// ReadUInt32 reads a uint32 from r.
func ReadUInt32(r io.Reader, byteOrder binary.ByteOrder) (uint32, error) {
var buf [4]byte
if _, err := io.ReadFull(r, buf[:]); err != nil {
return 0, err
}
return byteOrder.Uint32(buf[:]), nil
}
func NewNullFrame(data []byte, byteOrder binary.ByteOrder) (*NullFrame, error) {
if len(data) < NULL_FRAME_HEADER_LENGTH {
return nil, errors.New(fmt.Sprintf("required at least %d bytes of data.", NULL_FRAME_HEADER_LENGTH))
}
return &NullFrame{byteOrder.Uint32(data), data[4:]}, nil
}
func ReadFloat32(buf []byte, format byte, endianness binary.ByteOrder) float32 {
encoding := format & EncodingMask
if encoding == EncodingFloatingPoint {
return math.Float32frombits(endianness.Uint32(buf))
} else {
offset := 0
if endianness == binary.LittleEndian {
offset = len(buf) - 1
}
var neg byte = 0
if encoding == EncodingSignedInt && buf[offset]&(1<<7) != 0 {
neg = 0xFF
}
tmp := []byte{neg, neg, neg, neg}
if endianness == binary.BigEndian {
copy(tmp[4-len(buf):], buf)
} else {
copy(tmp, buf)
}
sample := endianness.Uint32(tmp)
div := math.Pow(2, float64(len(buf)*8-1))
if encoding == EncodingSignedInt {
return float32(float64(int32(sample)) / div)
} else {
return float32(float64(sample)/div - 1.0)
}
}
}
func (b *Buffer) ReadUint32(order binary.ByteOrder) (uint32, error) {
if b.readPos >= len(b.Buf)-4 {
return 0, io.EOF
}
u := order.Uint32(b.Buf[b.readPos:])
b.readPos += 4
return u, nil
}
func newQosHistoryFromBytes(bin binary.ByteOrder, b []byte) (qosHistory, error) {
if len(b) < 4+4 {
return qosHistory{}, io.EOF
}
return qosHistory{
kind: bin.Uint32(b[0:]),
depth: bin.Uint32(b[4:]),
}, nil
}
func timeFromBytes(order binary.ByteOrder, b []byte) (time.Time, error) {
if len(b) < 8 {
return timeInvalid, io.EOF
}
sec := int64(order.Uint32(b[0:]))
frac := int64(order.Uint32(b[4:]))
return time.Unix(sec, (frac*nanosPerSec)>>32).UTC(), nil
}
func durationFromBytes(order binary.ByteOrder, b []byte) (time.Duration, error) {
if len(b) < 8 {
return time.Duration(0), io.EOF
}
sec := order.Uint32(b[0:])
nsec := order.Uint32(b[4:])
return time.Duration(sec*nanosPerSec + nsec), nil
}
func makeGuid(b []byte, order binary.ByteOrder) Guid {
g := Guid{
DataA: order.Uint32(b[:4]),
DataB: order.Uint16(b[4:6]),
DataC: order.Uint16(b[6:8]),
DataD: [8]byte{},
}
copy(g.DataD[:], b[8:])
return g
}
func rvalSRational(in []byte, bo binary.ByteOrder) reflect.Value {
denom := int64(int32(bo.Uint32(in[4:])))
if denom == 0 {
// Prevent panics due to poorly written Rational fields with a
// denominator of 0. Their usable value would likely be 0.
return reflect.New(reflect.TypeOf(big.Rat{}))
}
numer := int64(int32(bo.Uint32(in)))
return reflect.ValueOf(big.NewRat(numer, denom))
}
func newUDPv4LocFromBytes(bin binary.ByteOrder, b []byte) (locator, error) {
if len(b) < 4+4+16 {
return locator{}, io.EOF
}
return locator{
kind: int32(bin.Uint32(b[0:])),
port: bin.Uint32(b[4:]),
addr: net.IPv4(b[20], b[21], b[22], b[23]), // xxx: ipv6 support
}, nil
}
// Uint32 reads four bytes from the provided reader using a buffer from the
// free list, converts it to a number using the provided byte order, and returns
// the resulting uint32.
func (l binaryFreeList) Uint32(r io.Reader, byteOrder binary.ByteOrder) (uint32, error) {
buf := l.Borrow()[:4]
if _, err := io.ReadFull(r, buf); err != nil {
l.Return(buf)
return 0, err
}
rv := byteOrder.Uint32(buf)
l.Return(buf)
return rv, nil
}
func (p *paramListItem) valToString(bin binary.ByteOrder) (string, error) {
if len(p.value) < 4 {
return "", io.EOF
}
sz := int(bin.Uint32(p.value[0:]))
if len(p.value) < 4+sz {
return "", io.EOF
}
// encoded with null terminator, strip that out
return string(p.value[4 : 4+sz-1]), nil
}
func walksymtab(data []byte, ptrsz int, fn func(sym) error) error {
var order binary.ByteOrder = binary.BigEndian
var s sym
p := data
for len(p) >= 4 {
// Symbol type, value.
if len(p) < ptrsz {
return &formatError{len(data), "unexpected EOF", nil}
}
// fixed-width value
if ptrsz == 8 {
s.value = order.Uint64(p[0:8])
p = p[8:]
} else {
s.value = uint64(order.Uint32(p[0:4]))
p = p[4:]
}
var typ byte
typ = p[0] & 0x7F
s.typ = typ
p = p[1:]
// Name.
var i int
var nnul int
for i = 0; i < len(p); i++ {
if p[i] == 0 {
nnul = 1
break
}
}
switch typ {
case 'z', 'Z':
p = p[i+nnul:]
for i = 0; i+2 <= len(p); i += 2 {
if p[i] == 0 && p[i+1] == 0 {
nnul = 2
break
}
}
}
if len(p) < i+nnul {
return &formatError{len(data), "unexpected EOF", nil}
}
s.name = p[0:i]
i += nnul
p = p[i:]
fn(s)
}
return nil
}
// decodeTag assumes len(buf) >= 8
func decodeTag(buf []byte, bo binary.ByteOrder) tag {
var t tag
smallTag := bo.Uint32(buf[:])
t.dataType = dataType(smallTag)
t.smallFormat = (smallTag >> 16) != 0
if t.smallFormat == true {
t.nBytes = uint32(smallTag >> 16)
} else {
t.nBytes = bo.Uint32(buf[4:])
}
return t
}
func newQosReliabilityFromBytes(bin binary.ByteOrder, b []byte) (qosReliability, error) {
if len(b) < 4+4+4 {
return qosReliability{}, io.EOF
}
dur, err := durationFromBytes(bin, b[4:])
if err != nil {
return qosReliability{}, err
}
return qosReliability{
kind: bin.Uint32(b[0:]),
maxBlockingTime: dur,
}, nil
}
// Look for the attribute that indicates the object uses the hard-float ABI (a
// file-level attribute with tag Tag_VFP_arch and value 1). Unfortunately the
// format used means that we have to parse all of the file-level attributes to
// find the one we are looking for. This format is slightly documented in "ELF
// for the ARM Architecture" but mostly this is derived from reading the source
// to gold and readelf.
func parseArmAttributes(ctxt *Link, e binary.ByteOrder, data []byte) {
// We assume the soft-float ABI unless we see a tag indicating otherwise.
if ehdr.flags == 0x5000002 {
ehdr.flags = 0x5000202
}
if data[0] != 'A' {
// TODO(dfc) should this be ctxt.Diag ?
ctxt.Logf(".ARM.attributes has unexpected format %c\n", data[0])
return
}
data = data[1:]
for len(data) != 0 {
sectionlength := e.Uint32(data)
sectiondata := data[4:sectionlength]
data = data[sectionlength:]
nulIndex := bytes.IndexByte(sectiondata, 0)
if nulIndex < 0 {
// TODO(dfc) should this be ctxt.Diag ?
ctxt.Logf("corrupt .ARM.attributes (section name not NUL-terminated)\n")
return
}
name := string(sectiondata[:nulIndex])
sectiondata = sectiondata[nulIndex+1:]
if name != "aeabi" {
continue
}
for len(sectiondata) != 0 {
subsectiontag, sz := binary.Uvarint(sectiondata)
subsectionsize := e.Uint32(sectiondata[sz:])
subsectiondata := sectiondata[sz+4 : subsectionsize]
sectiondata = sectiondata[subsectionsize:]
if subsectiontag == TagFile {
attrList := elfAttributeList{data: subsectiondata}
for !attrList.done() {
attr := attrList.armAttr()
if attr.tag == TagABIVFPArgs && attr.ival == 1 {
ehdr.flags = 0x5000402 // has entry point, Version5 EABI, hard-float ABI
}
}
if attrList.err != nil {
// TODO(dfc) should this be ctxt.Diag ?
ctxt.Logf("could not parse .ARM.attributes\n")
}
}
}
}
}
func walksymtab(data []byte, fn func(sym) error) error {
var order binary.ByteOrder = binary.BigEndian
if bytes.HasPrefix(data, littleEndianSymtab) {
data = data[6:]
order = binary.LittleEndian
}
var s sym
p := data
for len(p) >= 6 {
s.value = order.Uint32(p[0:4])
typ := p[4]
if typ&0x80 == 0 {
return &DecodingError{len(data) - len(p) + 4, "bad symbol type", typ}
}
typ &^= 0x80
s.typ = typ
p = p[5:]
var i int
var nnul int
for i = 0; i < len(p); i++ {
if p[i] == 0 {
nnul = 1
break
}
}
switch typ {
case 'z', 'Z':
p = p[i+nnul:]
for i = 0; i+2 <= len(p); i += 2 {
if p[i] == 0 && p[i+1] == 0 {
nnul = 2
break
}
}
}
if i+nnul+4 > len(p) {
return &DecodingError{len(data), "unexpected EOF", nil}
}
s.name = p[0:i]
i += nnul
s.gotype = order.Uint32(p[i : i+4])
p = p[i+4:]
fn(s)
}
return nil
}
func newSimpleProtocol(n int, byteOrder binary.ByteOrder) *simpleProtocol {
protocol := &simpleProtocol{
n: n,
bo: byteOrder,
}
switch n {
case 1:
protocol.encodeHead = func(buffer []byte) {
buffer[0] = byte(len(buffer) - n)
}
protocol.decodeHead = func(buffer []byte) int {
return int(buffer[0])
}
case 2:
protocol.encodeHead = func(buffer []byte) {
byteOrder.PutUint16(buffer, uint16(len(buffer)-n))
}
protocol.decodeHead = func(buffer []byte) int {
return int(byteOrder.Uint16(buffer))
}
case 4:
protocol.encodeHead = func(buffer []byte) {
byteOrder.PutUint32(buffer, uint32(len(buffer)-n))
}
protocol.decodeHead = func(buffer []byte) int {
return int(byteOrder.Uint32(buffer))
}
case 8:
protocol.encodeHead = func(buffer []byte) {
byteOrder.PutUint64(buffer, uint64(len(buffer)-n))
}
protocol.decodeHead = func(buffer []byte) int {
return int(byteOrder.Uint64(buffer))
}
default:
panic("unsupported packet head size")
}
return protocol
}
func (*RawEncoding) Read(c *ClientConn, rect *Rectangle, r io.Reader) (Encoding, error) {
bytesPerPixel := c.PixelFormat.BPP / 8
pixelBytes := make([]uint8, bytesPerPixel)
var byteOrder binary.ByteOrder = binary.LittleEndian
if c.PixelFormat.BigEndian {
byteOrder = binary.BigEndian
}
colors := make([]Color, int(rect.Height)*int(rect.Width))
for y := uint16(0); y < rect.Height; y++ {
for x := uint16(0); x < rect.Width; x++ {
if _, err := io.ReadFull(r, pixelBytes); err != nil {
return nil, err
}
var rawPixel uint32
if c.PixelFormat.BPP == 8 {
rawPixel = uint32(pixelBytes[0])
} else if c.PixelFormat.BPP == 16 {
rawPixel = uint32(byteOrder.Uint16(pixelBytes))
} else if c.PixelFormat.BPP == 32 {
rawPixel = byteOrder.Uint32(pixelBytes)
}
color := &colors[int(y)*int(rect.Width)+int(x)]
if c.PixelFormat.TrueColor {
color.R = uint16((rawPixel >> c.PixelFormat.RedShift) & uint32(c.PixelFormat.RedMax))
color.G = uint16((rawPixel >> c.PixelFormat.GreenShift) & uint32(c.PixelFormat.GreenMax))
color.B = uint16((rawPixel >> c.PixelFormat.BlueShift) & uint32(c.PixelFormat.BlueMax))
} else {
*color = c.ColorMap[rawPixel]
}
}
}
return &RawEncoding{colors}, nil
}
// Decode decodes the leading bytes in src as a single instruction using
// byte order ord.
func Decode(src []byte, ord binary.ByteOrder) (inst Inst, err error) {
if len(src) < 4 {
return inst, errShort
}
if decoderCover == nil {
decoderCover = make([]bool, len(instFormats))
}
inst.Len = 4 // only 4-byte instructions are supported
ui := ord.Uint32(src[:inst.Len])
inst.Enc = ui
for i, iform := range instFormats {
if ui&iform.Mask != iform.Value {
continue
}
if ui&iform.DontCare != 0 {
if debugDecode {
log.Printf("Decode(%#x): unused bit is 1 for Op %s", ui, iform.Op)
}
// to match GNU objdump (libopcodes), we ignore don't care bits
}
for i, argfield := range iform.Args {
if argfield == nil {
break
}
inst.Args[i] = argfield.Parse(ui)
}
inst.Op = iform.Op
if debugDecode {
log.Printf("%#x: search entry %d", ui, i)
continue
}
break
}
if inst.Op == 0 {
return inst, errUnknown
}
return inst, nil
}
// buildInputBig creates a byte-slice based on big-endian ordered input
func buildInput(in input, order binary.ByteOrder) []byte {
data := make([]byte, 0)
d, _ := hex.DecodeString(in.tgId)
data = append(data, d...)
d, _ = hex.DecodeString(in.tpe)
data = append(data, d...)
d, _ = hex.DecodeString(in.nVals)
data = append(data, d...)
d, _ = hex.DecodeString(in.offset)
data = append(data, d...)
if in.val != "" {
off := order.Uint32(d)
for i := 0; i < int(off)-12; i++ {
data = append(data, 0xFF)
}
d, _ = hex.DecodeString(in.val)
data = append(data, d...)
}
return data
}
func ldelf(f *Biobuf, pkg string, length int64, pn string) {
if Debug['v'] != 0 {
fmt.Fprintf(&Bso, "%5.2f ldelf %s\n", obj.Cputime(), pn)
}
Ctxt.Version++
base := int32(Boffset(f))
var add uint64
var e binary.ByteOrder
var elfobj *ElfObj
var err error
var flag int
var hdr *ElfHdrBytes
var hdrbuf [64]uint8
var info uint64
var is64 int
var j int
var n int
var name string
var p []byte
var r []Reloc
var rela int
var rp *Reloc
var rsect *ElfSect
var s *LSym
var sect *ElfSect
var sym ElfSym
var symbols []*LSym
if Bread(f, hdrbuf[:]) != len(hdrbuf) {
goto bad
}
hdr = new(ElfHdrBytes)
binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter
if string(hdr.Ident[:4]) != "\x7FELF" {
goto bad
}
switch hdr.Ident[5] {
case ElfDataLsb:
e = binary.LittleEndian
case ElfDataMsb:
e = binary.BigEndian
default:
goto bad
}
// read header
elfobj = new(ElfObj)
elfobj.e = e
elfobj.f = f
elfobj.base = int64(base)
elfobj.length = length
elfobj.name = pn
is64 = 0
if hdr.Ident[4] == ElfClass64 {
is64 = 1
hdr := new(ElfHdrBytes64)
binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter
elfobj.type_ = uint32(e.Uint16(hdr.Type[:]))
elfobj.machine = uint32(e.Uint16(hdr.Machine[:]))
elfobj.version = e.Uint32(hdr.Version[:])
elfobj.phoff = e.Uint64(hdr.Phoff[:])
elfobj.shoff = e.Uint64(hdr.Shoff[:])
elfobj.flags = e.Uint32(hdr.Flags[:])
elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:]))
elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:]))
elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:]))
elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:]))
elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:]))
elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:]))
} else {
elfobj.type_ = uint32(e.Uint16(hdr.Type[:]))
elfobj.machine = uint32(e.Uint16(hdr.Machine[:]))
elfobj.version = e.Uint32(hdr.Version[:])
elfobj.entry = uint64(e.Uint32(hdr.Entry[:]))
elfobj.phoff = uint64(e.Uint32(hdr.Phoff[:]))
elfobj.shoff = uint64(e.Uint32(hdr.Shoff[:]))
elfobj.flags = e.Uint32(hdr.Flags[:])
elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:]))
elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:]))
elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:]))
elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:]))
elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:]))
elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:]))
}
elfobj.is64 = is64
if uint32(hdr.Ident[6]) != elfobj.version {
goto bad
}
if e.Uint16(hdr.Type[:]) != ElfTypeRelocatable {
Diag("%s: elf but not elf relocatable object", pn)
return
}
switch Thearch.Thechar {
default:
Diag("%s: elf %s unimplemented", pn, Thestring)
return
case '5':
if e != binary.LittleEndian || elfobj.machine != ElfMachArm || hdr.Ident[4] != ElfClass32 {
Diag("%s: elf object but not arm", pn)
return
}
case '6':
if e != binary.LittleEndian || elfobj.machine != ElfMachAmd64 || hdr.Ident[4] != ElfClass64 {
Diag("%s: elf object but not amd64", pn)
return
}
case '7':
if e != binary.LittleEndian || elfobj.machine != ElfMachArm64 || hdr.Ident[4] != ElfClass64 {
Diag("%s: elf object but not arm64", pn)
return
}
case '8':
if e != binary.LittleEndian || elfobj.machine != ElfMach386 || hdr.Ident[4] != ElfClass32 {
Diag("%s: elf object but not 386", pn)
return
}
case '9':
if elfobj.machine != ElfMachPower64 || hdr.Ident[4] != ElfClass64 {
Diag("%s: elf object but not ppc64", pn)
return
}
}
// load section list into memory.
elfobj.sect = make([]ElfSect, elfobj.shnum)
elfobj.nsect = uint(elfobj.shnum)
for i := 0; uint(i) < elfobj.nsect; i++ {
if Bseek(f, int64(uint64(base)+elfobj.shoff+uint64(int64(i)*int64(elfobj.shentsize))), 0) < 0 {
goto bad
}
sect = &elfobj.sect[i]
if is64 != 0 {
var b ElfSectBytes64
if err = binary.Read(f, e, &b); err != nil {
goto bad
}
sect.nameoff = uint32(e.Uint32(b.Name[:]))
sect.type_ = e.Uint32(b.Type[:])
sect.flags = e.Uint64(b.Flags[:])
sect.addr = e.Uint64(b.Addr[:])
sect.off = e.Uint64(b.Off[:])
sect.size = e.Uint64(b.Size[:])
sect.link = e.Uint32(b.Link[:])
sect.info = e.Uint32(b.Info[:])
sect.align = e.Uint64(b.Align[:])
sect.entsize = e.Uint64(b.Entsize[:])
} else {
var b ElfSectBytes
if err = binary.Read(f, e, &b); err != nil {
goto bad
}
sect.nameoff = uint32(e.Uint32(b.Name[:]))
sect.type_ = e.Uint32(b.Type[:])
sect.flags = uint64(e.Uint32(b.Flags[:]))
sect.addr = uint64(e.Uint32(b.Addr[:]))
sect.off = uint64(e.Uint32(b.Off[:]))
sect.size = uint64(e.Uint32(b.Size[:]))
sect.link = e.Uint32(b.Link[:])
sect.info = e.Uint32(b.Info[:])
sect.align = uint64(e.Uint32(b.Align[:]))
sect.entsize = uint64(e.Uint32(b.Entsize[:]))
}
}
// read section string table and translate names
if elfobj.shstrndx >= uint32(elfobj.nsect) {
err = fmt.Errorf("shstrndx out of range %d >= %d", elfobj.shstrndx, elfobj.nsect)
goto bad
}
sect = &elfobj.sect[elfobj.shstrndx]
if err = elfmap(elfobj, sect); err != nil {
goto bad
}
for i := 0; uint(i) < elfobj.nsect; i++ {
if elfobj.sect[i].nameoff != 0 {
elfobj.sect[i].name = cstring(sect.base[elfobj.sect[i].nameoff:])
}
}
// load string table for symbols into memory.
elfobj.symtab = section(elfobj, ".symtab")
if elfobj.symtab == nil {
// our work is done here - no symbols means nothing can refer to this file
return
}
if elfobj.symtab.link <= 0 || elfobj.symtab.link >= uint32(elfobj.nsect) {
Diag("%s: elf object has symbol table with invalid string table link", pn)
return
}
elfobj.symstr = &elfobj.sect[elfobj.symtab.link]
if is64 != 0 {
elfobj.nsymtab = int(elfobj.symtab.size / ELF64SYMSIZE)
} else {
elfobj.nsymtab = int(elfobj.symtab.size / ELF32SYMSIZE)
}
if err = elfmap(elfobj, elfobj.symtab); err != nil {
goto bad
}
if err = elfmap(elfobj, elfobj.symstr); err != nil {
goto bad
}
// load text and data segments into memory.
// they are not as small as the section lists, but we'll need
// the memory anyway for the symbol images, so we might
// as well use one large chunk.
// create symbols for elfmapped sections
for i := 0; uint(i) < elfobj.nsect; i++ {
sect = &elfobj.sect[i]
if (sect.type_ != ElfSectProgbits && sect.type_ != ElfSectNobits) || sect.flags&ElfSectFlagAlloc == 0 {
continue
}
if sect.type_ != ElfSectNobits {
if err = elfmap(elfobj, sect); err != nil {
goto bad
}
}
name = fmt.Sprintf("%s(%s)", pkg, sect.name)
s = Linklookup(Ctxt, name, Ctxt.Version)
switch int(sect.flags) & (ElfSectFlagAlloc | ElfSectFlagWrite | ElfSectFlagExec) {
default:
err = fmt.Errorf("unexpected flags for ELF section %s", sect.name)
goto bad
case ElfSectFlagAlloc:
s.Type = SRODATA
case ElfSectFlagAlloc + ElfSectFlagWrite:
if sect.type_ == ElfSectNobits {
s.Type = SNOPTRBSS
} else {
s.Type = SNOPTRDATA
}
case ElfSectFlagAlloc + ElfSectFlagExec:
s.Type = STEXT
}
if sect.name == ".got" || sect.name == ".toc" {
s.Type = SELFGOT
}
if sect.type_ == ElfSectProgbits {
s.P = sect.base
s.P = s.P[:sect.size]
}
s.Size = int64(sect.size)
s.Align = int32(sect.align)
sect.sym = s
}
// enter sub-symbols into symbol table.
// symbol 0 is the null symbol.
symbols = make([]*LSym, elfobj.nsymtab)
if symbols == nil {
Diag("out of memory")
Errorexit()
}
for i := 1; i < elfobj.nsymtab; i++ {
if err = readelfsym(elfobj, i, &sym, 1); err != nil {
goto bad
}
symbols[i] = sym.sym
if sym.type_ != ElfSymTypeFunc && sym.type_ != ElfSymTypeObject && sym.type_ != ElfSymTypeNone {
continue
}
if sym.shndx == ElfSymShnCommon {
s = sym.sym
if uint64(s.Size) < sym.size {
s.Size = int64(sym.size)
}
if s.Type == 0 || s.Type == SXREF {
s.Type = SNOPTRBSS
}
continue
}
if uint(sym.shndx) >= elfobj.nsect || sym.shndx == 0 {
continue
}
// even when we pass needSym == 1 to readelfsym, it might still return nil to skip some unwanted symbols
if sym.sym == nil {
continue
}
sect = &elfobj.sect[sym.shndx:][0]
if sect.sym == nil {
if strings.HasPrefix(sym.name, ".Linfo_string") { // clang does this
continue
}
Diag("%s: sym#%d: ignoring %s in section %d (type %d)", pn, i, sym.name, sym.shndx, sym.type_)
continue
}
s = sym.sym
if s.Outer != nil {
if s.Dupok != 0 {
continue
}
Diag("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name)
Errorexit()
}
s.Sub = sect.sym.Sub
sect.sym.Sub = s
s.Type = sect.sym.Type | s.Type&^SMASK | SSUB
if s.Cgoexport&CgoExportDynamic == 0 {
s.Dynimplib = "" // satisfy dynimport
}
s.Value = int64(sym.value)
s.Size = int64(sym.size)
s.Outer = sect.sym
if sect.sym.Type == STEXT {
if s.External != 0 && s.Dupok == 0 {
Diag("%s: duplicate definition of %s", pn, s.Name)
}
s.External = 1
}
if elfobj.machine == ElfMachPower64 {
flag = int(sym.other) >> 5
if 2 <= flag && flag <= 6 {
s.Localentry = 1 << uint(flag-2)
} else if flag == 7 {
Diag("%s: invalid sym.other 0x%x for %s", pn, sym.other, s.Name)
}
}
}
// Sort outer lists by address, adding to textp.
// This keeps textp in increasing address order.
for i := 0; uint(i) < elfobj.nsect; i++ {
s = elfobj.sect[i].sym
if s == nil {
continue
}
if s.Sub != nil {
s.Sub = listsort(s.Sub, valuecmp, listsubp)
}
if s.Type == STEXT {
if s.Onlist != 0 {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Onlist = 1
if Ctxt.Etextp != nil {
Ctxt.Etextp.Next = s
} else {
Ctxt.Textp = s
}
Ctxt.Etextp = s
for s = s.Sub; s != nil; s = s.Sub {
if s.Onlist != 0 {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Onlist = 1
Ctxt.Etextp.Next = s
Ctxt.Etextp = s
}
}
}
// load relocations
for i := 0; uint(i) < elfobj.nsect; i++ {
rsect = &elfobj.sect[i]
if rsect.type_ != ElfSectRela && rsect.type_ != ElfSectRel {
continue
}
if rsect.info >= uint32(elfobj.nsect) || elfobj.sect[rsect.info].base == nil {
continue
}
sect = &elfobj.sect[rsect.info]
if err = elfmap(elfobj, rsect); err != nil {
goto bad
}
rela = 0
if rsect.type_ == ElfSectRela {
rela = 1
}
n = int(rsect.size / uint64(4+4*is64) / uint64(2+rela))
r = make([]Reloc, n)
p = rsect.base
for j = 0; j < n; j++ {
add = 0
rp = &r[j]
if is64 != 0 {
// 64-bit rel/rela
rp.Off = int32(e.Uint64(p))
p = p[8:]
info = e.Uint64(p)
p = p[8:]
if rela != 0 {
add = e.Uint64(p)
p = p[8:]
}
} else {
// 32-bit rel/rela
rp.Off = int32(e.Uint32(p))
p = p[4:]
info = uint64(e.Uint32(p))
info = info>>8<<32 | info&0xff // convert to 64-bit info
p = p[4:]
if rela != 0 {
add = uint64(e.Uint32(p))
p = p[4:]
}
}
if info&0xffffffff == 0 { // skip R_*_NONE relocation
j--
n--
continue
}
if info>>32 == 0 { // absolute relocation, don't bother reading the null symbol
rp.Sym = nil
} else {
if err = readelfsym(elfobj, int(info>>32), &sym, 0); err != nil {
goto bad
}
sym.sym = symbols[info>>32]
if sym.sym == nil {
err = fmt.Errorf("%s#%d: reloc of invalid sym #%d %s shndx=%d type=%d", sect.sym.Name, j, int(info>>32), sym.name, sym.shndx, sym.type_)
goto bad
}
rp.Sym = sym.sym
}
rp.Type = int32(reltype(pn, int(uint32(info)), &rp.Siz))
if rela != 0 {
rp.Add = int64(add)
} else {
// load addend from image
if rp.Siz == 4 {
rp.Add = int64(e.Uint32(sect.base[rp.Off:]))
} else if rp.Siz == 8 {
rp.Add = int64(e.Uint64(sect.base[rp.Off:]))
} else {
Diag("invalid rela size %d", rp.Siz)
}
}
if rp.Siz == 2 {
rp.Add = int64(int16(rp.Add))
}
if rp.Siz == 4 {
rp.Add = int64(int32(rp.Add))
}
}
//print("rel %s %d %d %s %#llx\n", sect->sym->name, rp->type, rp->siz, rp->sym->name, rp->add);
sort.Sort(rbyoff(r[:n]))
// just in case
s = sect.sym
s.R = r
s.R = s.R[:n]
}
return
bad:
Diag("%s: malformed elf file: %v", pn, err)
}
func (s Custom) Unpack(buf []byte, order binary.ByteOrder) ([]byte, error) {
*s.A = int(order.Uint32(buf[0:4]))
return buf[4:], nil
}
func ldelf(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
if ctxt.Debugvlog != 0 {
ctxt.Logf("%5.2f ldelf %s\n", obj.Cputime(), pn)
}
localSymVersion := ctxt.Syms.IncVersion()
base := f.Offset()
var add uint64
var e binary.ByteOrder
var elfobj *ElfObj
var err error
var flag int
var hdr *ElfHdrBytes
var hdrbuf [64]uint8
var info uint64
var is64 int
var j int
var n int
var name string
var p []byte
var r []Reloc
var rela int
var rp *Reloc
var rsect *ElfSect
var s *Symbol
var sect *ElfSect
var sym ElfSym
var symbols []*Symbol
if _, err := io.ReadFull(f, hdrbuf[:]); err != nil {
goto bad
}
hdr = new(ElfHdrBytes)
binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter
if string(hdr.Ident[:4]) != "\x7FELF" {
goto bad
}
switch hdr.Ident[5] {
case ElfDataLsb:
e = binary.LittleEndian
case ElfDataMsb:
e = binary.BigEndian
default:
goto bad
}
// read header
elfobj = new(ElfObj)
elfobj.e = e
elfobj.f = f
elfobj.base = base
elfobj.length = length
elfobj.name = pn
is64 = 0
if hdr.Ident[4] == ElfClass64 {
is64 = 1
hdr := new(ElfHdrBytes64)
binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter
elfobj.type_ = uint32(e.Uint16(hdr.Type[:]))
elfobj.machine = uint32(e.Uint16(hdr.Machine[:]))
elfobj.version = e.Uint32(hdr.Version[:])
elfobj.phoff = e.Uint64(hdr.Phoff[:])
elfobj.shoff = e.Uint64(hdr.Shoff[:])
elfobj.flags = e.Uint32(hdr.Flags[:])
elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:]))
elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:]))
elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:]))
elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:]))
elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:]))
elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:]))
} else {
elfobj.type_ = uint32(e.Uint16(hdr.Type[:]))
elfobj.machine = uint32(e.Uint16(hdr.Machine[:]))
elfobj.version = e.Uint32(hdr.Version[:])
elfobj.entry = uint64(e.Uint32(hdr.Entry[:]))
elfobj.phoff = uint64(e.Uint32(hdr.Phoff[:]))
elfobj.shoff = uint64(e.Uint32(hdr.Shoff[:]))
elfobj.flags = e.Uint32(hdr.Flags[:])
elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:]))
elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:]))
elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:]))
elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:]))
elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:]))
elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:]))
}
elfobj.is64 = is64
if uint32(hdr.Ident[6]) != elfobj.version {
goto bad
}
if e.Uint16(hdr.Type[:]) != ElfTypeRelocatable {
Errorf(nil, "%s: elf but not elf relocatable object", pn)
return
}
switch SysArch.Family {
default:
Errorf(nil, "%s: elf %s unimplemented", pn, SysArch.Name)
return
case sys.MIPS64:
if elfobj.machine != ElfMachMips || hdr.Ident[4] != ElfClass64 {
Errorf(nil, "%s: elf object but not mips64", pn)
return
}
case sys.ARM:
if e != binary.LittleEndian || elfobj.machine != ElfMachArm || hdr.Ident[4] != ElfClass32 {
Errorf(nil, "%s: elf object but not arm", pn)
return
}
case sys.AMD64:
if e != binary.LittleEndian || elfobj.machine != ElfMachAmd64 || hdr.Ident[4] != ElfClass64 {
Errorf(nil, "%s: elf object but not amd64", pn)
return
}
case sys.ARM64:
if e != binary.LittleEndian || elfobj.machine != ElfMachArm64 || hdr.Ident[4] != ElfClass64 {
Errorf(nil, "%s: elf object but not arm64", pn)
return
}
case sys.I386:
if e != binary.LittleEndian || elfobj.machine != ElfMach386 || hdr.Ident[4] != ElfClass32 {
Errorf(nil, "%s: elf object but not 386", pn)
return
}
case sys.PPC64:
if elfobj.machine != ElfMachPower64 || hdr.Ident[4] != ElfClass64 {
Errorf(nil, "%s: elf object but not ppc64", pn)
return
}
case sys.S390X:
if elfobj.machine != ElfMachS390 || hdr.Ident[4] != ElfClass64 {
Errorf(nil, "%s: elf object but not s390x", pn)
return
}
}
// load section list into memory.
elfobj.sect = make([]ElfSect, elfobj.shnum)
elfobj.nsect = uint(elfobj.shnum)
for i := 0; uint(i) < elfobj.nsect; i++ {
if f.Seek(int64(uint64(base)+elfobj.shoff+uint64(int64(i)*int64(elfobj.shentsize))), 0) < 0 {
goto bad
}
sect = &elfobj.sect[i]
if is64 != 0 {
var b ElfSectBytes64
if err = binary.Read(f, e, &b); err != nil {
goto bad
}
sect.nameoff = e.Uint32(b.Name[:])
sect.type_ = e.Uint32(b.Type[:])
sect.flags = e.Uint64(b.Flags[:])
sect.addr = e.Uint64(b.Addr[:])
sect.off = e.Uint64(b.Off[:])
sect.size = e.Uint64(b.Size[:])
sect.link = e.Uint32(b.Link[:])
sect.info = e.Uint32(b.Info[:])
sect.align = e.Uint64(b.Align[:])
sect.entsize = e.Uint64(b.Entsize[:])
} else {
var b ElfSectBytes
if err = binary.Read(f, e, &b); err != nil {
goto bad
}
sect.nameoff = e.Uint32(b.Name[:])
sect.type_ = e.Uint32(b.Type[:])
sect.flags = uint64(e.Uint32(b.Flags[:]))
sect.addr = uint64(e.Uint32(b.Addr[:]))
sect.off = uint64(e.Uint32(b.Off[:]))
sect.size = uint64(e.Uint32(b.Size[:]))
sect.link = e.Uint32(b.Link[:])
sect.info = e.Uint32(b.Info[:])
sect.align = uint64(e.Uint32(b.Align[:]))
sect.entsize = uint64(e.Uint32(b.Entsize[:]))
}
}
// read section string table and translate names
if elfobj.shstrndx >= uint32(elfobj.nsect) {
err = fmt.Errorf("shstrndx out of range %d >= %d", elfobj.shstrndx, elfobj.nsect)
goto bad
}
sect = &elfobj.sect[elfobj.shstrndx]
if err = elfmap(elfobj, sect); err != nil {
goto bad
}
for i := 0; uint(i) < elfobj.nsect; i++ {
if elfobj.sect[i].nameoff != 0 {
elfobj.sect[i].name = cstring(sect.base[elfobj.sect[i].nameoff:])
}
}
// load string table for symbols into memory.
elfobj.symtab = section(elfobj, ".symtab")
if elfobj.symtab == nil {
// our work is done here - no symbols means nothing can refer to this file
return
}
if elfobj.symtab.link <= 0 || elfobj.symtab.link >= uint32(elfobj.nsect) {
Errorf(nil, "%s: elf object has symbol table with invalid string table link", pn)
return
}
elfobj.symstr = &elfobj.sect[elfobj.symtab.link]
if is64 != 0 {
elfobj.nsymtab = int(elfobj.symtab.size / ELF64SYMSIZE)
} else {
elfobj.nsymtab = int(elfobj.symtab.size / ELF32SYMSIZE)
}
if err = elfmap(elfobj, elfobj.symtab); err != nil {
goto bad
}
if err = elfmap(elfobj, elfobj.symstr); err != nil {
goto bad
}
// load text and data segments into memory.
// they are not as small as the section lists, but we'll need
// the memory anyway for the symbol images, so we might
// as well use one large chunk.
// create symbols for elfmapped sections
for i := 0; uint(i) < elfobj.nsect; i++ {
sect = &elfobj.sect[i]
if sect.type_ == SHT_ARM_ATTRIBUTES && sect.name == ".ARM.attributes" {
if err = elfmap(elfobj, sect); err != nil {
goto bad
}
parseArmAttributes(ctxt, e, sect.base[:sect.size])
}
if (sect.type_ != ElfSectProgbits && sect.type_ != ElfSectNobits) || sect.flags&ElfSectFlagAlloc == 0 {
continue
}
if sect.type_ != ElfSectNobits {
if err = elfmap(elfobj, sect); err != nil {
goto bad
}
}
name = fmt.Sprintf("%s(%s)", pkg, sect.name)
s = ctxt.Syms.Lookup(name, localSymVersion)
switch int(sect.flags) & (ElfSectFlagAlloc | ElfSectFlagWrite | ElfSectFlagExec) {
default:
err = fmt.Errorf("unexpected flags for ELF section %s", sect.name)
goto bad
case ElfSectFlagAlloc:
s.Type = obj.SRODATA
case ElfSectFlagAlloc + ElfSectFlagWrite:
if sect.type_ == ElfSectNobits {
s.Type = obj.SNOPTRBSS
} else {
s.Type = obj.SNOPTRDATA
}
case ElfSectFlagAlloc + ElfSectFlagExec:
s.Type = obj.STEXT
}
if sect.name == ".got" || sect.name == ".toc" {
s.Type = obj.SELFGOT
}
if sect.type_ == ElfSectProgbits {
s.P = sect.base
s.P = s.P[:sect.size]
}
s.Size = int64(sect.size)
s.Align = int32(sect.align)
sect.sym = s
}
// enter sub-symbols into symbol table.
// symbol 0 is the null symbol.
symbols = make([]*Symbol, elfobj.nsymtab)
for i := 1; i < elfobj.nsymtab; i++ {
if err = readelfsym(ctxt, elfobj, i, &sym, 1, localSymVersion); err != nil {
goto bad
}
symbols[i] = sym.sym
if sym.type_ != ElfSymTypeFunc && sym.type_ != ElfSymTypeObject && sym.type_ != ElfSymTypeNone {
continue
}
if sym.shndx == ElfSymShnCommon {
s = sym.sym
if uint64(s.Size) < sym.size {
s.Size = int64(sym.size)
}
if s.Type == 0 || s.Type == obj.SXREF {
s.Type = obj.SNOPTRBSS
}
continue
}
if uint(sym.shndx) >= elfobj.nsect || sym.shndx == 0 {
continue
}
// even when we pass needSym == 1 to readelfsym, it might still return nil to skip some unwanted symbols
if sym.sym == nil {
continue
}
sect = &elfobj.sect[sym.shndx]
if sect.sym == nil {
if strings.HasPrefix(sym.name, ".Linfo_string") { // clang does this
continue
}
if sym.name == "" && sym.type_ == 0 && sect.name == ".debug_str" {
// This reportedly happens with clang 3.7 on ARM.
// See issue 13139.
continue
}
if strings.HasPrefix(sym.name, ".LASF") { // gcc on s390x does this
continue
}
Errorf(sym.sym, "%s: sym#%d: ignoring symbol in section %d (type %d)", pn, i, sym.shndx, sym.type_)
continue
}
s = sym.sym
if s.Outer != nil {
if s.Attr.DuplicateOK() {
continue
}
Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name)
}
s.Sub = sect.sym.Sub
sect.sym.Sub = s
s.Type = sect.sym.Type | s.Type&^obj.SMASK | obj.SSUB
if !s.Attr.CgoExportDynamic() {
s.Dynimplib = "" // satisfy dynimport
}
s.Value = int64(sym.value)
s.Size = int64(sym.size)
s.Outer = sect.sym
if sect.sym.Type == obj.STEXT {
if s.Attr.External() && !s.Attr.DuplicateOK() {
Errorf(s, "%s: duplicate symbol definition", pn)
}
s.Attr |= AttrExternal
}
if elfobj.machine == ElfMachPower64 {
flag = int(sym.other) >> 5
if 2 <= flag && flag <= 6 {
s.Localentry = 1 << uint(flag-2)
} else if flag == 7 {
Errorf(s, "%s: invalid sym.other 0x%x", pn, sym.other)
}
}
}
// Sort outer lists by address, adding to textp.
// This keeps textp in increasing address order.
for i := 0; uint(i) < elfobj.nsect; i++ {
s = elfobj.sect[i].sym
if s == nil {
continue
}
if s.Sub != nil {
s.Sub = listsort(s.Sub)
}
if s.Type == obj.STEXT {
if s.Attr.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Attr |= AttrOnList
ctxt.Textp = append(ctxt.Textp, s)
for s = s.Sub; s != nil; s = s.Sub {
if s.Attr.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Attr |= AttrOnList
ctxt.Textp = append(ctxt.Textp, s)
}
}
}
// load relocations
for i := 0; uint(i) < elfobj.nsect; i++ {
rsect = &elfobj.sect[i]
if rsect.type_ != ElfSectRela && rsect.type_ != ElfSectRel {
continue
}
if rsect.info >= uint32(elfobj.nsect) || elfobj.sect[rsect.info].base == nil {
continue
}
sect = &elfobj.sect[rsect.info]
if err = elfmap(elfobj, rsect); err != nil {
goto bad
}
rela = 0
if rsect.type_ == ElfSectRela {
rela = 1
}
n = int(rsect.size / uint64(4+4*is64) / uint64(2+rela))
r = make([]Reloc, n)
p = rsect.base
for j = 0; j < n; j++ {
add = 0
rp = &r[j]
if is64 != 0 {
// 64-bit rel/rela
rp.Off = int32(e.Uint64(p))
p = p[8:]
info = e.Uint64(p)
p = p[8:]
if rela != 0 {
add = e.Uint64(p)
p = p[8:]
}
} else {
// 32-bit rel/rela
rp.Off = int32(e.Uint32(p))
p = p[4:]
info = uint64(e.Uint32(p))
info = info>>8<<32 | info&0xff // convert to 64-bit info
p = p[4:]
if rela != 0 {
add = uint64(e.Uint32(p))
p = p[4:]
}
}
if info&0xffffffff == 0 { // skip R_*_NONE relocation
j--
n--
continue
}
if info>>32 == 0 { // absolute relocation, don't bother reading the null symbol
rp.Sym = nil
} else {
if err = readelfsym(ctxt, elfobj, int(info>>32), &sym, 0, 0); err != nil {
goto bad
}
sym.sym = symbols[info>>32]
if sym.sym == nil {
err = fmt.Errorf("%s#%d: reloc of invalid sym #%d %s shndx=%d type=%d", sect.sym.Name, j, int(info>>32), sym.name, sym.shndx, sym.type_)
goto bad
}
rp.Sym = sym.sym
}
rp.Type = 256 + obj.RelocType(info)
rp.Siz = relSize(ctxt, pn, uint32(info))
if rela != 0 {
rp.Add = int64(add)
} else {
// load addend from image
if rp.Siz == 4 {
rp.Add = int64(e.Uint32(sect.base[rp.Off:]))
} else if rp.Siz == 8 {
rp.Add = int64(e.Uint64(sect.base[rp.Off:]))
} else {
Errorf(nil, "invalid rela size %d", rp.Siz)
}
}
if rp.Siz == 2 {
rp.Add = int64(int16(rp.Add))
}
if rp.Siz == 4 {
rp.Add = int64(int32(rp.Add))
}
}
//print("rel %s %d %d %s %#llx\n", sect->sym->name, rp->type, rp->siz, rp->sym->name, rp->add);
sort.Sort(rbyoff(r[:n]))
// just in case
s = sect.sym
s.R = r
s.R = s.R[:n]
}
return
bad:
Errorf(nil, "%s: malformed elf file: %v", pn, err)
}
// decodeNumeric decodes a simple stream of numeric or character data
func decodeNumeric(de dataElement, bo binary.ByteOrder) (interface{}, error) {
var b [8]byte
var bs []byte
if int(de.nBytes) > len(b) {
bs = make([]byte, de.nBytes)
} else {
bs = b[:de.nBytes]
}
_, err := de.r.ReadAt(bs, 0)
if err != nil {
return nil, err
}
switch de.dataType {
case miINT8:
val := make([]int8, de.nBytes)
for i, x := range bs {
val[i] = int8(x)
}
return val, nil
case miUINT8:
val := make([]uint8, de.nBytes)
copy(val, bs)
return val, nil
case miINT16:
val := make([]int16, de.nBytes/2)
for i := range bs {
val[i] = int16(bo.Uint16(bs[2*i:]))
}
return val, nil
case miUINT16:
val := make([]uint16, de.nBytes/2)
for i := range bs {
val[i] = bo.Uint16(bs[2*i:])
}
return val, nil
case miINT32:
val := make([]int32, de.nBytes/4)
for i := range bs {
val[i] = int32(bo.Uint32(bs[4*i:]))
}
return val, nil
case miUINT32:
val := make([]uint32, de.nBytes/4)
for i := range bs {
val[i] = bo.Uint32(bs[4*i:])
}
return val, nil
case miINT64:
val := make([]int64, de.nBytes/8)
for i := range bs {
val[i] = int64(bo.Uint64(bs[8*i:]))
}
return val, nil
case miUINT64:
val := make([]uint64, de.nBytes/8)
for i := range bs {
val[i] = bo.Uint64(bs[8*i:])
}
return val, nil
case miSINGLE:
val := make([]float32, de.nBytes/4)
for i := range bs {
val[i] = math.Float32frombits(bo.Uint32(bs[4*i:]))
}
return val, nil
case miDOUBLE:
val := make([]float64, de.nBytes/8)
for i := range bs {
val[i] = math.Float64frombits(bo.Uint64(bs[8*i:]))
}
return val, nil
case miUTF8:
return string(bs), nil
case miUTF16:
x := make([]uint16, de.nBytes/2)
for i := range bs {
x[i] = bo.Uint16(bs[2*i:])
}
return string(utf16.Decode(x)), nil
case miUTF32:
runes := make([]rune, de.nBytes/4)
for i := range runes {
runes[i] = rune(bo.Uint32(bs[4*i:]))
}
return string(runes), nil
}
return nil, nil
}
func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
var err error
var j int
var is64 bool
var secaddr uint64
var hdr [7 * 4]uint8
var cmdp []byte
var dat []byte
var ncmd uint32
var cmdsz uint32
var ty uint32
var sz uint32
var off uint32
var m *LdMachoObj
var e binary.ByteOrder
var sect *LdMachoSect
var rel *LdMachoRel
var rpi int
var s *LSym
var s1 *LSym
var outer *LSym
var c *LdMachoCmd
var symtab *LdMachoSymtab
var dsymtab *LdMachoDysymtab
var sym *LdMachoSym
var r []Reloc
var rp *Reloc
var name string
Ctxt.IncVersion()
base := f.Offset()
if _, err := io.ReadFull(f, hdr[:]); err != nil {
goto bad
}
if binary.BigEndian.Uint32(hdr[:])&^1 == 0xFEEDFACE {
e = binary.BigEndian
} else if binary.LittleEndian.Uint32(hdr[:])&^1 == 0xFEEDFACE {
e = binary.LittleEndian
} else {
err = fmt.Errorf("bad magic - not mach-o file")
goto bad
}
is64 = e.Uint32(hdr[:]) == 0xFEEDFACF
ncmd = e.Uint32(hdr[4*4:])
cmdsz = e.Uint32(hdr[5*4:])
if ncmd > 0x10000 || cmdsz >= 0x01000000 {
err = fmt.Errorf("implausible mach-o header ncmd=%d cmdsz=%d", ncmd, cmdsz)
goto bad
}
if is64 {
f.Seek(4, 1) // skip reserved word in header
}
m = new(LdMachoObj)
m.f = f
m.e = e
m.cputype = uint(e.Uint32(hdr[1*4:]))
m.subcputype = uint(e.Uint32(hdr[2*4:]))
m.filetype = e.Uint32(hdr[3*4:])
m.ncmd = uint(ncmd)
m.flags = e.Uint32(hdr[6*4:])
m.is64 = is64
m.base = base
m.length = length
m.name = pn
switch SysArch.Family {
default:
Diag("%s: mach-o %s unimplemented", pn, SysArch.Name)
return
case sys.AMD64:
if e != binary.LittleEndian || m.cputype != LdMachoCpuAmd64 {
Diag("%s: mach-o object but not amd64", pn)
return
}
case sys.I386:
if e != binary.LittleEndian || m.cputype != LdMachoCpu386 {
Diag("%s: mach-o object but not 386", pn)
return
}
}
m.cmd = make([]LdMachoCmd, ncmd)
off = uint32(len(hdr))
cmdp = make([]byte, cmdsz)
if _, err2 := io.ReadFull(f, cmdp); err2 != nil {
err = fmt.Errorf("reading cmds: %v", err)
goto bad
}
// read and parse load commands
c = nil
symtab = nil
dsymtab = nil
for i := 0; uint32(i) < ncmd; i++ {
ty = e.Uint32(cmdp)
sz = e.Uint32(cmdp[4:])
m.cmd[i].off = off
unpackcmd(cmdp, m, &m.cmd[i], uint(ty), uint(sz))
cmdp = cmdp[sz:]
off += sz
if ty == LdMachoCmdSymtab {
if symtab != nil {
err = fmt.Errorf("multiple symbol tables")
goto bad
}
symtab = &m.cmd[i].sym
macholoadsym(m, symtab)
}
if ty == LdMachoCmdDysymtab {
dsymtab = &m.cmd[i].dsym
macholoaddsym(m, dsymtab)
}
if (is64 && ty == LdMachoCmdSegment64) || (!is64 && ty == LdMachoCmdSegment) {
if c != nil {
err = fmt.Errorf("multiple load commands")
goto bad
}
c = &m.cmd[i]
}
}
// load text and data segments into memory.
// they are not as small as the load commands, but we'll need
// the memory anyway for the symbol images, so we might
// as well use one large chunk.
if c == nil {
err = fmt.Errorf("no load command")
goto bad
}
if symtab == nil {
// our work is done here - no symbols means nothing can refer to this file
return
}
if int64(c.seg.fileoff+c.seg.filesz) >= length {
err = fmt.Errorf("load segment out of range")
goto bad
}
dat = make([]byte, c.seg.filesz)
if f.Seek(m.base+int64(c.seg.fileoff), 0) < 0 {
err = fmt.Errorf("cannot load object data: %v", err)
goto bad
}
if _, err2 := io.ReadFull(f, dat); err2 != nil {
err = fmt.Errorf("cannot load object data: %v", err)
goto bad
}
for i := 0; uint32(i) < c.seg.nsect; i++ {
sect = &c.seg.sect[i]
if sect.segname != "__TEXT" && sect.segname != "__DATA" {
continue
}
if sect.name == "__eh_frame" {
continue
}
name = fmt.Sprintf("%s(%s/%s)", pkg, sect.segname, sect.name)
s = Linklookup(Ctxt, name, Ctxt.Version)
if s.Type != 0 {
err = fmt.Errorf("duplicate %s/%s", sect.segname, sect.name)
goto bad
}
if sect.flags&0xff == 1 { // S_ZEROFILL
s.P = make([]byte, sect.size)
} else {
s.P = dat[sect.addr-c.seg.vmaddr:][:sect.size]
}
s.Size = int64(len(s.P))
if sect.segname == "__TEXT" {
if sect.name == "__text" {
s.Type = obj.STEXT
} else {
s.Type = obj.SRODATA
}
} else {
if sect.name == "__bss" {
s.Type = obj.SNOPTRBSS
s.P = s.P[:0]
} else {
s.Type = obj.SNOPTRDATA
}
}
sect.sym = s
}
// enter sub-symbols into symbol table.
// have to guess sizes from next symbol.
for i := 0; uint32(i) < symtab.nsym; i++ {
sym = &symtab.sym[i]
if sym.type_&N_STAB != 0 {
continue
}
// TODO: check sym->type against outer->type.
name = sym.name
if name[0] == '_' && name[1] != '\x00' {
name = name[1:]
}
v := 0
if sym.type_&N_EXT == 0 {
v = Ctxt.Version
}
s = Linklookup(Ctxt, name, v)
if sym.type_&N_EXT == 0 {
s.Attr |= AttrDuplicateOK
}
sym.sym = s
if sym.sectnum == 0 { // undefined
continue
}
if uint32(sym.sectnum) > c.seg.nsect {
err = fmt.Errorf("reference to invalid section %d", sym.sectnum)
goto bad
}
sect = &c.seg.sect[sym.sectnum-1]
outer = sect.sym
if outer == nil {
err = fmt.Errorf("reference to invalid section %s/%s", sect.segname, sect.name)
continue
}
if s.Outer != nil {
if s.Attr.DuplicateOK() {
continue
}
Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name)
}
s.Type = outer.Type | obj.SSUB
s.Sub = outer.Sub
outer.Sub = s
s.Outer = outer
s.Value = int64(sym.value - sect.addr)
if !s.Attr.CgoExportDynamic() {
s.Dynimplib = "" // satisfy dynimport
}
if outer.Type == obj.STEXT {
if s.Attr.External() && !s.Attr.DuplicateOK() {
Diag("%s: duplicate definition of %s", pn, s.Name)
}
s.Attr |= AttrExternal
}
sym.sym = s
}
// Sort outer lists by address, adding to textp.
// This keeps textp in increasing address order.
for i := 0; uint32(i) < c.seg.nsect; i++ {
sect = &c.seg.sect[i]
s = sect.sym
if s == nil {
continue
}
if s.Sub != nil {
s.Sub = listsort(s.Sub, valuecmp, listsubp)
// assign sizes, now that we know symbols in sorted order.
for s1 = s.Sub; s1 != nil; s1 = s1.Sub {
if s1.Sub != nil {
s1.Size = s1.Sub.Value - s1.Value
} else {
s1.Size = s.Value + s.Size - s1.Value
}
}
}
if s.Type == obj.STEXT {
if s.Attr.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Attr |= AttrOnList
Ctxt.Textp = append(Ctxt.Textp, s)
for s1 = s.Sub; s1 != nil; s1 = s1.Sub {
if s1.Attr.OnList() {
log.Fatalf("symbol %s listed multiple times", s1.Name)
}
s1.Attr |= AttrOnList
Ctxt.Textp = append(Ctxt.Textp, s1)
}
}
}
// load relocations
for i := 0; uint32(i) < c.seg.nsect; i++ {
sect = &c.seg.sect[i]
s = sect.sym
if s == nil {
continue
}
macholoadrel(m, sect)
if sect.rel == nil {
continue
}
r = make([]Reloc, sect.nreloc)
rpi = 0
Reloc:
for j = 0; uint32(j) < sect.nreloc; j++ {
rp = &r[rpi]
rel = §.rel[j]
if rel.scattered != 0 {
if SysArch.Family != sys.I386 {
// mach-o only uses scattered relocation on 32-bit platforms
Diag("unexpected scattered relocation")
continue
}
// on 386, rewrite scattered 4/1 relocation and some
// scattered 2/1 relocation into the pseudo-pc-relative
// reference that it is.
// assume that the second in the pair is in this section
// and use that as the pc-relative base.
if uint32(j+1) >= sect.nreloc {
err = fmt.Errorf("unsupported scattered relocation %d", int(rel.type_))
goto bad
}
if sect.rel[j+1].scattered == 0 || sect.rel[j+1].type_ != 1 || (rel.type_ != 4 && rel.type_ != 2) || uint64(sect.rel[j+1].value) < sect.addr || uint64(sect.rel[j+1].value) >= sect.addr+sect.size {
err = fmt.Errorf("unsupported scattered relocation %d/%d", int(rel.type_), int(sect.rel[j+1].type_))
goto bad
}
rp.Siz = rel.length
rp.Off = int32(rel.addr)
// NOTE(rsc): I haven't worked out why (really when)
// we should ignore the addend on a
// scattered relocation, but it seems that the
// common case is we ignore it.
// It's likely that this is not strictly correct
// and that the math should look something
// like the non-scattered case below.
rp.Add = 0
// want to make it pc-relative aka relative to rp->off+4
// but the scatter asks for relative to off = sect->rel[j+1].value - sect->addr.
// adjust rp->add accordingly.
rp.Type = obj.R_PCREL
rp.Add += int64(uint64(int64(rp.Off)+4) - (uint64(sect.rel[j+1].value) - sect.addr))
// now consider the desired symbol.
// find the section where it lives.
var ks *LdMachoSect
for k := 0; uint32(k) < c.seg.nsect; k++ {
ks = &c.seg.sect[k]
if ks.addr <= uint64(rel.value) && uint64(rel.value) < ks.addr+ks.size {
if ks.sym != nil {
rp.Sym = ks.sym
rp.Add += int64(uint64(rel.value) - ks.addr)
} else if ks.segname == "__IMPORT" && ks.name == "__pointers" {
// handle reference to __IMPORT/__pointers.
// how much worse can this get?
// why are we supporting 386 on the mac anyway?
rp.Type = 512 + MACHO_FAKE_GOTPCREL
// figure out which pointer this is a reference to.
k = int(uint64(ks.res1) + (uint64(rel.value)-ks.addr)/4)
// load indirect table for __pointers
// fetch symbol number
if dsymtab == nil || k < 0 || uint32(k) >= dsymtab.nindirectsyms || dsymtab.indir == nil {
err = fmt.Errorf("invalid scattered relocation: indirect symbol reference out of range")
goto bad
}
k = int(dsymtab.indir[k])
if k < 0 || uint32(k) >= symtab.nsym {
err = fmt.Errorf("invalid scattered relocation: symbol reference out of range")
goto bad
}
rp.Sym = symtab.sym[k].sym
} else {
err = fmt.Errorf("unsupported scattered relocation: reference to %s/%s", ks.segname, ks.name)
goto bad
}
rpi++
// skip #1 of 2 rel; continue skips #2 of 2.
j++
continue Reloc
}
}
err = fmt.Errorf("unsupported scattered relocation: invalid address %#x", rel.addr)
goto bad
}
rp.Siz = rel.length
rp.Type = 512 + (int32(rel.type_) << 1) + int32(rel.pcrel)
rp.Off = int32(rel.addr)
// Handle X86_64_RELOC_SIGNED referencing a section (rel->extrn == 0).
if SysArch.Family == sys.AMD64 && rel.extrn == 0 && rel.type_ == 1 {
// Calculate the addend as the offset into the section.
//
// The rip-relative offset stored in the object file is encoded
// as follows:
//
// movsd 0x00000360(%rip),%xmm0
//
// To get the absolute address of the value this rip-relative address is pointing
// to, we must add the address of the next instruction to it. This is done by
// taking the address of the relocation and adding 4 to it (since the rip-relative
// offset can at most be 32 bits long). To calculate the offset into the section the
// relocation is referencing, we subtract the vaddr of the start of the referenced
// section found in the original object file.
//
// [For future reference, see Darwin's /usr/include/mach-o/x86_64/reloc.h]
secaddr = c.seg.sect[rel.symnum-1].addr
rp.Add = int64(uint64(int64(int32(e.Uint32(s.P[rp.Off:])))+int64(rp.Off)+4) - secaddr)
} else {
rp.Add = int64(int32(e.Uint32(s.P[rp.Off:])))
}
// For i386 Mach-O PC-relative, the addend is written such that
// it *is* the PC being subtracted. Use that to make
// it match our version of PC-relative.
if rel.pcrel != 0 && SysArch.Family == sys.I386 {
rp.Add += int64(rp.Off) + int64(rp.Siz)
}
if rel.extrn == 0 {
if rel.symnum < 1 || rel.symnum > c.seg.nsect {
err = fmt.Errorf("invalid relocation: section reference out of range %d vs %d", rel.symnum, c.seg.nsect)
goto bad
}
rp.Sym = c.seg.sect[rel.symnum-1].sym
if rp.Sym == nil {
err = fmt.Errorf("invalid relocation: %s", c.seg.sect[rel.symnum-1].name)
goto bad
}
// References to symbols in other sections
// include that information in the addend.
// We only care about the delta from the
// section base.
if SysArch.Family == sys.I386 {
rp.Add -= int64(c.seg.sect[rel.symnum-1].addr)
}
} else {
if rel.symnum >= symtab.nsym {
err = fmt.Errorf("invalid relocation: symbol reference out of range")
goto bad
}
rp.Sym = symtab.sym[rel.symnum].sym
}
rpi++
}
sort.Sort(rbyoff(r[:rpi]))
s.R = r
s.R = s.R[:rpi]
}
return
bad:
Diag("%s: malformed mach-o file: %v", pn, err)
}
// Convert raw image data into a 2d array of 64-bit labels
func (d *Data) convertTo64bit(geom dvid.Geometry, data []uint8, bytesPerVoxel, stride int) ([]byte, error) {
nx := int(geom.Size().Value(0))
ny := int(geom.Size().Value(1))
numBytes := nx * ny * 8
data64 := make([]byte, numBytes, numBytes)
var byteOrder binary.ByteOrder
if geom.DataShape().ShapeDimensions() == 2 {
byteOrder = binary.BigEndian // This is the default for PNG
} else {
byteOrder = binary.LittleEndian
}
switch bytesPerVoxel {
case 1:
dstI := 0
for y := 0; y < ny; y++ {
srcI := y * stride
for x := 0; x < nx; x++ {
binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(data[srcI]))
srcI++
dstI += 8
}
}
case 2:
dstI := 0
for y := 0; y < ny; y++ {
srcI := y * stride
for x := 0; x < nx; x++ {
value := byteOrder.Uint16(data[srcI : srcI+2])
binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
srcI += 2
dstI += 8
}
}
case 4:
dstI := 0
for y := 0; y < ny; y++ {
srcI := y * stride
for x := 0; x < nx; x++ {
value := byteOrder.Uint32(data[srcI : srcI+4])
binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
srcI += 4
dstI += 8
}
}
case 8:
dstI := 0
for y := 0; y < ny; y++ {
srcI := y * stride
for x := 0; x < nx; x++ {
value := byteOrder.Uint64(data[srcI : srcI+8])
binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
srcI += 8
dstI += 8
}
}
default:
return nil, fmt.Errorf("could not convert to 64-bit label given %d bytes/voxel", bytesPerVoxel)
}
return data64, nil
}
// parseNotes returns the notes from a SHT_NOTE section or PT_NOTE segment.
func parseNotes(reader io.Reader, alignment int, order binary.ByteOrder) ([]elfNote, error) {
r := bufio.NewReader(reader)
// padding returns the number of bytes required to pad the given size to an
// alignment boundary.
padding := func(size int) int {
return ((size + (alignment - 1)) &^ (alignment - 1)) - size
}
var notes []elfNote
for {
noteHeader := make([]byte, 12) // 3 4-byte words
if _, err := io.ReadFull(r, noteHeader); err == io.EOF {
break
} else if err != nil {
return nil, err
}
namesz := order.Uint32(noteHeader[0:4])
descsz := order.Uint32(noteHeader[4:8])
typ := order.Uint32(noteHeader[8:12])
if uint64(namesz) > uint64(maxNoteSize) {
return nil, fmt.Errorf("note name too long (%d bytes)", namesz)
}
var name string
if namesz > 0 {
// Documentation differs as to whether namesz is meant to include the
// trailing zero, but everyone agrees that name is null-terminated.
// So we'll just determine the actual length after the fact.
var err error
name, err = r.ReadString('\x00')
if err == io.EOF {
return nil, fmt.Errorf("missing note name (want %d bytes)", namesz)
} else if err != nil {
return nil, err
}
namesz = uint32(len(name))
name = name[:len(name)-1]
}
// Drop padding bytes until the desc field.
for n := padding(len(noteHeader) + int(namesz)); n > 0; n-- {
if _, err := r.ReadByte(); err == io.EOF {
return nil, fmt.Errorf(
"missing %d bytes of padding after note name", n)
} else if err != nil {
return nil, err
}
}
if uint64(descsz) > uint64(maxNoteSize) {
return nil, fmt.Errorf("note desc too long (%d bytes)", descsz)
}
desc := make([]byte, int(descsz))
if _, err := io.ReadFull(r, desc); err == io.EOF {
return nil, fmt.Errorf("missing desc (want %d bytes)", len(desc))
} else if err != nil {
return nil, err
}
notes = append(notes, elfNote{Name: name, Desc: desc, Type: typ})
// Drop padding bytes until the next note or the end of the section,
// whichever comes first.
for n := padding(len(desc)); n > 0; n-- {
if _, err := r.ReadByte(); err == io.EOF {
// We hit the end of the section before an alignment boundary.
// This can happen if this section is at the end of the file or the next
// section has a smaller alignment requirement.
break
} else if err != nil {
return nil, err
}
}
}
return notes, nil
}
func walksymtab(data []byte, fn func(sym) error) error {
if len(data) == 0 { // missing symtab is okay
return nil
}
var order binary.ByteOrder = binary.BigEndian
newTable := false
switch {
case bytes.HasPrefix(data, oldLittleEndianSymtab):
// Same as Go 1.0, but little endian.
// Format was used during interim development between Go 1.0 and Go 1.1.
// Should not be widespread, but easy to support.
data = data[6:]
order = binary.LittleEndian
case bytes.HasPrefix(data, bigEndianSymtab):
newTable = true
case bytes.HasPrefix(data, littleEndianSymtab):
newTable = true
order = binary.LittleEndian
}
var ptrsz int
if newTable {
if len(data) < 8 {
return &DecodingError{len(data), "unexpected EOF", nil}
}
ptrsz = int(data[7])
if ptrsz != 4 && ptrsz != 8 {
return &DecodingError{7, "invalid pointer size", ptrsz}
}
data = data[8:]
}
var s sym
p := data
for len(p) >= 4 {
var typ byte
if newTable {
// Symbol type, value, Go type.
typ = p[0] & 0x3F
wideValue := p[0]&0x40 != 0
goType := p[0]&0x80 != 0
if typ < 26 {
typ += 'A'
} else {
typ += 'a' - 26
}
s.typ = typ
p = p[1:]
if wideValue {
if len(p) < ptrsz {
return &DecodingError{len(data), "unexpected EOF", nil}
}
// fixed-width value
if ptrsz == 8 {
s.value = order.Uint64(p[0:8])
p = p[8:]
} else {
s.value = uint64(order.Uint32(p[0:4]))
p = p[4:]
}
} else {
// varint value
s.value = 0
shift := uint(0)
for len(p) > 0 && p[0]&0x80 != 0 {
s.value |= uint64(p[0]&0x7F) << shift
shift += 7
p = p[1:]
}
if len(p) == 0 {
return &DecodingError{len(data), "unexpected EOF", nil}
}
s.value |= uint64(p[0]) << shift
p = p[1:]
}
if goType {
if len(p) < ptrsz {
return &DecodingError{len(data), "unexpected EOF", nil}
}
// fixed-width go type
if ptrsz == 8 {
s.gotype = order.Uint64(p[0:8])
p = p[8:]
} else {
s.gotype = uint64(order.Uint32(p[0:4]))
p = p[4:]
}
}
} else {
// Value, symbol type.
s.value = uint64(order.Uint32(p[0:4]))
if len(p) < 5 {
return &DecodingError{len(data), "unexpected EOF", nil}
}
typ = p[4]
if typ&0x80 == 0 {
return &DecodingError{len(data) - len(p) + 4, "bad symbol type", typ}
}
typ &^= 0x80
s.typ = typ
p = p[5:]
}
// Name.
var i int
var nnul int
for i = 0; i < len(p); i++ {
if p[i] == 0 {
nnul = 1
break
}
}
switch typ {
case 'z', 'Z':
p = p[i+nnul:]
for i = 0; i+2 <= len(p); i += 2 {
if p[i] == 0 && p[i+1] == 0 {
nnul = 2
break
}
}
}
if len(p) < i+nnul {
return &DecodingError{len(data), "unexpected EOF", nil}
}
s.name = p[0:i]
i += nnul
p = p[i:]
if !newTable {
if len(p) < 4 {
return &DecodingError{len(data), "unexpected EOF", nil}
}
// Go type.
s.gotype = uint64(order.Uint32(p[:4]))
p = p[4:]
}
fn(s)
}
return nil
}
func (s *Stream) readSectionHeaderBlockBody(headerData []byte) (header *SectionHeaderBlock, err error) {
//
// read byte-order magic, version and section length
//
bodyData, err := s.read(16)
if err != nil {
return nil, err
}
//
// read byte-order magic
//
var byteOrder binary.ByteOrder
if bodyData[0] == 0x1A && bodyData[1] == 0x2B && bodyData[2] == 0x3C && bodyData[3] == 0x4D {
byteOrder = binary.BigEndian
} else if bodyData[3] == 0x1A && bodyData[2] == 0x2B && bodyData[1] == 0x3C && bodyData[0] == 0x4D {
byteOrder = binary.LittleEndian
} else {
return nil, errors.New("invalid byte order mark")
}
//
// read other fields
//
versionMajor := byteOrder.Uint16(bodyData[4:6])
versionMinor := byteOrder.Uint16(bodyData[6:8])
sectionLength := int64(byteOrder.Uint64(bodyData[8:16]))
//
// Read options
//
totalLength := byteOrder.Uint32(headerData[4:8])
optsLen := totalLength - 28
rawOpts, err := s.readOptions(optsLen, byteOrder)
if err != nil {
return nil, err
}
opts, err := parseSectionHeaderOptions(rawOpts)
if err != nil {
return nil, err
}
//
// Read last block total length
//
_, err = s.readExactly(4)
if err != nil {
return nil, err
}
retval := &SectionHeaderBlock{
totalLength: totalLength,
ByteOrder: byteOrder,
VersionMajor: versionMajor,
VersionMinor: versionMinor,
SectionLength: sectionLength,
RawOptions: rawOpts,
Options: opts,
}
s.sectionHeader = retval
return retval, nil
}
