Messages in this thread | | | Date | Sat, 17 Oct 2009 23:51:32 +0900 | Subject | Re: [PATCH 2/8] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area | From | FUJITA Tomonori <> |
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On Sat, 17 Oct 2009 23:43:56 +0900 Akinobu Mita <akinobu.mita@gmail.com> wrote:
> 2009/10/17 FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>: > > On Tue, 13 Oct 2009 18:10:17 +0900 > > Akinobu Mita <akinobu.mita@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@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. > > It looks ok to me. Without above change, find_next_zero_area cannot > find a 64 bits zeroed area in next sample code.
I meant that we don't want to find such area for IOMMUs (IIRC, it code came from POWER IOMMU).
> unsigned long offset; > > DECLARE_BITMAP(map, 64); > > bitmap_clear(map, 0, 64); > offset = find_next_zero_area(map, 64, 0, 64, 0); > if (offset >= 64) > printf("not found\n"); > else > printf("found\n"); > -- > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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