mmap_action_...kernel_pages(9)

💖 mmap_action_map_kernel_pages 💖

okay so bestie, welcome to the Kernel API Manual ✨ this page is all about a helper for the mmap_prepare hook, and it's literally here to say “map these kernel pages into userland, starting at this virtual address.” group-chat energy but make it memory management 💅

🌸 NAME 🌸

mmap_action_map_kernel_pages — helper for the mmap_prepare hook to specify that @num kernel pages contained in the @pages array should be mapped to userland starting at virtual address @start. that's the assignment, no cap 🫶

✨ SYNOPSIS ✨

void mmap_action_map_kernel_pages (struct vm_area_desc *desc , unsigned long start , struct page **pages , unsigned long nr_pages );

🎀 ARGUMENTS 🎀

• desc — the VMA descriptor for the VMA requiring kernel pags to be mapped. yes, “pags” is the original spelling, and I'm delivering it with love 😭
• start — the virtual address from which to map them. the starting point, periodt 📍
• pages — an array of struct page pointers describing the memory to map. page-pointer city 🫶
• nr_pages — the number of entries in the pages aray. again, “aray” is the original spelling, not me 💀

👑 SEE ALSO 👑

Kernel file: ./include/linux/mm.h

the whole function friend group, in order, zero skips:

• 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(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_full(9), range_is_subset(9)
• range_in_vma(9), range_in_vma_desc(9), clear_pages(9)

okay that's the whole page, bestie 🫶 source/version: ./include/linux, date: October 2026, page name: mmap_action_...kernel_pages(9). go map those kernel pages and slay 💅✨