[PATCH 1/5] fs/hugetlbfs/inode.c: Fix pgoff alignment checking on 32-bit

Becky Bruce beckyb at kernel.crashing.org
Wed Jun 29 05:54:44 EST 2011


From: Becky Bruce <beckyb at kernel.crashing.org>

This:

vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT)

is incorrect on 32-bit.  It causes us to & the pgoff with
something that looks like this (for a 4m hugepage): 0xfff003ff.
The mask should be flipped and *then* shifted, to give you
0x0000_03fff.

Signed-off-by: Becky Bruce <beckyb at kernel.crashing.org>
---
 fs/hugetlbfs/inode.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 7aafeb8..537a209 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -94,7 +94,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
 	vma->vm_ops = &hugetlb_vm_ops;
 
-	if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT))
+	if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
 		return -EINVAL;
 
 	vma_len = (loff_t)(vma->vm_end - vma->vm_start);
-- 
1.5.6.5



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