Editing Page fault (section)

=== Invalid page fault ===
If a page fault occurs for a reference to an address that is not part of the virtual [[address space]], meaning there cannot be a page in memory corresponding to it, then it is called an ''invalid'' page fault.  The page fault handler in the operating system will then generally pass a [[segmentation fault]] to the offending process, indicating that the access was invalid; this usually results in [[abnormal termination]] of the code that made the invalid reference. A [[null pointer]] is usually represented as a pointer to address 0 in the address space; many operating systems set up the MMU to indicate that the page that contains that address is not in memory, and do not include that page in the virtual address space, so that attempts to read or write the memory referenced by a null pointer get an invalid page fault.