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Wed, 21 Oct 2026 05:40:35 +0000 X-Mizu-Trace-ID: d2fc8a9e32f8bec1 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: songmuchun@bytedance.com Cc: akpm@linux-foundation.org, david@kernel.org, osalvador@suse.de, maddy@linux.ibm.com, corbet@lwn.net, muchun.song@linux.dev, lance.yang@linux.dev, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, ritesh.list@gmail.com, sshegde@linux.ibm.com, skhan@linuxfoundation.org, rdunlap@infradead.org, qi.zheng@linux.dev, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] powerpc/mm: map shared vmemmap tail pages as read-only Date: Wed, 21 Oct 2026 13:40:29 +0800 Message-ID: <20261021054029.98875-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261019090830.1917657-3-songmuchun@bytedance.com> References: <20261019090830.1917657-3-songmuchun@bytedance.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: E52B0C0002 X-Stat-Signature: gizypr8u7gtzre4ukkukdefuwcap4gb3 X-Rspamd-Server: rspam06 X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1792561238-837932 X-HE-Meta: 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 QSkBFwB6 sMNSB5GRqfP4cDK8JfldkjdPmQZNc9rrjcxmqVblXEXJAsetZ7NrTB3Ct9Ee6nHkGnptt2xcODVKyoY7VN2b8r5yNa4x4y1XAl0HXlpsb2aG4mWmczCTIpZcM/SlTqy5O/6ZIZ8njf8qSHvRQj61W66amSP/e8vh1qpD1QidW//YCJuRZGWTgrCiH0Lwz4AYF6d1wqaO3zv+CB9efkQiwgrw3Y5WhS61l0qBldUt5u2f7aQ/1nFPZMfMAEgetH5T2oK1ovc9dBBuq2tyo0O+hyWM765G28EbUb8TMK9AjiBKrrsZZe/7hSR0cAYRYpUzG4rNCfG0QoHIXHJw= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 19, 2026 at 05:08:28PM +0800, Muchun Song wrote: >PowerPC radix uses an architecture-specific vmemmap population path for >shared tail mappings, so it does not inherit the read-only protection added >to the common path. > >Protect these mappings as well so illegal writes fault instead of >corrupting metadata shared by multiple tail pages. > >Signed-off-by: Muchun Song >--- Nothing jumped out at me, feel free to add: Reviewed-by: Lance Yang