From: Jason Gunthorpe <jgg@nvidia.com>
To: Pranjal Shrivastava <praan@google.com>
Cc: Ashish Mhetre <amhetre@nvidia.com>,
Leon Romanovsky <leon@kernel.org>,
robin.murphy@arm.com, joro@8bytes.org, will@kernel.org,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-tegra@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH RFC] iommu/dma: Validate page before accessing P2PDMA state
Date: Fri, 27 Feb 2026 10:13:30 -0400 [thread overview]
Message-ID: <20260227141330.GK5933@nvidia.com> (raw)
In-Reply-To: <aaGlapPSmFJcXsDh@google.com>
On Fri, Feb 27, 2026 at 02:08:42PM +0000, Pranjal Shrivastava wrote:
> The question is, are we sure to use scatterlists to represent non-paged
> memory?
This is absolutely illegal and a driver bug to put non-struct page
memory into a scatter list. It was never an acceptable "work
around". What driver is doing this??
If you want to improve robustness add some pfn_valid/etc checks under
the CONFING DMA DEBUG and throw warns for these mistakes.
Jason
next prev parent reply other threads:[~2026-02-27 14:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-24 10:42 [PATCH RFC] iommu/dma: Validate page before accessing P2PDMA state Ashish Mhetre
2026-02-24 12:32 ` Leon Romanovsky
2026-02-24 20:57 ` Pranjal Shrivastava
2026-02-25 4:49 ` Ashish Mhetre
2026-02-25 7:56 ` Leon Romanovsky
2026-02-25 20:11 ` Pranjal Shrivastava
2026-02-26 7:58 ` Leon Romanovsky
2026-02-27 5:46 ` Ashish Mhetre
2026-02-27 14:05 ` Robin Murphy
2026-02-27 14:08 ` Pranjal Shrivastava
2026-02-27 14:13 ` Jason Gunthorpe [this message]
2026-02-25 7:50 ` Leon Romanovsky
2026-02-25 20:15 ` Pranjal Shrivastava
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