pkg/proc: pad variable mem in extractVarInfoFromEntry (#3365)

* pkg/proc: pad variable mem in extractVarInfoFromEntry

On 64 bit system, the byte size of the following struct is 16:
    type myStruct struct {
       a int
       b uint32
    }
But extractVarInfoFromEntry only allocates a mem of 12 bytes for it.
When calling method of this struct with the "call" command, it will
result in this error:
    write out of bounds

This patch extends the mem by adding padding bytes to the end of the
mem.

Fixes #3364.

* move the padding logic into newCompositeMemory
This commit is contained in:
Zeke Lu 2023-05-16 05:46:33 +08:00 committed by GitHub
parent 1c9792bce4
commit 463b97dd36
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 29 additions and 10 deletions

@ -199,6 +199,15 @@ func (i Issue2698) String() string {
return fmt.Sprintf("%d %d %d %d", i.a, i.b, i.c, i.d)
}
type Issue3364 struct {
a int
b uint32
}
func (i Issue3364) String() string {
return fmt.Sprintf("%d %d", i.a, i.b)
}
func main() {
one, two := 1, 2
intslice := []int{1, 2, 3}
@ -222,6 +231,10 @@ func main() {
c: 3,
d: 4,
}
issue3364 := Issue3364{
a: 1,
b: 2,
}
fn2clos := makeclos(pa)
fn2glob := call1
@ -241,5 +254,5 @@ func main() {
d.Method()
d.Base.Method()
x.CallMe()
fmt.Println(one, two, zero, call, call0, call2, callexit, callpanic, callbreak, callstacktrace, stringsJoin, intslice, stringslice, comma, a.VRcvr, a.PRcvr, pa, vable_a, vable_pa, pable_pa, fn2clos, fn2glob, fn2valmeth, fn2ptrmeth, fn2nil, ga, escapeArg, a2, square, intcallpanic, onetwothree, curriedAdd, getAStruct, getAStructPtr, getVRcvrableFromAStruct, getPRcvrableFromAStructPtr, getVRcvrableFromAStructPtr, pa2, noreturncall, str, d, x, x2.CallMe(5), longstrs, regabistacktest, regabistacktest2, issue2698.String(), regabistacktest3, rast3, floatsum, ref)
fmt.Println(one, two, zero, call, call0, call2, callexit, callpanic, callbreak, callstacktrace, stringsJoin, intslice, stringslice, comma, a.VRcvr, a.PRcvr, pa, vable_a, vable_pa, pable_pa, fn2clos, fn2glob, fn2valmeth, fn2ptrmeth, fn2nil, ga, escapeArg, a2, square, intcallpanic, onetwothree, curriedAdd, getAStruct, getAStructPtr, getVRcvrableFromAStruct, getPRcvrableFromAStructPtr, getVRcvrableFromAStructPtr, pa2, noreturncall, str, d, x, x2.CallMe(5), longstrs, regabistacktest, regabistacktest2, issue2698.String(), issue3364.String(), regabistacktest3, rast3, floatsum, ref)
}

@ -20,7 +20,7 @@ func NewCompositeMemory(p *Target, pieces []op.Piece, base uint64) (*compositeMe
dwarfregs := arch.RegistersToDwarfRegisters(0, regs)
dwarfregs.ChangeFunc = p.CurrentThread().SetReg
mem, err := newCompositeMemory(p.Memory(), arch, *dwarfregs, pieces)
mem, err := newCompositeMemory(p.Memory(), arch, *dwarfregs, pieces, 0)
if mem != nil {
mem.base = base
}

@ -98,17 +98,17 @@ type compositeMemory struct {
// CreateCompositeMemory created a new composite memory type using the provided MemoryReadWriter as the
// underlying memory buffer.
func CreateCompositeMemory(mem MemoryReadWriter, arch *Arch, regs op.DwarfRegisters, pieces []op.Piece) (*compositeMemory, error) {
func CreateCompositeMemory(mem MemoryReadWriter, arch *Arch, regs op.DwarfRegisters, pieces []op.Piece, size int64) (*compositeMemory, error) {
// This is basically a small wrapper to avoid having to change all callers
// of newCompositeMemory since it existed first.
cm, err := newCompositeMemory(mem, arch, regs, pieces)
cm, err := newCompositeMemory(mem, arch, regs, pieces, size)
if cm != nil {
cm.base = fakeAddressUnresolv
}
return cm, err
}
func newCompositeMemory(mem MemoryReadWriter, arch *Arch, regs op.DwarfRegisters, pieces []op.Piece) (*compositeMemory, error) {
func newCompositeMemory(mem MemoryReadWriter, arch *Arch, regs op.DwarfRegisters, pieces []op.Piece, size int64) (*compositeMemory, error) {
cmem := &compositeMemory{realmem: mem, arch: arch, regs: regs, pieces: pieces, data: []byte{}}
for i := range pieces {
piece := &pieces[i]
@ -147,6 +147,11 @@ func newCompositeMemory(mem MemoryReadWriter, arch *Arch, regs op.DwarfRegisters
panic("unsupported piece kind")
}
}
paddingBytes := int(size) - len(cmem.data)
if paddingBytes > 0 && paddingBytes < arch.ptrSize {
padding := make([]byte, paddingBytes)
cmem.data = append(cmem.data, padding...)
}
return cmem, nil
}

@ -454,7 +454,7 @@ func (t *Target) GetBufferedTracepoints() []*UProbeTraceResult {
v.Kind = ip.Kind
cachedMem := CreateLoadedCachedMemory(ip.Data)
compMem, _ := CreateCompositeMemory(cachedMem, t.BinInfo().Arch, op.DwarfRegisters{}, ip.Pieces)
compMem, _ := CreateCompositeMemory(cachedMem, t.BinInfo().Arch, op.DwarfRegisters{}, ip.Pieces, ip.RealType.Common().ByteSize)
v.mem = compMem
// Load the value here so that we don't have to export
@ -506,7 +506,7 @@ const (
// This caching is primarily done so that registerized variables don't get a
// different address every time they are evaluated, which would be confusing
// and leak memory.
func (t *Target) newCompositeMemory(mem MemoryReadWriter, regs op.DwarfRegisters, pieces []op.Piece, descr *locationExpr) (int64, *compositeMemory, error) {
func (t *Target) newCompositeMemory(mem MemoryReadWriter, regs op.DwarfRegisters, pieces []op.Piece, descr *locationExpr, size int64) (int64, *compositeMemory, error) {
var key string
if regs.CFA != 0 && len(pieces) > 0 {
// key is created by concatenating the location expression with the CFA,
@ -521,7 +521,7 @@ func (t *Target) newCompositeMemory(mem MemoryReadWriter, regs op.DwarfRegisters
}
}
cmem, err := newCompositeMemory(mem, t.BinInfo().Arch, regs, pieces)
cmem, err := newCompositeMemory(mem, t.BinInfo().Arch, regs, pieces, size)
if err != nil {
return 0, cmem, err
}

@ -1198,9 +1198,9 @@ func extractVarInfoFromEntry(tgt *Target, bi *BinaryInfo, image *Image, regs op.
if pieces != nil {
var cmem *compositeMemory
if tgt != nil {
addr, cmem, err = tgt.newCompositeMemory(mem, regs, pieces, descr)
addr, cmem, err = tgt.newCompositeMemory(mem, regs, pieces, descr, t.Common().ByteSize)
} else {
cmem, err = newCompositeMemory(mem, bi.Arch, regs, pieces)
cmem, err = newCompositeMemory(mem, bi.Arch, regs, pieces, t.Common().ByteSize)
if cmem != nil {
cmem.base = fakeAddressUnresolv
addr = int64(cmem.base)

@ -1267,6 +1267,7 @@ func TestCallFunction(t *testing.T) {
{`regabistacktest("one", "two", "three", "four", "five", 4)`, []string{`:string:"onetwo"`, `:string:"twothree"`, `:string:"threefour"`, `:string:"fourfive"`, `:string:"fiveone"`, ":uint8:8"}, nil},
{`regabistacktest2(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)`, []string{":int:3", ":int:5", ":int:7", ":int:9", ":int:11", ":int:13", ":int:15", ":int:17", ":int:19", ":int:11"}, nil},
{`issue2698.String()`, []string{`:string:"1 2 3 4"`}, nil},
{`issue3364.String()`, []string{`:string:"1 2"`}, nil},
{`regabistacktest3(rast3, 5)`, []string{`:[10]string:[10]string ["onetwo","twothree","threefour","fourfive","fivesix","sixseven","sevenheight","heightnine","nineten","tenone"]`, ":uint8:15"}, nil},
{`floatsum(1, 2)`, []string{":float64:3"}, nil},
}