#include <stdio.h>
#include <sys/mman.h>

//#define ENABLE_MPROTECT 1

__attribute__((aligned(4096))) char codebuf[] = { 0xc3 }; // ret

int main() {
  void (*f)() = (void *)codebuf;
#ifdef ENABLE_MPROTECT
  mprotect(codebuf, 1, PROT_READ | PROT_WRITE | PROT_EXEC);
#endif
  f();
  printf("I am alive!\n");
  return 0;
}