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[2620:137:e000::1:20]) by mx.google.com with ESMTP id jj4-20020a170903048400b001752bed9278si110304plb.461.2022.08.29.22.04.42; Mon, 29 Aug 2022 22:04:53 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=Lfi5ILY7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229939AbiH3Esi (ORCPT + 99 others); Tue, 30 Aug 2022 00:48:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229957AbiH3EsR (ORCPT ); Tue, 30 Aug 2022 00:48:17 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89146B02BA; Mon, 29 Aug 2022 21:48:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3B2F9B811B9; Tue, 30 Aug 2022 04:48:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2FF2C433D7; Tue, 30 Aug 2022 04:48:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661834894; bh=fx/2R2KpWM7H7A+xXD+jhcW9b7yHd7jYx/HOk0b0+FM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Lfi5ILY7H7MlFVkOoxKjJwpESchr+4w3n5xuiE4sXXJySElHGle+AWHp2j3itzS/b 1FzA3t1FdGjnVZpulB3FDolZ28wXbpWg1dj89dYE+zEyh4ULGAyH4Pn4ti9NS7kvxL K11VRl/0ic+6/L5rpXm1QLo+sjBgLzjVKzzmR/DvYWjgx5I3b2qk/6RuMVQvknoRhA sGmj3xCJFv8VUlPM5CB2RDBWUnn6HRiWsxt+X6LehzqNuKGmcOjtydPaKZFHoxTSXV Gtf83tVJQvUOyRhdABK9Yi23Y++hAN5DD7CYfhNW6wdjLoBWWb3wrqYuZprKL9yPMz 2ebaN29wWwh9g== Date: Mon, 29 Aug 2022 21:48:11 -0700 From: Josh Poimboeuf To: David Laight Cc: 'Peter Zijlstra' , Segher Boessenkool , Borislav Petkov , X86 ML , Michael Matz , "linux-toolchains@vger.kernel.org" , LKML , Josh Poimboeuf Subject: Re: [PATCH] x86/sev: Mark snp_abort() noreturn Message-ID: <20220830044811.jad66k4sxdfnprul@treble> References: <20220824152420.20547-1-bp@alien8.de> <20220824172929.GA25951@gate.crashing.org> <20220824224144.GC25951@gate.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 25, 2022 at 01:12:42PM +0000, David Laight wrote: > ... > > Objtool follows control flow. As you said above, noreturn functions > > behave differently and code-gen after a call to a noreturn function > > stops. > > Thinks.... > > How near is objtool to outputting a list of functions and the > stack offset at which they call something else? It basically already does this. > With the 'magic numbers' to track indirect jumps that is very > nearly enough information to do full static stack depth checking. What do you mean by 'magic numbers'? -- Josh