/
moduledata.go
205 lines (168 loc) · 4.7 KB
/
moduledata.go
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package proc
import (
"go/constant"
"unsafe"
)
// delve counterpart to runtime.moduledata
type moduleData struct {
text, etext uint64
types, etypes uint64
typemapVar *Variable
}
func loadModuleData(bi *BinaryInfo, mem MemoryReadWriter) ([]moduleData, error) {
scope := globalScope(bi, bi.Images[0], mem)
var md *Variable
md, err := scope.findGlobal("runtime", "firstmoduledata")
if err != nil {
return nil, err
}
r := []moduleData{}
for md.Addr != 0 {
const (
typesField = "types"
etypesField = "etypes"
textField = "text"
etextField = "etext"
nextField = "next"
typemapField = "typemap"
)
vars := map[string]*Variable{}
for _, fieldName := range []string{typesField, etypesField, textField, etextField, nextField, typemapField} {
var err error
vars[fieldName], err = md.structMember(fieldName)
if err != nil {
return nil, err
}
}
var err error
touint := func(name string) (ret uint64) {
if err == nil {
var n uint64
n, err = vars[name].asUint()
ret = n
}
return ret
}
r = append(r, moduleData{
types: touint(typesField), etypes: touint(etypesField),
text: touint(textField), etext: touint(etextField),
typemapVar: vars[typemapField],
})
if err != nil {
return nil, err
}
md = vars[nextField].maybeDereference()
if md.Unreadable != nil {
return nil, md.Unreadable
}
}
return r, nil
}
func findModuleDataForType(bi *BinaryInfo, mds []moduleData, typeAddr uint64, mem MemoryReadWriter) *moduleData {
for i := range mds {
if typeAddr >= mds[i].types && typeAddr < mds[i].etypes {
return &mds[i]
}
}
return nil
}
func resolveTypeOff(bi *BinaryInfo, mds []moduleData, typeAddr, off uint64, mem MemoryReadWriter) (*Variable, error) {
// See runtime.(*_type).typeOff in $GOROOT/src/runtime/type.go
md := findModuleDataForType(bi, mds, typeAddr, mem)
rtyp, err := bi.findType("runtime._type")
if err != nil {
return nil, err
}
if md == nil {
v, err := reflectOffsMapAccess(bi, off, mem)
if err != nil {
return nil, err
}
v.loadValue(LoadConfig{false, 1, 0, 0, -1, 0})
addr, _ := constant.Int64Val(v.Value)
return v.newVariable(v.Name, uint64(addr), rtyp, mem), nil
}
if t, _ := md.typemapVar.mapAccess(newConstant(constant.MakeUint64(uint64(off)), mem)); t != nil {
return t, nil
}
res := md.types + off
return newVariable("", uint64(res), rtyp, bi, mem), nil
}
func resolveNameOff(bi *BinaryInfo, mds []moduleData, typeAddr, off uint64, mem MemoryReadWriter) (name, tag string, pkgpathoff int32, err error) {
// See runtime.resolveNameOff in $GOROOT/src/runtime/type.go
for _, md := range mds {
if typeAddr >= md.types && typeAddr < md.etypes {
return loadName(bi, md.types+off, mem)
}
}
v, err := reflectOffsMapAccess(bi, off, mem)
if err != nil {
return "", "", 0, err
}
resv := v.maybeDereference()
if resv.Unreadable != nil {
return "", "", 0, resv.Unreadable
}
return loadName(bi, resv.Addr, mem)
}
func reflectOffsMapAccess(bi *BinaryInfo, off uint64, mem MemoryReadWriter) (*Variable, error) {
scope := globalScope(bi, bi.Images[0], mem)
reflectOffs, err := scope.findGlobal("runtime", "reflectOffs")
if err != nil {
return nil, err
}
reflectOffsm, err := reflectOffs.structMember("m")
if err != nil {
return nil, err
}
return reflectOffsm.mapAccess(newConstant(constant.MakeUint64(uint64(off)), mem))
}
const (
// flags for the name struct (see 'type name struct' in $GOROOT/src/reflect/type.go)
nameflagExported = 1 << 0
nameflagHasTag = 1 << 1
nameflagHasPkg = 1 << 2
)
func loadName(bi *BinaryInfo, addr uint64, mem MemoryReadWriter) (name, tag string, pkgpathoff int32, err error) {
off := addr
namedata := make([]byte, 3)
_, err = mem.ReadMemory(namedata, off)
off += 3
if err != nil {
return "", "", 0, err
}
namelen := uint16(namedata[1])<<8 | uint16(namedata[2])
rawstr := make([]byte, int(namelen))
_, err = mem.ReadMemory(rawstr, off)
off += uint64(namelen)
if err != nil {
return "", "", 0, err
}
name = string(rawstr)
if namedata[0]&nameflagHasTag != 0 {
taglendata := make([]byte, 2)
_, err = mem.ReadMemory(taglendata, off)
off += 2
if err != nil {
return "", "", 0, err
}
taglen := uint16(taglendata[0])<<8 | uint16(taglendata[1])
rawstr := make([]byte, int(taglen))
_, err = mem.ReadMemory(rawstr, off)
off += uint64(taglen)
if err != nil {
return "", "", 0, err
}
tag = string(rawstr)
}
if namedata[0]&nameflagHasPkg != 0 {
pkgdata := make([]byte, 4)
_, err = mem.ReadMemory(pkgdata, off)
if err != nil {
return "", "", 0, err
}
// see func pkgPath in $GOROOT/src/reflect/type.go
copy((*[4]byte)(unsafe.Pointer(&pkgpathoff))[:], pkgdata)
}
return name, tag, pkgpathoff, nil
}