I have local changes to the 4.15 kernel which use the address argument to pte_alloc_one(). The address arg was otherwise unused and has been removed in 5.0.

The short explanation:

I want to allocate page table pages from memory that was reserved during boot, but only for memory allocated by mmap() when called with a specific MAP_ flag set. When do_mmap() sees that flag, it sets a flag in vm_flags. When pte_alloc_one() is called, if the special VM_ flag is set in the mm_struct and the address is between vm_start and vm_end, the page is allocated from the memory that was reserved at boot.

My question:

Without the address argument, how can I determine if the faulting address belongs to memory that was allocated by mmap() with the special MAP_ flag set?