Re: [PATCH v3 08/24] iommu/io-pgtable-arm-v7s: Use ias to check the valid iova in unmap
From: Will Deacon <will@kernel.org>
Date: 2020-10-23 11:17:52
Also in:
linux-devicetree, linux-iommu, linux-mediatek, lkml
On Wed, Sep 30, 2020 at 03:06:31PM +0800, Yong Wu wrote:
quoted hunk ↗ jump to hunk
Use the ias for the valid iova checking in arm_v7s_unmap. This is a preparing patch for supporting iova 34bit for MediaTek. BTW, change the ias/oas checking format in arm_v7s_map. Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/io-pgtable-arm-v7s.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index a688f22cbe3b..4c9d8dccfc5a 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c@@ -526,8 +526,7 @@ static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova, if (!(prot & (IOMMU_READ | IOMMU_WRITE))) return 0; - if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || - paddr >= (1ULL << data->iop.cfg.oas))) + if (WARN_ON(iova >> data->iop.cfg.ias || paddr >> data->iop.cfg.oas)) return -ERANGE;
As discussed when reviewing these for Android, please leave this code as-is.
quoted hunk ↗ jump to hunk
ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd, gfp);@@ -717,7 +716,7 @@ static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova, { struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); - if (WARN_ON(upper_32_bits(iova))) + if (WARN_ON(iova >> data->iop.cfg.ias)) return 0;
And avoid the UB here for 32-bit machines by comparing with 1ULL << iop.cfg.ias instead. Thanks, Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel