forked from google/syzkaller
/
validation.go
285 lines (275 loc) · 9.02 KB
/
validation.go
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// Copyright 2015 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 prog
import (
"fmt"
)
var debug = false // enabled in tests
type validCtx struct {
args map[Arg]bool
uses map[Arg]Arg
}
func (p *Prog) Validate() error {
return p.validate()
}
func (p *Prog) validate() error {
ctx := &validCtx{make(map[Arg]bool), make(map[Arg]Arg)}
for _, c := range p.Calls {
if err := c.validate(ctx); err != nil {
return err
}
}
for u, orig := range ctx.uses {
if !ctx.args[u] {
return fmt.Errorf("use of %+v referes to an out-of-tree arg\narg: %#v", orig, u)
}
}
return nil
}
func (c *Call) validate(ctx *validCtx) error {
if c.Meta == nil {
return fmt.Errorf("call does not have meta information")
}
if len(c.Args) != len(c.Meta.Args) {
return fmt.Errorf("syscall %v: wrong number of arguments, want %v, got %v", c.Meta.Name, len(c.Meta.Args), len(c.Args))
}
var checkArg func(arg Arg) error
checkArg = func(arg Arg) error {
if arg == nil {
return fmt.Errorf("syscall %v: nil arg", c.Meta.Name)
}
if ctx.args[arg] {
return fmt.Errorf("syscall %v: arg is referenced several times in the tree", c.Meta.Name)
}
ctx.args[arg] = true
if used, ok := arg.(ArgUsed); ok {
for u := range *used.Used() {
if u == nil {
return fmt.Errorf("syscall %v: nil reference in uses for arg %+v", c.Meta.Name, arg)
}
ctx.uses[u] = arg
}
}
if arg.Type() == nil {
return fmt.Errorf("syscall %v: no type", c.Meta.Name)
}
if arg.Type().Dir() == DirOut {
switch a := arg.(type) {
case *ConstArg:
// We generate output len arguments, which makes sense since it can be
// a length of a variable-length array which is not known otherwise.
if _, ok := a.Type().(*LenType); ok {
break
}
if a.Val != 0 && a.Val != a.Type().Default() {
return fmt.Errorf("syscall %v: output arg '%v'/'%v' has non default value '%+v'", c.Meta.Name, a.Type().FieldName(), a.Type().Name(), a)
}
case *DataArg:
for _, v := range a.Data {
if v != 0 {
return fmt.Errorf("syscall %v: output arg '%v' has data", c.Meta.Name, a.Type().Name())
}
}
}
}
switch typ1 := arg.Type().(type) {
case *IntType:
switch a := arg.(type) {
case *ConstArg:
if a.Type().Dir() == DirOut && (a.Val != 0 && a.Val != a.Type().Default()) {
return fmt.Errorf("syscall %v: out int arg '%v' has bad const value %v", c.Meta.Name, a.Type().Name(), a.Val)
}
case *ReturnArg:
default:
return fmt.Errorf("syscall %v: int arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *ResourceType:
switch a := arg.(type) {
case *ResultArg:
if a.Type().Dir() == DirOut && (a.Val != 0 && a.Val != a.Type().Default()) {
return fmt.Errorf("syscall %v: out resource arg '%v' has bad const value %v", c.Meta.Name, a.Type().Name(), a.Val)
}
case *ReturnArg:
case *ConstArg:
return fmt.Errorf("syscall %v: fd arg '%v' has bad kind ConstantArg %v", c.Meta.Name, arg.Type().Name(), arg)
default:
return fmt.Errorf("syscall %v: fd arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *StructType, *ArrayType:
switch arg.(type) {
case *GroupArg:
default:
return fmt.Errorf("syscall %v: struct/array arg '%v' has bad kind %#v",
c.Meta.Name, arg.Type().Name(), arg)
}
case *UnionType:
switch arg.(type) {
case *UnionArg:
case *GroupArg:
return fmt.Errorf("syscall %v: union arg '%v' instead has a group kind %v %s", c.Meta.Name, arg.Type().Name(), arg)
default:
return fmt.Errorf("syscall %v: union arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *ProcType:
switch a := arg.(type) {
case *ConstArg:
if a.Val >= typ1.ValuesPerProc {
return fmt.Errorf("syscall %v: per proc arg '%v' has bad value '%v'", c.Meta.Name, a.Type().Name(), a.Val)
}
default:
return fmt.Errorf("syscall %v: proc arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *BufferType:
switch a := arg.(type) {
case *DataArg:
switch typ1.Kind {
case BufferString:
if typ1.TypeSize != 0 && uint64(len(a.Data)) != typ1.TypeSize {
return fmt.Errorf("syscall %v: string arg '%v' has size %v, which should be %v",
c.Meta.Name, a.Type().Name(), len(a.Data), typ1.TypeSize)
}
}
default:
return fmt.Errorf("syscall %v: buffer arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *CsumType:
switch a := arg.(type) {
case *ConstArg:
if a.Val != 0 {
return fmt.Errorf("syscall %v: csum arg '%v' has nonzero value %v", c.Meta.Name, a.Type().Name(), a.Val)
}
default:
return fmt.Errorf("syscall %v: csum arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
case *PtrType:
switch a := arg.(type) {
case *PointerArg:
if a.Type().Dir() == DirOut {
return fmt.Errorf("syscall %v: pointer arg '%v' has output direction", c.Meta.Name, a.Type().Name())
}
if a.Res == nil && !a.Type().Optional() {
return fmt.Errorf("syscall %v: non optional pointer arg '%v' is nil", c.Meta.Name, a.Type().Name())
}
default:
return fmt.Errorf("syscall %v: ptr arg '%v' has bad kind %v", c.Meta.Name, arg.Type().Name(), arg)
}
}
switch a := arg.(type) {
case *ConstArg:
case *PointerArg:
switch t := a.Type().(type) {
case *VmaType:
if a.Res != nil {
return fmt.Errorf("syscall %v: vma arg '%v' has data", c.Meta.Name, a.Type().Name())
}
if a.PagesNum == 0 && t.Dir() != DirOut && !t.Optional() {
return fmt.Errorf("syscall %v: vma arg '%v' has size 0", c.Meta.Name, a.Type().Name())
}
case *PtrType:
if a.Res != nil {
if err := checkArg(a.Res); err != nil {
return err
}
}
if a.PagesNum != 0 {
return fmt.Errorf("syscall %v: pointer arg '%v' has nonzero size", c.Meta.Name, a.Type().Name())
}
default:
return fmt.Errorf("syscall %v: pointer arg '%v' has bad meta type %+v", c.Meta.Name, arg.Type().Name(), arg.Type())
}
case *DataArg:
switch typ1 := a.Type().(type) {
case *ArrayType:
if typ2, ok := typ1.Type.(*IntType); !ok || typ2.Size() != 1 {
return fmt.Errorf("syscall %v: data arg '%v' should be an array", c.Meta.Name, a.Type().Name())
}
}
case *GroupArg:
switch typ1 := a.Type().(type) {
case *StructType:
if len(a.Inner) != len(typ1.Fields) {
return fmt.Errorf("syscall %v: struct arg '%v' has wrong number of fields: want %v, got %v", c.Meta.Name, a.Type().Name(), len(typ1.Fields), len(a.Inner))
}
for _, arg1 := range a.Inner {
if err := checkArg(arg1); err != nil {
return err
}
}
case *ArrayType:
for _, arg1 := range a.Inner {
if err := checkArg(arg1); err != nil {
return err
}
}
default:
return fmt.Errorf("syscall %v: group arg '%v' has bad underlying type %+v", c.Meta.Name, arg.Type().Name(), arg.Type())
}
case *UnionArg:
typ1, ok := a.Type().(*UnionType)
if !ok {
return fmt.Errorf("syscall %v: union arg '%v' has bad type", c.Meta.Name, a.Type().Name())
}
found := false
for _, typ2 := range typ1.Fields {
if a.OptionType.Name() == typ2.Name() {
found = true
break
}
}
if !found {
return fmt.Errorf("syscall %v: union arg '%v' has bad option", c.Meta.Name, a.Type().Name())
}
if err := checkArg(a.Option); err != nil {
return err
}
case *ResultArg:
switch a.Type().(type) {
case *ResourceType:
default:
return fmt.Errorf("syscall %v: result arg '%v' has bad meta type %+v", c.Meta.Name, arg.Type().Name(), arg.Type())
}
if a.Res == nil {
break
}
if !ctx.args[a.Res] {
return fmt.Errorf("syscall %v: result arg '%v' references out-of-tree result: %p%+v -> %p%+v",
c.Meta.Name, a.Type().Name(), arg, arg, a.Res, a.Res)
}
if _, ok := (*a.Res.(ArgUsed).Used())[arg]; !ok {
return fmt.Errorf("syscall %v: result arg '%v' has broken link (%+v)", c.Meta.Name, a.Type().Name(), *a.Res.(ArgUsed).Used())
}
case *ReturnArg:
switch a.Type().(type) {
case *ResourceType:
case *VmaType:
default:
return fmt.Errorf("syscall %v: result arg '%v' has bad meta type %+v", c.Meta.Name, arg.Type().Name(), arg.Type())
}
default:
return fmt.Errorf("syscall %v: unknown arg '%v' kind", c.Meta.Name, arg.Type().Name())
}
return nil
}
for _, arg := range c.Args {
if _, ok := arg.(*ReturnArg); ok {
return fmt.Errorf("syscall %v: arg '%v' has wrong return kind", c.Meta.Name, arg.Type().Name())
}
if err := checkArg(arg); err != nil {
return err
}
}
if c.Ret == nil {
return fmt.Errorf("syscall %v: return value is absent", c.Meta.Name)
}
if _, ok := c.Ret.(*ReturnArg); !ok {
return fmt.Errorf("syscall %v: return value has wrong kind %v", c.Meta.Name, c.Ret)
}
if c.Meta.Ret != nil {
if err := checkArg(c.Ret); err != nil {
return err
}
} else if c.Ret.Type() != nil {
return fmt.Errorf("syscall %v: return value has spurious type: %+v", c.Meta.Name, c.Ret.Type())
}
return nil
}