[PATCH] mm/page_vma_mapped.c: Exactly compare hugetlbfs page's pfn in pfn_in_hpage()

[Li Xinhai <lixinhai.lxh@gmail.com>]

check_pte is called for hugetlbfs page and comparing pfn in pfn_in_page,
where pfn is compared in range [hpage_pfn, hpage_pfn+HPAGE_PMD_NR). Now
change it to match exactly for hugetlbfs page to avoid hiding any
potential problems.

Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 mm/page_vma_mapped.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index eff4b45..434978b 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -55,6 +55,8 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw)
 static inline bool pfn_in_hpage(struct page *hpage, unsigned long pfn)
 {
 	unsigned long hpage_pfn = page_to_pfn(hpage);
+	if (unlikely(PageHuge(hpage)))
+		return pfn == hpage_pfn;
 
 	/* THP can be referenced by any subpage */
 	return pfn >= hpage_pfn && pfn - hpage_pfn < hpage_nr_pages(hpage);
-- 
1.8.3.1