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From: Joerg Roedel <joro@8bytes.org>
To: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
	Rob Herring <robh+dt@kernel.org>,
	iommu@lists.linux-foundation.org, devicetree@vger.kernel.org,
	Baolin Wang <baolin.wang7@gmail.com>,
	linux-kernel@vger.kernel.org, Orson Zhai <orsonzhai@gmail.com>,
	Sheng Xu <sheng.xu@unisoc.com>,
	Chunyan Zhang <chunyan.zhang@unisoc.com>
Subject: Re: [PATCH 2/2] iommu: add Unisoc iommu basic driver
Date: Tue, 2 Feb 2021 15:13:50 +0100	[thread overview]
Message-ID: <20210202141349.GB32671@8bytes.org> (raw)
In-Reply-To: <20210202104257.736836-1-zhang.lyra@gmail.com>

On Tue, Feb 02, 2021 at 06:42:57PM +0800, Chunyan Zhang wrote:
> +static phys_addr_t sprd_iommu_iova_to_phys(struct iommu_domain *domain,
> +					   dma_addr_t iova)
> +{
> +	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
> +	unsigned long flags;
> +	phys_addr_t pa;
> +	unsigned long start = domain->geometry.aperture_start;
> +	unsigned long end = domain->geometry.aperture_end;
> +
> +	if (iova < start || iova > end)
> +		pr_err("iova (0x%llx) exceed the vpn range[0x%lx-0x%lx]!\n",
> +		       iova, start, end);

It is not a good idea to continue here with an out-of-range iova. The
code below might access random memory for its checks. Better do a
WARN_ON here and return an invalid physical address.

> +
> +	spin_lock_irqsave(&dom->pgtlock, flags);
> +	pa = *(dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT));
> +	pa = (pa << SPRD_IOMMU_PAGE_SHIFT) + ((iova - start) & (SPRD_IOMMU_PAGE_SIZE - 1));
> +	spin_unlock_irqrestore(&dom->pgtlock, flags);
> +
> +	return pa;
> +}
> +

  parent reply	other threads:[~2021-02-02 17:27 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-02  7:32 [PATCH v2 0/2] Add Unisoc iommu basic driver Chunyan Zhang
2021-02-02  7:32 ` [PATCH v2 1/2] dt-bindings: iommu: add bindings for sprd iommu Chunyan Zhang
2021-02-02  7:32 ` [PATCH v2 2/2] iommu: add Unisoc iommu basic driver Chunyan Zhang
2021-02-02 10:42   ` [PATCH " Chunyan Zhang
2021-02-02 14:01     ` Joerg Roedel
2021-02-02 14:34       ` Robin Murphy
2021-02-02 14:41         ` Joerg Roedel
2021-02-02 18:02           ` Robin Murphy
2021-02-03  1:49             ` Chunyan Zhang
2021-02-02 14:13     ` Joerg Roedel [this message]
2021-02-03  1:45       ` Chunyan Zhang

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