mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-25 09:51:36 +00:00
284 lines
7.2 KiB
Go
284 lines
7.2 KiB
Go
// Copyright 2014 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.
|
|
|
|
package objfile
|
|
|
|
import (
|
|
"bufio"
|
|
"debug/gosym"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
"regexp"
|
|
"sort"
|
|
"strings"
|
|
"text/tabwriter"
|
|
|
|
"golang.org/x/arch/arm/armasm"
|
|
"golang.org/x/arch/ppc64/ppc64asm"
|
|
"golang.org/x/arch/x86/x86asm"
|
|
)
|
|
|
|
// Disasm is a disassembler for a given File.
|
|
type Disasm struct {
|
|
syms []Sym //symbols in file, sorted by address
|
|
pcln Liner // pcln table
|
|
text []byte // bytes of text segment (actual instructions)
|
|
textStart uint64 // start PC of text
|
|
textEnd uint64 // end PC of text
|
|
goarch string // GOARCH string
|
|
disasm disasmFunc // disassembler function for goarch
|
|
byteOrder binary.ByteOrder // byte order for goarch
|
|
}
|
|
|
|
// Disasm returns a disassembler for the file f.
|
|
func (f *File) Disasm() (*Disasm, error) {
|
|
syms, err := f.Symbols()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
pcln, err := f.PCLineTable()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
textStart, textBytes, err := f.Text()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
goarch := f.GOARCH()
|
|
disasm := disasms[goarch]
|
|
byteOrder := byteOrders[goarch]
|
|
if disasm == nil || byteOrder == nil {
|
|
return nil, fmt.Errorf("unsupported architecture")
|
|
}
|
|
|
|
// Filter out section symbols, overwriting syms in place.
|
|
keep := syms[:0]
|
|
for _, sym := range syms {
|
|
switch sym.Name {
|
|
case "runtime.text", "text", "_text", "runtime.etext", "etext", "_etext":
|
|
// drop
|
|
default:
|
|
keep = append(keep, sym)
|
|
}
|
|
}
|
|
syms = keep
|
|
d := &Disasm{
|
|
syms: syms,
|
|
pcln: pcln,
|
|
text: textBytes,
|
|
textStart: textStart,
|
|
textEnd: textStart + uint64(len(textBytes)),
|
|
goarch: goarch,
|
|
disasm: disasm,
|
|
byteOrder: byteOrder,
|
|
}
|
|
|
|
return d, nil
|
|
}
|
|
|
|
// lookup finds the symbol name containing addr.
|
|
func (d *Disasm) lookup(addr uint64) (name string, base uint64) {
|
|
i := sort.Search(len(d.syms), func(i int) bool { return addr < d.syms[i].Addr })
|
|
if i > 0 {
|
|
s := d.syms[i-1]
|
|
if s.Addr != 0 && s.Addr <= addr && addr < s.Addr+uint64(s.Size) {
|
|
return s.Name, s.Addr
|
|
}
|
|
}
|
|
return "", 0
|
|
}
|
|
|
|
// base returns the final element in the path.
|
|
// It works on both Windows and Unix paths,
|
|
// regardless of host operating system.
|
|
func base(path string) string {
|
|
path = path[strings.LastIndex(path, "/")+1:]
|
|
path = path[strings.LastIndex(path, `\`)+1:]
|
|
return path
|
|
}
|
|
|
|
// Print prints a disassembly of the file to w.
|
|
// If filter is non-nil, the disassembly only includes functions with names matching filter.
|
|
// The disassembly only includes functions that overlap the range [start, end).
|
|
func (d *Disasm) Print(w io.Writer, filter *regexp.Regexp, start, end uint64) {
|
|
if start < d.textStart {
|
|
start = d.textStart
|
|
}
|
|
if end > d.textEnd {
|
|
end = d.textEnd
|
|
}
|
|
printed := false
|
|
bw := bufio.NewWriter(w)
|
|
for _, sym := range d.syms {
|
|
symStart := sym.Addr
|
|
symEnd := sym.Addr + uint64(sym.Size)
|
|
relocs := sym.Relocs
|
|
if sym.Code != 'T' && sym.Code != 't' ||
|
|
symStart < d.textStart ||
|
|
symEnd <= start || end <= symStart ||
|
|
filter != nil && !filter.MatchString(sym.Name) {
|
|
continue
|
|
}
|
|
if printed {
|
|
fmt.Fprintf(bw, "\n")
|
|
}
|
|
printed = true
|
|
|
|
file, _, _ := d.pcln.PCToLine(sym.Addr)
|
|
fmt.Fprintf(bw, "TEXT %s(SB) %s\n", sym.Name, file)
|
|
|
|
tw := tabwriter.NewWriter(bw, 1, 8, 1, '\t', 0)
|
|
if symEnd > end {
|
|
symEnd = end
|
|
}
|
|
code := d.text[:end-d.textStart]
|
|
d.Decode(symStart, symEnd, relocs, func(pc, size uint64, file string, line int, text string) {
|
|
i := pc - d.textStart
|
|
fmt.Fprintf(tw, "\t%s:%d\t%#x\t", base(file), line, pc)
|
|
if size%4 != 0 || d.goarch == "386" || d.goarch == "amd64" {
|
|
// Print instruction as bytes.
|
|
fmt.Fprintf(tw, "%x", code[i:i+size])
|
|
} else {
|
|
// Print instruction as 32-bit words.
|
|
for j := uint64(0); j < size; j += 4 {
|
|
if j > 0 {
|
|
fmt.Fprintf(tw, " ")
|
|
}
|
|
fmt.Fprintf(tw, "%08x", d.byteOrder.Uint32(code[i+j:]))
|
|
}
|
|
}
|
|
fmt.Fprintf(tw, "\t%s\n", text)
|
|
})
|
|
tw.Flush()
|
|
}
|
|
bw.Flush()
|
|
}
|
|
|
|
// Decode disassembles the text segment range [start, end), calling f for each instruction.
|
|
func (d *Disasm) Decode(start, end uint64, relocs []Reloc, f func(pc, size uint64, file string, line int, text string)) {
|
|
if start < d.textStart {
|
|
start = d.textStart
|
|
}
|
|
if end > d.textEnd {
|
|
end = d.textEnd
|
|
}
|
|
code := d.text[:end-d.textStart]
|
|
lookup := d.lookup
|
|
for pc := start; pc < end; {
|
|
i := pc - d.textStart
|
|
text, size := d.disasm(code[i:], pc, lookup, d.byteOrder)
|
|
file, line, _ := d.pcln.PCToLine(pc)
|
|
text += "\t"
|
|
first := true
|
|
for len(relocs) > 0 && relocs[0].Addr < i+uint64(size) {
|
|
if first {
|
|
first = false
|
|
} else {
|
|
text += " "
|
|
}
|
|
text += relocs[0].Stringer.String(pc - start)
|
|
relocs = relocs[1:]
|
|
}
|
|
f(pc, uint64(size), file, line, text)
|
|
pc += uint64(size)
|
|
}
|
|
}
|
|
|
|
type lookupFunc func(addr uint64) (sym string, base uint64)
|
|
type disasmFunc func(code []byte, pc uint64, lookup lookupFunc, ord binary.ByteOrder) (text string, size int)
|
|
|
|
func disasm_386(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
|
|
return disasm_x86(code, pc, lookup, 32)
|
|
}
|
|
|
|
func disasm_amd64(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
|
|
return disasm_x86(code, pc, lookup, 64)
|
|
}
|
|
|
|
func disasm_x86(code []byte, pc uint64, lookup lookupFunc, arch int) (string, int) {
|
|
inst, err := x86asm.Decode(code, 64)
|
|
var text string
|
|
size := inst.Len
|
|
if err != nil || size == 0 || inst.Op == 0 {
|
|
size = 1
|
|
text = "?"
|
|
} else {
|
|
text = x86asm.GoSyntax(inst, pc, lookup)
|
|
}
|
|
return text, size
|
|
}
|
|
|
|
type textReader struct {
|
|
code []byte
|
|
pc uint64
|
|
}
|
|
|
|
func (r textReader) ReadAt(data []byte, off int64) (n int, err error) {
|
|
if off < 0 || uint64(off) < r.pc {
|
|
return 0, io.EOF
|
|
}
|
|
d := uint64(off) - r.pc
|
|
if d >= uint64(len(r.code)) {
|
|
return 0, io.EOF
|
|
}
|
|
n = copy(data, r.code[d:])
|
|
if n < len(data) {
|
|
err = io.ErrUnexpectedEOF
|
|
}
|
|
return
|
|
}
|
|
|
|
func disasm_arm(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
|
|
inst, err := armasm.Decode(code, armasm.ModeARM)
|
|
var text string
|
|
size := inst.Len
|
|
if err != nil || size == 0 || inst.Op == 0 {
|
|
size = 4
|
|
text = "?"
|
|
} else {
|
|
text = armasm.GoSyntax(inst, pc, lookup, textReader{code, pc})
|
|
}
|
|
return text, size
|
|
}
|
|
|
|
func disasm_ppc64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder) (string, int) {
|
|
inst, err := ppc64asm.Decode(code, byteOrder)
|
|
var text string
|
|
size := inst.Len
|
|
if err != nil || size == 0 || inst.Op == 0 {
|
|
size = 4
|
|
text = "?"
|
|
} else {
|
|
text = ppc64asm.GoSyntax(inst, pc, lookup)
|
|
}
|
|
return text, size
|
|
}
|
|
|
|
var disasms = map[string]disasmFunc{
|
|
"386": disasm_386,
|
|
"amd64": disasm_amd64,
|
|
"arm": disasm_arm,
|
|
"ppc64": disasm_ppc64,
|
|
"ppc64le": disasm_ppc64,
|
|
}
|
|
|
|
var byteOrders = map[string]binary.ByteOrder{
|
|
"386": binary.LittleEndian,
|
|
"amd64": binary.LittleEndian,
|
|
"arm": binary.LittleEndian,
|
|
"ppc64": binary.BigEndian,
|
|
"ppc64le": binary.LittleEndian,
|
|
"s390x": binary.BigEndian,
|
|
}
|
|
|
|
type Liner interface {
|
|
// Given a pc, returns the corresponding file, line, and function data.
|
|
// If unknown, returns "",0,nil.
|
|
PCToLine(uint64) (string, int, *gosym.Func)
|
|
}
|