mmap_action_remap(9)

🌸 NAME 🌸

okay so bestie, this is mmap_action_remap(9) from the Kernel API Manual, and it's literally the helper for the mmap_prepare hook that specifies a pure PFN remap is required. That's the vibe. 💅

✨ SYNOPSIS ✨

void mmap_action_remap (struct vm_area_desc *desc , unsigned long start , unsigned long start_pfn , unsigned long size );

🎀 ARGUMENTS 🎀

Four args, no cap, and every one matters:

• desc — the VMA descriptor for the VMA that needs the remap. main character energy, fr fr.
• start — the virtual address where the remap starts; it must be within the VMA. no wandering off, bestie 🫶.
• start_pfn — the first PFN in the range to remap. iconic little starting point ✨.
• size — the size of the range to remap, in bytes, and it can span at most to the end of the VMA. don't overshoot the vibe check 💀.

🦋 SEE ALSO 🦋

Kernel file ./include/linux/mm.h — that's the home base 🏠.

The whole friend group, iykyk: folio_page_idx(9), vma_flag_t(9), fault_flag_allow_retry_first(9), vma_kernel_pagesize(9), folio_order(9), folio_reset_order(9), folio_mapcount(9), folio_mapped(9), thp_order(9), thp_size(9), folio_get(9), folio_put(9), folio_put_refs(9), folios_put(9), vma_flags_is_cow_mapping(9), vma_is_cow_mapping(9), vma_desc_is_cow_mapping(9), folio_pfn(9), folio_mk_pte(9), folio_mk_pmd(9), folio_mk_pud(9), folio_maybe_dma_pinned(9), is_zero_page(9), is_zero_folio(9), folio_nr_pages(9), folio_next(9), folio_shift(9), folio_size(9), folio_maybe_mapped_shared(9), folio_expected_ref_count(9), zap_vma(9), ptdesc_address(9), ptdesc_set_kernel(9), ptdesc_clear_kernel(9), ptdesc_test_kernel(9), pagetable_alloc(9), pagetable_free(9), vma_lookup(9), vma_start_pgoff(9), vma_end_pgoff(9), vma_last_pgoff(9), vma_start_anon_pgoff(9), vma_end_anon_pgoff(9), vma_last_anon_pgoff(9), mmap_action_remap_full(9), mmap_action_ioremap(9), mmap_action_ioremap_full(9), mmap_action_simple_ioremap(9), mmap_action_map_kernel_pages(9), mmap_action_map_kernel_pages_full(9), range_is_subset(9), range_in_vma(9), range_in_vma_desc(9), clear_pages(9)

xoxo, your Unix bestie 💖 — source/version: ./include/linux, date: October 2026. periodt.