From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3B83606A319 for ; Wed, 21 Oct 2026 05:40:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=C+vG9SFB Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4j8dRt43Wcz2xLv; Wed, 21 Oct 2026 16:40:58 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2001:41d0:203:375::26" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1792561258; cv=none; b=FCaXNhdsPe0/kuFmHMloY4E1aE4jGDorkgmT5ihu088KzA6/Vd1j2I2og4qIyPwDYHWPhNrc77aM4P/1EAbzK2t7efNhsmeRJHHacHKjFubrF5KQubd89sj/gKrMseFhAjzD+MH+feBgjRqx4t++PK/X06Qd8q2YFIvAE44ViZxoCR4ZQS+9q6egtW1GEQMNJx9bgkhu1oQGeRRhGR4r4FBYtZ2tYwbeu0ksqPTSi85N1UMUKlRzShGY1eb6IWDUJPLjYjrEMOEej/J8akY2Mn2zv9xZKjrs7U+J4s1ojFweuQe9CAqKSNCmkZnpAoAY51fJtmi64Dh/2wWKlBSNFQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1792561258; c=relaxed/relaxed; bh=MXiUGp1caAHyyuVtstCR/2L4nYD+n3m1gvu2wPtLXMI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FZ+TkxQnnLssDBsulLKzQaVAGOWnDjnEZ6Kuf8t+mCePM7qT5BQACSQkZs0YGGlceDLvL8WVtfk4wIeSbSnaQxI72zPprBMJzvDX637cTWeUh125PWBjj3mjn+Dk+XsGQg5dukJmQFqbcjG8e7XMDCRnqbzn3zDC44iKr9l4cKEmv6HAJe+Hf74+UIChKDA9GPBu8fOo6lKe8cNrwf1vhtLi0DiBQ6+zAx272Rtejw1azQ6TkoAdXQDWudVeJj/ulp8VKz1QruDHpb4B8iw8as2h/ps8uSq7C75JFgiJzl8ClhivLPtDue62mgE0fk32LXXCMowNObEX4nyEvQWx2A== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=C+vG9SFB; dkim-atps=neutral; spf=pass (client-ip=2001:41d0:203:375::26; helo=mta1.migadu.com; envelope-from=lance.yang@linux.dev; receiver=lists.ozlabs.org) smtp.mailfrom=linux.dev Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=C+vG9SFB; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=2001:41d0:203:375::26; helo=mta1.migadu.com; envelope-from=lance.yang@linux.dev; receiver=lists.ozlabs.org) Received: from mta1.migadu.com (out-38.mta1.migadu.com [IPv6:2001:41d0:203:375::26]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4j8dRs2Y8Yz2xLt for ; Wed, 21 Oct 2026 16:40:56 +1100 (AEDT) X-Envelope-To: linuxppc-dev@lists.ozlabs.org DKIM-Signature: a=rsa-sha256; bh=MXiUGp1caAHyyuVtstCR/2L4nYD+n3m1gvu2wPtLXMI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792561237; v=1; x=1793166037; b=C+vG9SFBdBQyzmPAziKyxgOkVqVFMKpFAz91RKnVqhXiTWdcCNqsz48DU9VR4qp/m0yzSUQV Ukar89XaW1+7SLsXgAbtzL1jRmim1TE67erPvFkI9qwWgjmSW5einQc4C9m+YgKG5Gw8xPPaM06 EGYG7YWYbrPWjGGM4uejPjW4= X-Envelope-To: linuxppc-dev@lists.ozlabs.org Received: by smtp.migadu.com with ESMTPS id d2fc8a9e32f8bec1; 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-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , Precedence: list X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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=unavailable autolearn_force=no version=4.0.1 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