From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BAA777B; Fri, 27 Jan 2023 11:29:45 +0000 (UTC) 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 5829F1570; Fri, 27 Jan 2023 03:30:27 -0800 (PST) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 44C4A3F64C; Fri, 27 Jan 2023 03:29:42 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev Subject: [RFC PATCH 01/28] arm64: RME: Handle Granule Protection Faults (GPFs) Date: Fri, 27 Jan 2023 11:29:05 +0000 Message-Id: <20230127112932.38045-2-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230127112932.38045-1-steven.price@arm.com> References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If the host attempts to access granules that have been delegated for use in a realm these accesses will be caught and will trigger a Granule Protection Fault (GPF). A fault during a page walk signals a bug in the kernel and is handled by oopsing the kernel. A non-page walk fault could be caused by user space having access to a page which has been delegated to the kernel and will trigger a SIGBUS to allow debugging why user space is trying to access a delegated page. Signed-off-by: Steven Price --- arch/arm64/mm/fault.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 596f46dabe4e..fd84be115657 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -756,6 +756,25 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr, return 0; } +static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + const struct fault_info *inf = esr_to_fault_info(esr); + + die_kernel_fault(inf->name, far, esr, regs); + return 0; +} + +static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + const struct fault_info *inf = esr_to_fault_info(esr); + + if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) + return 0; + + arm64_notify_die(inf->name, regs, inf->sig, inf->code, far, esr); + return 0; +} + static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, @@ -793,11 +812,11 @@ static const struct fault_info fault_info[] = { { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 36" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 37" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 0" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 1" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 2" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 3" }, + { do_gpf, SIGBUS, SI_KERNEL, "Granule Protection Fault not on table walk" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 41" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 43" }, -- 2.34.1 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 00855C54EAA for ; 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Fri, 27 Jan 2023 11:36:16 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pLMvT-00E7r9-5O for linux-arm-kernel@lists.infradead.org; Fri, 27 Jan 2023 11:29:48 +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 5829F1570; Fri, 27 Jan 2023 03:30:27 -0800 (PST) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 44C4A3F64C; Fri, 27 Jan 2023 03:29:42 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev Subject: [RFC PATCH 01/28] arm64: RME: Handle Granule Protection Faults (GPFs) Date: Fri, 27 Jan 2023 11:29:05 +0000 Message-Id: <20230127112932.38045-2-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230127112932.38045-1-steven.price@arm.com> References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230127_032947_345014_C8D18165 X-CRM114-Status: GOOD ( 13.44 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If the host attempts to access granules that have been delegated for use in a realm these accesses will be caught and will trigger a Granule Protection Fault (GPF). A fault during a page walk signals a bug in the kernel and is handled by oopsing the kernel. A non-page walk fault could be caused by user space having access to a page which has been delegated to the kernel and will trigger a SIGBUS to allow debugging why user space is trying to access a delegated page. Signed-off-by: Steven Price --- arch/arm64/mm/fault.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 596f46dabe4e..fd84be115657 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -756,6 +756,25 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr, return 0; } +static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + const struct fault_info *inf = esr_to_fault_info(esr); + + die_kernel_fault(inf->name, far, esr, regs); + return 0; +} + +static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs) +{ + const struct fault_info *inf = esr_to_fault_info(esr); + + if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) + return 0; + + arm64_notify_die(inf->name, regs, inf->sig, inf->code, far, esr); + return 0; +} + static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, @@ -793,11 +812,11 @@ static const struct fault_info fault_info[] = { { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 36" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 37" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 0" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 1" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 2" }, + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 3" }, + { do_gpf, SIGBUS, SI_KERNEL, "Granule Protection Fault not on table walk" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 41" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 43" }, -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel