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[34.140.140.54]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-477bf226c2asm188677715e9.10.2025.11.24.03.04.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Nov 2025 03:04:40 -0800 (PST) Date: Mon, 24 Nov 2025 11:04:37 +0000 From: Mostafa Saleh To: Randy Dunlap Cc: linux-mm@kvack.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, corbet@lwn.net, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, akpm@linux-foundation.org, vbabka@suse.cz, surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, rppt@kernel.org, Qinxin Xia Subject: Re: [PATCH v2 1/4] drivers/iommu: Add page_ext for IOMMU_DEBUG_PAGEALLOC Message-ID: References: <20251106163953.1971067-1-smostafa@google.com> <20251106163953.1971067-2-smostafa@google.com> <55391dad-339b-47f8-8996-afe337b238e0@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55391dad-339b-47f8-8996-afe337b238e0@infradead.org> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 2913A14000B X-Stat-Signature: x5cmw3xw73xuudrmx87esckoomt4z5ps X-Rspam-User: X-HE-Tag: 1763982282-69556 X-HE-Meta: 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 Kv/mK1f6 0KabS+6UA9vy58K7IuuL6lUIg5+cKCerai8gnaU2OI1j+HGj8kDkt5dUBrmcUPOMD6N7BgslFlewf5refHthMHbtvdTohu95hySfPaUjQ0fGhYgVln92Le52asJUaTGomtxxWrybliggDEengaZ2Uaojm6/P/QZiNFmvZZQf4en1MBtLVj0FzkavIhfsg1joDujtujsWG5wGSgjloJTXHnoPNXeiZVrdw2dq7ldPIhUm9RrBk0/A5g1VDK8AL8x4P6Gat4Dkc0qn3ZNllUDuol5tckB2fa5gl3laMHzfHSRjH62kOoITsXALNArhDIP+IF7JpgNKJ8h9L/YyJiTTQqS1BFLSAjdCuxE9lykn3zkdp3uqgenEAyw2K5tV8kCM3wB5QTqSKCmzWHoReUuVT9agmJXQixndEswdY X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Nov 06, 2025 at 11:50:11AM -0800, Randy Dunlap wrote: > > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index 70d29b14d851..6b5e9a2d936a 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -383,4 +383,19 @@ config SPRD_IOMMU > > > > Say Y here if you want to use the multimedia devices listed above. > > > > +config IOMMU_DEBUG_PAGEALLOC > > + bool "Debug page memory allocations against IOMMU" > > + depends on DEBUG_PAGEALLOC && IOMMU_API && PAGE_EXTENSION > > + help > > + This config checks that a page is freed(unmapped) or mapped by the > > + kernel is not mapped in any IOMMU domain. It can help with debugging > > + use-after-free or out-of-bound maps from drivers doing DMA through > > + the IOMMU API. > > + This santaizer can have false-negative cases where some problems > > sanitizer I will fix it. Thanks, Mostafa > > > + won't be detected. > > + Expect overhead when enabling this and enabling the kernel command > > + line iommu.debug_pagealloc. > > + > > + If unsure, say N here. > > + > > endif # IOMMU_SUPPORT > > > -- > ~Randy >