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 4A404CA0FF6 for ; Fri, 29 Aug 2025 01:52:21 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rJSmlrtHRgipmFLQ1cB4+eN1E17IeSUAH/qu+rWD7a0=; b=mEucobmmQAd5eOTEZpiP/nNo9J EPFT7p/eOQScXwJg40nhuo73KF7TvdsREqbYvpMnmwotWYhyZv7zqIDDdljw4zpMv33Ep2IrzIa1f q4WVq6JGcMuZXTi6EREqYLPx+4kt5hg0pNk0H/JK3shfK4+jwwoaXDGH7Kz0/QX98XyOoaDt/Ubo9 LbQ7OjrO4KiXVWN2N6kdfgAgTs2h34v+hxkGVUrLSs8nKhNZS/iA92ZTGyRxo+bjZpT4U/HRwxtPA RwzWZXnfula0CyGuKZt3IBP/LgwldBmgYm0J0WVtkWGLtlCsPYy1hAMUh15wNI4gnvjzvkNIBEnJ0 gpOqutNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uroHo-000000043rM-0HtP; Fri, 29 Aug 2025 01:52:16 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uroF5-000000043Vh-0qC9; Fri, 29 Aug 2025 01:49:28 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id A149543F48; Fri, 29 Aug 2025 01:49:26 +0000 (UTC) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250827195753.GB3572128@ax162> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250828_184927_263628_12772D55 X-CRM114-Status: GOOD ( 17.04 ) 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 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