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/mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch
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@xxxxxxxxxx>
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@xxxxxxxx
Fixes: eeb0efd071d8 ("mm,memory_hotplug: fix scan_movable_pages() for gigantic hugepages")
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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
