Commit 2b37c35e authored Jul 25, 2011 by Becky Bruce Committed by Linus Torvalds Jul 25, 2011

fs/hugetlbfs/inode.c: fix pgoff alignment checking on 32-bit



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>

parent d694ad62

fs/hugetlbfs/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);