// Inferno utils/5l/asm.c // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/5l/asm.c // // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) // Portions Copyright © 1997-1999 Vita Nuova Limited // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) // Portions Copyright © 2004,2006 Bruce Ellis // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others // Portions Copyright © 2009 The Go Authors. All rights reserved. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. package arm import ( "cmd/internal/objabi" "cmd/internal/sys" "cmd/link/internal/ld" "cmd/link/internal/sym" "debug/elf" "fmt" "log" ) // This assembler: // // .align 2 // local.dso_init: // ldr r0, .Lmoduledata // .Lloadfrom: // ldr r0, [r0] // b runtime.addmoduledata@plt // .align 2 // .Lmoduledata: // .word local.moduledata(GOT_PREL) + (. - (.Lloadfrom + 4)) // assembles to: // // 00000000 <local.dso_init>: // 0: e59f0004 ldr r0, [pc, #4] ; c <local.dso_init+0xc> // 4: e5900000 ldr r0, [r0] // 8: eafffffe b 0 <runtime.addmoduledata> // 8: R_ARM_JUMP24 runtime.addmoduledata // c: 00000004 .word 0x00000004 // c: R_ARM_GOT_PREL local.moduledata 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 uint32) { initfunc.AddUint32(ctxt.Arch, op) } o(0xe59f0004) o(0xe08f0000) o(0xeafffffe) rel := initfunc.AddRel() rel.Off = 8 rel.Siz = 4 rel.Sym = ctxt.Syms.Lookup("runtime.addmoduledata", 0) rel.Type = objabi.R_CALLARM rel.Add = 0xeafffffe // vomit o(0x00000000) rel = initfunc.AddRel() rel.Off = 12 rel.Siz = 4 rel.Sym = ctxt.Moduledata rel.Type = objabi.R_PCREL rel.Add = 4 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) } // Preserve highest 8 bits of a, and do addition to lower 24-bit // of a and b; used to adjust ARM branch instruction's target func braddoff(a int32, b int32) int32 { return int32((uint32(a))&0xff000000 | 0x00ffffff&uint32(a+b)) } 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_ARM_PLT32): r.Type = objabi.R_CALLARM if targ.Type == sym.SDYNIMPORT { addpltsym(ctxt, targ) r.Sym = ctxt.Syms.Lookup(".plt", 0) r.Add = int64(braddoff(int32(r.Add), targ.Plt/4)) } return true case 256 + objabi.RelocType(elf.R_ARM_THM_PC22): // R_ARM_THM_CALL ld.Exitf("R_ARM_THM_CALL, are you using -marm?") return false case 256 + objabi.RelocType(elf.R_ARM_GOT32): // R_ARM_GOT_BREL if targ.Type != sym.SDYNIMPORT { addgotsyminternal(ctxt, targ) } else { addgotsym(ctxt, targ) } r.Type = objabi.R_CONST // write r->add during relocsym r.Sym = nil r.Add += int64(targ.Got) return true case 256 + objabi.RelocType(elf.R_ARM_GOT_PREL): // GOT(nil) + A - nil if targ.Type != sym.SDYNIMPORT { addgotsyminternal(ctxt, targ) } else { addgotsym(ctxt, targ) } r.Type = objabi.R_PCREL r.Sym = ctxt.Syms.Lookup(".got", 0) r.Add += int64(targ.Got) + 4 return true case 256 + objabi.RelocType(elf.R_ARM_GOTOFF): // R_ARM_GOTOFF32 r.Type = objabi.R_GOTOFF return true case 256 + objabi.RelocType(elf.R_ARM_GOTPC): // R_ARM_BASE_PREL r.Type = objabi.R_PCREL r.Sym = ctxt.Syms.Lookup(".got", 0) r.Add += 4 return true case 256 + objabi.RelocType(elf.R_ARM_CALL): r.Type = objabi.R_CALLARM if targ.Type == sym.SDYNIMPORT { addpltsym(ctxt, targ) r.Sym = ctxt.Syms.Lookup(".plt", 0) r.Add = int64(braddoff(int32(r.Add), targ.Plt/4)) } return true case 256 + objabi.RelocType(elf.R_ARM_REL32): // R_ARM_REL32 r.Type = objabi.R_PCREL r.Add += 4 return true case 256 + objabi.RelocType(elf.R_ARM_ABS32): if targ.Type == sym.SDYNIMPORT { ld.Errorf(s, "unexpected R_ARM_ABS32 relocation for dynamic symbol %s", targ.Name) } r.Type = objabi.R_ADDR return true // we can just ignore this, because we are targeting ARM V5+ anyway case 256 + objabi.RelocType(elf.R_ARM_V4BX): if r.Sym != nil { // R_ARM_V4BX is ABS relocation, so this symbol is a dummy symbol, ignore it r.Sym.Type = 0 } r.Sym = nil return true case 256 + objabi.RelocType(elf.R_ARM_PC24), 256 + objabi.RelocType(elf.R_ARM_JUMP24): r.Type = objabi.R_CALLARM if targ.Type == sym.SDYNIMPORT { addpltsym(ctxt, targ) r.Sym = ctxt.Syms.Lookup(".plt", 0) r.Add = int64(braddoff(int32(r.Add), targ.Plt/4)) } return true } // Handle references to ELF symbols from our own object files. if targ.Type != sym.SDYNIMPORT { return true } switch r.Type { case objabi.R_CALLARM: 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.SDATA { break } if ctxt.IsELF { ld.Adddynsym(ctxt, targ) rel := ctxt.Syms.Lookup(".rel", 0) rel.AddAddrPlus(ctxt.Arch, s, int64(r.Off)) rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(targ.Dynid), uint32(elf.R_ARM_GLOB_DAT))) // we need a nil + A dynamic reloc r.Type = objabi.R_CONST // write r->add during relocsym r.Sym = nil return true } } return false } func elfreloc1(ctxt *ld.Link, r *sym.Reloc, sectoff int64) bool { ctxt.Out.Write32(uint32(sectoff)) elfsym := r.Xsym.ElfsymForReloc() switch r.Type { default: return false case objabi.R_ADDR: if r.Siz == 4 { ctxt.Out.Write32(uint32(elf.R_ARM_ABS32) | uint32(elfsym)<<8) } else { return false } case objabi.R_PCREL: if r.Siz == 4 { ctxt.Out.Write32(uint32(elf.R_ARM_REL32) | uint32(elfsym)<<8) } else { return false } case objabi.R_CALLARM: if r.Siz == 4 { if r.Add&0xff000000 == 0xeb000000 { // BL ctxt.Out.Write32(uint32(elf.R_ARM_CALL) | uint32(elfsym)<<8) } else { ctxt.Out.Write32(uint32(elf.R_ARM_JUMP24) | uint32(elfsym)<<8) } } else { return false } case objabi.R_TLS_LE: ctxt.Out.Write32(uint32(elf.R_ARM_TLS_LE32) | uint32(elfsym)<<8) case objabi.R_TLS_IE: ctxt.Out.Write32(uint32(elf.R_ARM_TLS_IE32) | uint32(elfsym)<<8) case objabi.R_GOTPCREL: if r.Siz == 4 { ctxt.Out.Write32(uint32(elf.R_ARM_GOT_PREL) | uint32(elfsym)<<8) } else { return false } } return true } func elfsetupplt(ctxt *ld.Link) { plt := ctxt.Syms.Lookup(".plt", 0) got := ctxt.Syms.Lookup(".got.plt", 0) if plt.Size == 0 { // str lr, [sp, #-4]! plt.AddUint32(ctxt.Arch, 0xe52de004) // ldr lr, [pc, #4] plt.AddUint32(ctxt.Arch, 0xe59fe004) // add lr, pc, lr plt.AddUint32(ctxt.Arch, 0xe08fe00e) // ldr pc, [lr, #8]! plt.AddUint32(ctxt.Arch, 0xe5bef008) // .word &GLOBAL_OFFSET_TABLE[0] - . plt.AddPCRelPlus(ctxt.Arch, got, 4) // the first .plt entry requires 3 .plt.got entries got.AddUint32(ctxt.Arch, 0) got.AddUint32(ctxt.Arch, 0) got.AddUint32(ctxt.Arch, 0) } } func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool { var v uint32 rs := r.Xsym if r.Type == objabi.R_PCREL { if rs.Type == sym.SHOSTOBJ { ld.Errorf(s, "pc-relative relocation of external symbol is not supported") return false } if r.Siz != 4 { return false } // emit a pair of "scattered" relocations that // resolve to the difference of section addresses of // the symbol and the instruction // this value is added to the field being relocated o1 := uint32(sectoff) o1 |= 1 << 31 // scattered bit o1 |= ld.MACHO_ARM_RELOC_SECTDIFF << 24 o1 |= 2 << 28 // size = 4 o2 := uint32(0) o2 |= 1 << 31 // scattered bit o2 |= ld.MACHO_ARM_RELOC_PAIR << 24 o2 |= 2 << 28 // size = 4 out.Write32(o1) out.Write32(uint32(ld.Symaddr(rs))) out.Write32(o2) out.Write32(uint32(s.Value + int64(r.Off))) return true } if rs.Type == sym.SHOSTOBJ || r.Type == objabi.R_CALLARM { 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_GENERIC_RELOC_VANILLA << 28 case objabi.R_CALLARM: v |= 1 << 24 // pc-relative bit v |= ld.MACHO_ARM_RELOC_BR24 << 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 } // sign extend a 24-bit integer func signext24(x int64) int32 { return (int32(x) << 8) >> 8 } // encode an immediate in ARM's imm12 format. copied from ../../../internal/obj/arm/asm5.go func immrot(v uint32) uint32 { for i := 0; i < 16; i++ { if v&^0xff == 0 { return uint32(i<<8) | v | 1<<25 } v = v<<2 | v>>30 } return 0 } // Convert the direct jump relocation r to refer to a trampoline if the target is too far func trampoline(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol) { switch r.Type { case objabi.R_CALLARM: // r.Add is the instruction // low 24-bit encodes the target address t := (ld.Symaddr(r.Sym) + int64(signext24(r.Add&0xffffff)*4) - (s.Value + int64(r.Off))) / 4 if t > 0x7fffff || t < -0x800000 || (*ld.FlagDebugTramp > 1 && s.File != r.Sym.File) { // direct call too far, need to insert trampoline. // look up existing trampolines first. if we found one within the range // of direct call, we can reuse it. otherwise create a new one. offset := (signext24(r.Add&0xffffff) + 2) * 4 var tramp *sym.Symbol for i := 0; ; i++ { name := r.Sym.Name + fmt.Sprintf("%+d-tramp%d", offset, i) tramp = ctxt.Syms.Lookup(name, int(r.Sym.Version)) if tramp.Type == sym.SDYNIMPORT { // don't reuse trampoline defined in other module continue } if tramp.Value == 0 { // either the trampoline does not exist -- we need to create one, // or found one the address which is not assigned -- this will be // laid down immediately after the current function. use this one. break } t = (ld.Symaddr(tramp) - 8 - (s.Value + int64(r.Off))) / 4 if t >= -0x800000 && t < 0x7fffff { // found an existing trampoline that is not too far // we can just use it break } } if tramp.Type == 0 { // trampoline does not exist, create one ctxt.AddTramp(tramp) if ctxt.DynlinkingGo() { if immrot(uint32(offset)) == 0 { ld.Errorf(s, "odd offset in dynlink direct call: %v+%d", r.Sym, offset) } gentrampdyn(ctxt.Arch, tramp, r.Sym, int64(offset)) } else if ctxt.BuildMode == ld.BuildModeCArchive || ctxt.BuildMode == ld.BuildModeCShared || ctxt.BuildMode == ld.BuildModePIE { gentramppic(ctxt.Arch, tramp, r.Sym, int64(offset)) } else { gentramp(ctxt.Arch, ctxt.LinkMode, tramp, r.Sym, int64(offset)) } } // modify reloc to point to tramp, which will be resolved later r.Sym = tramp r.Add = r.Add&0xff000000 | 0xfffffe // clear the offset embedded in the instruction r.Done = false } default: ld.Errorf(s, "trampoline called with non-jump reloc: %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type)) } } // generate a trampoline to target+offset func gentramp(arch *sys.Arch, linkmode ld.LinkMode, tramp, target *sym.Symbol, offset int64) { tramp.Size = 12 // 3 instructions tramp.P = make([]byte, tramp.Size) t := ld.Symaddr(target) + int64(offset) o1 := uint32(0xe5900000 | 11<<12 | 15<<16) // MOVW (R15), R11 // R15 is actual pc + 8 o2 := uint32(0xe12fff10 | 11) // JMP (R11) o3 := uint32(t) // WORD $target arch.ByteOrder.PutUint32(tramp.P, o1) arch.ByteOrder.PutUint32(tramp.P[4:], o2) arch.ByteOrder.PutUint32(tramp.P[8:], o3) if linkmode == ld.LinkExternal { r := tramp.AddRel() r.Off = 8 r.Type = objabi.R_ADDR r.Siz = 4 r.Sym = target r.Add = offset } } // generate a trampoline to target+offset in position independent code func gentramppic(arch *sys.Arch, tramp, target *sym.Symbol, offset int64) { tramp.Size = 16 // 4 instructions tramp.P = make([]byte, tramp.Size) o1 := uint32(0xe5900000 | 11<<12 | 15<<16 | 4) // MOVW 4(R15), R11 // R15 is actual pc + 8 o2 := uint32(0xe0800000 | 11<<12 | 15<<16 | 11) // ADD R15, R11, R11 o3 := uint32(0xe12fff10 | 11) // JMP (R11) o4 := uint32(0) // WORD $(target-pc) // filled in with relocation arch.ByteOrder.PutUint32(tramp.P, o1) arch.ByteOrder.PutUint32(tramp.P[4:], o2) arch.ByteOrder.PutUint32(tramp.P[8:], o3) arch.ByteOrder.PutUint32(tramp.P[12:], o4) r := tramp.AddRel() r.Off = 12 r.Type = objabi.R_PCREL r.Siz = 4 r.Sym = target r.Add = offset + 4 } // generate a trampoline to target+offset in dynlink mode (using GOT) func gentrampdyn(arch *sys.Arch, tramp, target *sym.Symbol, offset int64) { tramp.Size = 20 // 5 instructions o1 := uint32(0xe5900000 | 11<<12 | 15<<16 | 8) // MOVW 8(R15), R11 // R15 is actual pc + 8 o2 := uint32(0xe0800000 | 11<<12 | 15<<16 | 11) // ADD R15, R11, R11 o3 := uint32(0xe5900000 | 11<<12 | 11<<16) // MOVW (R11), R11 o4 := uint32(0xe12fff10 | 11) // JMP (R11) o5 := uint32(0) // WORD $target@GOT // filled in with relocation o6 := uint32(0) if offset != 0 { // insert an instruction to add offset tramp.Size = 24 // 6 instructions o6 = o5 o5 = o4 o4 = uint32(0xe2800000 | 11<<12 | 11<<16 | immrot(uint32(offset))) // ADD $offset, R11, R11 o1 = uint32(0xe5900000 | 11<<12 | 15<<16 | 12) // MOVW 12(R15), R11 } tramp.P = make([]byte, tramp.Size) arch.ByteOrder.PutUint32(tramp.P, o1) arch.ByteOrder.PutUint32(tramp.P[4:], o2) arch.ByteOrder.PutUint32(tramp.P[8:], o3) arch.ByteOrder.PutUint32(tramp.P[12:], o4) arch.ByteOrder.PutUint32(tramp.P[16:], o5) if offset != 0 { arch.ByteOrder.PutUint32(tramp.P[20:], o6) } r := tramp.AddRel() r.Off = 16 r.Type = objabi.R_GOTPCREL r.Siz = 4 r.Sym = target r.Add = 8 if offset != 0 { // increase reloc offset by 4 as we inserted an ADD instruction r.Off = 20 r.Add = 12 } } func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val *int64) bool { if ctxt.LinkMode == ld.LinkExternal { switch r.Type { case objabi.R_CALLARM: r.Done = false // set up addend for eventual relocation via outer symbol. rs := r.Sym r.Xadd = int64(signext24(r.Add & 0xffffff)) r.Xadd *= 4 for rs.Outer != nil { r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer) rs = rs.Outer } if rs.Type != sym.SHOSTOBJ && rs.Type != sym.SDYNIMPORT && rs.Sect == nil { ld.Errorf(s, "missing section for %s", rs.Name) } r.Xsym = rs // ld64 for arm seems to want the symbol table to contain offset // into the section rather than pseudo virtual address that contains // the section load address. // we need to compensate that by removing the instruction's address // from addend. if ctxt.HeadType == objabi.Hdarwin { r.Xadd -= ld.Symaddr(s) + int64(r.Off) } if r.Xadd/4 > 0x7fffff || r.Xadd/4 < -0x800000 { ld.Errorf(s, "direct call too far %d", r.Xadd/4) } *val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&uint32(r.Xadd/4)))) return true } return false } switch r.Type { case objabi.R_CONST: *val = r.Add return true case objabi.R_GOTOFF: *val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ctxt.Syms.Lookup(".got", 0)) return true // The following three arch specific relocations are only for generation of // Linux/ARM ELF's PLT entry (3 assembler instruction) case objabi.R_PLT0: // add ip, pc, #0xXX00000 if ld.Symaddr(ctxt.Syms.Lookup(".got.plt", 0)) < ld.Symaddr(ctxt.Syms.Lookup(".plt", 0)) { ld.Errorf(s, ".got.plt should be placed after .plt section.") } *val = 0xe28fc600 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ctxt.Syms.Lookup(".plt", 0))+int64(r.Off))+r.Add)) >> 20)) return true case objabi.R_PLT1: // add ip, ip, #0xYY000 *val = 0xe28cca00 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ctxt.Syms.Lookup(".plt", 0))+int64(r.Off))+r.Add+4)) >> 12)) return true case objabi.R_PLT2: // ldr pc, [ip, #0xZZZ]! *val = 0xe5bcf000 + (0xfff & int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ctxt.Syms.Lookup(".plt", 0))+int64(r.Off))+r.Add+8))) return true case objabi.R_CALLARM: // bl XXXXXX or b YYYYYY // r.Add is the instruction // low 24-bit encodes the target address t := (ld.Symaddr(r.Sym) + int64(signext24(r.Add&0xffffff)*4) - (s.Value + int64(r.Off))) / 4 if t > 0x7fffff || t < -0x800000 { ld.Errorf(s, "direct call too far: %s %x", r.Sym.Name, t) } *val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&t))) return true } return false } func archrelocvariant(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, t int64) int64 { log.Fatalf("unexpected relocation variant") return t } func addpltreloc(ctxt *ld.Link, plt *sym.Symbol, got *sym.Symbol, s *sym.Symbol, typ objabi.RelocType) *sym.Reloc { r := plt.AddRel() r.Sym = got r.Off = int32(plt.Size) r.Siz = 4 r.Type = typ r.Add = int64(s.Got) - 8 plt.Attr |= sym.AttrReachable plt.Size += 4 plt.Grow(plt.Size) return r } 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) rel := ctxt.Syms.Lookup(".rel.plt", 0) if plt.Size == 0 { elfsetupplt(ctxt) } // .got entry s.Got = int32(got.Size) // In theory, all GOT should point to the first PLT entry, // Linux/ARM's dynamic linker will do that for us, but FreeBSD/ARM's // dynamic linker won't, so we'd better do it ourselves. got.AddAddrPlus(ctxt.Arch, plt, 0) // .plt entry, this depends on the .got entry s.Plt = int32(plt.Size) addpltreloc(ctxt, plt, got, s, objabi.R_PLT0) // add lr, pc, #0xXX00000 addpltreloc(ctxt, plt, got, s, objabi.R_PLT1) // add lr, lr, #0xYY000 addpltreloc(ctxt, plt, got, s, objabi.R_PLT2) // ldr pc, [lr, #0xZZZ]! // rel rel.AddAddrPlus(ctxt.Arch, got, int64(s.Got)) rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(s.Dynid), uint32(elf.R_ARM_JUMP_SLOT))) } else { ld.Errorf(s, "addpltsym: unsupported binary format") } } func addgotsyminternal(ctxt *ld.Link, s *sym.Symbol) { if s.Got >= 0 { return } got := ctxt.Syms.Lookup(".got", 0) s.Got = int32(got.Size) got.AddAddrPlus(ctxt.Arch, s, 0) if ctxt.IsELF { } else { ld.Errorf(s, "addgotsyminternal: 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.Got = int32(got.Size) got.AddUint32(ctxt.Arch, 0) if ctxt.IsELF { rel := ctxt.Syms.Lookup(".rel", 0) rel.AddAddrPlus(ctxt.Arch, got, int64(s.Got)) rel.AddUint32(ctxt.Arch, ld.ELF32_R_INFO(uint32(s.Dynid), uint32(elf.R_ARM_GLOB_DAT))) } 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.IsELF { ld.Asmbelfsetup() } sect := ld.Segtext.Sections[0] ctxt.Out.SeekSet(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Codeblk(ctxt, int64(sect.Vaddr), int64(sect.Length)) 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 := uint32(0) if ctxt.HeadType == objabi.Hdarwin { machlink = uint32(ld.Domacholink(ctxt)) } /* output symbol table */ ld.Symsize = 0 ld.Lcsize = 0 symo := uint32(0) if !*ld.FlagS { // TODO: rationalize if ctxt.Debugvlog != 0 { ctxt.Logf("%5.2f sym\n", ld.Cputime()) } switch ctxt.HeadType { default: if ctxt.IsELF { symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = uint32(ld.Rnd(int64(symo), int64(*ld.FlagRound))) } case objabi.Hplan9: symo = uint32(ld.Segdata.Fileoff + ld.Segdata.Filelen) case objabi.Hdarwin: symo = uint32(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(*ld.FlagRound))) + uint64(machlink)) } ctxt.Out.SeekSet(int64(symo)) switch ctxt.HeadType { default: if ctxt.IsELF { if ctxt.Debugvlog != 0 { ctxt.Logf("%5.2f elfsym\n", ld.Cputime()) } ld.Asmelfsym(ctxt) ctxt.Out.Flush() ctxt.Out.Write(ld.Elfstrdat) 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.Hdarwin: if ctxt.LinkMode == ld.LinkExternal { ld.Machoemitreloc(ctxt) } } } if ctxt.Debugvlog != 0 { ctxt.Logf("%5.2f header\n", ld.Cputime()) } ctxt.Out.SeekSet(0) switch ctxt.HeadType { default: case objabi.Hplan9: /* plan 9 */ ctxt.Out.Write32b(0x647) /* 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 */ ctxt.Out.Write32b(uint32(ld.Entryvalue(ctxt))) /* va of entry */ ctxt.Out.Write32b(0) ctxt.Out.Write32b(uint32(ld.Lcsize)) case objabi.Hlinux, objabi.Hfreebsd, objabi.Hnetbsd, objabi.Hopenbsd, objabi.Hnacl: ld.Asmbelf(ctxt, int64(symo)) case objabi.Hdarwin: ld.Asmbmacho(ctxt) } ctxt.Out.Flush() if *ld.FlagC { fmt.Printf("textsize=%d\n", ld.Segtext.Filelen) fmt.Printf("datsize=%d\n", ld.Segdata.Filelen) fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen) fmt.Printf("symsize=%d\n", ld.Symsize) fmt.Printf("lcsize=%d\n", ld.Lcsize) fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize)) } }