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.
13 "cmd/link/internal/loader"
14 "cmd/link/internal/sym"
24 // TODO: the Microsoft doco says IMAGE_SYM_DTYPE_ARRAY is 3 (same with IMAGE_SYM_DTYPE_POINTER and IMAGE_SYM_DTYPE_FUNCTION)
25 IMAGE_SYM_UNDEFINED = 0
26 IMAGE_SYM_ABSOLUTE = -1
28 IMAGE_SYM_TYPE_NULL = 0
29 IMAGE_SYM_TYPE_VOID = 1
30 IMAGE_SYM_TYPE_CHAR = 2
31 IMAGE_SYM_TYPE_SHORT = 3
32 IMAGE_SYM_TYPE_INT = 4
33 IMAGE_SYM_TYPE_LONG = 5
34 IMAGE_SYM_TYPE_FLOAT = 6
35 IMAGE_SYM_TYPE_DOUBLE = 7
36 IMAGE_SYM_TYPE_STRUCT = 8
37 IMAGE_SYM_TYPE_UNION = 9
38 IMAGE_SYM_TYPE_ENUM = 10
39 IMAGE_SYM_TYPE_MOE = 11
40 IMAGE_SYM_TYPE_BYTE = 12
41 IMAGE_SYM_TYPE_WORD = 13
42 IMAGE_SYM_TYPE_UINT = 14
43 IMAGE_SYM_TYPE_DWORD = 15
44 IMAGE_SYM_TYPE_PCODE = 32768
45 IMAGE_SYM_DTYPE_NULL = 0
46 IMAGE_SYM_DTYPE_POINTER = 0x10
47 IMAGE_SYM_DTYPE_FUNCTION = 0x20
48 IMAGE_SYM_DTYPE_ARRAY = 0x30
49 IMAGE_SYM_CLASS_END_OF_FUNCTION = -1
50 IMAGE_SYM_CLASS_NULL = 0
51 IMAGE_SYM_CLASS_AUTOMATIC = 1
52 IMAGE_SYM_CLASS_EXTERNAL = 2
53 IMAGE_SYM_CLASS_STATIC = 3
54 IMAGE_SYM_CLASS_REGISTER = 4
55 IMAGE_SYM_CLASS_EXTERNAL_DEF = 5
56 IMAGE_SYM_CLASS_LABEL = 6
57 IMAGE_SYM_CLASS_UNDEFINED_LABEL = 7
58 IMAGE_SYM_CLASS_MEMBER_OF_STRUCT = 8
59 IMAGE_SYM_CLASS_ARGUMENT = 9
60 IMAGE_SYM_CLASS_STRUCT_TAG = 10
61 IMAGE_SYM_CLASS_MEMBER_OF_UNION = 11
62 IMAGE_SYM_CLASS_UNION_TAG = 12
63 IMAGE_SYM_CLASS_TYPE_DEFINITION = 13
64 IMAGE_SYM_CLASS_UNDEFINED_STATIC = 14
65 IMAGE_SYM_CLASS_ENUM_TAG = 15
66 IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16
67 IMAGE_SYM_CLASS_REGISTER_PARAM = 17
68 IMAGE_SYM_CLASS_BIT_FIELD = 18
69 IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */
70 IMAGE_SYM_CLASS_BLOCK = 100
71 IMAGE_SYM_CLASS_FUNCTION = 101
72 IMAGE_SYM_CLASS_END_OF_STRUCT = 102
73 IMAGE_SYM_CLASS_FILE = 103
74 IMAGE_SYM_CLASS_SECTION = 104
75 IMAGE_SYM_CLASS_WEAK_EXTERNAL = 105
76 IMAGE_SYM_CLASS_CLR_TOKEN = 107
77 IMAGE_REL_I386_ABSOLUTE = 0x0000
78 IMAGE_REL_I386_DIR16 = 0x0001
79 IMAGE_REL_I386_REL16 = 0x0002
80 IMAGE_REL_I386_DIR32 = 0x0006
81 IMAGE_REL_I386_DIR32NB = 0x0007
82 IMAGE_REL_I386_SEG12 = 0x0009
83 IMAGE_REL_I386_SECTION = 0x000A
84 IMAGE_REL_I386_SECREL = 0x000B
85 IMAGE_REL_I386_TOKEN = 0x000C
86 IMAGE_REL_I386_SECREL7 = 0x000D
87 IMAGE_REL_I386_REL32 = 0x0014
88 IMAGE_REL_AMD64_ABSOLUTE = 0x0000
89 IMAGE_REL_AMD64_ADDR64 = 0x0001
90 IMAGE_REL_AMD64_ADDR32 = 0x0002
91 IMAGE_REL_AMD64_ADDR32NB = 0x0003
92 IMAGE_REL_AMD64_REL32 = 0x0004
93 IMAGE_REL_AMD64_REL32_1 = 0x0005
94 IMAGE_REL_AMD64_REL32_2 = 0x0006
95 IMAGE_REL_AMD64_REL32_3 = 0x0007
96 IMAGE_REL_AMD64_REL32_4 = 0x0008
97 IMAGE_REL_AMD64_REL32_5 = 0x0009
98 IMAGE_REL_AMD64_SECTION = 0x000A
99 IMAGE_REL_AMD64_SECREL = 0x000B
100 IMAGE_REL_AMD64_SECREL7 = 0x000C
101 IMAGE_REL_AMD64_TOKEN = 0x000D
102 IMAGE_REL_AMD64_SREL32 = 0x000E
103 IMAGE_REL_AMD64_PAIR = 0x000F
104 IMAGE_REL_AMD64_SSPAN32 = 0x0010
105 IMAGE_REL_ARM_ABSOLUTE = 0x0000
106 IMAGE_REL_ARM_ADDR32 = 0x0001
107 IMAGE_REL_ARM_ADDR32NB = 0x0002
108 IMAGE_REL_ARM_BRANCH24 = 0x0003
109 IMAGE_REL_ARM_BRANCH11 = 0x0004
110 IMAGE_REL_ARM_SECTION = 0x000E
111 IMAGE_REL_ARM_SECREL = 0x000F
112 IMAGE_REL_ARM_MOV32 = 0x0010
113 IMAGE_REL_THUMB_MOV32 = 0x0011
114 IMAGE_REL_THUMB_BRANCH20 = 0x0012
115 IMAGE_REL_THUMB_BRANCH24 = 0x0014
116 IMAGE_REL_THUMB_BLX23 = 0x0015
117 IMAGE_REL_ARM_PAIR = 0x0016
118 IMAGE_REL_ARM64_ABSOLUTE = 0x0000
119 IMAGE_REL_ARM64_ADDR32 = 0x0001
120 IMAGE_REL_ARM64_ADDR32NB = 0x0002
121 IMAGE_REL_ARM64_BRANCH26 = 0x0003
122 IMAGE_REL_ARM64_PAGEBASE_REL21 = 0x0004
123 IMAGE_REL_ARM64_REL21 = 0x0005
124 IMAGE_REL_ARM64_PAGEOFFSET_12A = 0x0006
125 IMAGE_REL_ARM64_PAGEOFFSET_12L = 0x0007
126 IMAGE_REL_ARM64_SECREL = 0x0008
127 IMAGE_REL_ARM64_SECREL_LOW12A = 0x0009
128 IMAGE_REL_ARM64_SECREL_HIGH12A = 0x000A
129 IMAGE_REL_ARM64_SECREL_LOW12L = 0x000B
130 IMAGE_REL_ARM64_TOKEN = 0x000C
131 IMAGE_REL_ARM64_SECTION = 0x000D
132 IMAGE_REL_ARM64_ADDR64 = 0x000E
133 IMAGE_REL_ARM64_BRANCH19 = 0x000F
134 IMAGE_REL_ARM64_BRANCH14 = 0x0010
135 IMAGE_REL_ARM64_REL32 = 0x0011
138 // TODO(crawshaw): de-duplicate these symbols with cmd/internal/ld, ideally in debug/pe.
140 IMAGE_SCN_CNT_CODE = 0x00000020
141 IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040
142 IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080
143 IMAGE_SCN_MEM_DISCARDABLE = 0x02000000
144 IMAGE_SCN_MEM_EXECUTE = 0x20000000
145 IMAGE_SCN_MEM_READ = 0x40000000
146 IMAGE_SCN_MEM_WRITE = 0x80000000
149 // TODO(brainman): maybe just add ReadAt method to bio.Reader instead of creating peBiobuf
151 // peBiobuf makes bio.Reader look like io.ReaderAt.
152 type peBiobuf bio.Reader
154 func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) {
155 ret := ((*bio.Reader)(f)).MustSeek(off, 0)
157 return 0, errors.New("fail to seek")
166 // makeUpdater creates a loader.SymbolBuilder if one hasn't been created previously.
167 // We use this to lazily make SymbolBuilders as we don't always need a builder, and creating them for all symbols might be an error.
168 func makeUpdater(l *loader.Loader, bld *loader.SymbolBuilder, s loader.Sym) *loader.SymbolBuilder {
172 bld = l.MakeSymbolUpdater(s)
176 // peLoaderState holds various bits of useful state information needed
177 // while loading a PE object file.
178 type peLoaderState struct {
182 sectsyms map[*pe.Section]loader.Sym
183 sectdata map[*pe.Section][]byte
187 // Load loads the PE file pn from input.
188 // Symbols are written into syms, and a slice of the text symbols is returned.
189 // If an .rsrc section or set of .rsrc$xx sections is found, its symbols are
191 func Load(l *loader.Loader, arch *sys.Arch, localSymVersion int, input *bio.Reader, pkg string, length int64, pn string) (textp []loader.Sym, rsrc []loader.Sym, err error) {
192 state := &peLoaderState{
195 sectsyms: make(map[*pe.Section]loader.Sym),
196 sectdata: make(map[*pe.Section][]byte),
197 localSymVersion: localSymVersion,
200 // Some input files are archives containing multiple of
201 // object files, and pe.NewFile seeks to the start of
202 // input file and get confused. Create section reader
203 // to stop pe.NewFile looking before current position.
204 sr := io.NewSectionReader((*peBiobuf)(input), input.Offset(), 1<<63-1)
206 // TODO: replace pe.NewFile with pe.Load (grep for "add Load function" in debug/pe for details)
207 f, err := pe.NewFile(sr)
214 // TODO return error if found .cormeta
216 // create symbols for mapped sections
217 for _, sect := range f.Sections {
218 if sect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
222 if sect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
223 // This has been seen for .idata sections, which we
224 // want to ignore. See issues 5106 and 5273.
228 name := fmt.Sprintf("%s(%s)", pkg, sect.Name)
229 s := state.l.LookupOrCreateCgoExport(name, localSymVersion)
230 bld := l.MakeSymbolUpdater(s)
232 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) {
233 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata
234 bld.SetType(sym.SRODATA)
236 case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss
237 bld.SetType(sym.SNOPTRBSS)
239 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data
240 bld.SetType(sym.SNOPTRDATA)
242 case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text
243 bld.SetType(sym.STEXT)
246 return nil, nil, fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name)
249 if bld.Type() != sym.SNOPTRBSS {
250 data, err := sect.Data()
254 state.sectdata[sect] = data
257 bld.SetSize(int64(sect.Size))
258 state.sectsyms[sect] = s
259 if sect.Name == ".rsrc" || strings.HasPrefix(sect.Name, ".rsrc$") {
260 rsrc = append(rsrc, s)
265 for _, rsect := range f.Sections {
266 if _, found := state.sectsyms[rsect]; !found {
269 if rsect.NumberOfRelocations == 0 {
272 if rsect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
275 if rsect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
276 // This has been seen for .idata sections, which we
277 // want to ignore. See issues 5106 and 5273.
281 splitResources := strings.HasPrefix(rsect.Name, ".rsrc$")
282 sb := l.MakeSymbolUpdater(state.sectsyms[rsect])
283 for j, r := range rsect.Relocs {
284 if int(r.SymbolTableIndex) >= len(f.COFFSymbols) {
285 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))
287 pesym := &f.COFFSymbols[r.SymbolTableIndex]
288 _, gosym, err := state.readpesym(pesym)
293 name, err := pesym.FullName(f.StringTable)
295 name = string(pesym.Name[:])
297 return nil, nil, fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type)
302 rOff := int32(r.VirtualAddress)
304 var rType objabi.RelocType
307 return nil, nil, fmt.Errorf("%s: unsupported arch %v", pn, arch.Family)
308 case sys.I386, sys.AMD64:
311 return nil, nil, fmt.Errorf("%s: %v: unknown relocation type %v", pn, state.sectsyms[rsect], r.Type)
313 case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32,
314 IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32
315 IMAGE_REL_AMD64_ADDR32NB:
316 rType = objabi.R_PCREL
318 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
320 case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32:
321 rType = objabi.R_ADDR
323 // load addend from image
324 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
326 case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64
329 rType = objabi.R_ADDR
331 // load addend from image
332 rAdd = int64(binary.LittleEndian.Uint64(state.sectdata[rsect][rOff:]))
338 return nil, nil, fmt.Errorf("%s: %v: unknown ARM relocation type %v", pn, state.sectsyms[rsect], r.Type)
340 case IMAGE_REL_ARM_SECREL:
341 rType = objabi.R_PCREL
343 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
345 case IMAGE_REL_ARM_ADDR32, IMAGE_REL_ARM_ADDR32NB:
346 rType = objabi.R_ADDR
348 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
350 case IMAGE_REL_ARM_BRANCH24:
351 rType = objabi.R_CALLARM
353 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
359 return nil, nil, fmt.Errorf("%s: %v: unknown ARM64 relocation type %v", pn, state.sectsyms[rsect], r.Type)
361 case IMAGE_REL_ARM64_ADDR32, IMAGE_REL_ARM64_ADDR32NB:
362 rType = objabi.R_ADDR
364 rAdd = int64(int32(binary.LittleEndian.Uint32(state.sectdata[rsect][rOff:])))
368 // ld -r could generate multiple section symbols for the
369 // same section but with different values, we have to take
370 // that into account, or in the case of split resources,
371 // the section and its symbols are split into two sections.
372 if issect(pesym) || splitResources {
373 rAdd += int64(pesym.Value)
376 rel, _ := sb.AddRel(rType)
386 // enter sub-symbols into symbol table.
387 for i, numaux := 0, 0; i < len(f.COFFSymbols); i += numaux + 1 {
388 pesym := &f.COFFSymbols[i]
390 numaux = int(pesym.NumberOfAuxSymbols)
392 name, err := pesym.FullName(f.StringTable)
402 if int(pesym.SectionNumber) > len(f.Sections) {
405 if pesym.SectionNumber == IMAGE_SYM_DEBUG {
408 if pesym.SectionNumber == IMAGE_SYM_ABSOLUTE && bytes.Equal(pesym.Name[:], []byte("@feat.00")) {
409 // Microsoft's linker looks at whether all input objects have an empty
410 // section called @feat.00. If all of them do, then it enables SEH;
411 // otherwise it doesn't enable that feature. So, since around the Windows
412 // XP SP2 era, most tools that make PE objects just tack on that section,
413 // so that it won't gimp Microsoft's linker logic. Go doesn't support SEH,
414 // so in theory, none of this really matters to us. But actually, if the
415 // linker tries to ingest an object with @feat.00 -- which are produced by
416 // LLVM's resource compiler, for example -- it chokes because of the
417 // IMAGE_SYM_ABSOLUTE section that it doesn't know how to deal with. Since
418 // @feat.00 is just a marking anyway, skip IMAGE_SYM_ABSOLUTE sections that
419 // are called @feat.00.
423 if pesym.SectionNumber > 0 {
424 sect = f.Sections[pesym.SectionNumber-1]
425 if _, found := state.sectsyms[sect]; !found {
430 bld, s, err := state.readpesym(pesym)
435 if pesym.SectionNumber == 0 { // extern
436 if l.SymType(s) == sym.SDYNIMPORT {
437 bld = makeUpdater(l, bld, s)
438 bld.SetPlt(-2) // flag for dynimport in PE object files.
440 if l.SymType(s) == sym.SXREF && pesym.Value > 0 { // global data
441 bld = makeUpdater(l, bld, s)
442 bld.SetType(sym.SNOPTRDATA)
443 bld.SetSize(int64(pesym.Value))
447 } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) {
448 sect = f.Sections[pesym.SectionNumber-1]
449 if _, found := state.sectsyms[sect]; !found {
450 return nil, nil, fmt.Errorf("%s: %v: missing sect.sym", pn, s)
453 return nil, nil, fmt.Errorf("%s: %v: sectnum < 0!", pn, s)
460 if l.OuterSym(s) != 0 {
461 if l.AttrDuplicateOK(s) {
464 outerName := l.SymName(l.OuterSym(s))
465 sectName := l.SymName(state.sectsyms[sect])
466 return nil, nil, fmt.Errorf("%s: duplicate symbol reference: %s in both %s and %s", pn, l.SymName(s), outerName, sectName)
469 bld = makeUpdater(l, bld, s)
470 sectsym := state.sectsyms[sect]
471 bld.SetType(l.SymType(sectsym))
472 l.AddInteriorSym(sectsym, s)
473 bld.SetValue(int64(pesym.Value))
475 if l.SymType(sectsym) == sym.STEXT {
476 if bld.External() && !bld.DuplicateOK() {
477 return nil, nil, fmt.Errorf("%s: duplicate symbol definition", l.SymName(s))
479 bld.SetExternal(true)
483 // Sort outer lists by address, adding to textp.
484 // This keeps textp in increasing address order.
485 for _, sect := range f.Sections {
486 s := state.sectsyms[sect]
491 if l.SymType(s) == sym.STEXT {
492 for ; s != 0; s = l.SubSym(s) {
494 return nil, nil, fmt.Errorf("symbol %s listed multiple times", l.SymName(s))
496 l.SetAttrOnList(s, true)
497 textp = append(textp, s)
502 return textp, rsrc, nil
505 func issect(s *pe.COFFSymbol) bool {
506 return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.'
509 func (state *peLoaderState) readpesym(pesym *pe.COFFSymbol) (*loader.SymbolBuilder, loader.Sym, error) {
510 symname, err := pesym.FullName(state.f.StringTable)
516 name = state.l.SymName(state.sectsyms[state.f.Sections[pesym.SectionNumber-1]])
519 switch state.arch.Family {
521 if name == "__imp___acrt_iob_func" {
522 // Do not rename __imp___acrt_iob_func into __acrt_iob_func,
523 // because __imp___acrt_iob_func symbol is real
524 // (see commit b295099 from git://git.code.sf.net/p/mingw-w64/mingw-w64 for details).
526 name = strings.TrimPrefix(name, "__imp_") // __imp_Name => Name
529 if name == "__imp____acrt_iob_func" {
530 // Do not rename __imp____acrt_iob_func into ___acrt_iob_func,
531 // because __imp____acrt_iob_func symbol is real
532 // (see commit b295099 from git://git.code.sf.net/p/mingw-w64/mingw-w64 for details).
534 name = strings.TrimPrefix(name, "__imp_") // __imp_Name => Name
537 name = name[1:] // _Name => Name
543 if i := strings.LastIndex(name, "@"); i >= 0 {
548 var bld *loader.SymbolBuilder
551 return nil, 0, fmt.Errorf("%s: invalid symbol type %d", symname, pesym.Type)
553 case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL:
554 switch pesym.StorageClass {
555 case IMAGE_SYM_CLASS_EXTERNAL: //global
556 s = state.l.LookupOrCreateCgoExport(name, 0)
558 case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL:
559 s = state.l.LookupOrCreateCgoExport(name, state.localSymVersion)
560 bld = makeUpdater(state.l, bld, s)
561 bld.SetDuplicateOK(true)
564 return nil, 0, fmt.Errorf("%s: invalid symbol binding %d", symname, pesym.StorageClass)
568 if s != 0 && state.l.SymType(s) == 0 && (pesym.StorageClass != IMAGE_SYM_CLASS_STATIC || pesym.Value != 0) {
569 bld = makeUpdater(state.l, bld, s)
570 bld.SetType(sym.SXREF)
572 if strings.HasPrefix(symname, "__imp_") {
573 bld = makeUpdater(state.l, bld, s)
574 bld.SetGot(-2) // flag for __imp_