forked from cadey/xesite
135 lines
3.0 KiB
Go
135 lines
3.0 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Parsing of Mach-O executables (OS X).
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package objfile
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import (
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"debug/dwarf"
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"debug/macho"
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"fmt"
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"os"
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"sort"
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)
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const stabTypeMask = 0xe0
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type machoFile struct {
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macho *macho.File
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}
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func openMacho(r *os.File) (rawFile, error) {
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f, err := macho.NewFile(r)
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if err != nil {
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return nil, err
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}
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return &machoFile{f}, nil
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}
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func (f *machoFile) symbols() ([]Sym, error) {
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if f.macho.Symtab == nil {
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return nil, fmt.Errorf("missing symbol table")
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}
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// Build sorted list of addresses of all symbols.
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// We infer the size of a symbol by looking at where the next symbol begins.
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var addrs []uint64
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for _, s := range f.macho.Symtab.Syms {
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// Skip stab debug info.
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if s.Type&stabTypeMask == 0 {
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addrs = append(addrs, s.Value)
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}
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}
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sort.Sort(uint64s(addrs))
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var syms []Sym
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for _, s := range f.macho.Symtab.Syms {
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if s.Type&stabTypeMask != 0 {
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// Skip stab debug info.
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continue
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}
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sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'}
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i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
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if i < len(addrs) {
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sym.Size = int64(addrs[i] - s.Value)
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}
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if s.Sect == 0 {
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sym.Code = 'U'
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} else if int(s.Sect) <= len(f.macho.Sections) {
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sect := f.macho.Sections[s.Sect-1]
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switch sect.Seg {
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case "__TEXT":
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sym.Code = 'R'
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case "__DATA":
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sym.Code = 'D'
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}
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switch sect.Seg + " " + sect.Name {
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case "__TEXT __text":
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sym.Code = 'T'
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case "__DATA __bss", "__DATA __noptrbss":
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sym.Code = 'B'
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}
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}
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syms = append(syms, sym)
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}
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return syms, nil
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}
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func (f *machoFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
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if sect := f.macho.Section("__text"); sect != nil {
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textStart = sect.Addr
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}
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if sect := f.macho.Section("__gosymtab"); sect != nil {
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if symtab, err = sect.Data(); err != nil {
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return 0, nil, nil, err
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}
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}
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if sect := f.macho.Section("__gopclntab"); sect != nil {
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if pclntab, err = sect.Data(); err != nil {
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return 0, nil, nil, err
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}
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}
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return textStart, symtab, pclntab, nil
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}
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func (f *machoFile) text() (textStart uint64, text []byte, err error) {
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sect := f.macho.Section("__text")
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if sect == nil {
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return 0, nil, fmt.Errorf("text section not found")
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}
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textStart = sect.Addr
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text, err = sect.Data()
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return
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}
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func (f *machoFile) goarch() string {
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switch f.macho.Cpu {
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case macho.Cpu386:
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return "386"
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case macho.CpuAmd64:
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return "amd64"
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case macho.CpuArm:
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return "arm"
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case macho.CpuPpc64:
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return "ppc64"
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}
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return ""
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}
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type uint64s []uint64
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func (x uint64s) Len() int { return len(x) }
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func (x uint64s) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
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func (x uint64s) Less(i, j int) bool { return x[i] < x[j] }
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func (f *machoFile) loadAddress() (uint64, error) {
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return 0, fmt.Errorf("unknown load address")
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}
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func (f *machoFile) dwarf() (*dwarf.Data, error) {
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return f.macho.DWARF()
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}
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