ptdesc_test_kernel(9)

💅 ptdesc_test_kernel(9) — like, the Kernel API Manual, bestie ✨

okay so picture this: it's giving official kernel documentation, it's from the Kernel API Manual, and it's here to answer exactly one (1) question for you. no cap. 🎀

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🌸 NAME 🌸

ptdesc_test_kernel — the little check that tells you whether a ptdesc is, in fact, being used to map the kernel 👑

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✨ SYNOPSIS ✨

bool ptdesc_test_kernel (const struct ptdesc *ptdesc );

that's it. that's the whole vibe. returns a bool, takes a pointer, slays. 💖

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🫶 ARGUMENTS 🫶

• ptdesc — the ptdesc being tested. yeah. that one. the one you're side-eyeing to find out what it's about. 👀

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🦋 DESCRIPTION 🦋

okay so literally what this does: you call it, and it tells you if the ptdesc was used to map the kernel. that's the whole thing. it's giving "yes or no bestie, no essay questions." 😭✨

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💀 SEE ALSO 💀

the extended universe, fr fr — all of these live in the kernel file ./include/linux/mm.h:

• 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)
• 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(9)
• mmap_action_map_kernel_pages_full(9)
• range_is_subset(9)
• range_in_vma(9)
• range_in_vma_desc(9)
• clear_pages(9)

like, read the whole friend group, iykyk 💅

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ngl the whole page is short and that's the point — one function, one question, one bool. iconic behavior honestly. 🌈

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and that's the tea, bestie 🍓 this cutie pie lives in ./include/linux, dated October 2026, and yeah — still the Kernel API Manual, still ptdesc_test_kernel(9). mwah. 💜🧚‍♀️