| Message ID | 1297177190-1423-2-git-send-email-akinobu.mita@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
From: Akinobu Mita <akinobu.mita@gmail.com> Date: Tue, 8 Feb 2011 23:59:50 +0900 > iommu_alloc_ctx() finds a zero bit in iommu->ctx_bitmap. It starts > searching from iommu->ctx_lowest_free to the end of the bitmap. > But the size argument to find_next_zero_bit() in iommu_alloc_ctx() > is wrong. It should be the bitmap size, not the maximum size to > search from the offset argument. > > Fortunately iommu->ctx_lowest_free is almost unused and it will not > be more than 1. So the bug wasted only 1-bit at the end of > iommu->ctx_bitmap. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Thank you for fixing this bug, applied! -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 47977a7..72509d0 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -255,10 +255,9 @@ static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu, static int iommu_alloc_ctx(struct iommu *iommu) { int lowest = iommu->ctx_lowest_free; - int sz = IOMMU_NUM_CTXS - lowest; - int n = find_next_zero_bit(iommu->ctx_bitmap, sz, lowest); + int n = find_next_zero_bit(iommu->ctx_bitmap, IOMMU_NUM_CTXS, lowest); - if (unlikely(n == sz)) { + if (unlikely(n == IOMMU_NUM_CTXS)) { n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1); if (unlikely(n == lowest)) { printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");
iommu_alloc_ctx() finds a zero bit in iommu->ctx_bitmap. It starts searching from iommu->ctx_lowest_free to the end of the bitmap. But the size argument to find_next_zero_bit() in iommu_alloc_ctx() is wrong. It should be the bitmap size, not the maximum size to search from the offset argument. Fortunately iommu->ctx_lowest_free is almost unused and it will not be more than 1. So the bug wasted only 1-bit at the end of iommu->ctx_bitmap. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: sparclinux@vger.kernel.org --- arch/sparc/kernel/iommu.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-)