From mboxrd@z Thu Jan 1 00:00:00 1970 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 1594B152178; Fri, 23 Aug 2024 09:48:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724406536; cv=none; b=b7Z3ZoX5Ld5iNKAV4kciU2lXkuOjwwFH3ojTBXAM75Oen27BYWdjL0/z9X/pmIFXj9PGoNwcBVrjH7pS3n0DU6uAt7wN8Rv1x/8UXR2FbMv4j47kvfttEbHN8c0WXEkmQ9WAjFmRioMJtEDa2SWri3p85XgdfDMbu+dgNaECzFI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724406536; c=relaxed/simple; bh=shLl9B9UeieVDAiPc96T6YsYCgNbh9Jph92u4fXeHmI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rjkVwPt/ZpoBC6st2UEXBO6yUzL7f+4QzEmQHEs9Lui2zIMBv1SBUveZm13Mus4JjMAd0folne2DOSz7XeNf6YUtuXmT3dSRmxUb3rtIJzd1w6V+i7JGb8dD4JOjo/h23S9CD5tSGyLDP4z3vYTzK95XRD3uHVgAV80uxTfk8lM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6993C32786; Fri, 23 Aug 2024 09:48:49 +0000 (UTC) Date: Fri, 23 Aug 2024 10:48:47 +0100 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , Yury Khrustalev , Wilco Dijkstra , 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 Subject: Re: [PATCH v11 27/39] arm64: Add Kconfig for Guarded Control Stack (GCS) Message-ID: References: <20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org> <20240822-arm64-gcs-v11-27-41b81947ecb5@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240822-arm64-gcs-v11-27-41b81947ecb5@kernel.org> On Thu, Aug 22, 2024 at 02:15:30AM +0100, Mark Brown wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index a2f8ff354ca6..772f9ba99fe8 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -2137,6 +2137,26 @@ 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" BTW, as Mark R spotted we'd also need to handle uprobes. Since that's off in defconfig, I think it can be done separately on top of this series. In the meantime, we could make this dependent on !UPROBES. -- Catalin