relocations found in Mach-O object files. | |
| case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0, | |
| 512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0, | |
| 512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0: | |
| // TODO: What is the difference between all these? | |
| r.Type = objabi.R_ADDR | |
| if targ.Type == sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected reloc for dynamic symbol %s", targ.Name) | |
| } | |
| return true | |
| case 512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1: | |
| if targ.Type == sym.SDYNIMPORT { | |
| addpltsym(ctxt, targ) | |
| r.Sym = ctxt.Syms.Lookup(".plt", 0) | |
| r.Add = int64(targ.Plt()) | |
| r.Type = objabi.R_PCREL | |
| return true | |
| } | |
| fallthrough | |
| case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1, | |
| 512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1, | |
| 512 + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1, | |
| 512 + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1, | |
| 512 + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1: | |
| r.Type = objabi.R_PCREL | |
| if targ.Type == sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected pc-relative reloc for dynamic symbol %s", targ.Name) | |
| } | |
| return true | |
| case 512 + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1: | |
| if targ.Type != sym.SDYNIMPORT { | |
| // have symbol | |
| // turn MOVQ of GOT entry into LEAQ of symbol itself | |
| if r.Off < 2 || s.P[r.Off-2] != 0x8b { | |
| ld.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", targ.Name) | |
| return false | |
| } | |
| s.P[r.Off-2] = 0x8d | |
| r.Type = objabi.R_PCREL | |
| return true | |
| } | |
| fallthrough | |
| case 512 + ld.MACHO_X86_64_RELOC_GOT*2 + 1: | |
| if targ.Type != sym.SDYNIMPORT { | |
| ld.Errorf(s, "unexpected GOT reloc for non-dynamic symbol %s", targ.Name) | |
| } | |
| addgotsym(ctxt, targ) | |
| r.Type = objabi.R_PCREL | |
| r.Sym = ctxt.Syms.Lookup(".got", 0) | |
| r.Add += int64(targ.Got()) | |
| return true | |
| } | |
| switch r.Type { | |
| case objabi.R_CALL, | |
| objabi.R_PCREL: | |
| if targ.Type != sym.SDYNIMPORT { | |
| // nothing to do, the relocation will be laid out in reloc | |
| return true | |
| } | |
| if ctxt.LinkMode == ld.LinkExternal { | |
| // 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(ctxt, targ) | |
| r.Sym = ctxt.Syms.Lookup(".plt", 0) | |
| r.Add = int64(targ.Plt()) | |
| return true | |
| case objabi.R_ADDR: | |
| if s.Type == sym.STEXT && ctxt.IsELF { | |
| if ctxt.HeadType == objabi.Hsolaris { | |
| addpltsym(ctxt, targ) | |
| r.Sym = ctxt.Syms.Lookup(".plt", 0) | |
| r.Add += int64(targ.Plt()) | |
| return true | |
| } | |
| // The code is asking for the address of an external | |
| // function. We provide it with the address of the | |
| // correspondent GOT symbol. | |
| addgotsym(ctxt, targ) | |
| r.Sym = ctxt.Syms.Lookup(".got", 0) | |
| r.Add += int64(targ.Got()) | |
| return true | |
| } | |
| // Process dynamic relocations for the data sections. | |
| if ctxt.BuildMode == ld.BuildModePIE && ctxt.LinkMode == ld.LinkInternal { | |
| // 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 s.Name { | |
| 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 s.Type != sym.SDATA && s.Type != sym.SRODATA { | |
| break | |
| } | |
| } | |
| if ctxt.IsELF { | |
| // TODO: We generate a R_X86_64_64 relocation for every R_ADDR, even | |
| // though it would be more efficient (for the dynamic linker) if we | |
| // generated R_X86_RELATIVE instead. | |
| ld.Adddynsym(ctxt, targ) | |
| rela := ctxt.Syms.Lookup(".rela", 0) | |
| rela.AddAddrPlus(ctxt.Arch, s, int64(r.Off)) | |
| if r.Siz == 8 { | |
| rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(targ.Dynid), uint32(elf.R_X86_64_64))) | |
| } else { | |
| // TODO: never happens, remove. | |
| rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(targ.Dynid), uint32(elf.R_X86_64_32))) | |
| } | |
| rela.AddUint64(ctxt.Arch, uint64(r.Add)) | |
| r.Type = 256 // ignore during relocsym | |
| return true | |
| } | |
| if ctxt.HeadType == objabi.Hdarwin && s.Size == int64(ctxt.Arch.PtrSize) && r.Off == 0 { | |
| // Mach-O relocations are a royal pain to lay out. | |
| // They use a compact stateful bytecode representation | |
| // that is too much bother to deal with. | |
| // Instead, interpret the C declaration | |
| // void *_Cvar_stderr = &stderr; | |
| // as making _Cvar_stderr the name of a GOT entry | |
| // for stderr. This is separate from the usual GOT entry, | |
| // just in case the C code assigns to the variable, | |
| // and of course it only works for single pointers, | |
| // but we only need to support cgo and that's all it needs. | |
| ld.Adddynsym(ctxt, targ) | |
| got := ctxt.Syms.Lookup(".got", 0) | |
| s.Type = got.Type | |
| s.Attr |= sym.AttrSubSymbol | |
| s.Outer = got | |
| s.Sub = got.Sub | |
| got.Sub = s | |
| s.Value = got.Size | |
| got.AddUint64(ctxt.Arch, 0) | |
| ctxt.Syms.Lookup(".linkedit.got", 0).AddUint32(ctxt.Arch, uint32(targ.Dynid)) | |
| r.Type = 256 // ignore during relocsym | |
| return true | |
| } | |
| } | |
| return false | |
| } | |
| func elfreloc1(ctxt *ld.Link, r *sym.Reloc, sectoff int64) bool { | |
| ctxt.Out.Write64(uint64(sectoff)) | |
| elfsym := r.Xsym.ElfsymForReloc() | |
| switch r.Type { | |
| default: | |
| return false | |
| case objabi.R_ADDR: | |
| if r.Siz == 4 { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_32) | uint64(elfsym)<<32) | |
| } else if r.Siz == 8 { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_64) | uint64(elfsym)<<32) | |
| } else { | |
| return false | |
| } | |
| case objabi.R_TLS_LE: | |
| if r.Siz == 4 { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_TPOFF32) | uint64(elfsym)<<32) | |
| } else { | |
| return false | |
| } | |
| case objabi.R_TLS_IE: | |
| if r.Siz == 4 { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_GOTTPOFF) | uint64(elfsym)<<32) | |
| } else { | |
| return false | |
| } | |
| case objabi.R_CALL: | |
| if r.Siz == 4 { | |
| if r.Xsym.Type == sym.SDYNIMPORT { | |
| if ctxt.DynlinkingGo() { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_PLT32) | uint64(elfsym)<<32) | |
| } else { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_GOTPCREL) | uint64(elfsym)<<32) | |
| } | |
| } else { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_PC32) | uint64(elfsym)<<32) | |
| } | |
| } else { | |
| return false | |
| } | |
| case objabi.R_PCREL: | |
| if r.Siz == 4 { | |
| if r.Xsym.Type == sym.SDYNIMPORT && r.Xsym.ElfType() == elf.STT_FUNC { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_PLT32) | uint64(elfsym)<<32) | |
| } else { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_PC32) | uint64(elfsym)<<32) | |
| } | |
| } else { | |
| return false | |
| } | |
| case objabi.R_GOTPCREL: | |
| if r.Siz == 4 { | |
| ctxt.Out.Write64(uint64(elf.R_X86_64_GOTPCREL) | uint64(elfsym)<<32) | |
| } else { | |
| return false | |
| } | |
| } | |
| ctxt.Out.Write64(uint64(r.Xadd)) | |
| return true | |
| } | |
| func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool { | |
| var v uint32 | |
| rs := r.Xsym | |
| if rs.Type == sym.SHOSTOBJ || r.Type == objabi.R_PCREL || r.Type == objabi.R_GOTPCREL || r.Type == objabi.R_CALL { | |
| if rs.Dynid < 0 { | |
| 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) | |
| return false | |
| } | |
| v = uint32(rs.Dynid) | |
| v |= 1 << 27 // external relocation | |
| } else { | |
| v = uint32(rs.Sect.Extnum) | |
| if v == 0 { | |
| 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) | |
| return false | |
| } | |
| } | |
| switch r.Type { | |
| 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.Siz { | |
| 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, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool { | |
| var v uint32 | |
| rs := r.Xsym | |
| if rs.Dynid < 0 { | |
| ld.Errorf(s, "reloc %d (%s) to non-coff symbol %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Type, rs.Type) | |
| return false | |
| } | |
| out.Write32(uint32(sectoff)) | |
| out.Write32(uint32(rs.Dynid)) | |
| switch r.Type { | |
| default: | |
| return false | |
| case objabi.R_DWARFSECREF: | |
| v = ld.IMAGE_REL_AMD64_SECREL | |
| case objabi.R_ADDR: | |
| if r.Siz == 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(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bool) { | |
| return val, false | |
| } | |
| func archrelocvariant(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, t int64) int64 { | |
| log.Fatalf("unexpected relocation variant") | |
| return t | |
| } | |
| func elfsetupplt(ctxt *ld.Link) { | |
| plt := ctxt.Syms.Lookup(".plt", 0) | |
| got := ctxt.Syms.Lookup(".got.plt", 0) | |
| if plt.Size == 0 { | |
| // pushq got+8(IP) | |
| plt.AddUint8(0xff) | |
| plt.AddUint8(0x35) | |
| plt.AddPCRelPlus(ctxt.Arch, got, 8) | |
| // jmpq got+16(IP) | |
| plt.AddUint8(0xff) | |
| plt.AddUint8(0x25) | |
| plt.AddPCRelPlus(ctxt.Arch, got, 16) | |
| // nopl 0(AX) | |
| plt.AddUint32(ctxt.Arch, 0x00401f0f) | |
| // assume got->size == 0 too | |
| got.AddAddrPlus(ctxt.Arch, ctxt.Syms.Lookup(".dynamic", 0), 0) | |
| got.AddUint64(ctxt.Arch, 0) | |
| got.AddUint64(ctxt.Arch, 0) | |
| } | |
| } | |
| func addpltsym(ctxt *ld.Link, s *sym.Symbol) { | |
| if s.Plt() >= 0 { | |
| return | |
| } | |
| ld.Adddynsym(ctxt, s) | |
| if ctxt.IsELF { | |
| plt := ctxt.Syms.Lookup(".plt", 0) | |
| got := ctxt.Syms.Lookup(".got.plt", 0) | |
| rela := ctxt.Syms.Lookup(".rela.plt", 0) | |
| if plt.Size == 0 { | |
| elfsetupplt(ctxt) | |
| } | |
| // jmpq *got+size(IP) | |
| plt.AddUint8(0xff) | |
| plt.AddUint8(0x25) | |
| plt.AddPCRelPlus(ctxt.Arch, got, got.Size) | |
| // add to got: pointer to current pos in plt | |
| got.AddAddrPlus(ctxt.Arch, plt, plt.Size) | |
| // pushq $x | |
| plt.AddUint8(0x68) | |
| plt.AddUint32(ctxt.Arch, uint32((got.Size-24-8)/8)) | |
| // jmpq .plt | |
| plt.AddUint8(0xe9) | |
| plt.AddUint32(ctxt.Arch, uint32(-(plt.Size + 4))) | |
| // rela | |
| rela.AddAddrPlus(ctxt.Arch, got, got.Size-8) | |
| rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_X86_64_JMP_SLOT))) | |
| rela.AddUint64(ctxt.Arch, 0) | |
| s.SetPlt(int32(plt.Size - 16)) | |
| } else if ctxt.HeadType == objabi.Hdarwin { | |
| // To do lazy symbol lookup right, we're supposed | |
| // to tell the dynamic loader which library each | |
| // symbol comes from and format the link info | |
| // section just so. I'm too lazy (ha!) to do that | |
| // so for now we'll just use non-lazy pointers, | |
| // which don't need to be told which library to use. | |
| // | |
| // https://networkpx.blogspot.com/2009/09/about-lcdyldinfoonly-command.html | |
| // has details about what we're avoiding. | |
| addgotsym(ctxt, s) | |
| plt := ctxt.Syms.Lookup(".plt", 0) | |
| ctxt.Syms.Lookup(".linkedit.plt", 0).AddUint32(ctxt.Arch, uint32(s.Dynid)) | |
| // jmpq *got+size(IP) | |
| s.SetPlt(int32(plt.Size)) | |
| plt.AddUint8(0xff) | |
| plt.AddUint8(0x25) | |
| plt.AddPCRelPlus(ctxt.Arch, ctxt.Syms.Lookup(".got", 0), int64(s.Got())) | |
| } else { | |
| ld.Errorf(s, "addpltsym: unsupported binary format") | |
| } | |
| } | |
| func addgotsym(ctxt *ld.Link, s *sym.Symbol) { | |
| if s.Got() >= 0 { | |
| return | |
| } | |
| ld.Adddynsym(ctxt, s) | |
| got := ctxt.Syms.Lookup(".got", 0) | |
| s.SetGot(int32(got.Size)) | |
| got.AddUint64(ctxt.Arch, 0) | |
| if ctxt.IsELF { | |
| rela := ctxt.Syms.Lookup(".rela", 0) | |
| rela.AddAddrPlus(ctxt.Arch, got, int64(s.Got())) | |
| rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_X86_64_GLOB_DAT))) | |
| rela.AddUint64(ctxt.Arch, 0) | |
| } else if ctxt.HeadType == objabi.Hdarwin { | |
| ctxt.Syms.Lookup(".linkedit.got", 0).AddUint32(ctxt.Arch, uint32(s.Dynid)) | |
| } else { | |
| ld.Errorf(s, "addgotsym: unsupported binary format") | |
| } | |
| } | |
| func asmb(ctxt *ld.Link) { | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f asmb\n", ld.Cputime()) | |
| } | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f codeblk\n", ld.Cputime()) | |
| } | |
| if ctxt.IsELF { | |
| ld.Asmbelfsetup() | |
| } | |
| sect := ld.Segtext.Sections[0] | |
| ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) | |
| // 0xCC is INT $3 - breakpoint instruction | |
| ld.CodeblkPad(ctxt, int64(sect.Vaddr), int64(sect.Length), []byte{0xCC}) | |
| for _, sect = range ld.Segtext.Sections[1:] { | |
| ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) | |
| ld.Datblk(ctxt, int64(sect.Vaddr), int64(sect.Length)) | |
| } | |
| if ld.Segrodata.Filelen > 0 { | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f rodatblk\n", ld.Cputime()) | |
| } | |
| ctxt.Out.SeekSet(int64(ld.Segrodata.Fileoff)) | |
| ld.Datblk(ctxt, int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen)) | |
| } | |
| if ld.Segrelrodata.Filelen > 0 { | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f relrodatblk\n", ld.Cputime()) | |
| } | |
| ctxt.Out.SeekSet(int64(ld.Segrelrodata.Fileoff)) | |
| ld.Datblk(ctxt, int64(ld.Segrelrodata.Vaddr), int64(ld.Segrelrodata.Filelen)) | |
| } | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f datblk\n", ld.Cputime()) | |
| } | |
| ctxt.Out.SeekSet(int64(ld.Segdata.Fileoff)) | |
| ld.Datblk(ctxt, int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen)) | |
| ctxt.Out.SeekSet(int64(ld.Segdwarf.Fileoff)) | |
| ld.Dwarfblk(ctxt, int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen)) | |
| machlink := int64(0) | |
| if ctxt.HeadType == objabi.Hdarwin { | |
| machlink = ld.Domacholink(ctxt) | |
| } | |
| switch ctxt.HeadType { | |
| default: | |
| ld.Errorf(nil, "unknown header type %v", ctxt.HeadType) | |
| fallthrough | |
| case objabi.Hplan9: | |
| break | |
| case objabi.Hdarwin: | |
| ld.Flag8 = true /* 64-bit addresses */ | |
| case objabi.Hlinux, | |
| objabi.Hfreebsd, | |
| objabi.Hnetbsd, | |
| objabi.Hopenbsd, | |
| objabi.Hdragonfly, | |
| objabi.Hsolaris: | |
| ld.Flag8 = true /* 64-bit addresses */ | |
| case objabi.Hnacl, | |
| objabi.Hwindows: | |
| break | |
| } | |
| ld.Symsize = 0 | |
| ld.Spsize = 0 | |
| ld.Lcsize = 0 | |
| symo := int64(0) | |
| if !*ld.FlagS { | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f sym\n", ld.Cputime()) | |
| } | |
| switch ctxt.HeadType { | |
| default: | |
| case objabi.Hplan9: | |
| *ld.FlagS = true | |
| symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen) | |
| case objabi.Hdarwin: | |
| symo = int64(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(*ld.FlagRound))) + uint64(machlink)) | |
| case objabi.Hlinux, | |
| objabi.Hfreebsd, | |
| objabi.Hnetbsd, | |
| objabi.Hopenbsd, | |
| objabi.Hdragonfly, | |
| objabi.Hsolaris, | |
| objabi.Hnacl: | |
| symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) | |
| symo = ld.Rnd(symo, int64(*ld.FlagRound)) | |
| case objabi.Hwindows: | |
| symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) | |
| symo = ld.Rnd(symo, ld.PEFILEALIGN) | |
| } | |
| ctxt.Out.SeekSet(symo) | |
| switch ctxt.HeadType { | |
| default: | |
| if ctxt.IsELF { | |
| ctxt.Out.SeekSet(symo) | |
| ld.Asmelfsym(ctxt) | |
| ctxt.Out.Flush() | |
| ctxt.Out.Write(ld.Elfstrdat) | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f dwarf\n", ld.Cputime()) | |
| } | |
| if ctxt.LinkMode == ld.LinkExternal { | |
| ld.Elfemitreloc(ctxt) | |
| } | |
| } | |
| case objabi.Hplan9: | |
| ld.Asmplan9sym(ctxt) | |
| ctxt.Out.Flush() | |
| sym := ctxt.Syms.Lookup("pclntab", 0) | |
| if sym != nil { | |
| ld.Lcsize = int32(len(sym.P)) | |
| ctxt.Out.Write(sym.P) | |
| ctxt.Out.Flush() | |
| } | |
| case objabi.Hwindows: | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f dwarf\n", ld.Cputime()) | |
| } | |
| case objabi.Hdarwin: | |
| if ctxt.LinkMode == ld.LinkExternal { | |
| ld.Machoemitreloc(ctxt) | |
| } | |
| } | |
| } | |
| if ctxt.Debugvlog != 0 { | |
| ctxt.Logf("%5.2f headr\n", ld.Cputime()) | |
| } | |
| ctxt.Out.SeekSet(0) | |
| switch ctxt.HeadType { | |
| default: | |
| case objabi.Hplan9: /* plan9 */ | |
| magic := int32(4*26*26 + 7) | |
| magic |= 0x00008000 /* fat header */ | |
| ctxt.Out.Write32b(uint32(magic)) /* magic */ | |
| ctxt.Out.Write32b(uint32(ld.Segtext.Filelen)) /* sizes */ | |
| ctxt.Out.Write32b(uint32(ld.Segdata.Filelen)) | |
| ctxt.Out.Write32b(uint32(ld.Segdata.Length - ld.Segdata.Filelen)) | |
| ctxt.Out.Write32b(uint32(ld.Symsize)) /* nsyms */ | |
| vl := ld.Entryvalue(ctxt) | |
| ctxt.Out.Write32b(PADDR(uint32(vl))) /* va of entry */ | |
| ctxt.Out.Write32b(uint32(ld.Spsize)) /* sp offsets */ | |
| ctxt.Out.Write32b(uint32(ld.Lcsize)) /* line offsets */ | |
| ctxt.Out.Write64b(uint64(vl)) /* va of entry */ | |
| case objabi.Hdarwin: | |
| ld.Asmbmacho(ctxt) | |
| case objabi.Hlinux, | |
| objabi.Hfreebsd, | |
| objabi.Hnetbsd, | |
| objabi.Hopenbsd, | |
| objabi.Hdragonfly, | |
| objabi.Hsolaris, | |
| objabi.Hnacl: | |
| ld.Asmbelf(ctxt, symo) | |
| case objabi.Hwindows: | |
| ld.Asmbpe(ctxt) | |
| } | |
| ctxt.Out.Flush() | |
| } | |
| func tlsIEtoLE(s *sym.Symbol, 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 := s.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) | |
| } | |
| } |