fs/hugetlbfs/inode.c: fix pgoff alignment checking on 32-bit
Becky Bruce [Tue, 26 Jul 2011 00:11:49 +0000 (17:11 -0700)]
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@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hugetlbfs/inode.c

index 7aafeb8..537a209 100644 (file)
@@ -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);