golang git

gistfile1.txt

package main

import (
    "fmt"
    "syscall"
    "unsafe"
)

type printFunc func()

func main() {
    printFunction := []uint16{
        0x48c7, 0xc001, 0x0, // mov %rax,$0x1
        0x48, 0xc7c7, 0x100, 0x0, // mov %rdi,$0x1
        0x48c7, 0xc20e, 0x0, // mov 0x13, %rdx
        0x48, 0x8d35, 0x400, 0x0, // lea 0x4(%rip), %rsi
        0xf05,                  // syscall
        0xc3cc,                 // ret
        0x4865, 0x6c6c, 0x6f20, // Hello_(whitespace)
        0x576f, 0x726c, 0x6421, 0xa, // World!
    }
    executablePrintFunc, err := syscall.Mmap(
        -1,
        0,
        128,
        syscall.PROT_READ|syscall.PROT_WRITE|syscall.PROT_EXEC,
        syscall.MAP_PRIVATE|syscall.MAP_ANONYMOUS)
    if err != nil {
        fmt.Printf("mmap err: %v", err)
    }
    j := 0
    for i := range printFunction {
        executablePrintFunc[j] = byte(printFunction[i] >> 8)
        executablePrintFunc[j+1] = byte(printFunction[i])
        j = j + 2
    }
    type printFunc func()
    unsafePrintFunc := (uintptr)(unsafe.Pointer(&executablePrintFunc))
    printer := *(*printFunc)(unsafe.Pointer(&unsafePrintFunc))
    printer()
}