text: #include <errno.h>
  #include <sys/types.h>
  
  void _exit(void) {
      while (1) __asm__("hlt");
  }
  
  caddr_t program_break, program_break_end;
  caddr_t sbrk(int incr){
      if (program_break == 0 || program_break + incr >= program_break_end ) {
          errno = ENOMEM;
          return (caddr_t)-1;
      }
  
      caddr_t prev_break = program_break;
      program_break += incr;
      return prev_break;
  }
  
  int getpid(void) {
      return 1;
  }
  
  int kill(int pid, int sig) {
      errno = EINVAL;
      return -1;
  }