The patch titled Subject: mm/memory_hotplug: use pfn math in place of direct struct page manipulation has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days

------------------------------------------------------ From: Zi Yan ziy@nvidia.com Subject: mm/memory_hotplug: use pfn math in place of direct struct page manipulation Date: Wed, 13 Sep 2023 16:12:46 -0400

When dealing with hugetlb pages, manipulating struct page pointers directly can get to wrong struct page, since struct page is not guaranteed to be contiguous on SPARSEMEM without VMEMMAP. Use pfn calculation to handle it properly.

Link: https://lkml.kernel.org/r/20230913201248.452081-4-zi.yan@sent.com Fixes: eeb0efd071d8 ("mm,memory_hotplug: fix scan_movable_pages() for gigantic hugepages") Signed-off-by: Zi Yan ziy@nvidia.com Reviewed-by: Muchun Song songmuchun@bytedance.com Acked-by: David Hildenbrand david@redhat.com Cc: stable@vger.kernel.org Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Mike Rapoport (IBM) rppt@kernel.org Cc: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/memory_hotplug.c~mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation +++ a/mm/memory_hotplug.c @@ -1689,7 +1689,7 @@ static int scan_movable_pages(unsigned l */ if (HPageMigratable(head)) goto found; - skip = compound_nr(head) - (page - head); + skip = compound_nr(head) - (pfn - page_to_pfn(head)); pfn += skip - 1; } return -ENOENT; _

Patches currently in -mm which might be from ziy@nvidia.com are

mm-cma-use-nth_page-in-place-of-direct-struct-page-manipulation.patch mm-hugetlb-use-nth_page-in-place-of-direct-struct-page-manipulation.patch mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch fs-use-nth_page-in-place-of-direct-struct-page-manipulation.patch mips-use-nth_page-in-place-of-direct-struct-page-manipulation.patch