From: Christoph Hellwig <hch@infradead.org>
To: Leon Romanovsky <leon@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
jgg@ziepe.ca, zyjzyj2000@gmail.com,
Daisuke Matsuda <dskmtsd@gmail.com>,
hch@infradead.org
Subject: Re: [PATCH for-next v3] RDMA/core: Avoid hmm_dma_map_alloc() for virtual DMA devices
Date: Sun, 25 May 2025 23:57:14 -0700 [thread overview]
Message-ID: <aDQQyjJv9YKK_ZoV@infradead.org> (raw)
In-Reply-To: <174815946854.1055673.18158398913709776499.b4-ty@kernel.org>
On Sun, May 25, 2025 at 03:51:08AM -0400, Leon Romanovsky wrote:
>
> On Sat, 24 May 2025 14:43:28 +0000, Daisuke Matsuda wrote:
> > Drivers such as rxe, which use virtual DMA, must not call into the DMA
> > mapping core since they lack physical DMA capabilities. Otherwise, a NULL
> > pointer dereference is observed as shown below. This patch ensures the RDMA
> > core handles virtual and physical DMA paths appropriately.
> >
> > This fixes the following kernel oops:
> >
> > [...]
>
> Applied, thanks!
So while this version look correct, the idea of open coding the
virtual device version of hmm_dma_map directly in the ODP code
is a nasty leaky abstraction. Please pull it into a proper ib_dma_*
wrapper.
next prev parent reply other threads:[~2025-05-26 6:57 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-24 14:43 [PATCH for-next v3] RDMA/core: Avoid hmm_dma_map_alloc() for virtual DMA devices Daisuke Matsuda
2025-05-24 21:27 ` Greg Sword
2025-05-25 2:54 ` Daisuke Matsuda
2025-05-26 17:51 ` Greg Sword
2025-05-25 6:05 ` Leon Romanovsky
2025-05-26 17:52 ` Greg Sword
2025-05-27 6:35 ` Leon Romanovsky
2025-05-25 5:22 ` Zhu Yanjun
2025-05-25 6:03 ` Daisuke Matsuda
2025-05-25 14:17 ` Zhu Yanjun
2025-05-25 7:08 ` Leon Romanovsky
2025-05-25 9:34 ` Daisuke Matsuda
2025-05-25 10:24 ` Leon Romanovsky
2025-05-25 7:51 ` Leon Romanovsky
2025-05-26 6:57 ` Christoph Hellwig [this message]
2025-05-26 9:07 ` Leon Romanovsky
2025-05-26 19:57 ` Jason Gunthorpe
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