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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 000DBC6FD1C for ; Thu, 23 Mar 2023 12:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231903AbjCWMio (ORCPT ); Thu, 23 Mar 2023 08:38:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231926AbjCWMid (ORCPT ); Thu, 23 Mar 2023 08:38:33 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30F022A98A for ; Thu, 23 Mar 2023 05:38:25 -0700 (PDT) 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=IUAjpgywdEv9m2kYI9XNVC5x6XA0EKoC2enruDplZ2g=; b=s6KI97mtOQKlhamo8U8JGA1Nyw T1JiZdEeyLwhRChj0KMzY8+Lb0dFAZbyx/84x5qqgn62WTEwctVVDdA1C9YSZdgwacz1vELO9DYOL Z2TUJhvwe5/QTaIu2iF+Tej/HRGLm53tIrfjMlTf53FI95PAsVAvCVB3aiyZwDrlqglRFKZDUMrxp Tmogs/UcgDUyA6zHqsJuF3V421AP7hnjgQc+ymn/DeDs8dvoQpmbYDuibkP2mr5+cbFzg4Fk3tn0P OpEnrMqVFi2J5W/0MF7l9loV9CoHyEsPEuBXUHxhnGo7OqA2bnExnx9MF9Yd6HafVuZWT4A/jwXnl m3n0w3ZA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pfKCw-003wrc-Lw; Thu, 23 Mar 2023 12:38:18 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A6C8E300237; Thu, 23 Mar 2023 13:38:17 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8388E2420A896; Thu, 23 Mar 2023 13:38:17 +0100 (CET) Date: Thu, 23 Mar 2023 13:38:17 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: x86@kernel.org, Mark Rutland , live-patching@vger.kernel.org, Steven Rostedt Subject: Re: [PATCH 0/6] x86,objtool: Split UNWIND_HINT_EMPTY in two Message-ID: <20230323123817.GA2512024@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On Wed, Mar 01, 2023 at 07:13:06AM -0800, Josh Poimboeuf wrote: > Based on tip/objtool/core. > > Mark reported that the ORC unwinder incorrectly marks an unwind as > reliable when the unwind terminates prematurely in the dark corners of > return_to_handler() due to lack of information about the next frame. > > The problem is UNWIND_HINT_EMPTY is used in two different situations: > end-of-stack marker and undefined stack state. > > Split it up into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED. > > Josh Poimboeuf (6): > objtool: Add objtool_types.h > objtool: Use relative pointers for annotations > objtool: Change UNWIND_HINT() argument order > x86,objtool: Introduce ORC_TYPE_* > x86,objtool: Separate unret validation from unwind hints > x86,objtool: Split UNWIND_HINT_EMPTY in two Quite a bit of churn, but the end result does seem cleaner. Acked-by: Peter Zijlstra (Intel)