Comment by xmcqdpt2

> Since the code in question was doing IO that you knew could fail handling the situation can be as simple as setting a flag from within the signal handler.

If you are using mmap like malloc (as the article does) you don't necessarily know that you are "reading" from disk. You may have passed the disk-backed pointers to other code. The fact that malloc and mmap return the same type of values is what makes mmap in C so powerful AND so prone to issues.