From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: include/linux/huge_mm.h: check PageTail in hpage_nr_pages even when !THP It's even more important to check that we don't have a tail page when calling hpage_nr_pages() when THP are disabled. Link: http://lkml.kernel.org/r/20200318140253.6141-4-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/huge_mm.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/include/linux/huge_mm.h~mm-check-pagetail-in-hpage_nr_pages-even-when-thp +++ a/include/linux/huge_mm.h @@ -287,7 +287,11 @@ static inline struct list_head *page_def #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; }) #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; }) -#define hpage_nr_pages(x) 1 +static inline int hpage_nr_pages(struct page *page) +{ + VM_BUG_ON_PAGE(PageTail(page), page); + return 1; +} static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) { _
