[PATCH 2/8] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area

[FUJITA Tomonori]

On Tue, 13 Oct 2009 18:10:17 +0900
Akinobu Mita <akinobu.mita at gmail.com> wrote:

> My user space testing exposed off-by-one error find_next_zero_area
> in iommu-helper. Some zero area cannot be found by this bug.
> 
> Subject: [PATCH] Fix off-by-one error in find_next_zero_area
> 
> Signed-off-by: Akinobu Mita <akinobu.mita at gmail.com>
> ---
>  lib/iommu-helper.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
> index 75dbda0..afc58bc 100644
> --- a/lib/iommu-helper.c
> +++ b/lib/iommu-helper.c
> @@ -19,7 +19,7 @@ again:
>  	index = (index + align_mask) & ~align_mask;
>  
>  	end = index + nr;
> -	if (end >= size)
> +	if (end > size)

I think that this is intentional; the last byte of the limit doesn't
work.