From nobody Sun Sep 14 03:54:37 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D846F322A14; Wed, 20 Aug 2025 14:57:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755701842; cv=none; b=pFWtYGnKg3qtoovvGmRXz4DcXEYGWvhaYdxWrNUWg+b6CB6nEifJi4HKZUNVsPLGnq9t1gNVEJ+wDeLwYYGcIHetHRKR6gK4OO/SnvuEr/gSwXnK27nlR4D8cbnV9tXuWcZzEPmvdZ6IkfphCfbv1BxhM1fB7/xbjpg6EeY6cOg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755701842; c=relaxed/simple; bh=Age74y4MlXUlaeN7cLn7tJBXQPhdVkd/itcOLKTSl2I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jk2W1SgFbVmYxo4TGyj/yEfFray4thD2kZhX63W8bi4ftC6hqIuhSLGSikCxoqdiFN+pVeUwpYWoAIA86N6qCfBmaUgOq26q0bEPzXBlNn5VEoXQxQlDo6GOoDQXP+Iq8wqkF8T6uTXUQ9TJfXncszJaKyExj3vvbLz629mCMmY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 084ED2C27; Wed, 20 Aug 2025 07:57:12 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.2.58]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 47C1A3F738; Wed, 20 Aug 2025 07:57:16 -0700 (PDT) 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, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve Subject: [PATCH v10 02/43] arm64: RME: Handle Granule Protection Faults (GPFs) Date: Wed, 20 Aug 2025 15:55:22 +0100 Message-ID: <20250820145606.180644-3-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250820145606.180644-1-steven.price@arm.com> References: <20250820145606.180644-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Reviewed-by: Suzuki K Poulose Reviewed-by: Gavin Shan Signed-off-by: Steven Price --- Changes since v2: * Include missing "Granule Protection Fault at level -1" --- arch/arm64/mm/fault.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index d816ff44faff..e4237637cd8f 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -854,6 +854,25 @@ static int do_tag_check_fault(unsigned long far, unsig= ned long esr, return 0; } =20 +static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs= *regs) +{ + const struct fault_info *inf =3D 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 *re= gs) +{ + const struct fault_info *inf =3D esr_to_fault_info(esr); + + if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr)) + return 0; + + arm64_notify_die(inf->name, regs, inf->sig, inf->code, far, esr); + return 0; +} + static const struct fault_info fault_info[] =3D { { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, @@ -890,12 +909,12 @@ static const struct fault_info fault_info[] =3D { { do_bad, SIGKILL, SI_KERNEL, "unknown 32" }, { 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 -1"= }, + { 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 wal= k" }, { do_bad, SIGKILL, SI_KERNEL, "level -1 address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level -1 translation fault= " }, --=20 2.43.0