From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 D8AA51EB5C1 for ; Thu, 20 Feb 2025 11:27:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740050840; cv=none; b=Akvwytx+NiIFkXqrjKZZ6i7kGSbJME9ddsN8YXgQIXsWQgrtTF2Oo0wM0kSPGEkAF4MWWP9MqZFGqCRdG8ii+zKHtmEE8RQVIFt4dn5Gow+ZKjHH7cCWFB3vPt8npkGbk3OkW2gLPg/rH9Fo7wQoW3pcJgzkNj9ulqs72kVPwrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740050840; c=relaxed/simple; bh=ZrlRfrcBXh4uaH0Ud+OUgXEPg7k8eqGRpbqwRuRQEc0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EwmkqxOs7J6TMwnkqJGKuD2n1yXdkUaPT5kSmX8VLl9oz6mPpdYDa78n7cdUjLTUUSsP3xyV+YUyXhlcjZ/eP65SyU0bOWZ7Iz1IRVW8bgWyaiWDugTzRt6zzGDsBSp2CsFa1bHDTc8lKWsiE4J3FazvOCRcw4BgF94Jqsx3yzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=tY1va3X1; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="tY1va3X1" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xeieqahpS1+yJtpt/ipGZCcQwPWo1aVFI5tk9S0PZhU=; b=tY1va3X1uwaU2ZKt/+jqdSJUWY ePxCbX1xb3etkeFOzffue+f2+9pjNoExM+MWBJMC5zKckArxIWlkW3KeTVTTI64CBNpdQM7Fg1xwe PCelEW4LiNmaRyLcXB4diNP3iIlhtw9swOHnePPm3zgIhNvz5nxoMAi2bJ1qhyEg3gH1SJ68yi/aw zfJ26SgSUbYdW/lKSt/inDK5GaYlsWg1wkwoA6Z53xE/6P/MluNujtNn899N3+tDi+grYV5ko1MTa A52cgpnku0x9GcvfOZcbzEtL5uD/zG4FbSAHwvetzVl7R0HxniSiPNpDz7tg8hSfRQTuYR/YzVPuq hm/6smNA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tl4hz-00000009PWb-1Xh8; Thu, 20 Feb 2025 11:27:11 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id E5B7B300677; Thu, 20 Feb 2025 12:27:10 +0100 (CET) Date: Thu, 20 Feb 2025 12:27:10 +0100 From: Peter Zijlstra To: x86@kernel.org Cc: 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, kees@kernel.org, alexei.starovoitov@gmail.com, mhiramat@kernel.org, jmill@asu.edu Subject: Re: [PATCH v3 00/10] x86/ibt: FineIBT-BHI Message-ID: <20250220112710.GK34567@noisy.programming.kicks-ass.net> 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: > Hi all! > > Having landed much of the previous series in tip/x86/core, I was hoping for an > easy time landing the final two patches.. alas. > > This whole FineIBT SYSCALL pivot thing showed up, which got me to develop the > paranoid FineIBT variant. And because testing I added a cfi=warn knob, and then > I migrated bhi to an option etc.. > > Then just as I was to post this stuff, Scott out-nerds me with a whole new > instruction sequence. Which got me to rework the entire pile once again, and > it is now another 10 patches again :/ > > Anyway, be warned, Scott loves overlapping instructions. > > This is tested with: > > cfi=fineibt,warn > cfi=fineibt,warn,paranoid > cfi=fineibt,warn,bhi > cfi=fineibt,warn,paranoid,bhi > cfi=fineibt,paranoid,bhi > > 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. > > Also available at: > > git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/fineibt-bhi2 I've updated this tree with the latest version of the patches. Notably, Kees, I've not taken your Reviewed-by tag for patches that saw significant rework -- even when in response to your own feedback :) (ud_type propagation is now gone) I'll repost in a few days, to give people a chance to catch up.