README
¶
Goloader
Goloader can load and run Golang code at runtime.
Forked from https://github.com/dearplain/goloader, Take over maintenance because the original author is not in maintenance
How does it work?
Goloader works like a linker: it relocates the address of symbols in an object file, generates runnable code, and then reuses the runtime function and the type pointer of the loader.
Goloader provides some information to the runtime and gc of Go, which allows it to work correctly with them.
Please note that Goloader is not a scripting engine. It reads the output of Go compiler and makes them runnable. All features of Go are supported, and run just as fast and lightweight as native Go code.
Comparison with plugin
Goloader reuses the Go runtime, which makes it much smaller. And code loaded by Goloader is unloadable.
Goloader supports pprof tool(Yes, you can see code loaded by Goloader in pprof).
Goloader don't support obj file with cgo.
Build
Make sure you're using go >= 1.8.
First, execute the following command, then do build and test. This is because Goloader relies on the internal package, which is forbidden by the Go compiler.
cp -r $GOROOT/src/cmd/internal $GOROOT/src/cmd/objfile
Examples
#Build Loader:
If use go version >= 1.23
go build --ldflags="-checklinkname=0" github.com/pkujhd/goloader/examples/loader
If use go version <= 1.22
go build github.com/pkujhd/goloader/examples/loader
#Compile Object File and Run:
If use go module or go version >= 1.20
export GO111MODULE=on
go list -export -f '{{if .Export}}packagefile {{.ImportPath}}={{.Export}}{{end}}' std `go list -f {{.Imports}} $GOPATH/src/github.com/pkujhd/goloader/examples/schedule/schedule.go | awk '{sub(/^\[/, ""); print }' | awk '{sub(/\]$/, ""); print }'` > importcfg
go tool compile -importcfg importcfg $GOPATH/src/github.com/pkujhd/goloader/examples/schedule/schedule.go
./loader -o schedule.o -run main.main -times 10
If use go path and go version < 1.20
export GO111MODULE=auto
go tool compile $GOPATH/src/github.com/pkujhd/goloader/examples/schedule/schedule.go
./loader -o schedule.o -run main.main -times 10
go tool compile $GOPATH/src/github.com/pkujhd/goloader/examples/base/base.go
./loader -o base.o -run main.main
go tool compile $GOPATH/src/github.com/pkujhd/goloader/examples/http/http.go
./loader -o http.o -run main.main
go install github.com/pkujhd/goloader/examples/basecontext
go tool compile -I $GOPATH/pkg/`go env GOOS`_`go env GOARCH`/ $GOPATH/src/github.com/pkujhd/goloader/examples/inter/inter.go
./loader -o $GOPATH/pkg/`go env GOOS`_`go env GOARCH`/github.com/pkujhd/goloader/examples/basecontext.a:github.com/pkujhd/goloader/examples/basecontext -o inter.o
#Build multiple go files
go tool compile -I $GOPATH/pkg/`go env GOOS`_`go env GOARCH`/ -o test.o test1.go test2.go
./loader -o test.o -run main.main
Warning
Don't use "-s -w" compile argument, It strips symbol table.
This has currently only been tested and developed on:
Golang 1.8-1.23 (x64/x86, darwin, linux, windows)
Golang 1.10-1.23 (arm, linux, android)
Golang 1.8-1.23 (arm64, linux, android)
Golang 1.16-1.23 (arm64, darwin)
Documentation
¶
Index ¶
- Constants
- func MakeThreadJITCodeExecutable(ptr uintptr, len int)
- func Mmap(size int) ([]byte, error)
- func MmapData(size int) ([]byte, error)
- func Munmap(b []byte) (err error)
- func Parse(file, pkgpath string) ([]string, error)
- func RegSymbol(symPtr map[string]uintptr) error
- func RegSymbolWithPath(symPtr map[string]uintptr, path string) error
- func RegSymbolWithSo(symPtr map[string]uintptr, path string) error
- func RegTypes(symPtr map[string]uintptr, interfaces ...interface{})
- func Serialize(linker *Linker, writer io.Writer) error
- func UnresolvedSymbols(linker *Linker, symPtr map[string]uintptr) []string
- type CodeModule
- type Linker
- type LinkerData
Constants ¶
const ( PtrSize = 4 << (^uintptr(0) >> 63) Uint32Size = int(unsafe.Sizeof(uint32(0))) IntSize = int(unsafe.Sizeof(int(0))) UInt64Size = int(unsafe.Sizeof(uint64(0))) FindFuncBucketSize = int(unsafe.Sizeof(findfuncbucket{})) PCHeaderSize = int(unsafe.Sizeof(pcHeader{})) InvalidHandleValue = ^uintptr(0) InvalidOffset = int(-1) PageSize = 1 << 12 //4096 )
size
const ( EmptyString = "" DefaultPkgPath = "main" ZeroByte = byte(0x00) )
const ( FileSymPrefix = "gofile.." MainPkgPrefix = "main." OsStdout = "os.Stdout" GOTPCRELSuffix = "·f" )
string match prefix/suffix
const (
KindGCProg = 1 << 6
)
const (
RuntimeDeferReturn = "runtime.deferreturn"
)
runtime symbol
Variables ¶
This section is empty.
Functions ¶
func MakeThreadJITCodeExecutable ¶ added in v0.0.17
func RegSymbolWithPath ¶ added in v0.0.19
func RegSymbolWithSo ¶ added in v0.0.13
Types ¶
type CodeModule ¶
func Load ¶
func Load(linker *Linker, symPtr map[string]uintptr) (codeModule *CodeModule, err error)
func (*CodeModule) Unload ¶
func (cm *CodeModule) Unload()
type Linker ¶ added in v0.0.12
type Linker struct {
LinkerData
SymMap map[string]*obj.Sym
ObjSymbolMap map[string]*obj.ObjSymbol
NameMap map[string]int
StringMap map[string]*string
CgoImportMap map[string]*obj.CgoImport
CgoFuncs map[string]int
Filetab []uint32
Pclntable []byte
Funcs []*_func
Packages map[string]*obj.Pkg
Arch *sys.Arch
CUOffset int32
AdaptedOffset bool
}
Source Files
Directories