Source file src/pkg/cmd/link/internal/loadpe/ldpe.go
1
2
3
4
5
6 package loadpe
7
8 import (
9 "cmd/internal/bio"
10 "cmd/internal/objabi"
11 "cmd/internal/sys"
12 "cmd/link/internal/sym"
13 "debug/pe"
14 "encoding/binary"
15 "errors"
16 "fmt"
17 "io"
18 "sort"
19 "strings"
20 )
21
22 const (
23
24 IMAGE_SYM_UNDEFINED = 0
25 IMAGE_SYM_ABSOLUTE = -1
26 IMAGE_SYM_DEBUG = -2
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
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
104 IMAGE_REL_ARM_ABSOLUTE = 0x0000
105 IMAGE_REL_ARM_ADDR32 = 0x0001
106 IMAGE_REL_ARM_ADDR32NB = 0x0002
107 IMAGE_REL_ARM_BRANCH24 = 0x0003
108 IMAGE_REL_ARM_BRANCH11 = 0x0004
109 IMAGE_REL_ARM_SECTION = 0x000E
110 IMAGE_REL_ARM_SECREL = 0x000F
111 IMAGE_REL_ARM_MOV32 = 0x0010
112 IMAGE_REL_THUMB_MOV32 = 0x0011
113 IMAGE_REL_THUMB_BRANCH20 = 0x0012
114 IMAGE_REL_THUMB_BRANCH24 = 0x0014
115 IMAGE_REL_THUMB_BLX23 = 0x0015
116 IMAGE_REL_ARM_PAIR = 0x0016
117 )
118
119
120 const (
121 IMAGE_SCN_CNT_CODE = 0x00000020
122 IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040
123 IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080
124 IMAGE_SCN_MEM_DISCARDABLE = 0x02000000
125 IMAGE_SCN_MEM_EXECUTE = 0x20000000
126 IMAGE_SCN_MEM_READ = 0x40000000
127 IMAGE_SCN_MEM_WRITE = 0x80000000
128 )
129
130
131
132
133 type peBiobuf bio.Reader
134
135 func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) {
136 ret := ((*bio.Reader)(f)).MustSeek(off, 0)
137 if ret < 0 {
138 return 0, errors.New("fail to seek")
139 }
140 n, err := f.Read(p)
141 if err != nil {
142 return 0, err
143 }
144 return n, nil
145 }
146
147
148
149
150 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) {
151 localSymVersion := syms.IncVersion()
152
153 sectsyms := make(map[*pe.Section]*sym.Symbol)
154 sectdata := make(map[*pe.Section][]byte)
155
156
157
158
159
160 sr := io.NewSectionReader((*peBiobuf)(input), input.Offset(), 1<<63-1)
161
162
163 f, err := pe.NewFile(sr)
164 if err != nil {
165 return nil, nil, err
166 }
167 defer f.Close()
168
169
170
171
172 for _, sect := range f.Sections {
173 if sect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
174 continue
175 }
176
177 if sect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
178
179
180 continue
181 }
182
183 name := fmt.Sprintf("%s(%s)", pkg, sect.Name)
184 s := syms.Lookup(name, localSymVersion)
185
186 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) {
187 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ:
188 s.Type = sym.SRODATA
189
190 case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE:
191 s.Type = sym.SNOPTRBSS
192
193 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE:
194 s.Type = sym.SNOPTRDATA
195
196 case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ:
197 s.Type = sym.STEXT
198
199 default:
200 return nil, nil, fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name)
201 }
202
203 if s.Type != sym.SNOPTRBSS {
204 data, err := sect.Data()
205 if err != nil {
206 return nil, nil, err
207 }
208 sectdata[sect] = data
209 s.P = data
210 }
211 s.Size = int64(sect.Size)
212 sectsyms[sect] = s
213 if sect.Name == ".rsrc" {
214 rsrc = s
215 }
216 }
217
218
219 for _, rsect := range f.Sections {
220 if _, found := sectsyms[rsect]; !found {
221 continue
222 }
223 if rsect.NumberOfRelocations == 0 {
224 continue
225 }
226 if rsect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 {
227 continue
228 }
229 if rsect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 {
230
231
232 continue
233 }
234
235 rs := make([]sym.Reloc, rsect.NumberOfRelocations)
236 for j, r := range rsect.Relocs {
237 rp := &rs[j]
238 if int(r.SymbolTableIndex) >= len(f.COFFSymbols) {
239 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))
240 }
241 pesym := &f.COFFSymbols[r.SymbolTableIndex]
242 gosym, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion)
243 if err != nil {
244 return nil, nil, err
245 }
246 if gosym == nil {
247 name, err := pesym.FullName(f.StringTable)
248 if err != nil {
249 name = string(pesym.Name[:])
250 }
251 return nil, nil, fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type)
252 }
253
254 rp.Sym = gosym
255 rp.Siz = 4
256 rp.Off = int32(r.VirtualAddress)
257 switch arch.Family {
258 default:
259 return nil, nil, fmt.Errorf("%s: unsupported arch %v", pn, arch.Family)
260 case sys.I386, sys.AMD64:
261 switch r.Type {
262 default:
263 return nil, nil, fmt.Errorf("%s: %v: unknown relocation type %v", pn, sectsyms[rsect], r.Type)
264
265 case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32,
266 IMAGE_REL_AMD64_ADDR32,
267 IMAGE_REL_AMD64_ADDR32NB:
268 rp.Type = objabi.R_PCREL
269
270 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
271
272 case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32:
273 rp.Type = objabi.R_ADDR
274
275
276 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
277
278 case IMAGE_REL_AMD64_ADDR64:
279 rp.Siz = 8
280
281 rp.Type = objabi.R_ADDR
282
283
284 rp.Add = int64(binary.LittleEndian.Uint64(sectdata[rsect][rp.Off:]))
285 }
286
287 case sys.ARM:
288 switch r.Type {
289 default:
290 return nil, nil, fmt.Errorf("%s: %v: unknown ARM relocation type %v", pn, sectsyms[rsect], r.Type)
291
292 case IMAGE_REL_ARM_SECREL:
293 rp.Type = objabi.R_PCREL
294
295 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
296
297 case IMAGE_REL_ARM_ADDR32:
298 rp.Type = objabi.R_ADDR
299
300 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
301
302 case IMAGE_REL_ARM_BRANCH24:
303 rp.Type = objabi.R_CALLARM
304
305 rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:])))
306 }
307 }
308
309
310
311
312 if issect(pesym) {
313 rp.Add += int64(pesym.Value)
314 }
315 }
316
317 sort.Sort(sym.RelocByOff(rs[:rsect.NumberOfRelocations]))
318
319 s := sectsyms[rsect]
320 s.R = rs
321 s.R = s.R[:rsect.NumberOfRelocations]
322 }
323
324
325 for i, numaux := 0, 0; i < len(f.COFFSymbols); i += numaux + 1 {
326 pesym := &f.COFFSymbols[i]
327
328 numaux = int(pesym.NumberOfAuxSymbols)
329
330 name, err := pesym.FullName(f.StringTable)
331 if err != nil {
332 return nil, nil, err
333 }
334 if name == "" {
335 continue
336 }
337 if issect(pesym) {
338 continue
339 }
340 if int(pesym.SectionNumber) > len(f.Sections) {
341 continue
342 }
343 if pesym.SectionNumber == IMAGE_SYM_DEBUG {
344 continue
345 }
346 var sect *pe.Section
347 if pesym.SectionNumber > 0 {
348 sect = f.Sections[pesym.SectionNumber-1]
349 if _, found := sectsyms[sect]; !found {
350 continue
351 }
352 }
353
354 s, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion)
355 if err != nil {
356 return nil, nil, err
357 }
358
359 if pesym.SectionNumber == 0 {
360 if s.Type == sym.SDYNIMPORT {
361 s.SetPlt(-2)
362 }
363 if s.Type == sym.SXREF && pesym.Value > 0 {
364 s.Type = sym.SNOPTRDATA
365 s.Size = int64(pesym.Value)
366 }
367
368 continue
369 } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) {
370 sect = f.Sections[pesym.SectionNumber-1]
371 if _, found := sectsyms[sect]; !found {
372 return nil, nil, fmt.Errorf("%s: %v: missing sect.sym", pn, s)
373 }
374 } else {
375 return nil, nil, fmt.Errorf("%s: %v: sectnum < 0!", pn, s)
376 }
377
378 if sect == nil {
379 return nil, rsrc, nil
380 }
381
382 if s.Outer != nil {
383 if s.Attr.DuplicateOK() {
384 continue
385 }
386 return nil, nil, fmt.Errorf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sectsyms[sect].Name)
387 }
388
389 sectsym := sectsyms[sect]
390 s.Sub = sectsym.Sub
391 sectsym.Sub = s
392 s.Type = sectsym.Type
393 s.Attr |= sym.AttrSubSymbol
394 s.Value = int64(pesym.Value)
395 s.Size = 4
396 s.Outer = sectsym
397 if sectsym.Type == sym.STEXT {
398 if s.Attr.External() && !s.Attr.DuplicateOK() {
399 return nil, nil, fmt.Errorf("%s: duplicate symbol definition", s.Name)
400 }
401 s.Attr |= sym.AttrExternal
402 }
403 }
404
405
406
407 for _, sect := range f.Sections {
408 s := sectsyms[sect]
409 if s == nil {
410 continue
411 }
412 if s.Sub != nil {
413 s.Sub = sym.SortSub(s.Sub)
414 }
415 if s.Type == sym.STEXT {
416 if s.Attr.OnList() {
417 return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name)
418 }
419 s.Attr |= sym.AttrOnList
420 textp = append(textp, s)
421 for s = s.Sub; s != nil; s = s.Sub {
422 if s.Attr.OnList() {
423 return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name)
424 }
425 s.Attr |= sym.AttrOnList
426 textp = append(textp, s)
427 }
428 }
429 }
430
431 return textp, rsrc, nil
432 }
433
434 func issect(s *pe.COFFSymbol) bool {
435 return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.'
436 }
437
438 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) {
439 symname, err := pesym.FullName(f.StringTable)
440 if err != nil {
441 return nil, err
442 }
443 var name string
444 if issect(pesym) {
445 name = sectsyms[f.Sections[pesym.SectionNumber-1]].Name
446 } else {
447 name = symname
448 name = strings.TrimPrefix(name, "__imp_")
449 if arch.Family == sys.I386 && name[0] == '_' {
450 name = name[1:]
451 }
452 }
453
454
455 if i := strings.LastIndex(name, "@"); i >= 0 {
456 name = name[:i]
457 }
458
459 var s *sym.Symbol
460 switch pesym.Type {
461 default:
462 return nil, fmt.Errorf("%s: invalid symbol type %d", symname, pesym.Type)
463
464 case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL:
465 switch pesym.StorageClass {
466 case IMAGE_SYM_CLASS_EXTERNAL:
467 s = syms.Lookup(name, 0)
468
469 case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL:
470 s = syms.Lookup(name, localSymVersion)
471 s.Attr |= sym.AttrDuplicateOK
472
473 default:
474 return nil, fmt.Errorf("%s: invalid symbol binding %d", symname, pesym.StorageClass)
475 }
476 }
477
478 if s != nil && s.Type == 0 && (pesym.StorageClass != IMAGE_SYM_CLASS_STATIC || pesym.Value != 0) {
479 s.Type = sym.SXREF
480 }
481 if strings.HasPrefix(symname, "__imp_") {
482 s.SetGot(-2)
483 }
484
485 return s, nil
486 }
487
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