6.6-stable review patch. If anyone has any objections, please let me know.
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From: Zi Yan ziy@nvidia.com
commit aa5fe31b6b59210cb4ea28a59e68781f48eeca74 upstream.
__flush_dcache_pages() is called during hugetlb migration via migrate_pages() -> migrate_hugetlbs() -> unmap_and_move_huge_page() -> move_to_new_folio() -> flush_dcache_folio(). And with hugetlb and without sparsemem vmemmap, struct page is not guaranteed to be contiguous beyond a section. Use nth_page() instead.
Without the fix, a wrong address might be used for data cache page flush. No bug is reported. The fix comes from code inspection.
Link: https://lkml.kernel.org/r/20230913201248.452081-6-zi.yan@sent.com Fixes: 15fa3e8e3269 ("mips: implement the new page table range API") Signed-off-by: Zi Yan ziy@nvidia.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: Muchun Song songmuchun@bytedance.com Cc: Thomas Bogendoerfer tsbogend@alpha.franken.de Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/mm/cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/mm/cache.c +++ b/arch/mips/mm/cache.c @@ -117,7 +117,7 @@ void __flush_dcache_pages(struct page *p * get faulted into the tlb (and thus flushed) anyways. */ for (i = 0; i < nr; i++) { - addr = (unsigned long)kmap_local_page(page + i); + addr = (unsigned long)kmap_local_page(nth_page(page, i)); flush_data_cache_page(addr); kunmap_local((void *)addr); }