From patchwork Mon Oct 9 12:09:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13413660 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 11269E95A8E for ; Mon, 9 Oct 2023 12:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346778AbjJIMVo (ORCPT ); Mon, 9 Oct 2023 08:21:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346686AbjJIMVR (ORCPT ); Mon, 9 Oct 2023 08:21:17 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31B28C6; Mon, 9 Oct 2023 05:13:47 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 922A0C433C9; Mon, 9 Oct 2023 12:13:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696853626; bh=HKr5dcgoD1HRE8Dfu3M7S45WXlztyGX1cPv4uDvvFRM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=H39Ysk/jv3RNdJhL+Jsv7sBxcXZHRih+ROezijJvWx9EN4JvZ8YLVnCFWuh5eiiAl J3BcFT9L59aj2K0HyS0TQb5id7+eKSVp9IjZACZ4PEq4aEUJjOSP7GkJfDBzcp2Jrb u93V6DlJLKNe93rxNaei3Ow4LXKe+OKHKlwDOxFWm1SDJ76Ri39wH5qX2/YhNNY5DJ oZm3ml3SR7XSkXmMZ2NeCqJMYBJ305rEf0L35tZkyRCWXvoBdQFqFuMqNZgytHtcPR nvWKeRmVjuWn6bsz71J5LB+/nVGpBcBAqwMVSDG3VYjbyzwNtsmi2AWTk0W5qcRWwU zkc7oXD/SsHuA== From: Mark Brown Date: Mon, 09 Oct 2023 13:09:01 +0100 Subject: [PATCH v6 27/38] arm64: Add Kconfig for Guarded Control Stack (GCS) MIME-Version: 1.0 Message-Id: <20231009-arm64-gcs-v6-27-78e55deaa4dd@kernel.org> References: <20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org> In-Reply-To: <20231009-arm64-gcs-v6-0-78e55deaa4dd@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 , Florian Weimer , Christian Brauner , 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-0438c X-Developer-Signature: v=1; a=openpgp-sha256; l=1334; i=broonie@kernel.org; h=from:subject:message-id; bh=HKr5dcgoD1HRE8Dfu3M7S45WXlztyGX1cPv4uDvvFRM=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlI+2m6LbrIKImLz43AhLYkdJ+mn8/n/WtjdVAC+Y3 I5cZkuiJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZSPtpgAKCRAk1otyXVSH0C9JB/ 9PeuQ7odFNzac2es7G1H21MYtcjVH9+a2Xh/QADOSwBO/AZwG1T+Q4oNOVnGIYZhsMy5AUgOtQDFOg zDd8RXL2Yzchc4BhE4Ekw1h1A8Fde16BC4U8J5YyfbQTWzzV5ZjYMZRgWLWLEmJ82HR2bI/yfKju2O yiag57d6zPB3jBl31kU7tVUGxpZ+W2N3e3w0Lsn0dB/LatGzkRPssH45VRWQSLCiWocphZV2S0FttF 8NdpTgTettJANn4cQtR8Ybduqa7BR2LVBS9TWMxRVAdrv8KMfeizfOEaa1rfjudAGqmDa9T2OYofSN a9bEGUta99nzCir41mnHoSZ0Cwo785 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 b10515c0200b..d235e725177b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2060,6 +2060,25 @@ 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