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 14598C433E0 for ; Wed, 10 Feb 2021 17:02:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAB1664E15 for ; Wed, 10 Feb 2021 17:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232159AbhBJRCa (ORCPT ); Wed, 10 Feb 2021 12:02:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233088AbhBJRCN (ORCPT ); Wed, 10 Feb 2021 12:02:13 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 402BCC061574 for ; Wed, 10 Feb 2021 09:01:34 -0800 (PST) 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=aUh0dYLcs0EmmNljHRiNDUD7+xy/uR4TKWhhdzvoI4Y=; b=ncD6hRh69zMf7I+/WfTq42FLV5 Bpy3g4+Ri6k6uQ8XVMoLg+YpNnd0oo5NZ4qsA2v5q3/+yIRJKzMr07sfmrzNfAUPsk8gpD0fMDQk7 hSC2wFZlSJJ1bp1ghJl5sI78dISR6hu3qOuzDU0Kh8pd+q1h/o58AQj/FU76Y5Y3rPedBSfWKcyNe zaDvrNhyRUfDYQFaRZByt+OIfb/KJyvwGnV6D/QrjOHdbpFukhbFdEzh0n+ylUdDEW7KEeCRJ0uSc +jEt1gYJT3kUS7OQsLgqaj2F0oa/luXfTm/AuLrGleewtpqT2sc0gQXHKsN/CpqH7/cBKJs2mzBPQ GNZzEVJQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1l9srV-0097sr-Rz; Wed, 10 Feb 2021 17:01:10 +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 66D1D301EFB; Wed, 10 Feb 2021 18:01:07 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 58371207C4A13; Wed, 10 Feb 2021 18:01:07 +0100 (CET) Date: Wed, 10 Feb 2021 18:01:07 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: Linus Torvalds , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, Steven Rostedt , yu-cheng.yu@intel.com Subject: Re: [RFC][PATCH] objtool: WARN about ENDBR instructions Message-ID: References: <20210210160945.73n5zhlfcii5t637@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210210160945.73n5zhlfcii5t637@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 10, 2021 at 10:09:45AM -0600, Josh Poimboeuf wrote: > On Wed, Feb 10, 2021 at 09:39:53AM +0100, Peter Zijlstra wrote: > > > > > > Given all the ENDBR fun we recently had, do we want the below? Until > > someone comes and fixes up kprobes/ftrace/livepatch etc.. having them is > > a giant pain and we'd better warn about it. > > Meh... > > Is there a point in doing this, now that we killed it with > -fcf-protection=none? > > That said, the patch is nicely small and localized. Yeah, paranoia, just making absolutely sure it doesn't sneak back in unexpected.