linux-kernel - [PATCH] mm: Use linear_page_index() in do

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Date:	Sun, 31 Jan 2016 23:13:21 +1100
From:	Matthew Wilcox <matthew.r.wilcox@...el.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Matthew Wilcox <matthew.r.wilcox@...el.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, willy@...ux.intel.com
Subject: [PATCH] mm: Use linear_page_index() in do_fault()

do_fault assumes that PAGE_SIZE is the same as PAGE_CACHE_SIZE.
Use linear_page_index() to calculate pgoff in the correct units.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@...el.com>
---
 mm/memory.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 554816b..5224c06 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3161,8 +3161,7 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		unsigned long address, pte_t *page_table, pmd_t *pmd,
 		unsigned int flags, pte_t orig_pte)
 {
-	pgoff_t pgoff = (((address & PAGE_MASK)
-			- vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+	pgoff_t pgoff = linear_page_index(vma, address);
 
 	pte_unmap(page_table);
 	/* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
-- 
2.7.0.rc3