The patch titled Subject: mm/cma: use nth_page() in place of direct struct page manipulation has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-cma-use-nth_page-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
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------------------------------------------------------ From: Zi Yan ziy@nvidia.com Subject: mm/cma: use nth_page() in place of direct struct page manipulation Date: Wed, 13 Sep 2023 16:12:44 -0400
Patch series "Use nth_page() in place of direct struct page manipulation", v3.
On SPARSEMEM without VMEMMAP, struct page is not guaranteed to be contiguous, since each memory section's memmap might be allocated independently. hugetlb pages can go beyond a memory section size, thus direct struct page manipulation on hugetlb pages/subpages might give wrong struct page. Kernel provides nth_page() to do the manipulation properly. Use that whenever code can see hugetlb pages.
This patch (of 5):
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 nth_page() to handle it properly.
Link: https://lkml.kernel.org/r/20230913201248.452081-1-zi.yan@sent.com Link: https://lkml.kernel.org/r/20230913201248.452081-2-zi.yan@sent.com Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc") Signed-off-by: Zi Yan ziy@nvidia.com Reviewed-by: Muchun Song songmuchun@bytedance.com Cc: David Hildenbrand david@redhat.com 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 Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/cma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/cma.c~mm-cma-use-nth_page-in-place-of-direct-struct-page-manipulation +++ a/mm/cma.c @@ -505,7 +505,7 @@ struct page *cma_alloc(struct cma *cma, */ if (page) { for (i = 0; i < count; i++) - page_kasan_tag_reset(page + i); + page_kasan_tag_reset(nth_page(page, i)); }
if (ret && !no_warn) { _
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