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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-15 14:31:32 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 19:42:46 -0700 |
| commit | 61883d3c32418f16e35e030ca0cfd5d2de95a649 (patch) | |
| tree | 6c53d37051e0158aba6a03e1f6a7fc8f1fa299a8 /drivers/iommu/dma-iommu.c | |
| parent | 7a16d7c7619b26e5e9bfc1360de0d02a94f7d9eb (diff) | |
| download | lwn-61883d3c32418f16e35e030ca0cfd5d2de95a649.tar.gz lwn-61883d3c32418f16e35e030ca0cfd5d2de95a649.zip | |
iommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages()
MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
can deliver is MAX_ORDER-1.
Fix MAX_ORDER usage in __iommu_dma_alloc_pages().
Also use GENMASK() instead of hard to read "(2U << order) - 1" magic.
Link: https://lkml.kernel.org/r/20230315113133.11326-10-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/iommu/dma-iommu.c')
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 99b2646cb5c7..ac996fd6bd9c 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -736,7 +736,7 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev, struct page **pages; unsigned int i = 0, nid = dev_to_node(dev); - order_mask &= (2U << MAX_ORDER) - 1; + order_mask &= GENMASK(MAX_ORDER - 1, 0); if (!order_mask) return NULL; @@ -756,7 +756,7 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev, * than a necessity, hence using __GFP_NORETRY until * falling back to minimum-order allocations. */ - for (order_mask &= (2U << __fls(count)) - 1; + for (order_mask &= GENMASK(__fls(count), 0); order_mask; order_mask &= ~order_size) { unsigned int order = __fls(order_mask); gfp_t alloc_flags = gfp; |