syzkaller/pkg/compiler/types.go
Dmitry Vyukov ffe7e17368 prog, sys: move types to prog
Large overhaul moves syscalls and arg types from sys to prog.
Sys package now depends on prog and contains only generated
descriptions of syscalls.
Introduce prog.Target type that encapsulates all targer properties,
like syscall list, ptr/page size, etc. Also moves OS-dependent pieces
like mmap call generation from prog to sys.

Update #191
2017-09-05 15:52:42 +02:00

681 lines
18 KiB
Go

// Copyright 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
package compiler
import (
"fmt"
"strconv"
"github.com/google/syzkaller/pkg/ast"
"github.com/google/syzkaller/prog"
)
// typeDesc is arg/field type descriptor.
type typeDesc struct {
Names []string
CanBeArg bool // can be argument of syscall?
CantBeOpt bool // can't be marked as opt?
CantBeRet bool // can't be syscall return (directly or indirectly)?
NeedBase bool // needs base type when used as field?
AllowColon bool // allow colon (int8:2) on fields?
ResourceBase bool // can be resource base type?
OptArgs int // number of optional arguments in Args array
Args []namedArg // type arguments
// Check does custom verification of the type (optional).
Check func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon)
// Varlen returns if the type is variable-length (false if not set).
Varlen func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool
// Gen generates corresponding prog.Type.
Gen func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type
}
// typeArg describes a type argument.
type typeArg struct {
Names []string
Kind int // int/ident/string
AllowColon bool // allow colon (2:3)?
// Check does custom verification of the arg (optional).
Check func(comp *compiler, t *ast.Type)
}
type namedArg struct {
Name string
Type *typeArg
}
const (
kindAny = iota
kindInt
kindIdent
kindString
)
var typeInt = &typeDesc{
Names: []string{"int8", "int16", "int32", "int64", "int16be", "int32be", "int64be", "intptr"},
CanBeArg: true,
AllowColon: true,
ResourceBase: true,
OptArgs: 1,
Args: []namedArg{{"range", typeArgRange}},
Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
typeArgBase.Type.Check(comp, t)
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
size, be := comp.parseIntType(t.Ident)
kind, rangeBegin, rangeEnd := prog.IntPlain, uint64(0), uint64(0)
if len(args) > 0 {
kind, rangeBegin, rangeEnd = prog.IntRange, args[0].Value, args[0].Value2
}
base.TypeSize = size
return &prog.IntType{
IntTypeCommon: genIntCommon(base.TypeCommon, t.Value2, be),
Kind: kind,
RangeBegin: rangeBegin,
RangeEnd: rangeEnd,
}
},
}
var typePtr = &typeDesc{
Names: []string{"ptr", "ptr64"},
CanBeArg: true,
Args: []namedArg{{"direction", typeArgDir}, {"type", typeArgType}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
base.ArgDir = prog.DirIn // pointers are always in
base.TypeSize = comp.ptrSize
if t.Ident == "ptr64" {
base.TypeSize = 8
}
return &prog.PtrType{
TypeCommon: base.TypeCommon,
Type: comp.genType(args[1], "", genDir(args[0]), false),
}
},
}
var typeArray = &typeDesc{
Names: []string{"array"},
CantBeOpt: true,
OptArgs: 1,
Args: []namedArg{{"type", typeArgType}, {"size", typeArgRange}},
Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
if len(args) > 1 && args[1].Value == 0 && args[1].Value2 == 0 {
// This is the only case that can yield 0 static type size.
comp.error(args[1].Pos, "arrays of size 0 are not supported")
}
},
Varlen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool {
if comp.isVarlen(args[0]) {
return true
}
if len(args) > 1 {
return args[1].Value != args[1].Value2
}
return true
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
elemType := comp.genType(args[0], "", base.ArgDir, false)
kind, begin, end := prog.ArrayRandLen, uint64(0), uint64(0)
if len(args) > 1 {
kind, begin, end = prog.ArrayRangeLen, args[1].Value, args[1].Value2
}
if it, ok := elemType.(*prog.IntType); ok && it.Kind == prog.IntPlain && it.TypeSize == 1 {
// Special case: buffer is better mutated.
bufKind := prog.BufferBlobRand
base.TypeSize = 0
if kind == prog.ArrayRangeLen {
bufKind = prog.BufferBlobRange
if begin == end {
base.TypeSize = begin * elemType.Size()
}
}
return &prog.BufferType{
TypeCommon: base.TypeCommon,
Kind: bufKind,
RangeBegin: begin,
RangeEnd: end,
}
}
// TypeSize is assigned later in genStructDescs.
return &prog.ArrayType{
TypeCommon: base.TypeCommon,
Type: elemType,
Kind: kind,
RangeBegin: begin,
RangeEnd: end,
}
},
}
var typeLen = &typeDesc{
Names: []string{"len", "bytesize", "bytesize2", "bytesize4", "bytesize8"},
CanBeArg: true,
CantBeOpt: true,
CantBeRet: true,
NeedBase: true,
Args: []namedArg{{"len target", typeArgLenTarget}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
var byteSize uint64
switch t.Ident {
case "bytesize":
byteSize = 1
case "bytesize2", "bytesize4", "bytesize8":
byteSize, _ = strconv.ParseUint(t.Ident[8:], 10, 8)
}
return &prog.LenType{
IntTypeCommon: base,
Buf: args[0].Ident,
ByteSize: byteSize,
}
},
}
var typeConst = &typeDesc{
Names: []string{"const"},
CanBeArg: true,
CantBeOpt: true,
NeedBase: true,
Args: []namedArg{{"value", typeArgInt}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
return &prog.ConstType{
IntTypeCommon: base,
Val: args[0].Value,
}
},
}
var typeArgLenTarget = &typeArg{
Kind: kindIdent,
}
var typeFlags = &typeDesc{
Names: []string{"flags"},
CanBeArg: true,
CantBeOpt: true,
NeedBase: true,
Args: []namedArg{{"flags", typeArgFlags}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
name := args[0].Ident
base.TypeName = name
f := comp.intFlags[name]
if len(f.Values) == 0 {
// We can get this if all values are unsupported consts.
return &prog.IntType{
IntTypeCommon: base,
Kind: prog.IntPlain,
}
}
return &prog.FlagsType{
IntTypeCommon: base,
Vals: genIntArray(f.Values),
}
},
}
var typeArgFlags = &typeArg{
Kind: kindIdent,
Check: func(comp *compiler, t *ast.Type) {
if comp.intFlags[t.Ident] == nil {
comp.error(t.Pos, "unknown flags %v", t.Ident)
return
}
},
}
var typeFilename = &typeDesc{
Names: []string{"filename"},
CantBeOpt: true,
Varlen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool {
return true
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
base.TypeSize = 0
return &prog.BufferType{
TypeCommon: base.TypeCommon,
Kind: prog.BufferFilename,
}
},
}
var typeFileoff = &typeDesc{
Names: []string{"fileoff"},
CanBeArg: true,
CantBeOpt: true,
NeedBase: true,
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
return &prog.IntType{
IntTypeCommon: base,
Kind: prog.IntFileoff,
}
},
}
var typeVMA = &typeDesc{
Names: []string{"vma"},
CanBeArg: true,
OptArgs: 1,
Args: []namedArg{{"size range", typeArgRange}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
begin, end := uint64(0), uint64(0)
if len(args) > 0 {
begin, end = args[0].Value, args[0].Value2
}
base.TypeSize = comp.ptrSize
return &prog.VmaType{
TypeCommon: base.TypeCommon,
RangeBegin: begin,
RangeEnd: end,
}
},
}
// TODO(dvyukov): perhaps, we need something like typedefs for such types.
// So that users can introduce them as necessary without modifying compiler:
// type signalno int32[0:64]
var typeSignalno = &typeDesc{
Names: []string{"signalno"},
CanBeArg: true,
CantBeOpt: true,
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
base.TypeSize = 4
return &prog.IntType{
IntTypeCommon: base,
Kind: prog.IntRange,
RangeBegin: 0,
RangeEnd: 65,
}
},
}
var typeCsum = &typeDesc{
Names: []string{"csum"},
NeedBase: true,
CantBeOpt: true,
CantBeRet: true,
OptArgs: 1,
Args: []namedArg{{"csum target", typeArgLenTarget}, {"kind", typeArgCsumType}, {"proto", typeArgInt}},
Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
if len(args) > 2 && genCsumKind(args[1]) != prog.CsumPseudo {
comp.error(args[2].Pos, "only pseudo csum can have proto")
}
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
var proto uint64
if len(args) > 2 {
proto = args[2].Value
}
return &prog.CsumType{
IntTypeCommon: base,
Buf: args[0].Ident,
Kind: genCsumKind(args[1]),
Protocol: proto,
}
},
}
var typeArgCsumType = &typeArg{
Kind: kindIdent,
Names: []string{"inet", "pseudo"},
}
func genCsumKind(t *ast.Type) prog.CsumKind {
switch t.Ident {
case "inet":
return prog.CsumInet
case "pseudo":
return prog.CsumPseudo
default:
panic(fmt.Sprintf("unknown csum kind %q", t.Ident))
}
}
var typeProc = &typeDesc{
Names: []string{"proc"},
CanBeArg: true,
CantBeOpt: true,
NeedBase: true,
Args: []namedArg{{"range start", typeArgInt}, {"per-proc values", typeArgInt}},
Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
start := args[0].Value
perProc := args[1].Value
if perProc == 0 {
comp.error(args[1].Pos, "proc per-process values must not be 0")
return
}
size := base.TypeSize * 8
if size != 64 {
const maxPids = 32 // executor knows about this constant (MAX_PIDS)
if start >= 1<<size {
comp.error(args[0].Pos, "values starting from %v overflow base type", start)
} else if start+maxPids*perProc >= 1<<size {
comp.error(args[0].Pos, "values starting from %v with step %v overflow base type for %v procs",
start, perProc, maxPids)
}
}
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
return &prog.ProcType{
IntTypeCommon: base,
ValuesStart: args[0].Value,
ValuesPerProc: args[1].Value,
}
},
}
var typeText = &typeDesc{
Names: []string{"text"},
CantBeOpt: true,
Args: []namedArg{{"kind", typeArgTextType}},
Varlen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool {
return true
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
base.TypeSize = 0
return &prog.BufferType{
TypeCommon: base.TypeCommon,
Kind: prog.BufferText,
Text: genTextType(args[0]),
}
},
}
var typeArgTextType = &typeArg{
Kind: kindIdent,
Names: []string{"x86_real", "x86_16", "x86_32", "x86_64", "arm64"},
}
func genTextType(t *ast.Type) prog.TextKind {
switch t.Ident {
case "x86_real":
return prog.Text_x86_real
case "x86_16":
return prog.Text_x86_16
case "x86_32":
return prog.Text_x86_32
case "x86_64":
return prog.Text_x86_64
case "arm64":
return prog.Text_arm64
default:
panic(fmt.Sprintf("unknown text type %q", t.Ident))
}
}
var typeBuffer = &typeDesc{
Names: []string{"buffer"},
CanBeArg: true,
Args: []namedArg{{"direction", typeArgDir}},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
base.TypeSize = comp.ptrSize
return &prog.PtrType{
TypeCommon: base.TypeCommon,
Type: &prog.BufferType{
// BufferBlobRand is always varlen.
TypeCommon: genCommon("", "", 0, genDir(args[0]), false),
Kind: prog.BufferBlobRand,
},
}
},
}
var typeString = &typeDesc{
Names: []string{"string"},
OptArgs: 2,
Args: []namedArg{{"literal or flags", typeArgStringFlags}, {"size", typeArgInt}},
Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
if len(args) > 1 {
size := args[1].Value
vals := []string{args[0].String}
if args[0].Ident != "" {
vals = genStrArray(comp.strFlags[args[0].Ident].Values)
}
for _, s := range vals {
s += "\x00"
if uint64(len(s)) > size {
comp.error(args[0].Pos, "string value %q exceeds buffer length %v",
s, size)
}
}
}
},
Varlen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool {
return comp.stringSize(args) == 0
},
Gen: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
subkind := ""
var vals []string
if len(args) > 0 {
if args[0].String != "" {
vals = append(vals, args[0].String)
} else {
subkind = args[0].Ident
vals = genStrArray(comp.strFlags[subkind].Values)
}
}
var size uint64
if len(args) > 1 {
size = args[1].Value
}
for i, s := range vals {
s += "\x00"
for uint64(len(s)) < size {
s += "\x00"
}
vals[i] = s
}
base.TypeSize = comp.stringSize(args)
return &prog.BufferType{
TypeCommon: base.TypeCommon,
Kind: prog.BufferString,
SubKind: subkind,
Values: vals,
}
},
}
// stringSize returns static string size, or 0 if it is variable length.
func (comp *compiler) stringSize(args []*ast.Type) uint64 {
switch len(args) {
case 0:
return 0 // a random string
case 1:
if args[0].String != "" {
return uint64(len(args[0].String)) + 1 // string constant
}
var size uint64
for _, s := range comp.strFlags[args[0].Ident].Values {
s1 := uint64(len(s.Value)) + 1
if size != 0 && size != s1 {
return 0 // strings of different lengths
}
size = s1
}
return size // all strings have the same length
case 2:
return args[1].Value // have explicit length
default:
panic("too many string args")
}
}
var typeArgStringFlags = &typeArg{
Check: func(comp *compiler, t *ast.Type) {
if t.String == "" && t.Ident == "" {
comp.error(t.Pos, "unexpected int %v, string arg must be a string literal or string flags", t.Value)
return
}
if t.Ident != "" && comp.strFlags[t.Ident] == nil {
comp.error(t.Pos, "unknown string flags %v", t.Ident)
return
}
},
}
// typeArgType is used as placeholder for any type (e.g. ptr target type).
var typeArgType = &typeArg{
Check: func(comp *compiler, t *ast.Type) {
panic("must not be called")
},
}
var typeResource = &typeDesc{
// No Names, but compiler knows how to match it.
CanBeArg: true,
ResourceBase: true,
// Gen is assigned below to avoid initialization loop.
}
func init() {
typeResource.Gen = func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
// Find and generate base type to get its size.
var baseType *ast.Type
for r := comp.resources[t.Ident]; r != nil; {
baseType = r.Base
r = comp.resources[r.Base.Ident]
}
base.TypeSize = comp.genType(baseType, "", prog.DirIn, false).Size()
return &prog.ResourceType{
TypeCommon: base.TypeCommon,
}
}
}
var typeStruct = &typeDesc{
// No Names, but compiler knows how to match it.
CantBeOpt: true,
// Varlen/Gen are assigned below due to initialization cycle.
}
func init() {
typeStruct.Varlen = func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) bool {
return comp.isStructVarlen(t.Ident)
}
typeStruct.Gen = func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) prog.Type {
s := comp.structs[t.Ident]
key := prog.StructKey{t.Ident, base.ArgDir}
desc := comp.structDescs[key]
if desc == nil {
// Need to assign to structDescs before calling genStructDesc to break recursion.
desc = new(prog.StructDesc)
comp.structDescs[key] = desc
comp.genStructDesc(desc, s, base.ArgDir)
}
if s.IsUnion {
return &prog.UnionType{
Key: key,
FldName: base.FldName,
StructDesc: desc,
}
} else {
return &prog.StructType{
Key: key,
FldName: base.FldName,
StructDesc: desc,
}
}
}
}
var typeArgDir = &typeArg{
Kind: kindIdent,
Names: []string{"in", "out", "inout"},
}
func genDir(t *ast.Type) prog.Dir {
switch t.Ident {
case "in":
return prog.DirIn
case "out":
return prog.DirOut
case "inout":
return prog.DirInOut
default:
panic(fmt.Sprintf("unknown direction %q", t.Ident))
}
}
var typeArgInt = &typeArg{
Kind: kindInt,
}
var typeArgRange = &typeArg{
Kind: kindInt,
AllowColon: true,
Check: func(comp *compiler, t *ast.Type) {
if !t.HasColon {
t.Value2 = t.Value
}
if t.Value > t.Value2 {
comp.error(t.Pos, "bad int range [%v:%v]", t.Value, t.Value2)
}
},
}
// Base type of const/len/etc. Same as typeInt, but can't have range.
var typeArgBase = namedArg{
Name: "base type",
Type: &typeArg{
Names: []string{"int8", "int16", "int32", "int64", "int16be", "int32be", "int64be", "intptr"},
AllowColon: true,
Check: func(comp *compiler, t *ast.Type) {
if t.HasColon {
if t.Value2 == 0 {
// This was not supported historically
// and does not work the way C bitfields of size 0 work.
// We could allow this, but then we need to make
// this work the way C bitfields work.
comp.error(t.Pos2, "bitfields of size 0 are not supported")
}
size, _ := comp.parseIntType(t.Ident)
if t.Value2 > size*8 {
comp.error(t.Pos2, "bitfield of size %v is too large for base type of size %v",
t.Value2, size*8)
}
}
},
},
}
var (
builtinTypes = make(map[string]*typeDesc)
// To avoid weird cases like ptr[in, in] and ptr[out, opt].
reservedName = map[string]bool{
"opt": true,
"in": true,
"out": true,
"inout": true,
}
)
func init() {
builtins := []*typeDesc{
typeInt,
typePtr,
typeArray,
typeLen,
typeConst,
typeFlags,
typeFilename,
typeFileoff,
typeVMA,
typeSignalno,
typeCsum,
typeProc,
typeText,
typeBuffer,
typeString,
typeResource,
typeStruct,
}
for _, desc := range builtins {
for _, name := range desc.Names {
if builtinTypes[name] != nil {
panic(fmt.Sprintf("duplicate builtin type %q", name))
}
builtinTypes[name] = desc
}
}
}