From patchwork Wed Nov 22 09:42:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 746286 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 903BE55791; Wed, 22 Nov 2023 09:46:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZNt/mhOl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 866E8C43395; Wed, 22 Nov 2023 09:46:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700646383; bh=0y6nS2SVdzl2qxV5TcDCnpKi8YQvhWLC/gR5WsuQggw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ZNt/mhOldQGyAGrFdcd7zCoYi9c4Cpbfl611N1nCbvre1FYvH7Zl1qxYMHlLUXK/R oTr4pGgCl3ZqkdfLg9vxV823aJQE0eCLlAhRLaW1gT0pmdwjk38uP6NXqfphyDxggd Nce0uiHdxAcfp2N1Y9laenaA7HV7sOUFODNyqrBMy7XcrOzKnRNQTKmHrYboi3WFf4 QOpE3cQlVvo2KE6NieOOuSEronhIGHfX5fucm1ZO0NVH0NxleNUmMK8+wdtaJLpRNh bN4Wz6vhiC+V3XP1enBFhlP/PZm5aE6IiSJnXGkBC62BqC2W7W+tQNNElkgCPc4NEY Pt1AESbQWlpmQ== From: Mark Brown Date: Wed, 22 Nov 2023 09:42:37 +0000 Subject: [PATCH v7 27/39] arm64: Add Kconfig for Guarded Control Stack (GCS) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231122-arm64-gcs-v7-27-201c483bd775@kernel.org> References: <20231122-arm64-gcs-v7-0-201c483bd775@kernel.org> In-Reply-To: <20231122-arm64-gcs-v7-0-201c483bd775@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 , Thiago Jung Bauermann , 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=1372; i=broonie@kernel.org; h=from:subject:message-id; bh=0y6nS2SVdzl2qxV5TcDCnpKi8YQvhWLC/gR5WsuQggw=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlXc0LjTRQMrZZBOJgPLB48tbG4uiml7CZIDEV5 uQD798eCNqJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZV3NCwAKCRAk1otyXVSH 0Iq3B/9HlE8pfPFk2nuyqu1U5wC2TDnfo30tlZoqa72rjxWoZMeOZIt03d7ifiDGT60BAhV7DR/ X2q4ijl0gxsqAdoQTECIT09I17i0jhkg4sOrFnUM9S88Dc3B+OIQORdu8k6AozeCurJMkcd/ICY snWt5N0Nh2ox8T7U6IwsCVSrOZfctm8ylWDVAVHxsy53/DBhuI0FtT+rlbYGseRcYj1zRLPXpf+ BVttx7Ntz2AelFYWVTuV1+GEKIwFIHMxKR/QSrU8uS9CzItwTUAOZKN30cLz7YqjsJMsYAnSVKN Bd8Eqt+f6s9NrIoUWZmOF8FfRH4sNLQwPl0XXWRCxkdsmJNx X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB 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 | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b071a00425d..05cffc0f5786 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2078,6 +2078,26 @@ 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_HAS_USER_SHADOW_STACK + 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