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[47.55.120.4]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8828613962esm135128356d6.0.2025.11.19.05.37.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Nov 2025 05:37:09 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vLiMu-00000000ZAY-2EdI; Wed, 19 Nov 2025 09:37:08 -0400 Date: Wed, 19 Nov 2025 09:37:08 -0400 From: Jason Gunthorpe To: Leon Romanovsky Cc: "Tian, Kevin" , Bjorn Helgaas , Logan Gunthorpe , Jens Axboe , Robin Murphy , Joerg Roedel , Will Deacon , Marek Szyprowski , Andrew Morton , Jonathan Corbet , Sumit Semwal , Christian =?utf-8?B?S8O2bmln?= , Kees Cook , "Gustavo A. R. Silva" , Ankit Agrawal , Yishai Hadas , Shameer Kolothum , Alex Williamson , Krishnakant Jaju , Matt Ochs , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "iommu@lists.linux.dev" , "linux-mm@kvack.org" , "linux-doc@vger.kernel.org" , "linux-media@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linaro-mm-sig@lists.linaro.org" , "kvm@vger.kernel.org" , "linux-hardening@vger.kernel.org" , Alex Mastro , Nicolin Chen Subject: Re: [PATCH v8 06/11] dma-buf: provide phys_vec to scatter-gather mapping routine Message-ID: <20251119133708.GM17968@ziepe.ca> References: <20251111-dmabuf-vfio-v8-0-fd9aa5df478f@nvidia.com> <20251111-dmabuf-vfio-v8-6-fd9aa5df478f@nvidia.com> <20251119133000.GB18335@unreal> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251119133000.GB18335@unreal> On Wed, Nov 19, 2025 at 03:30:00PM +0200, Leon Romanovsky wrote: > On Wed, Nov 19, 2025 at 05:54:55AM +0000, Tian, Kevin wrote: > > > From: Leon Romanovsky > > > Sent: Tuesday, November 11, 2025 5:58 PM > > > + > > > + if (dma->state && dma_use_iova(dma->state)) { > > > + WARN_ON_ONCE(mapped_len != size); > > > > then "goto err_unmap_dma". > > It never should happen, there is no need to provide error unwind to > something that you won't get. It is expected that WARN_ON has recovery code, if it is possible and not burdensome. Jason