// Copyright 2010 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package ld import ( "cmd/internal/obj" "encoding/binary" "fmt" "log" "sort" "strings" ) const ( IMAGE_SYM_UNDEFINED = 0 IMAGE_SYM_ABSOLUTE = -1 IMAGE_SYM_DEBUG = -2 IMAGE_SYM_TYPE_NULL = 0 IMAGE_SYM_TYPE_VOID = 1 IMAGE_SYM_TYPE_CHAR = 2 IMAGE_SYM_TYPE_SHORT = 3 IMAGE_SYM_TYPE_INT = 4 IMAGE_SYM_TYPE_LONG = 5 IMAGE_SYM_TYPE_FLOAT = 6 IMAGE_SYM_TYPE_DOUBLE = 7 IMAGE_SYM_TYPE_STRUCT = 8 IMAGE_SYM_TYPE_UNION = 9 IMAGE_SYM_TYPE_ENUM = 10 IMAGE_SYM_TYPE_MOE = 11 IMAGE_SYM_TYPE_BYTE = 12 IMAGE_SYM_TYPE_WORD = 13 IMAGE_SYM_TYPE_UINT = 14 IMAGE_SYM_TYPE_DWORD = 15 IMAGE_SYM_TYPE_PCODE = 32768 IMAGE_SYM_DTYPE_NULL = 0 IMAGE_SYM_DTYPE_POINTER = 0x10 IMAGE_SYM_DTYPE_FUNCTION = 0x20 IMAGE_SYM_DTYPE_ARRAY = 0x30 IMAGE_SYM_CLASS_END_OF_FUNCTION = -1 IMAGE_SYM_CLASS_NULL = 0 IMAGE_SYM_CLASS_AUTOMATIC = 1 IMAGE_SYM_CLASS_EXTERNAL = 2 IMAGE_SYM_CLASS_STATIC = 3 IMAGE_SYM_CLASS_REGISTER = 4 IMAGE_SYM_CLASS_EXTERNAL_DEF = 5 IMAGE_SYM_CLASS_LABEL = 6 IMAGE_SYM_CLASS_UNDEFINED_LABEL = 7 IMAGE_SYM_CLASS_MEMBER_OF_STRUCT = 8 IMAGE_SYM_CLASS_ARGUMENT = 9 IMAGE_SYM_CLASS_STRUCT_TAG = 10 IMAGE_SYM_CLASS_MEMBER_OF_UNION = 11 IMAGE_SYM_CLASS_UNION_TAG = 12 IMAGE_SYM_CLASS_TYPE_DEFINITION = 13 IMAGE_SYM_CLASS_UNDEFINED_STATIC = 14 IMAGE_SYM_CLASS_ENUM_TAG = 15 IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16 IMAGE_SYM_CLASS_REGISTER_PARAM = 17 IMAGE_SYM_CLASS_BIT_FIELD = 18 IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */ IMAGE_SYM_CLASS_BLOCK = 100 IMAGE_SYM_CLASS_FUNCTION = 101 IMAGE_SYM_CLASS_END_OF_STRUCT = 102 IMAGE_SYM_CLASS_FILE = 103 IMAGE_SYM_CLASS_SECTION = 104 IMAGE_SYM_CLASS_WEAK_EXTERNAL = 105 IMAGE_SYM_CLASS_CLR_TOKEN = 107 IMAGE_REL_I386_ABSOLUTE = 0x0000 IMAGE_REL_I386_DIR16 = 0x0001 IMAGE_REL_I386_REL16 = 0x0002 IMAGE_REL_I386_DIR32 = 0x0006 IMAGE_REL_I386_DIR32NB = 0x0007 IMAGE_REL_I386_SEG12 = 0x0009 IMAGE_REL_I386_SECTION = 0x000A IMAGE_REL_I386_SECREL = 0x000B IMAGE_REL_I386_TOKEN = 0x000C IMAGE_REL_I386_SECREL7 = 0x000D IMAGE_REL_I386_REL32 = 0x0014 IMAGE_REL_AMD64_ABSOLUTE = 0x0000 IMAGE_REL_AMD64_ADDR64 = 0x0001 IMAGE_REL_AMD64_ADDR32 = 0x0002 IMAGE_REL_AMD64_ADDR32NB = 0x0003 IMAGE_REL_AMD64_REL32 = 0x0004 IMAGE_REL_AMD64_REL32_1 = 0x0005 IMAGE_REL_AMD64_REL32_2 = 0x0006 IMAGE_REL_AMD64_REL32_3 = 0x0007 IMAGE_REL_AMD64_REL32_4 = 0x0008 IMAGE_REL_AMD64_REL32_5 = 0x0009 IMAGE_REL_AMD64_SECTION = 0x000A IMAGE_REL_AMD64_SECREL = 0x000B IMAGE_REL_AMD64_SECREL7 = 0x000C IMAGE_REL_AMD64_TOKEN = 0x000D IMAGE_REL_AMD64_SREL32 = 0x000E IMAGE_REL_AMD64_PAIR = 0x000F IMAGE_REL_AMD64_SSPAN32 = 0x0010 ) type PeSym struct { name string value uint32 sectnum uint16 type_ uint16 sclass uint8 aux uint8 sym *LSym } type PeSect struct { name string base []byte size uint64 sym *LSym sh IMAGE_SECTION_HEADER } type PeObj struct { f *obj.Biobuf name string base uint32 sect []PeSect nsect uint pesym []PeSym npesym uint fh IMAGE_FILE_HEADER snames []byte } func ldpe(f *obj.Biobuf, pkg string, length int64, pn string) { if Debug['v'] != 0 { fmt.Fprintf(&Bso, "%5.2f ldpe %s\n", obj.Cputime(), pn) } var sect *PeSect Ctxt.Version++ base := int32(obj.Boffset(f)) peobj := new(PeObj) peobj.f = f peobj.base = uint32(base) peobj.name = pn // read header var err error var j int var l uint32 var name string var numaux int var r []Reloc var rp *Reloc var rsect *PeSect var s *LSym var sym *PeSym var symbuf [18]uint8 if err = binary.Read(f, binary.LittleEndian, &peobj.fh); err != nil { goto bad } // load section list peobj.sect = make([]PeSect, peobj.fh.NumberOfSections) peobj.nsect = uint(peobj.fh.NumberOfSections) for i := 0; i < int(peobj.fh.NumberOfSections); i++ { if err = binary.Read(f, binary.LittleEndian, &peobj.sect[i].sh); err != nil { goto bad } peobj.sect[i].size = uint64(peobj.sect[i].sh.SizeOfRawData) peobj.sect[i].name = cstring(peobj.sect[i].sh.Name[:]) } // TODO return error if found .cormeta // load string table obj.Bseek(f, int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0) if obj.Bread(f, symbuf[:4]) != 4 { goto bad } l = Le32(symbuf[:]) peobj.snames = make([]byte, l) obj.Bseek(f, int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0) if obj.Bread(f, peobj.snames) != len(peobj.snames) { goto bad } // rewrite section names if they start with / for i := 0; i < int(peobj.fh.NumberOfSections); i++ { if peobj.sect[i].name == "" { continue } if peobj.sect[i].name[0] != '/' { continue } l = uint32(obj.Atoi(peobj.sect[i].name[1:])) peobj.sect[i].name = cstring(peobj.snames[l:]) } // read symbols peobj.pesym = make([]PeSym, peobj.fh.NumberOfSymbols) peobj.npesym = uint(peobj.fh.NumberOfSymbols) obj.Bseek(f, int64(base)+int64(peobj.fh.PointerToSymbolTable), 0) for i := 0; uint32(i) < peobj.fh.NumberOfSymbols; i += numaux + 1 { obj.Bseek(f, int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(i), 0) if obj.Bread(f, symbuf[:]) != len(symbuf) { goto bad } if (symbuf[0] == 0) && (symbuf[1] == 0) && (symbuf[2] == 0) && (symbuf[3] == 0) { l = Le32(symbuf[4:]) peobj.pesym[i].name = cstring(peobj.snames[l:]) // sym name length <= 8 } else { peobj.pesym[i].name = cstring(symbuf[:8]) } peobj.pesym[i].value = Le32(symbuf[8:]) peobj.pesym[i].sectnum = Le16(symbuf[12:]) peobj.pesym[i].sclass = symbuf[16] peobj.pesym[i].aux = symbuf[17] peobj.pesym[i].type_ = Le16(symbuf[14:]) numaux = int(peobj.pesym[i].aux) if numaux < 0 { numaux = 0 } } // create symbols for mapped sections for i := 0; uint(i) < peobj.nsect; i++ { sect = &peobj.sect[i] if sect.sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { continue } if sect.sh.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { // This has been seen for .idata sections, which we // want to ignore. See issues 5106 and 5273. continue } if pemap(peobj, sect) < 0 { goto bad } name = fmt.Sprintf("%s(%s)", pkg, sect.name) s = Linklookup(Ctxt, name, Ctxt.Version) switch sect.sh.Characteristics & (IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE) { case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata s.Type = obj.SRODATA case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss s.Type = obj.SNOPTRBSS case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data s.Type = obj.SNOPTRDATA case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text s.Type = obj.STEXT default: err = fmt.Errorf("unexpected flags %#06x for PE section %s", sect.sh.Characteristics, sect.name) goto bad } s.P = sect.base s.P = s.P[:sect.size] s.Size = int64(sect.size) sect.sym = s if sect.name == ".rsrc" { setpersrc(sect.sym) } } // load relocations for i := 0; uint(i) < peobj.nsect; i++ { rsect = &peobj.sect[i] if rsect.sym == nil || rsect.sh.NumberOfRelocations == 0 { continue } if rsect.sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { continue } if sect.sh.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { // This has been seen for .idata sections, which we // want to ignore. See issues 5106 and 5273. continue } r = make([]Reloc, rsect.sh.NumberOfRelocations) obj.Bseek(f, int64(peobj.base)+int64(rsect.sh.PointerToRelocations), 0) for j = 0; j < int(rsect.sh.NumberOfRelocations); j++ { rp = &r[j] if obj.Bread(f, symbuf[:10]) != 10 { goto bad } rva := Le32(symbuf[0:]) symindex := Le32(symbuf[4:]) type_ := Le16(symbuf[8:]) if err = readpesym(peobj, int(symindex), &sym); err != nil { goto bad } if sym.sym == nil { err = fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", sym.name, symindex, sym.type_) goto bad } rp.Sym = sym.sym rp.Siz = 4 rp.Off = int32(rva) switch type_ { default: Diag("%s: unknown relocation type %d;", pn, type_) fallthrough case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32, IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32 IMAGE_REL_AMD64_ADDR32NB: rp.Type = obj.R_PCREL rp.Add = int64(int32(Le32(rsect.base[rp.Off:]))) case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32: rp.Type = obj.R_ADDR // load addend from image rp.Add = int64(int32(Le32(rsect.base[rp.Off:]))) case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64 rp.Siz = 8 rp.Type = obj.R_ADDR // load addend from image rp.Add = int64(Le64(rsect.base[rp.Off:])) } // ld -r could generate multiple section symbols for the // same section but with different values, we have to take // that into account if issect(&peobj.pesym[symindex]) { rp.Add += int64(peobj.pesym[symindex].value) } } sort.Sort(rbyoff(r[:rsect.sh.NumberOfRelocations])) s = rsect.sym s.R = r s.R = s.R[:rsect.sh.NumberOfRelocations] } // enter sub-symbols into symbol table. for i := 0; uint(i) < peobj.npesym; i++ { if peobj.pesym[i].name == "" { continue } if issect(&peobj.pesym[i]) { continue } if uint(peobj.pesym[i].sectnum) > peobj.nsect { continue } if peobj.pesym[i].sectnum > 0 { sect = &peobj.sect[peobj.pesym[i].sectnum-1] if sect.sym == nil { continue } } if err = readpesym(peobj, i, &sym); err != nil { goto bad } s = sym.sym if sym.sectnum == 0 { // extern if s.Type == obj.SDYNIMPORT { s.Plt = -2 // flag for dynimport in PE object files. } if s.Type == obj.SXREF && sym.value > 0 { // global data s.Type = obj.SNOPTRDATA s.Size = int64(sym.value) } continue } else if sym.sectnum > 0 && uint(sym.sectnum) <= peobj.nsect { sect = &peobj.sect[sym.sectnum-1] if sect.sym == nil { Diag("%s: %s sym == 0!", pn, s.Name) } } else { Diag("%s: %s sectnum < 0!", pn, s.Name) } if sect == nil { return } if s.Outer != nil { if s.Dupok != 0 { continue } Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name) } s.Sub = sect.sym.Sub sect.sym.Sub = s s.Type = sect.sym.Type | obj.SSUB s.Value = int64(sym.value) s.Size = 4 s.Outer = sect.sym if sect.sym.Type == obj.STEXT { if s.External != 0 && s.Dupok == 0 { Diag("%s: duplicate definition of %s", pn, s.Name) } s.External = 1 } } // Sort outer lists by address, adding to textp. // This keeps textp in increasing address order. for i := 0; uint(i) < peobj.nsect; i++ { s = peobj.sect[i].sym if s == nil { continue } if s.Sub != nil { s.Sub = listsort(s.Sub, valuecmp, listsubp) } if s.Type == obj.STEXT { if s.Onlist != 0 { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Onlist = 1 if Ctxt.Etextp != nil { Ctxt.Etextp.Next = s } else { Ctxt.Textp = s } Ctxt.Etextp = s for s = s.Sub; s != nil; s = s.Sub { if s.Onlist != 0 { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Onlist = 1 Ctxt.Etextp.Next = s Ctxt.Etextp = s } } } return bad: Diag("%s: malformed pe file: %v", pn, err) } func pemap(peobj *PeObj, sect *PeSect) int { if sect.base != nil { return 0 } sect.base = make([]byte, sect.sh.SizeOfRawData) if sect.sh.PointerToRawData == 0 { // .bss doesn't have data in object file return 0 } if obj.Bseek(peobj.f, int64(peobj.base)+int64(sect.sh.PointerToRawData), 0) < 0 || obj.Bread(peobj.f, sect.base) != len(sect.base) { return -1 } return 0 } func issect(s *PeSym) bool { return s.sclass == IMAGE_SYM_CLASS_STATIC && s.type_ == 0 && s.name[0] == '.' } func readpesym(peobj *PeObj, i int, y **PeSym) (err error) { if uint(i) >= peobj.npesym || i < 0 { err = fmt.Errorf("invalid pe symbol index") return err } sym := &peobj.pesym[i] *y = sym var name string if issect(sym) { name = peobj.sect[sym.sectnum-1].sym.Name } else { name = sym.name if strings.HasPrefix(name, "__imp_") { name = name[6:] // __imp_Name => Name } if Thearch.Thechar == '8' && name[0] == '_' { name = name[1:] // _Name => Name } } // remove last @XXX if i := strings.LastIndex(name, "@"); i >= 0 { name = name[:i] } var s *LSym switch sym.type_ { default: err = fmt.Errorf("%s: invalid symbol type %d", sym.name, sym.type_) return err case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL: switch sym.sclass { case IMAGE_SYM_CLASS_EXTERNAL: //global s = Linklookup(Ctxt, name, 0) case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL: s = Linklookup(Ctxt, name, Ctxt.Version) s.Dupok = 1 default: err = fmt.Errorf("%s: invalid symbol binding %d", sym.name, sym.sclass) return err } } if s != nil && s.Type == 0 && (sym.sclass != IMAGE_SYM_CLASS_STATIC || sym.value != 0) { s.Type = obj.SXREF } if strings.HasPrefix(sym.name, "__imp_") { s.Got = -2 // flag for __imp_ } sym.sym = s return nil }