kernel/linux.git/mm/gup.c, branch v7.0.10

mm/gup: remove no longer used gup_fast_undo_dev_pagemap

2026-01-21T03:24:49+00:00

This helper is no longer used after commit fd2825b0760a ("mm/gup: remove pXX_devmap usage from get_user_pages()"). Link: https://lkml.kernel.org/r/20251219-gup-cleanup-v1-1-348a70d9eecb@tencent.com Signed-off-by: Kairui Song Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Alistair Popple Cc: Jason Gunthorpe Cc: John Hubbard Cc: Peter Xu Signed-off-by: Andrew Morton

mm: replace READ_ONCE() with standard page table accessors

2025-11-17T01:27:56+00:00

Replace all READ_ONCE() with a standard page table accessors i.e pxdp_get() that defaults into READ_ONCE() in cases where platform does not override. Link: https://lkml.kernel.org/r/20251007063100.2396936-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Acked-by: David Hildenbrand Reviewed-by: Lance Yang Reviewed-by: Wei Yang Reviewed-by: Dev Jain Signed-off-by: Andrew Morton

mm: fix some typos in mm module

2025-11-17T01:27:52+00:00

Below are some typos in the code comments: intevals ==> intervals addesses ==> addresses unavaliable ==> unavailable facor ==> factor droping ==> dropping exlusive ==> exclusive decription ==> description confict ==> conflict desriptions ==> descriptions otherwize ==> otherwise vlaue ==> value cheching ==> checking exisitng ==> existing modifed ==> modified differenciate ==> differentiate refernece ==> reference permissons ==> permissions indepdenent ==> independent spliting ==> splitting Just fix it. Link: https://lkml.kernel.org/r/20250929002608.1633825-1-jianyungao89@gmail.com Signed-off-by: jianyun.gao Reviewed-by: SeongJae Park Reviewed-by: Wei Yang Reviewed-by: Dev Jain Reviewed-by: Liam R. Howlett Acked-by: Chris Li Signed-off-by: Andrew Morton

mm/gup: fix handling of errors from arch_make_folio_accessible() in follow_page_pte()

2025-09-21T21:22:29+00:00

In case we call arch_make_folio_accessible() and it fails, we would incorrectly return a value that is "!= 0" to the caller, indicating that we pinned all requested pages and that the caller can keep going. follow_page_pte() is not supposed to return error values, but instead "0" on failure and "1" on success -- we'll clean that up separately. In case we return "!= 0", the caller will just keep going pinning more pages. If we happen to pin a page afterwards, we're in trouble, because we essentially skipped some pages in the requested range. Staring at the arch_make_folio_accessible() implementation on s390x, I assume it should actually never really fail unless something unexpected happens (BUG?). So let's not CC stable and just fix common code to do the right thing. Clean up the code a bit now that there is no reason to store the return value of arch_make_folio_accessible(). Link: https://lkml.kernel.org/r/20250908094517.303409-1-david@redhat.com Fixes: f28d43636d6f ("mm/gup/writeback: add callbacks for inaccessible pages") Signed-off-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Cc: Jason Gunthorpe Cc: John Hubbard Cc: Peter Xu Cc: Christian Borntraeger Signed-off-by: Andrew Morton

mm/gup: remove dead pgmap refcounting code

2025-09-21T21:22:21+00:00

Prior to commit aed877c2b425 ("device/dax: properly refcount device dax pages when mapping") ZONE_DEVICE pages were not fully reference counted when mapped into user page tables. Instead GUP would take a reference on the associated pgmap to ensure the results of pfn_to_page() remained valid. This is no longer required and most of the code was removed by commit fd2825b0760a ("mm/gup: remove pXX_devmap usage from get_user_pages()"). Finish cleaning this up by removing the dead calls to put_dev_pagemap() and the temporary context struct. Link: https://lkml.kernel.org/r/20250903225926.34702-1-apopple@nvidia.com Signed-off-by: Alistair Popple Acked-by: David Hildenbrand Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Reviewed-by: John Hubbard Cc: Oscar Salvador Cc: Peter Xu Signed-off-by: Andrew Morton

mm/gup: drop nth_page() usage in unpin_user_page_range_dirty_lock()

2025-09-21T21:22:09+00:00

There is the concern that unpin_user_page_range_dirty_lock() might do some weird merging of PFN ranges -- either now or in the future -- such that PFN range is contiguous but the page range might not be. Let's sanity-check for that and drop the nth_page() usage. Link: https://lkml.kernel.org/r/20250901150359.867252-35-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Signed-off-by: Andrew Morton

mm/gup: remove record_subpages()

2025-09-21T21:22:05+00:00

We can just cleanup the code by calculating the #refs earlier, so we can just inline what remains of record_subpages(). Calculate the number of references/pages ahead of times, and record them only once all our tests passed. [david@redhat.com: fix `pages' adjustment] Link: https://lkml.kernel.org/r/cc7f03f8-da8b-407e-a03a-e8e5a9ec5462@redhat.com Link: https://lkml.kernel.org/r/20250901150359.867252-20-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Eric Biggers Cc: Jens Axboe Signed-off-by: Andrew Morton

mm/gup: drop nth_page() usage within folio when recording subpages

2025-09-21T21:22:05+00:00

nth_page() is no longer required when iterating over pages within a single folio, so let's just drop it when recording subpages. Link: https://lkml.kernel.org/r/20250901150359.867252-19-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Signed-off-by: Andrew Morton

Merge branch 'mm-hotfixes-stable' into mm-stable in order to pick up

2025-09-21T21:19:36+00:00

changes required by mm-stable material: hugetlb and damon.

mm: add folio_is_pci_p2pdma()

2025-09-13T23:55:10+00:00

Reimplement is_pci_p2pdma_page() in terms of folio_is_pci_p2pdma(). Moves the page_folio() call from inside page_pgmap() to is_pci_p2pdma_page(). This removes a page_folio() call from try_grab_folio() which already has a folio and can pass it in. Link: https://lkml.kernel.org/r/20250805172307.1302730-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Shakeel Butt Cc: Zi Yan Signed-off-by: Andrew Morton