func (a *Arg) serialize(buf io.Writer, vars map[*Arg]int, varSeq *int) {
if a == nil {
fmt.Fprintf(buf, "nil")
return
}
if len(a.Uses) != 0 {
fmt.Fprintf(buf, "<r%v=>", *varSeq)
vars[a] = *varSeq
*varSeq++
}
switch a.Kind {
case ArgConst:
fmt.Fprintf(buf, "0x%x", a.Val)
case ArgResult:
id, ok := vars[a.Res]
if !ok {
panic("no result")
}
fmt.Fprintf(buf, "r%v", id)
if a.OpDiv != 0 {
fmt.Fprintf(buf, "/%v", a.OpDiv)
}
if a.OpAdd != 0 {
fmt.Fprintf(buf, "+%v", a.OpAdd)
}
case ArgPointer:
fmt.Fprintf(buf, "&%v=", serializeAddr(a, true))
a.Res.serialize(buf, vars, varSeq)
case ArgPageSize:
fmt.Fprintf(buf, "%v", serializeAddr(a, false))
case ArgData:
fmt.Fprintf(buf, "\"%v\"", hex.EncodeToString(a.Data))
case ArgGroup:
var delims []byte
switch a.Type.(type) {
case *sys.StructType:
delims = []byte{'{', '}'}
case sys.ArrayType:
delims = []byte{'[', ']'}
default:
panic("unknown group type")
}
buf.Write([]byte{delims[0]})
for i, a1 := range a.Inner {
if a1 != nil && sys.IsPad(a1.Type) {
continue
}
if i != 0 {
fmt.Fprintf(buf, ", ")
}
a1.serialize(buf, vars, varSeq)
}
buf.Write([]byte{delims[1]})
case ArgUnion:
fmt.Fprintf(buf, "@%v=", a.OptionType.Name())
a.Option.serialize(buf, vars, varSeq)
default:
panic("unknown arg kind")
}
}
func (p *Prog) Serialize() []byte {
/*
if err := p.validate(); err != nil {
panic("serializing invalid program")
}
*/
buf := new(bytes.Buffer)
vars := make(map[*Arg]int)
varSeq := 0
for _, c := range p.Calls {
if len(c.Ret.Uses) != 0 {
fmt.Fprintf(buf, "r%v = ", varSeq)
vars[c.Ret] = varSeq
varSeq++
}
fmt.Fprintf(buf, "%v(", c.Meta.Name)
for i, a := range c.Args {
if sys.IsPad(a.Type) {
continue
}
if i != 0 {
fmt.Fprintf(buf, ", ")
}
a.serialize(buf, vars, &varSeq)
}
fmt.Fprintf(buf, ")\n")
}
return buf.Bytes()
}
func assignSizes(args []*Arg) {
// Create a map of args and calculate size of the whole struct.
argsMap := make(map[string]*Arg)
var parentSize uintptr
for _, arg := range args {
parentSize += arg.Size()
if sys.IsPad(arg.Type) {
continue
}
argsMap[arg.Type.Name()] = arg
}
// Fill in size arguments.
for _, arg := range args {
if arg = arg.InnerArg(); arg == nil {
continue // Pointer to optional len field, no need to fill in value.
}
if typ, ok := arg.Type.(*sys.LenType); ok {
if typ.Buf == "parent" {
arg.Val = parentSize
continue
}
buf, ok := argsMap[typ.Buf]
if !ok {
panic(fmt.Sprintf("len field '%v' references non existent field '%v', argsMap: %+v",
typ.Name(), typ.Buf, argsMap))
}
*arg = *generateSize(buf.InnerArg(), typ)
}
}
}
func assignSizes(types []sys.Type, args []*Arg) {
argsMap := make(map[string]*Arg)
typesMap := make(map[string]sys.Type)
// Create a map of args and types.
for i, typ := range types {
if sys.IsPad(typ) {
continue
}
if typ.Name() == "parent" {
panic("parent is reserved len name")
}
innerArg := args[i].InnerArg(typ)
innerType := typ.InnerType()
if _, ok := argsMap[typ.Name()]; ok {
panic(fmt.Sprintf("mutiple args with the same name '%v', types: %+v, args: %+v", typ.Name(), types, args))
}
argsMap[typ.Name()] = innerArg
typesMap[typ.Name()] = innerType
}
// Calculate size of the whole struct.
var parentSize uintptr
for i, typ := range types {
parentSize += args[i].Size(typ)
}
// Fill in size arguments.
for i, typ := range types {
if lenType, ok := typ.InnerType().(sys.LenType); ok {
lenArg := args[i].InnerArg(typ)
if lenArg == nil {
// Pointer to optional len field, no need to fill in value.
continue
}
if lenType.Buf == "parent" {
*lenArg = *constArg(parentSize)
continue
}
arg, ok := argsMap[lenType.Buf]
if !ok {
panic(fmt.Sprintf("len field '%v' references non existent field '%v', argsMap: %+v, typesMap: %+v",
lenType.Name(), lenType.Buf, argsMap, typesMap))
}
typ := typesMap[lenType.Buf]
*lenArg = *generateSize(typ, arg, lenType)
}
}
}
func (p *Prog) SerializeForExec(pid int) []byte {
if err := p.validate(); err != nil {
panic(fmt.Errorf("serializing invalid program: %v", err))
}
var instrSeq uintptr
w := &execContext{args: make(map[*Arg]*argInfo)}
for _, c := range p.Calls {
// Calculate arg offsets within structs.
foreachArg(c, func(arg, base *Arg, _ *[]*Arg) {
if base == nil || arg.Kind == ArgGroup || arg.Kind == ArgUnion {
return
}
if w.args[base] == nil {
w.args[base] = &argInfo{}
}
w.args[arg] = &argInfo{Offset: w.args[base].CurSize}
w.args[base].CurSize += arg.Size()
})
// Generate copyin instructions that fill in data into pointer arguments.
foreachArg(c, func(arg, _ *Arg, _ *[]*Arg) {
if arg.Kind == ArgPointer && arg.Res != nil {
var rec func(*Arg)
rec = func(arg1 *Arg) {
if arg1.Kind == ArgGroup {
for _, arg2 := range arg1.Inner {
rec(arg2)
}
return
}
if arg1.Kind == ArgUnion {
rec(arg1.Option)
return
}
if sys.IsPad(arg1.Type) {
return
}
if arg1.Kind == ArgData && len(arg1.Data) == 0 {
return
}
if arg1.Type.Dir() != sys.DirOut {
w.write(ExecInstrCopyin)
w.write(physicalAddr(arg) + w.args[arg1].Offset)
w.writeArg(arg1, pid)
instrSeq++
}
}
rec(arg.Res)
}
})
// Generate the call itself.
w.write(uintptr(c.Meta.ID))
w.write(uintptr(len(c.Args)))
for _, arg := range c.Args {
w.writeArg(arg, pid)
}
w.args[c.Ret] = &argInfo{Idx: instrSeq}
instrSeq++
// Generate copyout instructions that persist interesting return values.
foreachArg(c, func(arg, base *Arg, _ *[]*Arg) {
if len(arg.Uses) == 0 {
return
}
switch arg.Kind {
case ArgReturn:
// Idx is already assigned above.
case ArgConst, ArgResult:
// Create a separate copyout instruction that has own Idx.
if base.Kind != ArgPointer {
panic("arg base is not a pointer")
}
info := w.args[arg]
info.Idx = instrSeq
instrSeq++
w.write(ExecInstrCopyout)
w.write(physicalAddr(base) + info.Offset)
w.write(arg.Size())
default:
panic("bad arg kind in copyout")
}
})
}
w.write(ExecInstrEOF)
return w.buf
}
func parseArg(typ sys.Type, p *parser, vars map[string]*Arg) (*Arg, error) {
r := ""
if p.Char() == '<' {
p.Parse('<')
r = p.Ident()
p.Parse('=')
p.Parse('>')
}
var arg *Arg
switch p.Char() {
case '0':
val := p.Ident()
v, err := strconv.ParseUint(val, 0, 64)
if err != nil {
return nil, fmt.Errorf("wrong arg value '%v': %v", val, err)
}
arg = constArg(uintptr(v))
case 'r':
id := p.Ident()
v, ok := vars[id]
if !ok || v == nil {
return nil, fmt.Errorf("result %v references unknown variable (vars=%+v)", id, vars)
}
arg = resultArg(v)
if p.Char() == '/' {
p.Parse('/')
op := p.Ident()
v, err := strconv.ParseUint(op, 0, 64)
if err != nil {
return nil, fmt.Errorf("wrong result div op: '%v'", op)
}
arg.OpDiv = uintptr(v)
}
if p.Char() == '+' {
p.Parse('+')
op := p.Ident()
v, err := strconv.ParseUint(op, 0, 64)
if err != nil {
return nil, fmt.Errorf("wrong result add op: '%v'", op)
}
arg.OpAdd = uintptr(v)
}
case '&':
var typ1 sys.Type
switch t1 := typ.(type) {
case sys.PtrType:
typ1 = t1.Type
case sys.VmaType:
default:
return nil, fmt.Errorf("& arg is not a pointer: %#v", typ)
}
p.Parse('&')
page, off, size, err := parseAddr(p, true)
if err != nil {
return nil, err
}
p.Parse('=')
inner, err := parseArg(typ1, p, vars)
if err != nil {
return nil, err
}
arg = pointerArg(page, off, size, inner)
case '(':
page, off, _, err := parseAddr(p, false)
if err != nil {
return nil, err
}
arg = pageSizeArg(page, off)
case '"':
p.Parse('"')
val := ""
if p.Char() != '"' {
val = p.Ident()
}
p.Parse('"')
data, err := hex.DecodeString(val)
if err != nil {
return nil, fmt.Errorf("data arg has bad value '%v'", val)
}
arg = dataArg(data)
case '{':
t1, ok := typ.(*sys.StructType)
if !ok {
return nil, fmt.Errorf("'{' arg is not a struct: %#v", typ)
}
p.Parse('{')
var inner []*Arg
for i := 0; p.Char() != '}'; i++ {
if i >= len(t1.Fields) {
return nil, fmt.Errorf("wrong struct arg count: %v, want %v", i+1, len(t1.Fields))
}
fld := t1.Fields[i]
if sys.IsPad(fld) {
inner = append(inner, constArg(0))
} else {
arg, err := parseArg(fld, p, vars)
if err != nil {
return nil, err
}
inner = append(inner, arg)
if p.Char() != '}' {
p.Parse(',')
}
}
}
p.Parse('}')
if sys.IsPad(t1.Fields[len(t1.Fields)-1]) {
inner = append(inner, constArg(0))
}
arg = groupArg(inner)
case '[':
t1, ok := typ.(sys.ArrayType)
if !ok {
return nil, fmt.Errorf("'[' arg is not an array: %#v", typ)
}
p.Parse('[')
var inner []*Arg
for i := 0; p.Char() != ']'; i++ {
arg, err := parseArg(t1.Type, p, vars)
if err != nil {
return nil, err
}
inner = append(inner, arg)
if p.Char() != ']' {
p.Parse(',')
}
}
p.Parse(']')
arg = groupArg(inner)
case '@':
t1, ok := typ.(*sys.UnionType)
if !ok {
return nil, fmt.Errorf("'@' arg is not a union: %#v", typ)
}
p.Parse('@')
name := p.Ident()
p.Parse('=')
var optType sys.Type
for _, t2 := range t1.Options {
if name == t2.Name() {
optType = t2
break
}
}
if optType == nil {
return nil, fmt.Errorf("union arg %v has unknown option: %v", typ.Name(), name)
}
opt, err := parseArg(optType, p, vars)
if err != nil {
return nil, err
}
arg = unionArg(opt, optType)
case 'n':
p.Parse('n')
p.Parse('i')
p.Parse('l')
if r != "" {
return nil, fmt.Errorf("named nil argument")
}
default:
return nil, fmt.Errorf("failed to parse argument at %v (line #%v/%v: %v)", int(p.Char()), p.l, p.i, p.s)
}
if r != "" {
vars[r] = arg
}
return arg, nil
}
func Deserialize(data []byte) (prog *Prog, err error) {
prog = new(Prog)
p := &parser{r: bufio.NewScanner(bytes.NewReader(data))}
vars := make(map[string]*Arg)
for p.Scan() {
if p.EOF() || p.Char() == '#' {
continue
}
name := p.Ident()
r := ""
if p.Char() == '=' {
r = name
p.Parse('=')
name = p.Ident()
}
meta := sys.CallMap[name]
if meta == nil {
return nil, fmt.Errorf("unknown syscall %v", name)
}
c := &Call{Meta: meta}
prog.Calls = append(prog.Calls, c)
p.Parse('(')
for i := 0; p.Char() != ')'; i++ {
if i >= len(meta.Args) {
return nil, fmt.Errorf("wrong call arg count: %v, want %v", i+1, len(meta.Args))
}
typ := meta.Args[i]
if sys.IsPad(typ) {
return nil, fmt.Errorf("padding in syscall %v arguments", name)
}
arg, err := parseArg(typ, p, vars)
if err != nil {
return nil, err
}
c.Args = append(c.Args, arg)
if p.Char() != ')' {
p.Parse(',')
}
}
p.Parse(')')
if !p.EOF() {
return nil, fmt.Errorf("tailing data (line #%v)", p.l)
}
if len(c.Args) != len(meta.Args) {
return nil, fmt.Errorf("wrong call arg count: %v, want %v", len(c.Args), len(meta.Args))
}
if err := assignTypeAndDir(c); err != nil {
return nil, err
}
if r != "" {
vars[r] = c.Ret
}
}
if p.Err() != nil {
return nil, err
}
if err := prog.validate(); err != nil {
return nil, err
}
return
}