From patchwork Mon Jul 31 13:43:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13334733 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 8F47FC00528 for ; Mon, 31 Jul 2023 13:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233077AbjGaN4r (ORCPT ); Mon, 31 Jul 2023 09:56:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232545AbjGaNzp (ORCPT ); Mon, 31 Jul 2023 09:55:45 -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 062F3210C; Mon, 31 Jul 2023 06:53:24 -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 CB85561154; Mon, 31 Jul 2023 13:53:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 909DCC433C9; Mon, 31 Jul 2023 13:53:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690811604; bh=H5XnWdFwxjuGxEH72kUlpbP8cfBTQj97MLlaTYR448U=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=nZYlPhlhjG2e1wEUfCei062MQ6Dbl9MfpeOxtlNby3v0voK/nj7N+EFE43JqQL5Wj Hs+p8A2tPXTny2c0NtxjgW+c3M4oxb4wc8WIG7tYH0TvYSaeNibc+wtlNZb6m0eiZT nITyOLlHdb1kCbgDuYgvG03K/DJCPIPSYtvfOgAj83T2kpc5aXM4HJ5jgHB5TEFg0T 6b2UTVk00oNA8JYYQ0yH6C0pGGkSz8r/rnHteFUub/w194oCNRHAYv+MI9Oe856TNL qn9c0Dtz3rc7tjgn/VHNe7PhELqGqzPCzLAepLqr16IwopZhGucEbInKA25AVHiUtN 8fRP8D8j3smag== From: Mark Brown Date: Mon, 31 Jul 2023 14:43:34 +0100 Subject: [PATCH v3 25/36] arm64: Add Kconfig for Guarded Control Stack (GCS) MIME-Version: 1.0 Message-Id: <20230731-arm64-gcs-v3-25-cddf9f980d98@kernel.org> References: <20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org> In-Reply-To: <20230731-arm64-gcs-v3-0-cddf9f980d98@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/pANAwAKASTWi3JdVIfQAcsmYgBkx7wnodnwjqoZK4muIg3jEUoRCGxezol4tgSrjmCI O795jHiJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZMe8JwAKCRAk1otyXVSH0MnuB/ sHfu5/n7b6sDdSTxDSHao/3yji1/B37g5tOzIcJILXPiDb3SHONtPUBN5opqReBE9DQcr+x0YI6Rkk jaJ4E5v3rXaHapeBP61QyIUI/8IIT146hHME6uvN2U4/budEmwshhRg+fRdusyAq2/VBIHsG0KX1da LZ099j1sMmvrMIKOrT2bpG0z98HXoIu3bz57PbEyiABWyHtIDeXiKt/QIStz4OVQ9hWYFZBjfNlzZa 6/4cBlW8YGgvKS16rKNTxnMLDhROElcWbnnfxdNpw4VknEPzhsdrkvkHTxnQ4zLcFoeC4yl/NW7Swa c8XQF5EFbcdiyln3+fENM9B7tSzFF8 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