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Howlett" , Asahi Lina , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, iommu@lists.linux.dev, linux-mm@kvack.org Content-Type: text/plain; charset="utf-8" X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 3C7ABC0016 X-Stat-Signature: 5kucdcuqr9dy9axmg188i4arigawgf1g X-HE-Tag: 1763397248-145041 X-HE-Meta: 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 zsYmSQ5X 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 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 Wed, Nov 12, 2025 at 09:57:09AM -0300, Daniel Almeida wrote: > Hi Alice, > > > On 12 Nov 2025, at 07:15, Alice Ryhl wrote: > > + /// Map a physically contiguous range of pages of the same size. > > + /// > > + /// # Safety > > + /// > > + /// * This page table must not contain any mapping that overlaps with the mapping created by > > + /// this call. > > I don't think there is a restriction that forbids you from mapping a region that has already been mapped. > > If A->B->C are adjacent regions, and you try to map A -> C when B->C is already mapped, I think this > call will simply return length(A->B). I think that such overlapping ranges are not allowed. It triggers a warn: } else if (pte) { /* We require an unmap first */ WARN_ON(!(cfg->quirks & IO_PGTABLE_QUIRK_NO_WARN)); return -EEXIST; Alice