From patchwork Mon Jul 24 12:46:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13324717 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16EC7C001B0 for ; Mon, 24 Jul 2023 12:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231513AbjGXMyG (ORCPT ); Mon, 24 Jul 2023 08:54:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231695AbjGXMxO (ORCPT ); Mon, 24 Jul 2023 08:53:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9807844BD; Mon, 24 Jul 2023 05:50:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 937B861152; Mon, 24 Jul 2023 12:49:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38E35C433C9; Mon, 24 Jul 2023 12:49:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690202979; bh=H5XnWdFwxjuGxEH72kUlpbP8cfBTQj97MLlaTYR448U=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=UOuiRDkBusphHSxvKkLrOi4hb6QDNJiEeqdsk+bAiNRlkVULSMR4LyXqN6lh8jEqU 6aY+o5iGUOA6CFekoyYKLuLpmCp+ki3We97BjjOgf1TovklVWs1IesDN2/4ZJCIFfS IKWq2s7SUCup5jqqhGVztCdgWGCi6H6vhnbavEeaeBK1/JuRYjJ9aPnPZUR/omR95F rxly5mAwX/l/+1i7EX1ua9A7x1W/LZ+n23XWxRezK9rDiN3SJ1xWbA9wJnBHy88E8Y vSfU0G78J8CFivTLw4aU6EPd8y37uIJOGTm2UJNJVqYpVChDBEi/Xr+hdmloQtpFzg l5nGgTUqt5dhw== From: Mark Brown Date: Mon, 24 Jul 2023 13:46:12 +0100 Subject: [PATCH v2 25/35] arm64: Add Kconfig for Guarded Control Stack (GCS) MIME-Version: 1.0 Message-Id: <20230724-arm64-gcs-v2-25-dc2c1d44c2eb@kernel.org> References: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org> In-Reply-To: <20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=1334; i=broonie@kernel.org; h=from:subject:message-id; bh=H5XnWdFwxjuGxEH72kUlpbP8cfBTQj97MLlaTYR448U=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkvnKnQmQDKgw1sV73XajzPOr/VVN8eYW4BuRVpTBw 6U/CDZaJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZL5ypwAKCRAk1otyXVSH0BjjB/ 4zmlP2LuDl/tCz3VO/DUeOVn6ZcSaI/xa1REDMlzha0SDGdV+QTgnOm9wNwq8WieSsejDlPhxDuvki paM4LrVSh1c5aAtMHMQ/HGCdvkCO5DgZgBqp71Vmbl6yz4Vi/gj0UfNJDOA3FLp9ww3m7Qe5H3UTpY SJsdjSeveABSRymkrBiBwjX6uOxi1DtrtMVpatbk1zkkjp5TTaBE35yRGdsgVgA8ODTsqZP5OKTSN3 4HIlACNi9tjNEGYf4wzBTSKJAaxhrT3jJQH6jMsMwwyXhVvlMx9/aQLLuBXlSZcSRJyqVsR/kzRIxf +bE7Fh1YOi9lG6dI2er5/PlgVCBoni X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Provide a Kconfig option allowing the user to select if GCS support is built into the kernel. Signed-off-by: Mark Brown --- arch/arm64/Kconfig | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a2511b30d0f6..b5ef1a698770 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2093,6 +2093,25 @@ config ARM64_EPAN if the cpu does not implement the feature. endmenu # "ARMv8.7 architectural features" +menu "v9.4 architectural features" + +config ARM64_GCS + bool "Enable support for Guarded Control Stack (GCS)" + default y + select ARCH_USES_HIGH_VMA_FLAGS + help + Guarded Control Stack (GCS) provides support for a separate + stack with restricted access which contains only return + addresses. This can be used to harden against some attacks + by comparing return address used by the program with what is + stored in the GCS, and may also be used to efficiently obtain + the call stack for applications such as profiling. + + The feature is detected at runtime, and will remain disabled + if the system does not implement the feature. + +endmenu # "v9.4 architectural features" + config ARM64_SVE bool "ARM Scalable Vector Extension support" default y