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From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: dafna.hirschfeld@collabora.com, hch@lst.de,
	m.szyprowski@samsung.com, robin.murphy@arm.com,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] dma-contiguous: page-align the size in dma_free_contiguous()
Date: Fri, 26 Jul 2019 08:30:25 +0200	[thread overview]
Message-ID: <20190726063025.GF22881@lst.de> (raw)
In-Reply-To: <20190725233959.15129-3-nicoleotsuka@gmail.com>

On Thu, Jul 25, 2019 at 04:39:59PM -0700, Nicolin Chen wrote:
> 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>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

      reply	other threads:[~2019-07-26  6:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-25 23:39 [PATCH 0/2] dma-contiguous: two bug fixes for dma_{alloc,free}_contiguous() Nicolin Chen
2019-07-25 23:39 ` [PATCH 1/2] dma-contiguous: do not overwrite align in dma_alloc_contiguous() Nicolin Chen
2019-07-26  6:28   ` Christoph Hellwig
2019-07-26 19:22     ` Nicolin Chen
2019-07-25 23:39 ` [PATCH 2/2] dma-contiguous: page-align the size in dma_free_contiguous() Nicolin Chen
2019-07-26  6:30   ` Christoph Hellwig [this message]

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