Hello everyone,

As we know, a page fault exception is caused when a process is seeking to access an area of virtual memory that is not mapped to any physical memory, when a write is attempted on a read-only page, when accessing a PTE or PDE with the reserved bit.

Regards to the reserved bit case, does anyone know how the page table is built for a process and for the kernel page table? When building the page table of a process, how can the reserved bit of a PTE or a PDE is set? Is it is set by MMU or from OS?.

Thank you,