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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 5151AC433DF for ; Fri, 12 Jun 2020 11:34:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AA0220792 for ; Fri, 12 Jun 2020 11:34:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="oCw3KNDX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726253AbgFLLeh (ORCPT ); Fri, 12 Jun 2020 07:34:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725791AbgFLLeh (ORCPT ); Fri, 12 Jun 2020 07:34:37 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02007C03E96F for ; Fri, 12 Jun 2020 04:34:36 -0700 (PDT) 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=KeIr7tqTdmTxWp0qLbXPXOvRu/jpVQnRhJVoQ2kBrSM=; b=oCw3KNDX0AVf+U81PyTyWou803 imm7191iocxcQquXKfKwALJLj+TKIEZdqNCmCyxJFoVdI0Fc1pZUAExcRyVEhkjZkDf2QQ1lsBpSF Sxnb7mRGT2R2ZXENaSoW5eCjXyMBt5JxDXgmSiVSaKW+Rje8HVHYNG1PqfBhJU1Lg1HmP6cSMYvQW z7oFpVbvpqVNs2HXtHXdoUOxdbxToR4USKum1W4PtarJIzLMu+9EHWtNRU/O4OtCq90BXT1Mca2Qm Lp3v7y+/lyQpKANNAbAhNOCaekQ++Ym+ZHqW4IJRd9P/LAyW2uhg9xjWpzB8a08zb1jo/6yktPLOO cUILSB9g==; 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 1jjhwi-0002Ob-Nd; Fri, 12 Jun 2020 11:34:05 +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 C57B83003E7; Fri, 12 Jun 2020 13:34:01 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AB98B29DB6157; Fri, 12 Jun 2020 13:34:01 +0200 (CEST) Date: Fri, 12 Jun 2020 13:34:01 +0200 From: Peter Zijlstra To: Dmitry Vyukov Cc: Marco Elver , Andrey Konovalov , Mark Rutland , Borislav Petkov , Thomas Gleixner , Ingo Molnar , clang-built-linux , "Paul E. McKenney" , Alexander Potapenko , kasan-dev , LKML , the arch/x86 maintainers , Andrew Morton , Josh Poimboeuf Subject: Re: [PATCH -tip v3 1/2] kcov: Make runtime functions noinstr-compatible Message-ID: <20200612113401.GC2554@hirez.programming.kicks-ass.net> References: <20200605082839.226418-1-elver@google.com> <20200605120352.GJ3976@hirez.programming.kicks-ass.net> <20200608110108.GB2497@hirez.programming.kicks-ass.net> <20200611215538.GE4496@worktop.programming.kicks-ass.net> <20200611215812.GF4496@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200611215812.GF4496@worktop.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 11, 2020 at 11:58:12PM +0200, Peter Zijlstra wrote: > On Thu, Jun 11, 2020 at 11:55:38PM +0200, Peter Zijlstra wrote: > > I'll have to dig around a little more to see if I can't get rid of the > > relocation entirely. Also, I need to steal better arch_nop_insn() from > > the kernel :-) Oh, I just realized that recordmcount does exactly this same thing, so I checked what that does to the relocation, and it turns out, it does the same thing I did. They change the relocation type to R_*_NONE too. So I suppose that's all right then. I suppose I ought to go look at the recordmcount to objtool patches to see if there's anything to share there.