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Date:   Sat, 6 Aug 2022 01:26:50 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Chao Gao <chao.gao@intel.com>
Cc:     iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
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Subject: Re: [PATCH] swiotlb: avoid potential left shift overflow
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On Fri, Aug 05, 2022 at 07:44:38PM +0800, Chao Gao wrote:
> The second operand passed to slot_addr() is declared as int or unsigned int
> in all call sites. The left-shift to get the offset of a slot can overflow
> if swiotlb size is larger than 4G.
> 
> Fixes: 26a7e094783d ("swiotlb: refactor swiotlb_tbl_map_single")
> Signed-off-by: Chao Gao <chao.gao@intel.com>

Can you just convert it to an inline function?  That will take care
of the typing in a much cleaner way than a cast.