From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.outflux.net (smtp.outflux.net [198.145.64.163]) (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 EC011169AE6; Mon, 25 Aug 2025 19:37:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.145.64.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756150622; cv=none; b=Lj/zMjllBqeAPYQ29SoGRDrKvyLoMp2e0JE1BM7wiftT1MGBmBC8cQUADpOFdsohzLCPcihiDNTJ1BAI4EioCtntUxop4F9B/3XALB6AUQcdkl/eWYyCw3oLTd5Ncl70Y1d1zNw9i/pKm+0151DC6R9wX+32ZDsX4WFt4XGODkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756150622; c=relaxed/simple; bh=Cc0A7KST88BbLESFvBNiNEgFzJEi7Yi2EVmfXhRgL6M=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=CHhUWVnPZVFNLan+Nka92dJUgT4BQL0Y0Lx+/48EhPgWG/Le5QY4hQN458pTmHGTwXViDZtTEkNDxMGro20ngdSCQJIUFJs5iiGEp0QvIMFFRzVQAWjauQpsJ+nLeBF1a3Vccofif0rLye4H0DBYT5GTRnOPY9fPTl35CGR1QGA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=outflux.net; spf=pass smtp.mailfrom=outflux.net; dkim=fail (1024-bit key) header.d=outflux.net header.i=@outflux.net header.b=dmm7Uk1r reason="signature verification failed"; arc=none smtp.client-ip=198.145.64.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=outflux.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=outflux.net Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=outflux.net header.i=@outflux.net header.b="dmm7Uk1r" Received: from auth (localhost [127.0.0.1]) (authenticated bits=0) by vinyl.outflux.net (8.15.2/8.15.2/Debian-10) with ESMTPSA id 57PJVcXW012364 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 25 Aug 2025 12:31:39 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=outflux.net; s=2016010; t=1756150300; bh=Cc0A7KST88BbLESFvBNiNEgFzJEi7Yi2EVmfXhRgL6M=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=dmm7Uk1rljY/b4/3j8njDIEy+Scks4cnfZAOL8qtbXCH9h9jV621co70Fuer5Vf17 2vNGEXeFRnmarqqQKCQXq3nlyBV+sTTzdmwDNFgEktyxTZkW7g83isIllAWQ5Jvik2 /8fn12aBvHvvu5EXYWBmhf7ySJSjrTUnGPHeNjnY= Date: Mon, 25 Aug 2025 15:31:34 -0400 From: Kees Cook To: Miguel Ojeda , Kees Cook CC: Peter Zijlstra , Sami Tolvanen , Linus Walleij , Mark Rutland , Puranjay Mohan , David Woodhouse , Jonathan Corbet , Nathan Chancellor , 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: References: <20250825141316.work.967-kees@kernel.org> <20250825142603.1907143-5-kees@kernel.org> <202508250834.E2456B9@keescook> Message-ID: <9CCDBE93-7DBD-41D0-B9B6-05900F2AB1EE@outflux.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-MIMEDefang-Filter: outflux$Revision: 1.316 $ X-HELO: [IPv6:::1] Envelope-To: linux-hardening@vger.kernel.org Envelope-To: llvm@lists.linux.dev Envelope-To: linux-riscv@lists.infradead.org Envelope-To: linux-arm-kernel@lists.infradead.org Envelope-To: linux-kbuild@vger.kernel.org Envelope-To: linux-doc@vger.kernel.org Envelope-To: x86@kernel.org Envelope-To: nathan@kernel.org Envelope-To: corbet@lwn.net Envelope-To: dwmw2@infradead.org Envelope-To: puranjay@kernel.org Envelope-To: mark.rutland@arm.com Envelope-To: linus.walleij@linaro.org Envelope-To: samitolvanen@google.com Envelope-To: peterz@infradead.org Envelope-To: kees@kernel.org Envelope-To: miguel.ojeda.sandonis@gmail.com X-Scanned-By: MIMEDefang 2.83 On August 25, 2025 1:00:22 PM EDT, Miguel Ojeda wrote: >On Mon, Aug 25, 2025 at 5:35=E2=80=AFPM Kees Cook wro= te: >> >> Yeah, that's a good idea=2E What the right way to do that? >> >> config CFI_CLANG >> bool "Use Clang's Control Flow Integrity (CFI)" >> depends on ARCH_SUPPORTS_CFI >> select CFI >> >> ? > >I don't recall what is the idiomatic solution for renames, but I >remember Linus talking about this topic and about avoiding losing old >values if possible (perhaps getting a new question in `oldconfig` is >OK as long as the `olddefconfig` respects the old value)=2E > >I think your suggestion above will still make it appear twice in >`menuconfig` -- there may be a way to play with visibility to make it >better=2E > >A simple possibility I can think of (assuming it works) is having the >CFI symbol for the time being introduced just as a `def_bool >CFI_CLANG` for a few releases so that people get the new one in their >configs=2E Ah, I think this works: config CFI_CLANG bool config CFI bool "=2E=2E=2E=2E" default CFI_CLANG I will add that for v2=2E -Kees --=20 Kees Cook