| // Inferno utils/6l/asm.c |
| // https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/asm.c |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) |
| // Portions Copyright © 1997-1999 Vita Nuova Limited |
| // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) |
| // Portions Copyright © 2004,2006 Bruce Ellis |
| // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) |
| // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others |
| // Portions Copyright © 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package amd64 |
| |
| import ( |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "cmd/link/internal/ld" |
| "cmd/link/internal/loader" |
| "cmd/link/internal/sym" |
| "debug/elf" |
| "log" |
| "sync" |
| ) |
| |
| func PADDR(x uint32) uint32 { |
| return x &^ 0x80000000 |
| } |
| |
| func gentext2(ctxt *ld.Link, ldr *loader.Loader) { |
| initfunc, addmoduledata := ld.PrepareAddmoduledata(ctxt) |
| if initfunc == nil { |
| return |
| } |
| |
| o := func(op ...uint8) { |
| for _, op1 := range op { |
| initfunc.AddUint8(op1) |
| } |
| } |
| |
| // 0000000000000000 <local.dso_init>: |
| // 0: 48 8d 3d 00 00 00 00 lea 0x0(%rip),%rdi # 7 <local.dso_init+0x7> |
| // 3: R_X86_64_PC32 runtime.firstmoduledata-0x4 |
| o(0x48, 0x8d, 0x3d) |
| initfunc.AddPCRelPlus(ctxt.Arch, ctxt.Moduledata2, 0) |
| // 7: e8 00 00 00 00 callq c <local.dso_init+0xc> |
| // 8: R_X86_64_PLT32 runtime.addmoduledata-0x4 |
| o(0xe8) |
| initfunc.AddSymRef(ctxt.Arch, addmoduledata, 0, objabi.R_CALL, 4) |
| // c: c3 retq |
| o(0xc3) |
| } |
| |
| // makeWritable makes a readonly symbol writable if we do opcode rewriting. |
| func makeWritable(s *sym.Symbol) { |
| if s.Attr.ReadOnly() { |
| s.Attr.Set(sym.AttrReadOnly, false) |
| s.P = append([]byte(nil), s.P...) |
| } |
| } |
| |
| func adddynrel2(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc2, 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 (%s)", r.Type(), sym.RelocName(target.Arch, r.Type())) |
| return false |
| } |
| |
| // Handle relocations found in ELF object files. |
| case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PC32): |
| if targType == sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected R_X86_64_PC32 relocation for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| // TODO(mwhudson): the test of VisibilityHidden here probably doesn't make |
| // sense and should be removed when someone has thought about it properly. |
| if (targType == 0 || targType == sym.SXREF) && !ldr.AttrVisibilityHidden(targ) { |
| ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ)) |
| } |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocAdd(rIdx, r.Add()+4) |
| return true |
| |
| case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PC64): |
| if targType == sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected R_X86_64_PC64 relocation for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| if targType == 0 || targType == sym.SXREF { |
| ldr.Errorf(s, "unknown symbol %s in pcrel", ldr.SymName(targ)) |
| } |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocAdd(rIdx, r.Add()+8) |
| return true |
| |
| case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_PLT32): |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocAdd(rIdx, r.Add()+4) |
| if targType == sym.SDYNIMPORT { |
| addpltsym2(target, ldr, syms, targ) |
| su.SetRelocSym(rIdx, syms.PLT2) |
| su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ))) |
| } |
| |
| return true |
| |
| case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_GOTPCREL), |
| objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_GOTPCRELX), |
| objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_REX_GOTPCRELX): |
| su := ldr.MakeSymbolUpdater(s) |
| if targType != sym.SDYNIMPORT { |
| // have symbol |
| sData := ldr.Data(s) |
| if r.Off() >= 2 && sData[r.Off()-2] == 0x8b { |
| su.MakeWritable() |
| // turn MOVQ of GOT entry into LEAQ of symbol itself |
| writeableData := su.Data() |
| writeableData[r.Off()-2] = 0x8d |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocAdd(rIdx, r.Add()+4) |
| return true |
| } |
| } |
| |
| // fall back to using GOT and hope for the best (CMOV*) |
| // TODO: just needs relocation, no need to put in .dynsym |
| addgotsym2(target, ldr, syms, targ) |
| |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocSym(rIdx, syms.GOT2) |
| su.SetRelocAdd(rIdx, r.Add()+4+int64(ldr.SymGot(targ))) |
| return true |
| |
| case objabi.ElfRelocOffset + objabi.RelocType(elf.R_X86_64_64): |
| if targType == sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected R_X86_64_64 relocation for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_ADDR) |
| if target.IsPIE() && target.IsInternal() { |
| // For internal linking PIE, this R_ADDR relocation cannot |
| // be resolved statically. We need to generate a dynamic |
| // relocation. Let the code below handle it. |
| break |
| } |
| return true |
| |
| // Handle relocations found in Mach-O object files. |
| case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0: |
| // TODO: What is the difference between all these? |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_ADDR) |
| |
| if targType == sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected reloc for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| return true |
| |
| case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1: |
| if targType == sym.SDYNIMPORT { |
| addpltsym2(target, ldr, syms, targ) |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocSym(rIdx, syms.PLT2) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ))) |
| return true |
| } |
| fallthrough |
| |
| case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1, |
| objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1: |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| |
| if targType == sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected pc-relative reloc for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| return true |
| |
| case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1: |
| if targType != sym.SDYNIMPORT { |
| // have symbol |
| // turn MOVQ of GOT entry into LEAQ of symbol itself |
| sdata := ldr.Data(s) |
| if r.Off() < 2 || sdata[r.Off()-2] != 0x8b { |
| ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ)) |
| return false |
| } |
| |
| su := ldr.MakeSymbolUpdater(s) |
| su.MakeWritable() |
| sdata = su.Data() |
| sdata[r.Off()-2] = 0x8d |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| return true |
| } |
| fallthrough |
| |
| case objabi.MachoRelocOffset + ld.MACHO_X86_64_RELOC_GOT*2 + 1: |
| if targType != sym.SDYNIMPORT { |
| ldr.Errorf(s, "unexpected GOT reloc for non-dynamic symbol %s", ldr.SymName(targ)) |
| } |
| addgotsym2(target, ldr, syms, targ) |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocType(rIdx, objabi.R_PCREL) |
| su.SetRelocSym(rIdx, syms.GOT2) |
| su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ))) |
| return true |
| } |
| |
| // Reread the reloc to incorporate any changes in type above. |
| relocs := ldr.Relocs(s) |
| r = relocs.At2(rIdx) |
| |
| switch r.Type() { |
| case objabi.R_CALL, |
| objabi.R_PCREL: |
| if targType != sym.SDYNIMPORT { |
| // nothing to do, the relocation will be laid out in reloc |
| return true |
| } |
| if target.IsExternal() { |
| // External linker will do this relocation. |
| return true |
| } |
| // Internal linking, for both ELF and Mach-O. |
| // Build a PLT entry and change the relocation target to that entry. |
| addpltsym2(target, ldr, syms, targ) |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocSym(rIdx, syms.PLT2) |
| su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ))) |
| return true |
| |
| case objabi.R_ADDR: |
| if ldr.SymType(s) == sym.STEXT && target.IsElf() { |
| su := ldr.MakeSymbolUpdater(s) |
| if target.IsSolaris() { |
| addpltsym2(target, ldr, syms, targ) |
| su.SetRelocSym(rIdx, syms.PLT2) |
| su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymPlt(targ))) |
| return true |
| } |
| // The code is asking for the address of an external |
| // function. We provide it with the address of the |
| // correspondent GOT symbol. |
| addgotsym2(target, ldr, syms, targ) |
| |
| su.SetRelocSym(rIdx, syms.GOT2) |
| su.SetRelocAdd(rIdx, r.Add()+int64(ldr.SymGot(targ))) |
| return true |
| } |
| |
| // Process dynamic relocations for the data sections. |
| if target.IsPIE() && target.IsInternal() { |
| // When internally linking, generate dynamic relocations |
| // for all typical R_ADDR relocations. The exception |
| // are those R_ADDR that are created as part of generating |
| // the dynamic relocations and must be resolved statically. |
| // |
| // There are three phases relevant to understanding this: |
| // |
| // dodata() // we are here |
| // address() // symbol address assignment |
| // reloc() // resolution of static R_ADDR relocs |
| // |
| // At this point symbol addresses have not been |
| // assigned yet (as the final size of the .rela section |
| // will affect the addresses), and so we cannot write |
| // the Elf64_Rela.r_offset now. Instead we delay it |
| // until after the 'address' phase of the linker is |
| // complete. We do this via Addaddrplus, which creates |
| // a new R_ADDR relocation which will be resolved in |
| // the 'reloc' phase. |
| // |
| // These synthetic static R_ADDR relocs must be skipped |
| // now, or else we will be caught in an infinite loop |
| // of generating synthetic relocs for our synthetic |
| // relocs. |
| // |
| // Furthermore, the rela sections contain dynamic |
| // relocations with R_ADDR relocations on |
| // Elf64_Rela.r_offset. This field should contain the |
| // symbol offset as determined by reloc(), not the |
| // final dynamically linked address as a dynamic |
| // relocation would provide. |
| switch ldr.SymName(s) { |
| case ".dynsym", ".rela", ".rela.plt", ".got.plt", ".dynamic": |
| return false |
| } |
| } else { |
| // Either internally linking a static executable, |
| // in which case we can resolve these relocations |
| // statically in the 'reloc' phase, or externally |
| // linking, in which case the relocation will be |
| // prepared in the 'reloc' phase and passed to the |
| // external linker in the 'asmb' phase. |
| if ldr.SymType(s) != sym.SDATA && ldr.SymType(s) != sym.SRODATA { |
| break |
| } |
| } |
| |
| if target.IsElf() { |
| // Generate R_X86_64_RELATIVE relocations for best |
| // efficiency in the dynamic linker. |
| // |
| // As noted above, symbol addresses have not been |
| // assigned yet, so we can't generate the final reloc |
| // entry yet. We ultimately want: |
| // |
| // r_offset = s + r.Off |
| // r_info = R_X86_64_RELATIVE |
| // r_addend = targ + r.Add |
| // |
| // The dynamic linker will set *offset = base address + |
| // addend. |
| // |
| // AddAddrPlus is used for r_offset and r_addend to |
| // generate new R_ADDR relocations that will update |
| // these fields in the 'reloc' phase. |
| rela := ldr.MakeSymbolUpdater(syms.Rela2) |
| rela.AddAddrPlus(target.Arch, s, int64(r.Off())) |
| if r.Siz() == 8 { |
| rela.AddUint64(target.Arch, ld.ELF64_R_INFO(0, uint32(elf.R_X86_64_RELATIVE))) |
| } else { |
| ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ)) |
| } |
| rela.AddAddrPlus(target.Arch, targ, int64(r.Add())) |
| // Not mark r done here. So we still apply it statically, |
| // so in the file content we'll also have the right offset |
| // to the relocation target. So it can be examined statically |
| // (e.g. go version). |
| return true |
| } |
| |
| if target.IsDarwin() && ldr.SymSize(s) == int64(target.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.Adddynsym2(ldr, target, syms, targ) |
| |
| got := ldr.MakeSymbolUpdater(syms.GOT2) |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetType(got.Type()) |
| got.PrependSub(s) |
| su.SetValue(got.Size()) |
| got.AddUint64(target.Arch, 0) |
| leg := ldr.MakeSymbolUpdater(syms.LinkEditGOT2) |
| leg.AddUint32(target.Arch, uint32(ldr.SymDynid(targ))) |
| su.SetRelocType(rIdx, objabi.ElfRelocOffset) // ignore during relocsym |
| return true |
| } |
| } |
| |
| return false |
| } |
| |
| func elfreloc2(ctxt *ld.Link, ldr *loader.Loader, s loader.Sym, r loader.ExtRelocView, sectoff int64) bool { |
| ctxt.Out.Write64(uint64(sectoff)) |
| |
| xsym := ldr.Syms[r.Xsym] |
| elfsym := ld.ElfSymForReloc(ctxt, xsym) |
| siz := r.Siz() |
| switch r.Type() { |
| default: |
| return false |
| case objabi.R_ADDR, objabi.R_DWARFSECREF: |
| if siz == 4 { |
| ctxt.Out.Write64(uint64(elf.R_X86_64_32) | uint64(elfsym)<<32) |
| } else if siz == 8 { |
| ctxt.Out.Write64(uint64(elf.R_X86_64_64) | uint64(elfsym)<<32) |
| } else { |
| return false |
| } |
| case objabi.R_TLS_LE: |
| if siz == 4 { |
| ctxt.Out.Write64(uint64(elf.R_X86_64_TPOFF32) | uint64(elfsym)<<32) |
| } else { |
| return false |
| } |
| case objabi.R_TLS_IE: |
| if siz == 4 { |
| ctxt.Out.Write64(uint64(elf.R_X86_64_GOTTPOFF) | uint64(elfsym)<<32) |
| } else { |
| return false |
| } |
| case objabi.R_CALL: |
| if siz == 4 { |
| if 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 siz == 4 { |
| if xsym.Type == sym.SDYNIMPORT && 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 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(target *ld.Target, syms *ld.ArchSyms, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bool) { |
| return val, false |
| } |
| |
| func archrelocvariant(target *ld.Target, syms *ld.ArchSyms, r *sym.Reloc, s *sym.Symbol, t int64) int64 { |
| log.Fatalf("unexpected relocation variant") |
| return t |
| } |
| |
| func elfsetupplt(ctxt *ld.Link, plt, got *loader.SymbolBuilder, dynamic loader.Sym) { |
| if plt.Size() == 0 { |
| // pushq got+8(IP) |
| plt.AddUint8(0xff) |
| |
| plt.AddUint8(0x35) |
| plt.AddPCRelPlus(ctxt.Arch, got.Sym(), 8) |
| |
| // jmpq got+16(IP) |
| plt.AddUint8(0xff) |
| |
| plt.AddUint8(0x25) |
| plt.AddPCRelPlus(ctxt.Arch, got.Sym(), 16) |
| |
| // nopl 0(AX) |
| plt.AddUint32(ctxt.Arch, 0x00401f0f) |
| |
| // assume got->size == 0 too |
| got.AddAddrPlus(ctxt.Arch, dynamic, 0) |
| |
| got.AddUint64(ctxt.Arch, 0) |
| got.AddUint64(ctxt.Arch, 0) |
| } |
| } |
| |
| func addpltsym2(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) { |
| if ldr.SymPlt(s) >= 0 { |
| return |
| } |
| |
| ld.Adddynsym2(ldr, target, syms, s) |
| |
| if target.IsElf() { |
| plt := ldr.MakeSymbolUpdater(syms.PLT2) |
| got := ldr.MakeSymbolUpdater(syms.GOTPLT2) |
| rela := ldr.MakeSymbolUpdater(syms.RelaPLT2) |
| if plt.Size() == 0 { |
| panic("plt is not set up") |
| } |
| |
| // jmpq *got+size(IP) |
| plt.AddUint8(0xff) |
| |
| plt.AddUint8(0x25) |
| plt.AddPCRelPlus(target.Arch, got.Sym(), got.Size()) |
| |
| // add to got: pointer to current pos in plt |
| got.AddAddrPlus(target.Arch, plt.Sym(), plt.Size()) |
| |
| // pushq $x |
| plt.AddUint8(0x68) |
| |
| plt.AddUint32(target.Arch, uint32((got.Size()-24-8)/8)) |
| |
| // jmpq .plt |
| plt.AddUint8(0xe9) |
| |
| plt.AddUint32(target.Arch, uint32(-(plt.Size() + 4))) |
| |
| // rela |
| rela.AddAddrPlus(target.Arch, got.Sym(), got.Size()-8) |
| |
| sDynid := ldr.SymDynid(s) |
| rela.AddUint64(target.Arch, ld.ELF64_R_INFO(uint32(sDynid), uint32(elf.R_X86_64_JMP_SLOT))) |
| rela.AddUint64(target.Arch, 0) |
| |
| ldr.SetPlt(s, int32(plt.Size()-16)) |
| } else if target.IsDarwin() { |
| // 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. |
| |
| addgotsym2(target, ldr, syms, s) |
| plt := ldr.MakeSymbolUpdater(syms.PLT2) |
| |
| sDynid := ldr.SymDynid(s) |
| lep := ldr.MakeSymbolUpdater(syms.LinkEditPLT2) |
| lep.AddUint32(target.Arch, uint32(sDynid)) |
| |
| // jmpq *got+size(IP) |
| ldr.SetPlt(s, int32(plt.Size())) |
| |
| plt.AddUint8(0xff) |
| plt.AddUint8(0x25) |
| plt.AddPCRelPlus(target.Arch, syms.GOT2, int64(ldr.SymGot(s))) |
| } else { |
| ldr.Errorf(s, "addpltsym: unsupported binary format") |
| } |
| } |
| |
| func addgotsym2(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) { |
| if ldr.SymGot(s) >= 0 { |
| return |
| } |
| |
| ld.Adddynsym2(ldr, target, syms, s) |
| got := ldr.MakeSymbolUpdater(syms.GOT2) |
| ldr.SetGot(s, int32(got.Size())) |
| got.AddUint64(target.Arch, 0) |
| |
| if target.IsElf() { |
| rela := ldr.MakeSymbolUpdater(syms.Rela2) |
| rela.AddAddrPlus(target.Arch, got.Sym(), int64(ldr.SymGot(s))) |
| rela.AddUint64(target.Arch, ld.ELF64_R_INFO(uint32(ldr.SymDynid(s)), uint32(elf.R_X86_64_GLOB_DAT))) |
| rela.AddUint64(target.Arch, 0) |
| } else if target.IsDarwin() { |
| leg := ldr.MakeSymbolUpdater(syms.LinkEditGOT2) |
| leg.AddUint32(target.Arch, uint32(ldr.SymDynid(s))) |
| } else { |
| ldr.Errorf(s, "addgotsym: unsupported binary format") |
| } |
| } |
| |
| func asmb(ctxt *ld.Link, _ *loader.Loader) { |
| if ctxt.IsELF { |
| ld.Asmbelfsetup() |
| } |
| |
| var wg sync.WaitGroup |
| sect := ld.Segtext.Sections[0] |
| offset := sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff |
| f := func(ctxt *ld.Link, out *ld.OutBuf, start, length int64) { |
| // 0xCC is INT $3 - breakpoint instruction |
| ld.CodeblkPad(ctxt, out, start, length, []byte{0xCC}) |
| } |
| ld.WriteParallel(&wg, f, ctxt, offset, sect.Vaddr, sect.Length) |
| |
| for _, sect := range ld.Segtext.Sections[1:] { |
| offset := sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff |
| ld.WriteParallel(&wg, ld.Datblk, ctxt, offset, sect.Vaddr, sect.Length) |
| } |
| |
| if ld.Segrodata.Filelen > 0 { |
| ld.WriteParallel(&wg, ld.Datblk, ctxt, ld.Segrodata.Fileoff, ld.Segrodata.Vaddr, ld.Segrodata.Filelen) |
| } |
| |
| if ld.Segrelrodata.Filelen > 0 { |
| ld.WriteParallel(&wg, ld.Datblk, ctxt, ld.Segrelrodata.Fileoff, ld.Segrelrodata.Vaddr, ld.Segrelrodata.Filelen) |
| } |
| |
| ld.WriteParallel(&wg, ld.Datblk, ctxt, ld.Segdata.Fileoff, ld.Segdata.Vaddr, ld.Segdata.Filelen) |
| |
| ld.WriteParallel(&wg, ld.Dwarfblk, ctxt, ld.Segdwarf.Fileoff, ld.Segdwarf.Vaddr, ld.Segdwarf.Filelen) |
| |
| wg.Wait() |
| } |
| |
| func asmb2(ctxt *ld.Link) { |
| 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.Hwindows: |
| break |
| } |
| |
| ld.Symsize = 0 |
| ld.Spsize = 0 |
| ld.Lcsize = 0 |
| symo := int64(0) |
| if !*ld.FlagS { |
| 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: |
| 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.Write(ld.Elfstrdat) |
| |
| if ctxt.LinkMode == ld.LinkExternal { |
| ld.Elfemitreloc(ctxt) |
| } |
| } |
| |
| case objabi.Hplan9: |
| ld.Asmplan9sym(ctxt) |
| |
| sym := ctxt.Syms.Lookup("pclntab", 0) |
| if sym != nil { |
| ld.Lcsize = int32(len(sym.P)) |
| ctxt.Out.Write(sym.P) |
| } |
| |
| case objabi.Hwindows: |
| // Do nothing |
| |
| case objabi.Hdarwin: |
| if ctxt.LinkMode == ld.LinkExternal { |
| ld.Machoemitreloc(ctxt) |
| } |
| } |
| } |
| |
| 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: |
| ld.Asmbelf(ctxt, symo) |
| |
| case objabi.Hwindows: |
| ld.Asmbpe(ctxt) |
| } |
| } |
| |
| func tlsIEtoLE(P []byte, off, size int) { |
| // Transform the PC-relative instruction into a constant load. |
| // That is, |
| // |
| // MOVQ X(IP), REG -> MOVQ $Y, REG |
| // |
| // To determine the instruction and register, we study the op codes. |
| // Consult an AMD64 instruction encoding guide to decipher this. |
| if off < 3 { |
| log.Fatal("R_X86_64_GOTTPOFF reloc not preceded by MOVQ or ADDQ instruction") |
| } |
| op := P[off-3 : off] |
| reg := op[2] >> 3 |
| |
| if op[1] == 0x8b || reg == 4 { |
| // MOVQ |
| if op[0] == 0x4c { |
| op[0] = 0x49 |
| } else if size == 4 && op[0] == 0x44 { |
| op[0] = 0x41 |
| } |
| if op[1] == 0x8b { |
| op[1] = 0xc7 |
| } else { |
| op[1] = 0x81 // special case for SP |
| } |
| op[2] = 0xc0 | reg |
| } else { |
| // An alternate op is ADDQ. This is handled by GNU gold, |
| // but right now is not generated by the Go compiler: |
| // ADDQ X(IP), REG -> ADDQ $Y, REG |
| // Consider adding support for it here. |
| log.Fatalf("expected TLS IE op to be MOVQ, got %v", op) |
| } |
| } |
