/
any.go
324 lines (305 loc) · 8.54 KB
/
any.go
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// Copyright 2018 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"
)
type anyTypes struct {
union *UnionType
array *ArrayType
blob *BufferType
ptrPtr *PtrType
ptr64 *PtrType
res8 *ResourceType
res16 *ResourceType
res32 *ResourceType
res64 *ResourceType
resdec *ResourceType
reshex *ResourceType
resoct *ResourceType
}
func (target *Target) initAnyTypes() {
var anyPtrs *UnionType
for _, typ := range target.types {
if typ.Name() == "ANYPTRS" {
anyPtrs = typ.(*UnionType)
break
}
}
if anyPtrs == nil {
panic("no builtin ANYPTRS type")
}
// These types are generated by builtin descriptions in pkg/compiler/types.go.
target.any.ptrPtr = anyPtrs.Fields[0].Type.(*PtrType)
target.any.ptr64 = anyPtrs.Fields[1].Type.(*PtrType)
target.any.array = target.any.ptrPtr.Elem.(*ArrayType)
target.any.union = target.any.array.Elem.(*UnionType)
target.any.blob = target.any.union.Fields[0].Type.(*BufferType)
target.any.res8 = target.any.union.Fields[1].Type.(*ResourceType)
target.any.res16 = target.any.union.Fields[2].Type.(*ResourceType)
target.any.res32 = target.any.union.Fields[3].Type.(*ResourceType)
target.any.res64 = target.any.union.Fields[4].Type.(*ResourceType)
target.any.resdec = target.any.union.Fields[5].Type.(*ResourceType)
target.any.reshex = target.any.union.Fields[6].Type.(*ResourceType)
target.any.resoct = target.any.union.Fields[7].Type.(*ResourceType)
}
func (target *Target) getAnyPtrType(size uint64) *PtrType {
if size == target.PtrSize {
return target.any.ptrPtr
} else if size == 8 {
return target.any.ptr64
}
panic(fmt.Sprintf("bad pointer size %v", size))
}
func (target *Target) isAnyPtr(typ Type) bool {
ptr, ok := typ.(*PtrType)
return ok && ptr.Elem == target.any.array
}
type complexPtr struct {
arg *PointerArg
call *Call
}
func (p *Prog) complexPtrs() (res []complexPtr) {
for _, c := range p.Calls {
ForeachArg(c, func(arg Arg, ctx *ArgCtx) {
if ptrArg, ok := arg.(*PointerArg); ok && p.Target.isComplexPtr(ptrArg) {
res = append(res, complexPtr{ptrArg, c})
ctx.Stop = true
}
})
}
return
}
func (target *Target) isComplexPtr(arg *PointerArg) bool {
if arg.Res == nil || !arg.Type().(*PtrType).SquashableElem {
return false
}
if target.isAnyPtr(arg.Type()) {
return true
}
complex := false
ForeachSubArg(arg.Res, func(a1 Arg, ctx *ArgCtx) {
switch typ := a1.Type().(type) {
case *StructType:
if typ.Varlen() {
complex = true
ctx.Stop = true
}
case *UnionType:
if typ.Varlen() && len(typ.Fields) > 5 {
complex = true
ctx.Stop = true
}
}
})
return complex
}
func (target *Target) isAnyRes(name string) bool {
return name == target.any.res8.TypeName ||
name == target.any.res16.TypeName ||
name == target.any.res32.TypeName ||
name == target.any.res64.TypeName ||
name == target.any.resdec.TypeName ||
name == target.any.reshex.TypeName ||
name == target.any.resoct.TypeName
}
func (target *Target) CallContainsAny(c *Call) (res bool) {
ForeachArg(c, func(arg Arg, ctx *ArgCtx) {
if target.isAnyPtr(arg.Type()) || res {
res = true
ctx.Stop = true
}
})
return
}
func (target *Target) ArgContainsAny(arg0 Arg) (res bool) {
ForeachSubArg(arg0, func(arg Arg, ctx *ArgCtx) {
if target.isAnyPtr(arg.Type()) || res {
res = true
ctx.Stop = true
}
})
return
}
func (target *Target) squashPtr(arg *PointerArg) {
if arg.Res == nil || arg.VmaSize != 0 {
panic("bad ptr arg")
}
res0 := arg.Res
size0 := res0.Size()
var elems []Arg
target.squashPtrImpl(arg.Res, &elems)
newType := target.getAnyPtrType(arg.Type().Size())
arg.ref = newType.ref()
arg.Res = MakeGroupArg(newType.Elem, DirIn, elems)
if size := arg.Res.Size(); size != size0 {
panic(fmt.Sprintf("squash changed size %v->%v for %v", size0, size, res0.Type()))
}
}
func (target *Target) squashPtrImpl(a Arg, elems *[]Arg) {
if a.Type().BitfieldLength() != 0 {
panic("bitfield in squash")
}
var pad uint64
switch arg := a.(type) {
case *ConstArg:
target.squashConst(arg, elems)
case *ResultArg:
target.squashResult(arg, elems)
case *UnionArg:
if !arg.Type().Varlen() {
pad = arg.Size() - arg.Option.Size()
}
target.squashPtrImpl(arg.Option, elems)
case *DataArg:
if arg.Dir() == DirOut {
pad = arg.Size()
} else {
elem := target.ensureDataElem(elems)
elem.data = append(elem.Data(), arg.Data()...)
}
case *GroupArg:
target.squashGroup(arg, elems)
default:
panic("bad arg kind")
}
if pad != 0 {
elem := target.ensureDataElem(elems)
elem.data = append(elem.Data(), make([]byte, pad)...)
}
}
func (target *Target) squashConst(arg *ConstArg, elems *[]Arg) {
if IsPad(arg.Type()) {
elem := target.ensureDataElem(elems)
elem.data = append(elem.Data(), make([]byte, arg.Size())...)
return
}
v, bf := target.squashedValue(arg)
var data []byte
switch bf {
case FormatNative:
for i := uint64(0); i < arg.Size(); i++ {
data = append(data, byte(v))
v >>= 8
}
case FormatStrDec:
data = []byte(fmt.Sprintf("%020v", v))
case FormatStrHex:
data = []byte(fmt.Sprintf("0x%016x", v))
case FormatStrOct:
data = []byte(fmt.Sprintf("%023o", v))
default:
panic(fmt.Sprintf("unknown binary format: %v", bf))
}
if uint64(len(data)) != arg.Size() {
panic("squashed value of wrong size")
}
elem := target.ensureDataElem(elems)
elem.data = append(elem.Data(), data...)
}
func (target *Target) squashResult(arg *ResultArg, elems *[]Arg) {
var typ *ResourceType
index := -1
switch arg.Type().Format() {
case FormatNative, FormatBigEndian:
switch arg.Size() {
case 1:
typ, index = target.any.res8, 1
case 2:
typ, index = target.any.res16, 2
case 4:
typ, index = target.any.res32, 3
case 8:
typ, index = target.any.res64, 4
default:
panic(fmt.Sprintf("bad size %v", arg.Size()))
}
case FormatStrDec:
typ, index = target.any.resdec, 5
case FormatStrHex:
typ, index = target.any.reshex, 6
case FormatStrOct:
typ, index = target.any.resoct, 7
default:
panic("bad")
}
arg.ref = typ.ref()
*elems = append(*elems, MakeUnionArg(target.any.union, DirIn, arg, index))
}
func (target *Target) squashGroup(arg *GroupArg, elems *[]Arg) {
if typ, ok := arg.Type().(*StructType); ok && typ.OverlayField != 0 {
panic("squashing out_overlay")
}
var bitfield, fieldsSize uint64
for _, fld := range arg.Inner {
fieldsSize += fld.Size()
// Squash bitfields separately.
if fld.Type().IsBitfield() {
bfLen := fld.Type().BitfieldLength()
bfOff := fld.Type().BitfieldOffset()
// Note: we can have a ResultArg here as well,
// but it is unsupported at the moment.
v, bf := target.squashedValue(fld.(*ConstArg))
if bf != FormatNative {
panic(fmt.Sprintf("bitfield has bad format %v", bf))
}
bitfield |= (v & ((1 << bfLen) - 1)) << bfOff
if fld.Size() != 0 {
elem := target.ensureDataElem(elems)
for i := uint64(0); i < fld.Size(); i++ {
elem.data = append(elem.Data(), byte(bitfield))
bitfield >>= 8
}
bitfield = 0
}
continue
}
target.squashPtrImpl(fld, elems)
}
// Add padding either due to dynamic alignment or overlay fields.
if pad := arg.Size() - fieldsSize; pad != 0 {
elem := target.ensureDataElem(elems)
elem.data = append(elem.Data(), make([]byte, pad)...)
}
}
func (target *Target) squashedValue(arg *ConstArg) (uint64, BinaryFormat) {
typ := arg.Type()
bf := typ.Format()
if _, ok := typ.(*CsumType); ok {
// We can't compute value for the checksum here,
// but at least leave something recognizable by hints code.
// TODO: hints code won't recognize this, because it won't find
// the const in any arg. We either need to put this const as
// actual csum arg value, or special case it in hints.
return 0xabcdef1234567890, FormatNative
}
// Note: we need a constant value, but it depends on pid for proc.
v, _ := arg.Value()
if bf == FormatBigEndian {
bf = FormatNative
switch typ.UnitSize() {
case 2:
v = uint64(swap16(uint16(v)))
case 4:
v = uint64(swap32(uint32(v)))
case 8:
v = swap64(v)
default:
panic(fmt.Sprintf("bad const size %v", arg.Size()))
}
}
return v, bf
}
func (target *Target) ensureDataElem(elems *[]Arg) *DataArg {
if len(*elems) == 0 {
res := MakeDataArg(target.any.blob, DirIn, nil)
*elems = append(*elems, MakeUnionArg(target.any.union, DirIn, res, 0))
return res
}
res, ok := (*elems)[len(*elems)-1].(*UnionArg).Option.(*DataArg)
if !ok {
res = MakeDataArg(target.any.blob, DirIn, nil)
*elems = append(*elems, MakeUnionArg(target.any.union, DirIn, res, 0))
}
return res
}