linux-kernel - Re: [PATCH v3 2/4] iommu/dma-iommu: Handle deferred devices

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20190507064000.GB5173@infradead.org>
Date:   Mon, 6 May 2019 23:40:00 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Tom Murphy <tmurphy@...sta.com>
Cc:     iommu@...ts.linux-foundation.org, murphyt7@....ie,
        Joerg Roedel <joro@...tes.org>,
        Will Deacon <will.deacon@....com>,
        Robin Murphy <robin.murphy@....com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Kukjin Kim <kgene@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        David Woodhouse <dwmw2@...radead.org>,
        Andy Gross <andy.gross@...aro.org>,
        David Brown <david.brown@...aro.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Rob Clark <robdclark@...il.com>,
        Heiko Stuebner <heiko@...ech.de>,
        Gerald Schaefer <gerald.schaefer@...ibm.com>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-mediatek@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org, linux-s390@...r.kernel.org,
        linux-tegra@...r.kernel.org
Subject: Re: [PATCH v3 2/4] iommu/dma-iommu: Handle deferred devices

On Mon, May 06, 2019 at 07:52:04PM +0100, Tom Murphy wrote:
> +static int handle_deferred_device(struct device *dev)
> +{
> +	struct iommu_domain *domain;
> +	const struct iommu_ops *ops;
> +
> +	if (!is_kdump_kernel())
> +		return 0;
> +
> +	domain = iommu_get_domain_for_dev(dev);

> -	dma_handle =__iommu_dma_map(dev, phys, size,
> +	if (unlikely(handle_deferred_device(dev)))
> +		return DMA_MAPPING_ERROR;
> +
> +	dma_handle = __iommu_dma_map(dev, phys, size,

__iommu_dma_map already looks up the domain, and as far as I can
tell all callers need the handle_deferred_device call.  Should we
just move it to there and pass the domain from the caller?

Also shouldn't the iommu_attach_device call inside
handle_deferred_device also get an unlikely marker?