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 F1922282F1; Fri, 29 Aug 2025 01:49:26 +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=1756432167; cv=none; b=hV1gQ9HtNyvR73QVi5uRcRZt2BLNUuWrfx2Fj8cJ+wXv5pjiJ9xteKeuTM8sc26khAW14rhUNsTlOBLhHpemaQH7NAjmw3yS05iAepo4XQraryCifNFftXrOJ+PDRGHjJnwqm92kswa6BeabytgCHi/WsKSwCyUuFQMTfMLgxl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756432167; c=relaxed/simple; bh=LnE97d/OL0MjX+YtgvWFnzZ3rGxg8lbiIKWtR2dnmu8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UltWcEXaiYZiKsM/g7/bouWfzO/3dHDszHlCLXs8wMAzmWE9So/jM9yPBrRlWTXwxhZq+1PFgdoQ3ngGrVsIKWs6yNAN1IVNu934Uon2umsrFOEMkIXp7h6aWOlqi02EOdofSF7sGMBuXs0pVloxix8rThS292kZlry/0PwdRqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EfKb6ou7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EfKb6ou7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 780CAC4CEEB; Fri, 29 Aug 2025 01:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756432166; bh=LnE97d/OL0MjX+YtgvWFnzZ3rGxg8lbiIKWtR2dnmu8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EfKb6ou7eLhltTeAmy5adRU6ZYG5j08nh6go592Gbcbr1P0UlEzUCAzDjIgy2eAIk Q787xvixvGptbR1lhkWGF5Lnbiic0wqz4WXljmJQFKdma+i3KkWA+AaRCZre4h24vO W6At4FWUuQH7m7eqXtD/8J51iu7jjUnFtxsH0U9kjq3MXSpLnx4UOwTwHWwsMO4ofk 11Qa7EZE1yp0Li8IVYIX3x6QoIgabURoYVT2Vut/4rlJX2vJVo48h5ZyTDBvpiXSrV oGk/n02YrmDWDiXUZcrGecTkYdWCLgBnuYOOityAIMmy8zRjyITGkJvRfleXYq2wbI HSav784NLGyBA== Date: Thu, 28 Aug 2025 18:49:26 -0700 From: Kees Cook To: Nathan Chancellor Cc: Peter Zijlstra , Kees Cook , Sami Tolvanen , David Woodhouse , Linus Walleij , Mark Rutland , Puranjay Mohan , 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 3/5] x86/cfi: Add option for cfi=debug bootparam Message-ID: <202508281848.A6EE3E4BA@keescook> References: <20250825141316.work.967-kees@kernel.org> <20250825142603.1907143-3-kees@kernel.org> <20250827195753.GB3572128@ax162> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250827195753.GB3572128@ax162> On Wed, Aug 27, 2025 at 12:57:53PM -0700, Nathan Chancellor wrote: > On Mon, Aug 25, 2025 at 07:25:50AM -0700, Kees Cook wrote: > > From: Kees Cook > > > > Add "debug" option for "cfi=" bootparam to get details on early CFI > > initialization steps. Standardize CFI pr_info() lines to use "CFI:" > > prefix. Standardize "CFI: Using ..." to always report which CFI mode is > > being used, regardless of CONFIG_FINEIBT. Document all the "cfi=" options. > > > > Signed-off-by: Kees Cook > > I am not sure if the x86 maintainers are "patch count adverse" but it > feels like this would be a little easier to review as four separate > patches. Every sentence in the commit message is basically its own > change. > > 1. The initial documentation for cfi= and its current values. > 2. Standardization of pr_info() calls to use "CFI:" > 3. Adding "CFI: Using" to __apply_fineibt() > 4. Adding cfi=debug > > Patch four would become much simpler to understand, especially with > Peter's suggested change. Yeah, that's entirely fair. :) I will split this up. -- Kees Cook