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/mm-cma-use-nth_page-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/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@xxxxxxxx
Link: https://lkml.kernel.org/r/20230913201248.452081-2-zi.yan@xxxxxxxx
Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@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
