From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A39E7CA0FF6 for ; Thu, 28 Aug 2025 23:26:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:References:In-Reply-To:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=x85rjdiLOCFPdJayXqYWI4upB1AsPjUc5jpFEoHoVuQ=; b=IK6dLesO215/41DFs0abJOsHYe 4VcoPAV4LBQpns9UOq5XrP4B8USlHNX2GcjITPXqz8725iwl8OGb3JTsXuXQIb8biZvisVwL1/jRu sckUox1bNmeWcH1BXCeSFnwp95wipW38jlyYKEikswBVDA99QVRLV2pdEoR7YbLRZwnE8R059QgBa tWeY+7hv186aYR0mh4vht+eDp8NX67Lqzqe5Da/dnoi/edav2ny+PtRwQdeUKIIvaLMeFGCTSfREf 97DtwPzxxsd/uIF9IbU410obEF5GQf9uy/69RnnAlW30RyHG9121c4TUSa9ZEHdEXPltJuokqwXSN l7epXQ9g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1urm0q-00000003f7l-06Vz; Thu, 28 Aug 2025 23:26:36 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1urjIC-00000003BFt-2dRb; Thu, 28 Aug 2025 20:32:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id EFE33432C4; Thu, 28 Aug 2025 20:32:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34509C4CEEB; Thu, 28 Aug 2025 20:32:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756413139; bh=LJ/nYBW1tIRXTpCBSiKp71T/i9+fSZdNs8DZzPqY1Ow=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=DGl5m61tjFO/RGbdmcv8xyDmu/ykBezYs0GHdT4DZw9Xhk3fSMKGKVpOWVqw5/86+ jK5yY+L4Bo1ZIZ8v3R6pXEW+Fjm53GisvnYMX/XpdM+rD/Z6hIBavWTcDeIfuLkZV1 OujLD+Q0WWVGa/LUPqHTaRku9THwma5s8N+6X6Ert3RAhSE6UW+cGdCYjC4CScygIJ Cj1DHZR7LIX821VJ2VhiEWxiG59HzBd0B8RaijpHpGW7OMJ8muA6HNFHK13GjY0yLf N1Mj4ArOxrslcU9fjauS/Fhpnt/uL/EXomlp9/E5Eieg9kjphzcZPHUoOzR0suUrJK kAVWObwlnDGbw== Date: Thu, 28 Aug 2025 16:32:16 -0400 From: Kees Cook To: Nathan Chancellor , Miguel Ojeda CC: Randy Dunlap , Kees Cook , Peter Zijlstra , Sami Tolvanen , Linus Walleij , Mark Rutland , Puranjay Mohan , David Woodhouse , Jonathan Corbet , x86@kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: Re: [PATCH 5/5] kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI User-Agent: K-9 Mail for Android In-Reply-To: <20250828201915.GA219815@ax162> References: <20250825141316.work.967-kees@kernel.org> <20250825142603.1907143-5-kees@kernel.org> <202508250834.E2456B9@keescook> <9CCDBE93-7DBD-41D0-B9B6-05900F2AB1EE@outflux.net> <20250827013444.GA2859318@ax162> <56c2b1ce-00a4-403c-9927-79bfd9a23574@infradead.org> <20250827193815.GA2293657@ax162> <20250828201915.GA219815@ax162> Message-ID: <25B398C8-4D9A-46C6-AED9-9DA2805DF9D7@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250828_133220_691474_69451570 X-CRM114-Status: GOOD ( 14.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On August 28, 2025 4:19:15 PM EDT, Nathan Chancellor = wrote: >On Thu, Aug 28, 2025 at 02:11:51PM +0200, Miguel Ojeda wrote: >> On Wed, Aug 27, 2025 at 9:38=E2=80=AFPM Nathan Chancellor wrote: >> > Another idea I had to avoid this is introducing CONFIG_CFI_GCC as a u= ser >> > selectable symbol and making CONFIG_CFI the hidden symbol that both >> > compiler symbols select=2E After a couple of releases (or maybe the n= ext >> > LTS), both CONFIG_CFI_CLANG and CONFIG_CFI_GCC could be eliminated wi= th >> > CONFIG_CFI becoming user selectable, which would keep things working >> > since CONFIG_CFI=3Dy will be present in the previous configuration=2E >>=20 >> If we are OK with something like this (i=2Ee=2E waiting a few releases)= , >> then isn't it simpler the `def_bool` approach I mentioned? i=2Ee=2E it >> means one less symbol and one less rename later, right? > >Ah yes, I reread your suggestion and that would probably be the best >course of action, as it does avoid the extra symbol (although I am not >sure what you mean by one less rename?)=2E As I understand it: > > config CFI_CLANG > bool "Use Kernel Control Flow Integrity (kCFI)" > depends on ARCH_SUPPORTS_CFI > depends on $(cc-option,-fsanitize=3Dkcfi) > help > > > config CFI > def_bool CFI_CLANG Oh! Keep CFI_CLANG the visible option? Will the later rename work right? I= 'll give it a try=2E -Kees --=20 Kees Cook