File size: 4,662 Bytes
d7a5f2f | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 | // Copyright 2013 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.
// Parsing of PE executables (Microsoft Windows).
package objfile
import (
"debug/dwarf"
"debug/pe"
"fmt"
"io"
"slices"
"sort"
)
type peFile struct {
pe *pe.File
}
func openPE(r io.ReaderAt) (rawFile, error) {
f, err := pe.NewFile(r)
if err != nil {
return nil, err
}
return &peFile{f}, nil
}
func (f *peFile) symbols() ([]Sym, error) {
// Build sorted list of addresses of all symbols.
// We infer the size of a symbol by looking at where the next symbol begins.
var addrs []uint64
imageBase, _ := f.imageBase()
var syms []Sym
for _, s := range f.pe.Symbols {
const (
N_UNDEF = 0 // An undefined (extern) symbol
N_ABS = -1 // An absolute symbol (e_value is a constant, not an address)
N_DEBUG = -2 // A debugging symbol
)
sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'}
switch s.SectionNumber {
case N_UNDEF:
sym.Code = 'U'
case N_ABS:
sym.Code = 'C'
case N_DEBUG:
sym.Code = '?'
default:
if s.SectionNumber < 0 || len(f.pe.Sections) < int(s.SectionNumber) {
return nil, fmt.Errorf("invalid section number in symbol table")
}
sect := f.pe.Sections[s.SectionNumber-1]
const (
text = 0x20
data = 0x40
bss = 0x80
permW = 0x80000000
)
ch := sect.Characteristics
switch {
case ch&text != 0:
sym.Code = 'T'
case ch&data != 0:
if ch&permW == 0 {
sym.Code = 'R'
} else {
sym.Code = 'D'
}
case ch&bss != 0:
sym.Code = 'B'
}
sym.Addr += imageBase + uint64(sect.VirtualAddress)
}
syms = append(syms, sym)
addrs = append(addrs, sym.Addr)
}
slices.Sort(addrs)
for i := range syms {
j := sort.Search(len(addrs), func(x int) bool { return addrs[x] > syms[i].Addr })
if j < len(addrs) {
syms[i].Size = int64(addrs[j] - syms[i].Addr)
}
}
return syms, nil
}
func (f *peFile) pcln() (textStart uint64, pclntab []byte, err error) {
imageBase, err := f.imageBase()
if err != nil {
return 0, nil, err
}
if sect := f.pe.Section(".text"); sect != nil {
textStart = imageBase + uint64(sect.VirtualAddress)
}
if pclntab, err = loadPETable(f.pe, "runtime.pclntab", "runtime.epclntab"); err != nil {
// We didn't find the symbols, so look for the names used in 1.3 and earlier.
// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
var err2 error
if pclntab, err2 = loadPETable(f.pe, "pclntab", "epclntab"); err2 != nil {
return 0, nil, err
}
}
return textStart, pclntab, nil
}
func (f *peFile) text() (textStart uint64, text []byte, err error) {
imageBase, err := f.imageBase()
if err != nil {
return 0, nil, err
}
sect := f.pe.Section(".text")
if sect == nil {
return 0, nil, fmt.Errorf("text section not found")
}
textStart = imageBase + uint64(sect.VirtualAddress)
text, err = sect.Data()
return
}
func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
for _, s := range f.Symbols {
if s.Name != name {
continue
}
if s.SectionNumber <= 0 {
return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
}
if len(f.Sections) < int(s.SectionNumber) {
return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
}
return s, nil
}
return nil, fmt.Errorf("no %s symbol found", name)
}
func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
ssym, err := findPESymbol(f, sname)
if err != nil {
return nil, err
}
esym, err := findPESymbol(f, ename)
if err != nil {
return nil, err
}
if ssym.SectionNumber != esym.SectionNumber {
return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
}
sect := f.Sections[ssym.SectionNumber-1]
data, err := sect.Data()
if err != nil {
return nil, err
}
return data[ssym.Value:esym.Value], nil
}
func (f *peFile) goarch() string {
switch f.pe.Machine {
case pe.IMAGE_FILE_MACHINE_I386:
return "386"
case pe.IMAGE_FILE_MACHINE_AMD64:
return "amd64"
case pe.IMAGE_FILE_MACHINE_ARM64:
return "arm64"
default:
return ""
}
}
func (f *peFile) loadAddress() (uint64, error) {
return f.imageBase()
}
func (f *peFile) imageBase() (uint64, error) {
switch oh := f.pe.OptionalHeader.(type) {
case *pe.OptionalHeader32:
return uint64(oh.ImageBase), nil
case *pe.OptionalHeader64:
return oh.ImageBase, nil
default:
return 0, fmt.Errorf("pe file format not recognized")
}
}
func (f *peFile) dwarf() (*dwarf.Data, error) {
return f.pe.DWARF()
}
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