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 1B2EF1B415B for ; Wed, 19 Feb 2025 17:36:38 +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=1739986598; cv=none; b=U9CXbG9jrejUr6JBQAfyOIOFtN0P0l4nPr1OiDm0/EpcONDt1UOR/v05JS9rI/C07ATE1jL+yT/yxQgW8OM+fQPuDwaTHraigdDm8G9qxLrnbWsDbe0cJYFpzYwHRGEdbButPffUWtAeGlslG3RysWAvIYJHowtWYfIbyGTBsLs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739986598; c=relaxed/simple; bh=N+qUOpNRVu6oRklpzQJqR+44U2yrPvBdb73H8aSu8zc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=V2GB6azvkK4sC0c/nlHSwDf0rh0jZ9WiemIgxO2EKo9Q//44YXJX1Db22RWCFi9SgjoHIbmaFahcviwFypJYtRW1MXP5wVxNxa3WZHyMxHOwiBA7AYoVpQxCIzjiptS1Rsc12CygkULikZRHoGeKFO1cUuX2bc0i/EI31sgZHzw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HJP43vzR; 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="HJP43vzR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3DB1C4CED1; Wed, 19 Feb 2025 17:36:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739986598; bh=N+qUOpNRVu6oRklpzQJqR+44U2yrPvBdb73H8aSu8zc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HJP43vzR6GTi7o28Hob6T3Ou0NTHez/UUlIa8SAjQaZqRz2vkLMij/hrmeAeSpt8M gZqX09B+paH+IMwBGDPEUe5pnpCGlsz8QGM+GRsdlQJ5iytfh7z3P1PHMUMG4nixXZ wJhvzV5VvZAvC8iubd2MceZ/m58IXFnfwI5+QD+9Bc4I8JS79dMrfz0J6EGiMZTihZ ZbNDb33nssLyjaMuG66wf7ScHy1X7y+Nu7kRI+LZeF+SQTqO+6aLrioZejQVKI395W /zy7yO4xnWZrbN0dGu6sBoPgsu5/Pr7TU+EIk7BZ9FkpiZN6DSrhpOAqZDkkuDe0jL QcwMI6ZOQIgTw== Date: Wed, 19 Feb 2025 09:36:34 -0800 From: Kees Cook To: Peter Zijlstra Cc: x86@kernel.org, linux-kernel@vger.kernel.org, alyssa.milburn@intel.com, scott.d.constable@intel.com, joao@overdrivepizza.com, andrew.cooper3@citrix.com, jpoimboe@kernel.org, jose.marchesi@oracle.com, hjl.tools@gmail.com, ndesaulniers@google.com, samitolvanen@google.com, nathan@kernel.org, ojeda@kernel.org, alexei.starovoitov@gmail.com, mhiramat@kernel.org, jmill@asu.edu Subject: Re: [PATCH v3 00/10] x86/ibt: FineIBT-BHI Message-ID: <202502190935.FCA10236C8@keescook> References: <20250219162107.880673196@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@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: <20250219162107.880673196@infradead.org> On Wed, Feb 19, 2025 at 05:21:07PM +0100, Peter Zijlstra wrote: > Also note that LKDTM's CFI_FORWARD_PROTO test will do a double splat for > paranoid in warn/permissive mode, since both the caller and callee hash check > will fail. Hah! I will declare that as Working As Intended, though I guess it is a bit noisy. But given permissive is mainly a debugging feature, I think this is fine. -- Kees Cook