From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: [PATCH v7 28/29] arm64: mte: Kconfig entry Date: Wed, 15 Jul 2020 18:08:43 +0100 Message-ID: <20200715170844.30064-29-catalin.marinas@arm.com> References: <20200715170844.30064-1-catalin.marinas@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mail.kernel.org ([198.145.29.99]:38222 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725907AbgGORJ4 (ORCPT ); Wed, 15 Jul 2020 13:09:56 -0400 In-Reply-To: <20200715170844.30064-1-catalin.marinas@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , Andrew Morton From: Vincenzo Frascino Add Memory Tagging Extension support to the arm64 kbuild. Signed-off-by: Vincenzo Frascino Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Cc: Will Deacon --- Notes: v7: - Binutils gained initial support for MTE in 2.32.0. However, a late architecture addition (LDGM/STGM) is only supported in the newer 2.32.x and 2.33 versions. Change the AS_HAS_MTE option to also check for stgm in addition to .arch armv8.5-a+memtag. v6: - Remove select ARCH_USES_PG_ARCH_2, no longer defined. v5: - Remove duplicate ARMv8.5 menu entry. v4: - select ARCH_USES_PG_ARCH_2. - remove ARCH_NO_SWAP. - default y. arch/arm64/Kconfig | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 66dc41fd49f2..32ceff21acc1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1664,6 +1664,37 @@ config ARCH_RANDOM provides a high bandwidth, cryptographically secure hardware random number generator. +config ARM64_AS_HAS_MTE + # Binutils gained initial support for MTE in 2.32.0. However, a + # late architecture addition (LDGM/STGM) is only supported in + # the newer 2.32.x and 2.33 versions. + def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) + +config ARM64_MTE + bool "Memory Tagging Extension support" + default y + depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI + select ARCH_USES_HIGH_VMA_FLAGS + help + Memory Tagging (part of the ARMv8.5 Extensions) provides + architectural support for run-time, always-on detection of + various classes of memory error to aid with software debugging + to eliminate vulnerabilities arising from memory-unsafe + languages. + + This option enables the support for the Memory Tagging + Extension at EL0 (i.e. for userspace). + + Selecting this option allows the feature to be detected at + runtime. Any secondary CPU not implementing this feature will + not be allowed a late bring-up. + + Userspace binaries that want to use this feature must + explicitly opt in. The mechanism for the userspace is + described in: + + Documentation/arm64/memory-tagging-extension.rst. + endmenu config ARM64_SVE