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 D9D50C433B4 for ; Tue, 18 May 2021 20:07:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABCA06109F for ; Tue, 18 May 2021 20:07:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237988AbhERUIU (ORCPT ); Tue, 18 May 2021 16:08:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232377AbhERUIS (ORCPT ); Tue, 18 May 2021 16:08:18 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6ABFBC061573 for ; Tue, 18 May 2021 13:06:59 -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=QAId92lKPjrNEd4X0TWB5CrklOE6Ccafm4FzhPHDeOQ=; b=Wpp3R7WsBgXwKusEqPFj2OH3sG Ush58BxOiX6UvX/g5kgt7OGpHgJCjbgr9Hfv4Ghg/bSmE1MteCWqjXD3htlPls6Jkxyk2CLutBa89 qbOQl4Imcs7RSa7O5piy17WX9eJ+OFOyVOVd0xn2GmpuIsy7H3QcCK7596iVFkdxAktrj0ME4k3xP tm7vc7fvZ2CdVC4JnI111mhPa4tzdrl75GF9UdssKToSWfqM2RHXtZd0VDd3BR2BKue0CBxjEGAsX nXeatGlYFnoVCM95gWv46iL8LwFV6GLVC1f/mwCZDK550JWjmm31avNwIKnJ6cBSFP01+UyTfOQgl RFKibvKQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lj5vn-00EJFx-9r; Tue, 18 May 2021 20:03:48 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 87613986465; Tue, 18 May 2021 22:03:06 +0200 (CEST) Date: Tue, 18 May 2021 22:03:06 +0200 From: Peter Zijlstra To: Nick Desaulniers Cc: Josh Poimboeuf , Will Deacon , "Jose E. Marchesi" , "Paul E. McKenney" , Ard Biesheuvel , Catalin Marinas , Mark Rutland , linux-toolchains@vger.kernel.org Subject: Re: Linux Plumbers Conf 2021 Message-ID: <20210518200306.GE21560@worktop.programming.kicks-ass.net> References: <20210518121447.GB7914@willie-the-truck> <20210518124311.r4fwv6lfz3erkqnb@treble> <20210518124819.lkzzgjcrh4cc5a6i@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-toolchains@vger.kernel.org On Tue, May 18, 2021 at 09:57:26AM -0700, Nick Desaulniers wrote: > On Tue, May 18, 2021 at 6:23 AM Peter Zijlstra wrote: > > - validates noinstr annotation; *HOWEVER* we rely on objtool to NOP > > all __sanitizer_cov_* calls in .noinstr/.entry text sections because > > __no_sanitize_cov is 'broken' in all known compilers. > > ^ Do you have more information on this? Random link in the middle of a relevant thread: https://lkml.kernel.org/r/CANpmjNPNa2f=kAF6c199oYVJ0iSyirQRGxeOBLxa9PmakSXRbA@mail.gmail.com Notable quote: "It's everywhere. We cannot mark noinstr functions to not be instrumented by KCOV/-fsanitize-coverage, because no compiler provides an attribute to do so. GCC doesn't have __attribute__((no_sanitize_coverage)) and Clang doesn't have __attribute__((no_sanitize("coverage")), and therefore we can't have __no_sanitize_coverage."