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 B01B6CD3442 for ; Tue, 3 Sep 2024 15:36:18 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Z3E9Vn4TKoaL9shXIlIYfEwTsVJ0llEy4ksrdeCUm6o=; b=KCwhbaPvmQzwjJ6HoeA7iwFXnH HYrOmnSXT57C9ei0l1SmfGzZerUi8UnmaRdSJxStgO2UpM3jndxklNPvQmfURB1MUJjdWw6eIPE/a CEZufNpT77mIDb9vzJKJ38bysOj+eFdnQamdDB6n9HRlnUlTCMS/SHQwUhfikf0rCA8Rn5pCD83m8 oQKuFfoDx+Asqcike0PsWqHfQ8U7Io7OXgwguc3nIku+abz7TlJlSyfUsIH8EFi+0lCMnGFCkas72 lSJpY1DC4bne8S3vYZOL3jCHRZNMTyGzN3CF1QplPBHqsByVG7pKvmmqATmeiUcCEKLp7JdVtVq4A 5fRefxkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1slVZe-00000000th5-39YT; Tue, 03 Sep 2024 15:36:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1slVTX-00000000rdw-14Va for linux-arm-kernel@lists.infradead.org; Tue, 03 Sep 2024 15:29:49 +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 46809FEC; Tue, 3 Sep 2024 08:30:12 -0700 (PDT) Received: from e124191.cambridge.arm.com (e124191.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 841EB3F66E; Tue, 3 Sep 2024 08:29:42 -0700 (PDT) Date: Tue, 3 Sep 2024 16:29:37 +0100 From: Joey Gouly To: Mark Brown Cc: linux-arm-kernel@lists.infradead.org, nd@arm.com, akpm@linux-foundation.org, aneesh.kumar@kernel.org, aneesh.kumar@linux.ibm.com, anshuman.khandual@arm.com, bp@alien8.de, catalin.marinas@arm.com, christophe.leroy@csgroup.eu, dave.hansen@linux.intel.com, hpa@zytor.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, maz@kernel.org, mingo@redhat.com, mpe@ellerman.id.au, naveen.n.rao@linux.ibm.com, npiggin@gmail.com, oliver.upton@linux.dev, shuah@kernel.org, skhan@linuxfoundation.org, szabolcs.nagy@arm.com, tglx@linutronix.de, will@kernel.org, x86@kernel.org, kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v5 16/30] arm64: handle PKEY/POE faults Message-ID: <20240903152937.GA3768522@e124191.cambridge.arm.com> References: <20240822151113.1479789-1-joey.gouly@arm.com> <20240822151113.1479789-17-joey.gouly@arm.com> <40600b75-68eb-421a-a122-256bd20afb89@sirena.org.uk> <20240903144823.GA3669886@e124191.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240903144823.GA3669886@e124191.cambridge.arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240903_082947_503450_BB0BEA26 X-CRM114-Status: GOOD ( 25.08 ) 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 Tue, Sep 03, 2024 at 03:50:46PM +0100, Joey Gouly wrote: > On Thu, Aug 29, 2024 at 06:55:07PM +0100, Mark Brown wrote: > > On Thu, Aug 22, 2024 at 04:10:59PM +0100, Joey Gouly wrote: > > > > > +static bool fault_from_pkey(unsigned long esr, struct vm_area_struct *vma, > > > + unsigned int mm_flags) > > > +{ > > > + unsigned long iss2 = ESR_ELx_ISS2(esr); > > > + > > > + if (!system_supports_poe()) > > > + return false; > > > + > > > + if (iss2 & ESR_ELx_Overlay) > > > + return true; > > > > Does this need an is_data_abort() && is_instruction_abort() check? > > Overlay doesn't appear to be defined for all exception types and it > > wasn't clear enough to me that the callers have done this check. > > The only callers are in do_page_fault(), which should only be data or > instruction aborts. I talked with Catalin and he said it's fine to not check > again here. > > I can add a permissions check though: > > commit 033270f5a9462e998b4dee11fc91b43ac7929756 > Author: Joey Gouly > Date: Tue Sep 3 15:45:59 2024 +0100 > > fixup! arm64: handle PKEY/POE faults > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index a68055150950..f651553a8ab8 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -495,6 +495,9 @@ static bool fault_from_pkey(unsigned long esr, struct vm_area_struct *vma, > if (!system_supports_poe()) > return false; > > + if (!esr_fsc_is_permission_fault(esr)) > + return false; > + > if (iss2 & ESR_ELx_Overlay) > return true; > > > > Since the ESR_EL1 documentation says: > If a memory access generates a Data Abort for a Permission fault, then this field holds information > about the fault. > Sorry, I was a bit too eager with that patch. The previous patch was bailing out before the vma-backed checks could take place. It should be: commit 7b67b149f2f492e907b27521c95639f4ea208221 (HEAD -> permission_overlay_v6) Author: Joey Gouly Date: Tue Sep 3 15:45:59 2024 +0100 fixup! arm64: handle PKEY/POE faults diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index a68055150950..8b281cf308b3 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -495,7 +495,7 @@ static bool fault_from_pkey(unsigned long esr, struct vm_area_struct *vma, if (!system_supports_poe()) return false; - if (iss2 & ESR_ELx_Overlay) + if (esr_fsc_is_permission_fault(esr) && (iss2 & ESR_ELx_Overlay)) return true; return !arch_vma_access_permitted(vma,