1 // Copyright 2010 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Package loadpe implements a PE/COFF file reader.
12 "cmd/link/internal/sym"
23 // TODO: the Microsoft doco says IMAGE_SYM_DTYPE_ARRAY is 3 (same with IMAGE_SYM_DTYPE_POINTER and IMAGE_SYM_DTYPE_FUNCTION)
24 IMAGE_SYM_UNDEFINED = 0
25 IMAGE_SYM_ABSOLUTE = -1
27 IMAGE_SYM_TYPE_NULL = 0
28 IMAGE_SYM_TYPE_VOID = 1
29 IMAGE_SYM_TYPE_CHAR = 2
30 IMAGE_SYM_TYPE_SHORT = 3
31 IMAGE_SYM_TYPE_INT = 4
32 IMAGE_SYM_TYPE_LONG = 5
33 IMAGE_SYM_TYPE_FLOAT = 6
34 IMAGE_SYM_TYPE_DOUBLE = 7
35 IMAGE_SYM_TYPE_STRUCT = 8
36 IMAGE_SYM_TYPE_UNION = 9
37 IMAGE_SYM_TYPE_ENUM = 10
38 IMAGE_SYM_TYPE_MOE = 11
39 IMAGE_SYM_TYPE_BYTE = 12
40 IMAGE_SYM_TYPE_WORD = 13
41 IMAGE_SYM_TYPE_UINT = 14
42 IMAGE_SYM_TYPE_DWORD = 15
43 IMAGE_SYM_TYPE_PCODE = 32768
44 IMAGE_SYM_DTYPE_NULL = 0
45 IMAGE_SYM_DTYPE_POINTER = 0x10
46 IMAGE_SYM_DTYPE_FUNCTION = 0x20
47 IMAGE_SYM_DTYPE_ARRAY = 0x30
48 IMAGE_SYM_CLASS_END_OF_FUNCTION = -1
49 IMAGE_SYM_CLASS_NULL = 0
50 IMAGE_SYM_CLASS_AUTOMATIC = 1
51 IMAGE_SYM_CLASS_EXTERNAL = 2
52 IMAGE_SYM_CLASS_STATIC = 3
53 IMAGE_SYM_CLASS_REGISTER = 4
54 IMAGE_SYM_CLASS_EXTERNAL_DEF = 5
55 IMAGE_SYM_CLASS_LABEL = 6
56 IMAGE_SYM_CLASS_UNDEFINED_LABEL = 7
57 IMAGE_SYM_CLASS_MEMBER_OF_STRUCT = 8
58 IMAGE_SYM_CLASS_ARGUMENT = 9
59 IMAGE_SYM_CLASS_STRUCT_TAG = 10
60 IMAGE_SYM_CLASS_MEMBER_OF_UNION = 11
61 IMAGE_SYM_CLASS_UNION_TAG = 12
62 IMAGE_SYM_CLASS_TYPE_DEFINITION = 13
63 IMAGE_SYM_CLASS_UNDEFINED_STATIC = 14
64 IMAGE_SYM_CLASS_ENUM_TAG = 15
65 IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16
66 IMAGE_SYM_CLASS_REGISTER_PARAM = 17
67 IMAGE_SYM_CLASS_BIT_FIELD = 18
68 IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */
69 IMAGE_SYM_CLASS_BLOCK = 100
70 IMAGE_SYM_CLASS_FUNCTION = 101
71 IMAGE_SYM_CLASS_END_OF_STRUCT = 102
72 IMAGE_SYM_CLASS_FILE = 103
73 IMAGE_SYM_CLASS_SECTION = 104
74 IMAGE_SYM_CLASS_WEAK_EXTERNAL = 105
75 IMAGE_SYM_CLASS_CLR_TOKEN = 107
76 IMAGE_REL_I386_ABSOLUTE = 0x0000
77 IMAGE_REL_I386_DIR16 = 0x0001
78 IMAGE_REL_I386_REL16 = 0x0002
79 IMAGE_REL_I386_DIR32 = 0x0006
80 IMAGE_REL_I386_DIR32NB = 0x0007
81 IMAGE_REL_I386_SEG12 = 0x0009
82 IMAGE_REL_I386_SECTION = 0x000A
83 IMAGE_REL_I386_SECREL = 0x000B
84 IMAGE_REL_I386_TOKEN = 0x000C
85 IMAGE_REL_I386_SECREL7 = 0x000D
86 IMAGE_REL_I386_REL32 = 0x0014
87 IMAGE_REL_AMD64_ABSOLUTE = 0x0000
88 IMAGE_REL_AMD64_ADDR64 = 0x0001
89 IMAGE_REL_AMD64_ADDR32 = 0x0002
90 IMAGE_REL_AMD64_ADDR32NB = 0x0003
91 IMAGE_REL_AMD64_REL32 = 0x0004
92 IMAGE_REL_AMD64_REL32_1 = 0x0005
93 IMAGE_REL_AMD64_REL32_2 = 0x0006
94 IMAGE_REL_AMD64_REL32_3 = 0x0007
95 IMAGE_REL_AMD64_REL32_4 = 0x0008
96 IMAGE_REL_AMD64_REL32_5 = 0x0009
97 IMAGE_REL_AMD64_SECTION = 0x000A
98 IMAGE_REL_AMD64_SECREL = 0x000B
99 IMAGE_REL_AMD64_SECREL7 = 0x000C
100 IMAGE_REL_AMD64_TOKEN = 0x000D
101 IMAGE_REL_AMD64_SREL32 = 0x000E
102 IMAGE_REL_AMD64_PAIR = 0x000F
103 IMAGE_REL_AMD64_SSPAN32 = 0x0010
106 // TODO(crawshaw): de-duplicate these symbols with cmd/internal/ld, ideally in debug/pe.
108 IMAGE_SCN_CNT_CODE = 0x00000020
109 IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040
110 IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080
111 IMAGE_SCN_MEM_DISCARDABLE = 0x02000000
112 IMAGE_SCN_MEM_EXECUTE = 0x20000000
113 IMAGE_SCN_MEM_READ = 0x40000000
114 IMAGE_SCN_MEM_WRITE = 0x80000000
117 // TODO(brainman): maybe just add ReadAt method to bio.Reader instead of creating peBiobuf
119 // peBiobuf makes bio.Reader look like io.ReaderAt.
120 type peBiobuf bio.Reader
122 func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) {
123 ret := ((*bio.Reader)(f)).Seek(off, 0)
125 return 0, errors.New("fail to seek")
134 // Load loads the PE file pn from input.
135 // Symbols are written into syms, and a slice of the text symbols is returned.
136 // If an .rsrc section is found, its symbol is returned as rsrc.
137 func Load(arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, rsrc *sym.Symbol, err error) {
138 localSymVersion := syms.IncVersion()
140 sectsyms := make(map[*pe.Section]*sym.Symbol)
141 sectdata := make(map[*pe.Section][]byte)
143 // Some input files are archives containing multiple of
144 // object files, and pe.NewFile seeks to the start of
145 // input file and get confused. Create section reader
146 // to stop pe.NewFile looking before current position.
147 sr := io.NewSectionReader((*peBiobuf)(input), input.Offset(), 1<<63-1)
149 // TODO: replace pe.NewFile with pe.Load (grep for "add Load function" in debug/pe for details)
150 f, err := pe.NewFile(sr)
156 // TODO return error if found .cormeta
158 // create symbols for mapped sections
159 for _, sect := range f.Sections {
160 if sect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
164 if sect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
165 // This has been seen for .idata sections, which we
166 // want to ignore. See issues 5106 and 5273.
170 name := fmt.Sprintf("%s(%s)", pkg, sect.Name)
171 s := syms.Lookup(name, localSymVersion)
173 switch sect.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) {
174 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata
177 case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss
178 s.Type = sym.SNOPTRBSS
180 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data
181 s.Type = sym.SNOPTRDATA
183 case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text
187 return nil, nil, fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name)
190 if s.Type != sym.SNOPTRBSS {
191 data, err := sect.Data()
195 sectdata[sect] = data
198 s.Size = int64(sect.Size)
200 if sect.Name == ".rsrc" {
206 for _, rsect := range f.Sections {
207 if _, found := sectsyms[rsect]; !found {
210 if rsect.NumberOfRelocations == 0 {
213 if rsect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
216 if rsect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
217 // This has been seen for .idata sections, which we
218 // want to ignore. See issues 5106 and 5273.
222 rs := make([]sym.Reloc, rsect.NumberOfRelocations)
223 for j, r := range rsect.Relocs {
225 if int(r.SymbolTableIndex) >= len(f.COFFSymbols) {
226 return nil, nil, fmt.Errorf("relocation number %d symbol index idx=%d cannot be large then number of symbols %d", j, r.SymbolTableIndex, len(f.COFFSymbols))
228 pesym := &f.COFFSymbols[r.SymbolTableIndex]
229 gosym, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion)
234 name, err := pesym.FullName(f.StringTable)
236 name = string(pesym.Name[:])
238 return nil, nil, fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type)
243 rp.Off = int32(r.VirtualAddress)
246 return nil, nil, fmt.Errorf("%s: %v: unknown relocation type %v", pn, sectsyms[rsect], r.Type)
248 case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32,
249 IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32
250 IMAGE_REL_AMD64_ADDR32NB:
251 rp.Type = objabi.R_PCREL
253 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
255 case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32:
256 rp.Type = objabi.R_ADDR
258 // load addend from image
259 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
261 case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64
264 rp.Type = objabi.R_ADDR
266 // load addend from image
267 rp.Add = int64(binary.LittleEndian.Uint64(sectdata[rsect][rp.Off:]))
270 // ld -r could generate multiple section symbols for the
271 // same section but with different values, we have to take
274 rp.Add += int64(pesym.Value)
278 sort.Sort(sym.RelocByOff(rs[:rsect.NumberOfRelocations]))
282 s.R = s.R[:rsect.NumberOfRelocations]
285 // enter sub-symbols into symbol table.
286 for i, numaux := 0, 0; i < len(f.COFFSymbols); i += numaux + 1 {
287 pesym := &f.COFFSymbols[i]
289 numaux = int(pesym.NumberOfAuxSymbols)
291 name, err := pesym.FullName(f.StringTable)
301 if int(pesym.SectionNumber) > len(f.Sections) {
304 if pesym.SectionNumber == IMAGE_SYM_DEBUG {
308 if pesym.SectionNumber > 0 {
309 sect = f.Sections[pesym.SectionNumber-1]
310 if _, found := sectsyms[sect]; !found {
315 s, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion)
320 if pesym.SectionNumber == 0 { // extern
321 if s.Type == sym.SDYNIMPORT {
322 s.Plt = -2 // flag for dynimport in PE object files.
324 if s.Type == sym.SXREF && pesym.Value > 0 { // global data
325 s.Type = sym.SNOPTRDATA
326 s.Size = int64(pesym.Value)
330 } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) {
331 sect = f.Sections[pesym.SectionNumber-1]
332 if _, found := sectsyms[sect]; !found {
333 return nil, nil, fmt.Errorf("%s: %v: missing sect.sym", pn, s)
336 return nil, nil, fmt.Errorf("%s: %v: sectnum < 0!", pn, s)
340 return nil, rsrc, nil
344 if s.Attr.DuplicateOK() {
347 return nil, nil, fmt.Errorf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sectsyms[sect].Name)
350 sectsym := sectsyms[sect]
353 s.Type = sectsym.Type
354 s.Attr |= sym.AttrSubSymbol
355 s.Value = int64(pesym.Value)
358 if sectsym.Type == sym.STEXT {
359 if s.Attr.External() && !s.Attr.DuplicateOK() {
360 return nil, nil, fmt.Errorf("%s: duplicate symbol definition", s.Name)
362 s.Attr |= sym.AttrExternal
366 // Sort outer lists by address, adding to textp.
367 // This keeps textp in increasing address order.
368 for _, sect := range f.Sections {
374 s.Sub = sym.SortSub(s.Sub)
376 if s.Type == sym.STEXT {
378 return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name)
380 s.Attr |= sym.AttrOnList
381 textp = append(textp, s)
382 for s = s.Sub; s != nil; s = s.Sub {
384 return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name)
386 s.Attr |= sym.AttrOnList
387 textp = append(textp, s)
392 return textp, rsrc, nil
395 func issect(s *pe.COFFSymbol) bool {
396 return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.'
399 func readpesym(arch *sys.Arch, syms *sym.Symbols, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Section]*sym.Symbol, localSymVersion int) (*sym.Symbol, error) {
400 symname, err := pesym.FullName(f.StringTable)
406 name = sectsyms[f.Sections[pesym.SectionNumber-1]].Name
409 name = strings.TrimPrefix(name, "__imp_") // __imp_Name => Name
410 if arch.Family == sys.I386 && name[0] == '_' {
411 name = name[1:] // _Name => Name
416 if i := strings.LastIndex(name, "@"); i >= 0 {
423 return nil, fmt.Errorf("%s: invalid symbol type %d", symname, pesym.Type)
425 case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL:
426 switch pesym.StorageClass {
427 case IMAGE_SYM_CLASS_EXTERNAL: //global
428 s = syms.Lookup(name, 0)
430 case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL:
431 s = syms.Lookup(name, localSymVersion)
432 s.Attr |= sym.AttrDuplicateOK
435 return nil, fmt.Errorf("%s: invalid symbol binding %d", symname, pesym.StorageClass)
439 if s != nil && s.Type == 0 && (pesym.StorageClass != IMAGE_SYM_CLASS_STATIC || pesym.Value != 0) {
442 if strings.HasPrefix(symname, "__imp_") {
443 s.Got = -2 // flag for __imp_