From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 752A3FF8867 for ; Wed, 29 Apr 2026 13:57:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dQtZTpELJ1liX6xujaqBk9rq103ELoK9RGJIqb5f6ZI=; b=y9QlaLzbXyfAD3sZccBTb/Big4 NpmbLZId1THiFTkWt0sFXSLjTQ4KKVlFijbxIB+NHomUmBb/cpFLAxcCBJYFIj0TahjNdMxPLkZyl noAJxfIOWnd47cH50jJKK9CE9crVa/xRyw+l5KwDAxuU1+iRTBAcXujeQZiTZ/jljlgdJ/eimfm7X z32tHMfs6JJ4HstYhDIR+XNS0S+y8QRrFdincdbV6d4hlo3DqEs089Cyask00HyCO/IRNJENyHSrn GvHkBsxn0wWt37a0pr6gohit3bv/s/Irr4zdcgdnBzGTvden1sbMquAQfDvM/6yq+juGQ0zktRS96 16ekUwZg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wI5Q2-00000003iSn-2JDN; Wed, 29 Apr 2026 13:57:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wI5Q0-00000003iS3-1uL3 for linux-arm-kernel@lists.infradead.org; Wed, 29 Apr 2026 13:57:37 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7FB45337B; Wed, 29 Apr 2026 06:57:30 -0700 (PDT) Received: from [10.57.62.76] (unknown [10.57.62.76]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B54813F62B; Wed, 29 Apr 2026 06:57:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777471056; bh=51AOjeUHqGDov+TlvZ961wTG4/ToLBw1MVjjZ/EnINw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VZYMMPruwp21m0Xl4JeKfECbeTob5+cc9VVBwFqewef4YFQpd9Inm1HT5mWQ5/6XG ItElSh4Ig+yLgjTKWv4g3SNaz5OOVx2Ve3sKphhXFiZ/dF5OXmmvFug+NBjU9oGbIA 5KSpb9He9n9hVC8WDP9z/KmEA1lJ8qPdpTJ9HzCk= Message-ID: <21a547ae-7121-4cd1-b203-4d8182eb7cc9@arm.com> Date: Wed, 29 Apr 2026 15:57:29 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 15/15] arm64: mm: Remap linear aliases of the fixmap page tables read-only To: Ard Biesheuvel , linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, Ard Biesheuvel , Ryan Roberts , Anshuman Khandual , Liz Prucka , Seth Jenkins , Kees Cook , Mike Rapoport , David Hildenbrand , Andrew Morton , linux-mm@kvack.org, linux-hardening@vger.kernel.org References: <20260427153416.2103979-17-ardb+git@google.com> <20260427153416.2103979-32-ardb+git@google.com> From: Kevin Brodsky Content-Language: en-GB In-Reply-To: <20260427153416.2103979-32-ardb+git@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260429_065736_537917_E9737E83 X-CRM114-Status: GOOD ( 10.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 27/04/2026 17:34, Ard Biesheuvel wrote: > [...] > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 84d81bae07a7..e76fe5b0c5fe 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1076,6 +1076,11 @@ void __init mark_linear_text_alias_ro(void) > (unsigned long)__init_begin - (unsigned long)_text, > pgprot_tagged(PAGE_KERNEL_RO)); > > + /* Map the fixmap PTE table at __fixmap_pgdir_start R/O in linear map too */ > + update_mapping_prot(__pa_symbol(__fixmap_pgdir_start), > + (unsigned long)lm_alias(__fixmap_pgdir_start), > + PAGE_SIZE, pgprot_tagged(PAGE_KERNEL_RO)); Is that definitely just one page? > + > remap_linear_data_alias(true); > > if (IS_ENABLED(CONFIG_HIBERNATION)) {