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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACFE9C4361B for ; Thu, 17 Dec 2020 10:46:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55DE62389A for ; Thu, 17 Dec 2020 10:46:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726983AbgLQKqm (ORCPT ); Thu, 17 Dec 2020 05:46:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725950AbgLQKqm (ORCPT ); Thu, 17 Dec 2020 05:46:42 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1C01C061794 for ; Thu, 17 Dec 2020 02:46:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=vD/MxHgLBcrC3XLRiPmHcUgbEPW0ezghwc6G56p2x2A=; b=m55HwJUJOGFKvCxqY5TQIaXtP9 bAHT0ddmDXXX/HgTcvwIv+U5htjAwvtKs5z4PaOPtCoL1RcdeD3Gnk3txBOBlL6ZWeybJO7K0lURX Bkg9LSUwyQTBGdcyOdHp7ydAcxXmNksvTsY7CVjH7yO/AtFjIJPBdFrFT4nWGlwM08qIvGQMVmts2 XNydp58QQAbguPg2fQq6G8tzLcAnAFctPFNcWcXhkzpRgS1wHfJdFzvUupsxoG92Ujip8cdG6m+KI mQX2i83cI0a+90iE7s/yhhhYtdx1EwCWWs1LW6zpxZiBxL+rHl6SIVIiUL0byB4o0ImiNWcj5PKSD c+v5Fzow==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kpqnG-0003eK-3P; Thu, 17 Dec 2020 10:45:58 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 47D3D300446; Thu, 17 Dec 2020 11:45:56 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2E3CD202395BD; Thu, 17 Dec 2020 11:45:56 +0100 (CET) Date: Thu, 17 Dec 2020 11:45:56 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: New objtool warning.. Message-ID: <20201217104556.GT3040@hirez.programming.kicks-ass.net> References: <20201216044918.jdmi32dz75uboybv@treble> <20201216200158.akf356yrw44o2rlb@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201216200158.akf356yrw44o2rlb@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 16, 2020 at 02:01:58PM -0600, Josh Poimboeuf wrote: > So this is kind of tricky, because the unreachable() annotation usually > means "the previous instruction is a dead end". Most of the time, the > next instruction -- the one actually pointed to by the annotation -- is > actually reachable from another path. *groan*, this is why I ended up sticking a nop in instrumentation_begin()/_end().