From nobody Sat Oct 11 08:30:36 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1776D27C149; Wed, 11 Jun 2025 10:49:11 +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=1749638954; cv=none; b=rbk/7Mp5sD+GVWneNTVtSIqhDVWc5Gaa+4M12SS4MM2S6qzP3iPbf5hL0rK84fM1P9qu3p0xqvXj6TxXEcCWTa1yTzQnLvcuQ6noftF1BdpLysM3NlsBMvMsNe9pU0ubMieukmsilOsoExTp6wNcgVlw/21IdDn9622PBYWL7aA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749638954; c=relaxed/simple; bh=aDuibA1ibdFiRfqzImyMZrWyhmqWUZQOt8aJMVDcAo0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O+scSysMM2ApwjrOSuAU7VcugGvCGSfisxeRs18kd/x1XACiI+EoodH6UgkodYObH9oKZvv5IXZQK/s13DmUtsOAtld7LNfiU6eiKr4zVOkGDmkPsi0qZF4LMpOJV7HnfjD1xq2aGHReH9m8nIxoPIeY6BnmLN7jEYiPrDidkEA= 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 B15CB15A1; Wed, 11 Jun 2025 03:48:51 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.67.107]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE92A3F673; Wed, 11 Jun 2025 03:49:06 -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 Subject: [PATCH v9 02/43] arm64: RME: Handle Granule Protection Faults (GPFs) Date: Wed, 11 Jun 2025 11:47:59 +0100 Message-ID: <20250611104844.245235-3-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250611104844.245235-1-steven.price@arm.com> References: <20250611104844.245235-1-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 ec0a337891dd..59a89a8fb226 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -844,6 +844,25 @@ 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" }, @@ -880,12 +899,12 @@ 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