From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7B39E2E7374; Sat, 25 Jul 2026 01:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784941212; cv=none; b=fyvdFbmrkufUD7zJ2cOXlcqLdJ3380DUm9cQwrfo4Q+HSNSPcC16J3Ftohl4eDWWD9zu4IaSEgl5k6iAuu/1LrsUto5V2eoPFKvHSz1wPPggO6VQV25v4Cqi/76zQW4Oq0kSSnikwfgJlD0FWC+vVG/I5mocu0VG85vnpcz2a/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784941212; c=relaxed/simple; bh=1RUFjWz6Rg1f1hrlS//lgaICRxO4c3YvsrZYedb7KL8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OP2yo7O6074+TU/EOVdu1CvavgsBkKUKpRCqvIrVYMqNuRITaDt4O0nilIloDdanMEJ/qgl/+VZbnBfnhlTN+URYdGIxKOPMJAy1jzQ74DzLWXupr3yetoobF/mjhz5CWkn4TOOJuFXEydwoFdz5R0MalzHOeBvAungFhI4gSRY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WpNkeymz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WpNkeymz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F37F51F000E9; Sat, 25 Jul 2026 01:00:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784941211; bh=As1VFAV4/mE6JvvbbxmZ+Bp8mI/fGVenXZeP4wEav0w=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=WpNkeymzxme+ejkFrlPhhO39hPAULrf6Ox8rY8fd5z66lDcD7sQMYqZ0OJIWqte6G lkyDdWeFmbLddAXwFMuEdKeJrEkhhZUj3GH1SGjHUGXlgZ1QKvxbUm9U7J8jFU38OJ lX+pgVE2Umo+C+zC0LEu5na/P+wWjTnlUYs/MTXAvZA/5ntkRilET4bXMRzu/nc+x/ MCg1V/7OAM+fxdaq7H3Kotho/ypxoMHFO6mcqiklqPugH/qnYOQzvSrhOZU6NNCQdd IuHFkwsLsIZxhbyfQnzcEl1liqC9puOGMLjdXRXenKjmr1vHlgNJNVgif65YY6jIMc N5UVIZqZhu7jg== Date: Fri, 24 Jul 2026 18:00:04 -0700 From: Nathan Chancellor To: Heiko Carstens Cc: Stefan Schulze Frielinghaus , Juergen Christ , Ilya Leoshkevich , Dominik Steenken , Alexander Gordeev , Sven Schnelle , Vasily Gorbik , Christian Borntraeger , Maxim Khmelevskii , Jens Remus , Sami Tolvanen , Kees Cook , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , llvm@lists.linux.dev, bpf@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/6] s390/Kconfig: Select ARCH_SUPPORTS_CFI Message-ID: <20260725010004.GA1686739@ax162> References: <20260724141318.1037434-1-hca@linux.ibm.com> <20260724141318.1037434-6-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@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: <20260724141318.1037434-6-hca@linux.ibm.com> Hi Heiko, On Fri, Jul 24, 2026 at 04:13:17PM +0200, Heiko Carstens wrote: > With all prerequisites in place select ARCH_SUPPORTS_CFI. > > Note that this support is supposed to work with the generic kcfi support > which is provided by clang. This comes with a couple of limitations: Consider adding select ARCH_USES_CFI_GENERIC_LLVM_PASS if CC_IS_CLANG to this change in case there are problems such as the one worked around by commit c57f5fee54df ("libeth: xdp: Disable generic kCFI pass for libeth_xdp_tx_xmit_bulk()"). Whenever clang grows an s390 backend expansion for kCFI, that can be version gated pretty easily. I will test this series fully next week. > --- > arch/s390/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index 84404e6778d5..d57a6c02f51d 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -144,6 +144,7 @@ config S390 > select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE > select ARCH_STACKWALK > select ARCH_SUPPORTS_ATOMIC_RMW > + select ARCH_SUPPORTS_CFI > select ARCH_SUPPORTS_DEBUG_PAGEALLOC > select ARCH_SUPPORTS_HUGETLBFS > select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG > -- > 2.53.0 > -- Cheers, Nathan