Golang程序
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635行
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15.11 KB
// 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"
"math/rand"
"unsafe"
)
const maxBlobLen = uint64(100 << 10)
func (p *Prog) Mutate(rs rand.Source, ncalls int, ct *ChoiceTable, corpus []*Prog) {
r := newRand(p.Target, rs)
ctx := &mutator{
p: p,
r: r,
ncalls: ncalls,
ct: ct,
corpus: corpus,
}
for stop, ok := false, false; !stop; stop = ok && r.oneOf(3) {
switch {
case r.oneOf(5):
// Not all calls have anything squashable,
// so this has lower priority in reality.
ok = ctx.squashAny()
case r.nOutOf(1, 100):
ok = ctx.splice()
case r.nOutOf(20, 31):
ok = ctx.insertCall()
case r.nOutOf(10, 11):
ok = ctx.mutateArg()
default:
ok = ctx.removeCall()
}
}
for _, c := range p.Calls {
p.Target.SanitizeCall(c)
}
p.debugValidate()
}
type mutator struct {
p *Prog
r *randGen
ncalls int
ct *ChoiceTable
corpus []*Prog
}
func (ctx *mutator) splice() bool {
p, r := ctx.p, ctx.r
if len(ctx.corpus) == 0 || len(p.Calls) == 0 {
return false
}
p0 := ctx.corpus[r.Intn(len(ctx.corpus))]
p0c := p0.Clone()
idx := r.Intn(len(p.Calls))
p.Calls = append(p.Calls[:idx], append(p0c.Calls, p.Calls[idx:]...)...)
for i := len(p.Calls) - 1; i >= ctx.ncalls; i-- {
p.removeCall(i)
}
return true
}
func (ctx *mutator) squashAny() bool {
p, r := ctx.p, ctx.r
complexPtrs := p.complexPtrs()
if len(complexPtrs) == 0 {
return false
}
ptr := complexPtrs[r.Intn(len(complexPtrs))]
if !p.Target.isAnyPtr(ptr.Type()) {
p.Target.squashPtr(ptr, true)
}
var blobs []*DataArg
var bases []*PointerArg
ForeachSubArg(ptr, func(arg Arg, ctx *ArgCtx) {
if data, ok := arg.(*DataArg); ok && arg.Type().Dir() != DirOut {
blobs = append(blobs, data)
bases = append(bases, ctx.Base)
}
})
if len(blobs) == 0 {
return false
}
// TODO(dvyukov): we probably want special mutation for ANY.
// E.g. merging adjacent ANYBLOBs (we don't create them,
// but they can appear in future); or replacing ANYRES
// with a blob (and merging it with adjacent blobs).
idx := r.Intn(len(blobs))
arg := blobs[idx]
base := bases[idx]
baseSize := base.Res.Size()
arg.data = mutateData(r, arg.Data(), 0, maxBlobLen)
// Update base pointer if size has increased.
if baseSize < base.Res.Size() {
s := analyze(ctx.ct, p, p.Calls[0])
newArg := r.allocAddr(s, base.Type(), base.Res.Size(), base.Res)
*base = *newArg
}
return true
}
func (ctx *mutator) insertCall() bool {
p, r := ctx.p, ctx.r
if len(p.Calls) >= ctx.ncalls {
return false
}
idx := r.biasedRand(len(p.Calls)+1, 5)
var c *Call
if idx < len(p.Calls) {
c = p.Calls[idx]
}
s := analyze(ctx.ct, p, c)
calls := r.generateCall(s, p)
p.insertBefore(c, calls)
return true
}
func (ctx *mutator) removeCall() bool {
p, r := ctx.p, ctx.r
if len(p.Calls) == 0 {
return false
}
idx := r.Intn(len(p.Calls))
p.removeCall(idx)
return true
}
func (ctx *mutator) mutateArg() bool {
p, r := ctx.p, ctx.r
if len(p.Calls) == 0 {
return false
}
c := p.Calls[r.Intn(len(p.Calls))]
if len(c.Args) == 0 {
return false
}
s := analyze(ctx.ct, p, c)
updateSizes := true
for stop, ok := false, false; !stop; stop = ok && r.oneOf(3) {
ok = true
ma := &mutationArgs{target: p.Target}
ForeachArg(c, ma.collectArg)
if len(ma.args) == 0 {
return false
}
idx := r.Intn(len(ma.args))
arg, ctx := ma.args[idx], ma.ctxes[idx]
calls, ok1 := p.Target.mutateArg(r, s, arg, ctx, &updateSizes)
if !ok1 {
ok = false
continue
}
p.insertBefore(c, calls)
if updateSizes {
p.Target.assignSizesCall(c)
}
p.Target.SanitizeCall(c)
}
return true
}
func (target *Target) mutateArg(r *randGen, s *state, arg Arg, ctx ArgCtx, updateSizes *bool) ([]*Call, bool) {
var baseSize uint64
if ctx.Base != nil {
baseSize = ctx.Base.Res.Size()
}
calls, retry, preserve := arg.Type().mutate(r, s, arg, ctx)
if retry {
return nil, false
}
if preserve {
*updateSizes = false
}
// Update base pointer if size has increased.
if base := ctx.Base; base != nil && baseSize < base.Res.Size() {
newArg := r.allocAddr(s, base.Type(), base.Res.Size(), base.Res)
replaceArg(base, newArg)
}
for _, c := range calls {
target.SanitizeCall(c)
}
return calls, true
}
func regenerate(r *randGen, s *state, arg Arg) (calls []*Call, retry, preserve bool) {
var newArg Arg
newArg, calls = r.generateArg(s, arg.Type())
replaceArg(arg, newArg)
return
}
func mutateInt(r *randGen, s *state, arg Arg) (calls []*Call, retry, preserve bool) {
if r.bin() {
return regenerate(r, s, arg)
}
a := arg.(*ConstArg)
switch {
case r.nOutOf(1, 3):
a.Val += uint64(r.Intn(4)) + 1
case r.nOutOf(1, 2):
a.Val -= uint64(r.Intn(4)) + 1
default:
a.Val ^= 1 << uint64(r.Intn(64))
}
return
}
func (t *IntType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
return mutateInt(r, s, arg)
}
func (t *FlagsType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
return mutateInt(r, s, arg)
}
func (t *LenType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
if !r.mutateSize(arg.(*ConstArg), *ctx.Parent) {
retry = true
return
}
preserve = true
return
}
func (t *ResourceType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
return regenerate(r, s, arg)
}
func (t *VmaType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
return regenerate(r, s, arg)
}
func (t *ProcType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
return regenerate(r, s, arg)
}
func (t *BufferType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
a := arg.(*DataArg)
switch t.Kind {
case BufferBlobRand, BufferBlobRange:
data := append([]byte{}, a.Data()...)
minLen, maxLen := uint64(0), maxBlobLen
if t.Kind == BufferBlobRange {
minLen, maxLen = t.RangeBegin, t.RangeEnd
}
a.data = mutateData(r, data, minLen, maxLen)
case BufferString:
data := append([]byte{}, a.Data()...)
if r.bin() {
minLen, maxLen := uint64(0), maxBlobLen
if t.TypeSize != 0 {
minLen, maxLen = t.TypeSize, t.TypeSize
}
a.data = mutateData(r, data, minLen, maxLen)
} else {
a.data = r.randString(s, t)
}
case BufferFilename:
a.data = []byte(r.filename(s, t))
case BufferText:
data := append([]byte{}, a.Data()...)
a.data = r.mutateText(t.Text, data)
default:
panic("unknown buffer kind")
}
return
}
func (t *ArrayType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
// TODO: swap elements of the array
a := arg.(*GroupArg)
count := uint64(0)
switch t.Kind {
case ArrayRandLen:
for count == uint64(len(a.Inner)) {
count = r.randArrayLen()
}
case ArrayRangeLen:
if t.RangeBegin == t.RangeEnd {
panic("trying to mutate fixed length array")
}
for count == uint64(len(a.Inner)) {
count = r.randRange(t.RangeBegin, t.RangeEnd)
}
}
if count > uint64(len(a.Inner)) {
for count > uint64(len(a.Inner)) {
newArg, newCalls := r.generateArg(s, t.Type)
a.Inner = append(a.Inner, newArg)
calls = append(calls, newCalls...)
for _, c := range newCalls {
s.analyze(c)
}
}
} else if count < uint64(len(a.Inner)) {
for _, arg := range a.Inner[count:] {
removeArg(arg)
}
a.Inner = a.Inner[:count]
}
return
}
func (t *PtrType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
a := arg.(*PointerArg)
newArg := r.allocAddr(s, t, a.Res.Size(), a.Res)
replaceArg(arg, newArg)
return
}
func (t *StructType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
gen := r.target.SpecialTypes[t.Name()]
if gen == nil {
panic("bad arg returned by mutationArgs: StructType")
}
var newArg Arg
newArg, calls = gen(&Gen{r, s}, t, arg)
a := arg.(*GroupArg)
for i, f := range newArg.(*GroupArg).Inner {
replaceArg(a.Inner[i], f)
}
return
}
func (t *UnionType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
if gen := r.target.SpecialTypes[t.Name()]; gen != nil {
var newArg Arg
newArg, calls = gen(&Gen{r, s}, t, arg)
replaceArg(arg, newArg)
} else {
a := arg.(*UnionArg)
current := -1
for i, option := range t.Fields {
if a.Option.Type().FieldName() == option.FieldName() {
current = i
break
}
}
if current == -1 {
panic("can't find current option in union")
}
newIdx := r.Intn(len(t.Fields) - 1)
if newIdx >= current {
newIdx++
}
optType := t.Fields[newIdx]
removeArg(a.Option)
var newOpt Arg
newOpt, calls = r.generateArg(s, optType)
replaceArg(arg, MakeUnionArg(t, newOpt))
}
return
}
func (t *CsumType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
panic("CsumType can't be mutated")
}
func (t *ConstType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
panic("ConstType can't be mutated")
}
type mutationArgs struct {
target *Target
args []Arg
ctxes []ArgCtx
ignoreSpecial bool
}
func (ma *mutationArgs) collectArg(arg Arg, ctx *ArgCtx) {
ignoreSpecial := ma.ignoreSpecial
ma.ignoreSpecial = false
switch typ := arg.Type().(type) {
case *StructType:
if ma.target.SpecialTypes[typ.Name()] == nil || ignoreSpecial {
return // For structs only individual fields are updated.
}
// These special structs are mutated as a whole.
ctx.Stop = true
case *UnionType:
if ma.target.SpecialTypes[typ.Name()] == nil && len(typ.Fields) == 1 || ignoreSpecial {
return
}
ctx.Stop = true
case *ArrayType:
// Don't mutate fixed-size arrays.
if typ.Kind == ArrayRangeLen && typ.RangeBegin == typ.RangeEnd {
return
}
case *CsumType:
return // Checksum is updated when the checksummed data changes.
case *ConstType:
return // Well, this is const.
case *BufferType:
if typ.Kind == BufferString && len(typ.Values) == 1 {
return // string const
}
case *PtrType:
if arg.(*PointerArg).IsNull() {
// TODO: we ought to mutate this, but we don't have code for this yet.
return
}
}
typ := arg.Type()
if typ == nil || typ.Dir() == DirOut || !typ.Varlen() && typ.Size() == 0 {
return
}
ma.args = append(ma.args, arg)
ma.ctxes = append(ma.ctxes, *ctx)
}
func mutateData(r *randGen, data []byte, minLen, maxLen uint64) []byte {
for stop := false; !stop; stop = stop && r.oneOf(3) {
f := mutateDataFuncs[r.Intn(len(mutateDataFuncs))]
data, stop = f(r, data, minLen, maxLen)
}
return data
}
const maxInc = 35
var mutateDataFuncs = [...]func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool){
// TODO(dvyukov): duplicate part of data.
// Flip bit in byte.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
if len(data) == 0 {
return data, false
}
byt := r.Intn(len(data))
bit := r.Intn(8)
data[byt] ^= 1 << uint(bit)
return data, true
},
// Insert random bytes.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
if len(data) == 0 {
return data, false
}
n := r.Intn(16) + 1
if r := int(maxLen) - len(data); n > r {
n = r
}
pos := r.Intn(len(data))
for i := 0; i < n; i++ {
data = append(data, 0)
}
copy(data[pos+n:], data[pos:])
for i := 0; i < n; i++ {
data[pos+i] = byte(r.Int31())
}
if uint64(len(data)) > maxLen || r.bin() {
data = data[:len(data)-n] // preserve original length
}
return data, true
},
// Remove bytes.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
if len(data) == 0 {
return data, false
}
n := r.Intn(16) + 1
if n > len(data) {
n = len(data)
}
pos := 0
if n < len(data) {
pos = r.Intn(len(data) - n)
}
copy(data[pos:], data[pos+n:])
data = data[:len(data)-n]
if uint64(len(data)) < minLen || r.bin() {
for i := 0; i < n; i++ {
data = append(data, 0) // preserve original length
}
}
return data, true
},
// Append a bunch of bytes.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
if uint64(len(data)) >= maxLen {
return data, false
}
const max = 256
n := max - r.biasedRand(max, 10)
if r := int(maxLen) - len(data); n > r {
n = r
}
for i := 0; i < n; i++ {
data = append(data, byte(r.rand(256)))
}
return data, true
},
// Replace int8/int16/int32/int64 with a random value.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
width := 1 << uint(r.Intn(4))
if len(data) < width {
return data, false
}
i := r.Intn(len(data) - width + 1)
storeInt(data[i:], r.Uint64(), width)
return data, true
},
// Add/subtract from an int8/int16/int32/int64.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
width := 1 << uint(r.Intn(4))
if len(data) < width {
return data, false
}
i := r.Intn(len(data) - width + 1)
v := loadInt(data[i:], width)
delta := r.rand(2*maxInc+1) - maxInc
if delta == 0 {
delta = 1
}
if r.oneOf(10) {
v = swapInt(v, width)
v += delta
v = swapInt(v, width)
} else {
v += delta
}
storeInt(data[i:], v, width)
return data, true
},
// Set int8/int16/int32/int64 to an interesting value.
func(r *randGen, data []byte, minLen, maxLen uint64) ([]byte, bool) {
width := 1 << uint(r.Intn(4))
if len(data) < width {
return data, false
}
i := r.Intn(len(data) - width + 1)
value := r.randInt()
if r.oneOf(10) {
value = swap64(value)
}
storeInt(data[i:], value, width)
return data, true
},
}
func swap16(v uint16) uint16 {
v0 := byte(v >> 0)
v1 := byte(v >> 8)
v = 0
v |= uint16(v1) << 0
v |= uint16(v0) << 8
return v
}
func swap32(v uint32) uint32 {
v0 := byte(v >> 0)
v1 := byte(v >> 8)
v2 := byte(v >> 16)
v3 := byte(v >> 24)
v = 0
v |= uint32(v3) << 0
v |= uint32(v2) << 8
v |= uint32(v1) << 16
v |= uint32(v0) << 24
return v
}
func swap64(v uint64) uint64 {
v0 := byte(v >> 0)
v1 := byte(v >> 8)
v2 := byte(v >> 16)
v3 := byte(v >> 24)
v4 := byte(v >> 32)
v5 := byte(v >> 40)
v6 := byte(v >> 48)
v7 := byte(v >> 56)
v = 0
v |= uint64(v7) << 0
v |= uint64(v6) << 8
v |= uint64(v5) << 16
v |= uint64(v4) << 24
v |= uint64(v3) << 32
v |= uint64(v2) << 40
v |= uint64(v1) << 48
v |= uint64(v0) << 56
return v
}
func swapInt(v uint64, size int) uint64 {
switch size {
case 1:
return v
case 2:
return uint64(swap16(uint16(v)))
case 4:
return uint64(swap32(uint32(v)))
case 8:
return swap64(v)
default:
panic(fmt.Sprintf("swapInt: bad size %v", size))
}
}
func loadInt(data []byte, size int) uint64 {
p := unsafe.Pointer(&data[0])
switch size {
case 1:
return uint64(*(*uint8)(p))
case 2:
return uint64(*(*uint16)(p))
case 4:
return uint64(*(*uint32)(p))
case 8:
return *(*uint64)(p)
default:
panic(fmt.Sprintf("loadInt: bad size %v", size))
}
}
func storeInt(data []byte, v uint64, size int) {
p := unsafe.Pointer(&data[0])
switch size {
case 1:
*(*uint8)(p) = uint8(v)
case 2:
*(*uint16)(p) = uint16(v)
case 4:
*(*uint32)(p) = uint32(v)
case 8:
*(*uint64)(p) = v
default:
panic(fmt.Sprintf("storeInt: bad size %v", size))
}
}