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. 4 5 package ld 6 7 import ( 8 "cmd/internal/bio" 9 "cmd/internal/obj" 10 "cmd/internal/sys" 11 "debug/pe" 12 "errors" 13 "fmt" 14 "io" 15 "log" 16 "sort" 17 "strings" 18 ) 19 20 const ( 21 IMAGE_SYM_UNDEFINED = 0 22 IMAGE_SYM_ABSOLUTE = -1 23 IMAGE_SYM_DEBUG = -2 24 IMAGE_SYM_TYPE_NULL = 0 25 IMAGE_SYM_TYPE_VOID = 1 26 IMAGE_SYM_TYPE_CHAR = 2 27 IMAGE_SYM_TYPE_SHORT = 3 28 IMAGE_SYM_TYPE_INT = 4 29 IMAGE_SYM_TYPE_LONG = 5 30 IMAGE_SYM_TYPE_FLOAT = 6 31 IMAGE_SYM_TYPE_DOUBLE = 7 32 IMAGE_SYM_TYPE_STRUCT = 8 33 IMAGE_SYM_TYPE_UNION = 9 34 IMAGE_SYM_TYPE_ENUM = 10 35 IMAGE_SYM_TYPE_MOE = 11 36 IMAGE_SYM_TYPE_BYTE = 12 37 IMAGE_SYM_TYPE_WORD = 13 38 IMAGE_SYM_TYPE_UINT = 14 39 IMAGE_SYM_TYPE_DWORD = 15 40 IMAGE_SYM_TYPE_PCODE = 32768 41 IMAGE_SYM_DTYPE_NULL = 0 42 IMAGE_SYM_DTYPE_POINTER = 0x10 43 IMAGE_SYM_DTYPE_FUNCTION = 0x20 44 IMAGE_SYM_DTYPE_ARRAY = 0x30 45 IMAGE_SYM_CLASS_END_OF_FUNCTION = -1 46 IMAGE_SYM_CLASS_NULL = 0 47 IMAGE_SYM_CLASS_AUTOMATIC = 1 48 IMAGE_SYM_CLASS_EXTERNAL = 2 49 IMAGE_SYM_CLASS_STATIC = 3 50 IMAGE_SYM_CLASS_REGISTER = 4 51 IMAGE_SYM_CLASS_EXTERNAL_DEF = 5 52 IMAGE_SYM_CLASS_LABEL = 6 53 IMAGE_SYM_CLASS_UNDEFINED_LABEL = 7 54 IMAGE_SYM_CLASS_MEMBER_OF_STRUCT = 8 55 IMAGE_SYM_CLASS_ARGUMENT = 9 56 IMAGE_SYM_CLASS_STRUCT_TAG = 10 57 IMAGE_SYM_CLASS_MEMBER_OF_UNION = 11 58 IMAGE_SYM_CLASS_UNION_TAG = 12 59 IMAGE_SYM_CLASS_TYPE_DEFINITION = 13 60 IMAGE_SYM_CLASS_UNDEFINED_STATIC = 14 61 IMAGE_SYM_CLASS_ENUM_TAG = 15 62 IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16 63 IMAGE_SYM_CLASS_REGISTER_PARAM = 17 64 IMAGE_SYM_CLASS_BIT_FIELD = 18 65 IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */ 66 IMAGE_SYM_CLASS_BLOCK = 100 67 IMAGE_SYM_CLASS_FUNCTION = 101 68 IMAGE_SYM_CLASS_END_OF_STRUCT = 102 69 IMAGE_SYM_CLASS_FILE = 103 70 IMAGE_SYM_CLASS_SECTION = 104 71 IMAGE_SYM_CLASS_WEAK_EXTERNAL = 105 72 IMAGE_SYM_CLASS_CLR_TOKEN = 107 73 IMAGE_REL_I386_ABSOLUTE = 0x0000 74 IMAGE_REL_I386_DIR16 = 0x0001 75 IMAGE_REL_I386_REL16 = 0x0002 76 IMAGE_REL_I386_DIR32 = 0x0006 77 IMAGE_REL_I386_DIR32NB = 0x0007 78 IMAGE_REL_I386_SEG12 = 0x0009 79 IMAGE_REL_I386_SECTION = 0x000A 80 IMAGE_REL_I386_SECREL = 0x000B 81 IMAGE_REL_I386_TOKEN = 0x000C 82 IMAGE_REL_I386_SECREL7 = 0x000D 83 IMAGE_REL_I386_REL32 = 0x0014 84 IMAGE_REL_AMD64_ABSOLUTE = 0x0000 85 IMAGE_REL_AMD64_ADDR64 = 0x0001 86 IMAGE_REL_AMD64_ADDR32 = 0x0002 87 IMAGE_REL_AMD64_ADDR32NB = 0x0003 88 IMAGE_REL_AMD64_REL32 = 0x0004 89 IMAGE_REL_AMD64_REL32_1 = 0x0005 90 IMAGE_REL_AMD64_REL32_2 = 0x0006 91 IMAGE_REL_AMD64_REL32_3 = 0x0007 92 IMAGE_REL_AMD64_REL32_4 = 0x0008 93 IMAGE_REL_AMD64_REL32_5 = 0x0009 94 IMAGE_REL_AMD64_SECTION = 0x000A 95 IMAGE_REL_AMD64_SECREL = 0x000B 96 IMAGE_REL_AMD64_SECREL7 = 0x000C 97 IMAGE_REL_AMD64_TOKEN = 0x000D 98 IMAGE_REL_AMD64_SREL32 = 0x000E 99 IMAGE_REL_AMD64_PAIR = 0x000F 100 IMAGE_REL_AMD64_SSPAN32 = 0x0010 101 ) 102 103 // TODO(brainman): maybe just add ReadAt method to bio.Reader instead of creating peBiobuf 104 105 // peBiobuf makes bio.Reader look like io.ReaderAt. 106 type peBiobuf bio.Reader 107 108 func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) { 109 ret := ((*bio.Reader)(f)).Seek(off, 0) 110 if ret < 0 { 111 return 0, errors.New("fail to seek") 112 } 113 n, err := f.Read(p) 114 if err != nil { 115 return 0, err 116 } 117 return n, nil 118 } 119 120 func ldpe(ctxt *Link, input *bio.Reader, pkg string, length int64, pn string) { 121 err := ldpeError(ctxt, input, pkg, length, pn) 122 if err != nil { 123 Errorf(nil, "%s: malformed pe file: %v", pn, err) 124 } 125 } 126 127 func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn string) error { 128 if ctxt.Debugvlog != 0 { 129 ctxt.Logf("%5.2f ldpe %s\n", obj.Cputime(), pn) 130 } 131 132 localSymVersion := ctxt.Syms.IncVersion() 133 134 sectsyms := make(map[*pe.Section]*Symbol) 135 sectdata := make(map[*pe.Section][]byte) 136 137 // Some input files are archives containing multiple of 138 // object files, and pe.NewFile seeks to the start of 139 // input file and get confused. Create section reader 140 // to stop pe.NewFile looking before current position. 141 sr := io.NewSectionReader((*peBiobuf)(input), input.Offset(), 1<<63-1) 142 143 // TODO: replace pe.NewFile with pe.Load (grep for "add Load function" in debug/pe for details) 144 f, err := pe.NewFile(sr) 145 if err != nil { 146 return err 147 } 148 defer f.Close() 149 150 // TODO return error if found .cormeta 151 152 // create symbols for mapped sections 153 for _, sect := range f.Sections { 154 if sect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { 155 continue 156 } 157 158 if sect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { 159 // This has been seen for .idata sections, which we 160 // want to ignore. See issues 5106 and 5273. 161 continue 162 } 163 164 data, err := sect.Data() 165 if err != nil { 166 return err 167 } 168 sectdata[sect] = data 169 170 name := fmt.Sprintf("%s(%s)", pkg, sect.Name) 171 s := ctxt.Syms.Lookup(name, localSymVersion) 172 173 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 175 s.Type = obj.SRODATA 176 177 case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss 178 s.Type = obj.SNOPTRBSS 179 180 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data 181 s.Type = obj.SNOPTRDATA 182 183 case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text 184 s.Type = obj.STEXT 185 186 default: 187 return fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name) 188 } 189 190 s.P = data 191 s.Size = int64(len(data)) 192 sectsyms[sect] = s 193 if sect.Name == ".rsrc" { 194 setpersrc(ctxt, s) 195 } 196 } 197 198 // load relocations 199 for _, rsect := range f.Sections { 200 if _, found := sectsyms[rsect]; !found { 201 continue 202 } 203 if rsect.NumberOfRelocations == 0 { 204 continue 205 } 206 if rsect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { 207 continue 208 } 209 if rsect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { 210 // This has been seen for .idata sections, which we 211 // want to ignore. See issues 5106 and 5273. 212 continue 213 } 214 215 rs := make([]Reloc, rsect.NumberOfRelocations) 216 for j, r := range rsect.Relocs { 217 rp := &rs[j] 218 if int(r.SymbolTableIndex) >= len(f.COFFSymbols) { 219 return fmt.Errorf("relocation number %d symbol index idx=%d cannot be large then number of symbols %d", j, r.SymbolTableIndex, len(f.COFFSymbols)) 220 } 221 pesym := &f.COFFSymbols[r.SymbolTableIndex] 222 gosym, err := readpesym(ctxt, f, pesym, sectsyms, localSymVersion) 223 if err != nil { 224 return err 225 } 226 if gosym == nil { 227 name, err := pesym.FullName(f.StringTable) 228 if err != nil { 229 name = string(pesym.Name[:]) 230 } 231 return fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type) 232 } 233 234 rp.Sym = gosym 235 rp.Siz = 4 236 rp.Off = int32(r.VirtualAddress) 237 switch r.Type { 238 default: 239 Errorf(sectsyms[rsect], "%s: unknown relocation type %d;", pn, r.Type) 240 fallthrough 241 242 case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32, 243 IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32 244 IMAGE_REL_AMD64_ADDR32NB: 245 rp.Type = obj.R_PCREL 246 247 rp.Add = int64(int32(Le32(sectdata[rsect][rp.Off:]))) 248 249 case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32: 250 rp.Type = obj.R_ADDR 251 252 // load addend from image 253 rp.Add = int64(int32(Le32(sectdata[rsect][rp.Off:]))) 254 255 case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64 256 rp.Siz = 8 257 258 rp.Type = obj.R_ADDR 259 260 // load addend from image 261 rp.Add = int64(Le64(sectdata[rsect][rp.Off:])) 262 } 263 264 // ld -r could generate multiple section symbols for the 265 // same section but with different values, we have to take 266 // that into account 267 if issect(pesym) { 268 rp.Add += int64(pesym.Value) 269 } 270 } 271 272 sort.Sort(rbyoff(rs[:rsect.NumberOfRelocations])) 273 274 s := sectsyms[rsect] 275 s.R = rs 276 s.R = s.R[:rsect.NumberOfRelocations] 277 } 278 279 // enter sub-symbols into symbol table. 280 for i, numaux := 0, 0; i < len(f.COFFSymbols); i += numaux + 1 { 281 pesym := &f.COFFSymbols[i] 282 283 numaux = int(pesym.NumberOfAuxSymbols) 284 285 name, err := pesym.FullName(f.StringTable) 286 if err != nil { 287 return err 288 } 289 if name == "" { 290 continue 291 } 292 if issect(pesym) { 293 continue 294 } 295 if int(pesym.SectionNumber) > len(f.Sections) { 296 continue 297 } 298 if pesym.SectionNumber == IMAGE_SYM_DEBUG { 299 continue 300 } 301 var sect *pe.Section 302 if pesym.SectionNumber > 0 { 303 sect = f.Sections[pesym.SectionNumber-1] 304 if _, found := sectsyms[sect]; !found { 305 continue 306 } 307 } 308 309 s, err := readpesym(ctxt, f, pesym, sectsyms, localSymVersion) 310 if err != nil { 311 return err 312 } 313 314 if pesym.SectionNumber == 0 { // extern 315 if s.Type == obj.SDYNIMPORT { 316 s.Plt = -2 // flag for dynimport in PE object files. 317 } 318 if s.Type == obj.SXREF && pesym.Value > 0 { // global data 319 s.Type = obj.SNOPTRDATA 320 s.Size = int64(pesym.Value) 321 } 322 323 continue 324 } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) { 325 sect = f.Sections[pesym.SectionNumber-1] 326 if _, found := sectsyms[sect]; !found { 327 Errorf(s, "%s: missing sect.sym", pn) 328 } 329 } else { 330 Errorf(s, "%s: sectnum < 0!", pn) 331 } 332 333 if sect == nil { 334 return nil 335 } 336 337 if s.Outer != nil { 338 if s.Attr.DuplicateOK() { 339 continue 340 } 341 Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sectsyms[sect].Name) 342 } 343 344 sectsym := sectsyms[sect] 345 s.Sub = sectsym.Sub 346 sectsym.Sub = s 347 s.Type = sectsym.Type | obj.SSUB 348 s.Value = int64(pesym.Value) 349 s.Size = 4 350 s.Outer = sectsym 351 if sectsym.Type == obj.STEXT { 352 if s.Attr.External() && !s.Attr.DuplicateOK() { 353 Errorf(s, "%s: duplicate symbol definition", pn) 354 } 355 s.Attr |= AttrExternal 356 } 357 } 358 359 // Sort outer lists by address, adding to textp. 360 // This keeps textp in increasing address order. 361 for _, sect := range f.Sections { 362 s := sectsyms[sect] 363 if s == nil { 364 continue 365 } 366 if s.Sub != nil { 367 s.Sub = listsort(s.Sub) 368 } 369 if s.Type == obj.STEXT { 370 if s.Attr.OnList() { 371 log.Fatalf("symbol %s listed multiple times", s.Name) 372 } 373 s.Attr |= AttrOnList 374 ctxt.Textp = append(ctxt.Textp, s) 375 for s = s.Sub; s != nil; s = s.Sub { 376 if s.Attr.OnList() { 377 log.Fatalf("symbol %s listed multiple times", s.Name) 378 } 379 s.Attr |= AttrOnList 380 ctxt.Textp = append(ctxt.Textp, s) 381 } 382 } 383 } 384 385 return nil 386 } 387 388 func issect(s *pe.COFFSymbol) bool { 389 return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.' 390 } 391 392 func readpesym(ctxt *Link, f *pe.File, sym *pe.COFFSymbol, sectsyms map[*pe.Section]*Symbol, localSymVersion int) (*Symbol, error) { 393 symname, err := sym.FullName(f.StringTable) 394 if err != nil { 395 return nil, err 396 } 397 var name string 398 if issect(sym) { 399 name = sectsyms[f.Sections[sym.SectionNumber-1]].Name 400 } else { 401 name = symname 402 if strings.HasPrefix(name, "__imp_") { 403 name = name[6:] // __imp_Name => Name 404 } 405 if SysArch.Family == sys.I386 && name[0] == '_' { 406 name = name[1:] // _Name => Name 407 } 408 } 409 410 // remove last @XXX 411 if i := strings.LastIndex(name, "@"); i >= 0 { 412 name = name[:i] 413 } 414 415 var s *Symbol 416 switch sym.Type { 417 default: 418 return nil, fmt.Errorf("%s: invalid symbol type %d", symname, sym.Type) 419 420 case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL: 421 switch sym.StorageClass { 422 case IMAGE_SYM_CLASS_EXTERNAL: //global 423 s = ctxt.Syms.Lookup(name, 0) 424 425 case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL: 426 s = ctxt.Syms.Lookup(name, localSymVersion) 427 s.Attr |= AttrDuplicateOK 428 429 default: 430 return nil, fmt.Errorf("%s: invalid symbol binding %d", symname, sym.StorageClass) 431 } 432 } 433 434 if s != nil && s.Type == 0 && (sym.StorageClass != IMAGE_SYM_CLASS_STATIC || sym.Value != 0) { 435 s.Type = obj.SXREF 436 } 437 if strings.HasPrefix(symname, "__imp_") { 438 s.Got = -2 // flag for __imp_ 439 } 440 441 return s, nil 442 } 443
