linux-kernel - Re: [PATCH] iommu/dma: add missing support for DMA_ATTR_MMIO for dma_iova

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <b890945a-49af-4c45-a325-0fb106be7832@samsung.com>
Date: Mon, 24 Nov 2025 19:46:12 +0100
From: Marek Szyprowski <m.szyprowski@...sung.com>
To: Jason Gunthorpe <jgg@...pe.ca>
Cc: iommu@...ts.linux.dev, linux-kernel@...r.kernel.org, Robin Murphy
	<robin.murphy@....com>, Joerg Roedel <joro@...tes.org>, Will Deacon
	<will@...nel.org>, Leon Romanovsky <leon@...nel.org>
Subject: Re: [PATCH] iommu/dma: add missing support for DMA_ATTR_MMIO for
 dma_iova_unlink()

On 24.11.2025 19:17, Jason Gunthorpe wrote:
> On Mon, Nov 24, 2025 at 06:09:55PM +0100, Marek Szyprowski wrote:
>> Commit c288d657dd51 added support for DMA_ATTR_MMIO attribute in the
>> dma_iova_link() code path, but missed that the CPU cache is being also
>> touched in the dma_iova_unlink() path. Fix this.
>>
>> Fixes: c288d657dd51 ("iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().")
>> Signed-off-by: Marek Szyprowski <m.szyprowski@...sung.com>
>> ---
>>   drivers/iommu/dma-iommu.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
> Reviewed-by: Jason Gunthorpe <jgg@...dia.com>
>
> Did you find it by code inspection?

Yes, I checked how the batched CPu sync will fit there and noticed the 
unlink path, see 
https://lore.kernel.org/all/f8a0b873-b93c-4a91-b47d-2d11bfcf36b4@samsung.com/

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland