2009/10/17 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>: > On Tue, 13 Oct 2009 18:10:17 +0900 > Akinobu Mita <akinobu.mita@xxxxxxxxx> 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@xxxxxxxxx> >> --- >> 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. 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
![]() |