Commit f46cc015 authored Jul 26, 2019 by Nicolin Chen Committed by Christoph Hellwig Jul 29, 2019

dma-contiguous: page-align the size in dma_free_contiguous()



According to the original dma_direct_alloc_pages() code:
{
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	if (!dma_release_from_contiguous(dev, page, count))
		__free_pages(page, get_order(size));
}

The count parameter for dma_release_from_contiguous() was page
aligned before the right-shifting operation, while the new API
dma_free_contiguous() forgets to have PAGE_ALIGN() at the size.

So this patch simply adds it to prevent any corner case.

Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

parent c6622a42

kernel/dma/contiguous.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -267,7 +267,8 @@ struct page dma_alloc_contiguous(struct device dev, size_t size, gfp_t gfp)
		*/
		void dma_free_contiguous(struct device dev, struct page page, size_t size)
		{
		if (!cma_release(dev_get_cma_area(dev), page, size >> PAGE_SHIFT))
		if (!cma_release(dev_get_cma_area(dev), page,
		PAGE_ALIGN(size) >> PAGE_SHIFT))
		__free_pages(page, get_order(size));
		}

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