* Re: [PATCH 1/5] fs/hugetlbfs/inode.c: Fix pgoff alignment checking on 32-bit
[not found] ` <13092909493748-git-send-email-beckyb@kernel.crashing.org>
@ 2011-07-19 4:43 ` Benjamin Herrenschmidt
0 siblings, 0 replies; only message in thread
From: Benjamin Herrenschmidt @ 2011-07-19 4:43 UTC (permalink / raw)
To: linux-mm
Cc: linux-kernel, linuxppc-dev, david, galak, Becky Bruce, Andrew Morton
Andrew, Anybody ? Can I have an -mm ack for this ?
Cheers,
Ben.
On Tue, 2011-06-28 at 14:54 -0500, Becky Bruce wrote:
> From: Becky Bruce <beckyb@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@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);
--
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