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=-0.8 required=3.0 tests=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 9A538C47254 for ; Tue, 5 May 2020 15:29:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76202206B9 for ; Tue, 5 May 2020 15:29:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729968AbgEEP3P (ORCPT ); Tue, 5 May 2020 11:29:15 -0400 Received: from mout.kundenserver.de ([217.72.192.74]:34801 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729392AbgEEP3O (ORCPT ); Tue, 5 May 2020 11:29:14 -0400 Received: from mail-qk1-f171.google.com ([209.85.222.171]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.145]) with ESMTPSA (Nemesis) id 1N4i3d-1j6vcM1OR5-011hLo for ; Tue, 05 May 2020 17:29:13 +0200 Received: by mail-qk1-f171.google.com with SMTP id t3so2708313qkg.1 for ; Tue, 05 May 2020 08:29:13 -0700 (PDT) X-Gm-Message-State: AGi0Pub9vNLVkkV5nOTNWRycAHBPZYj6sGmwid95hn5R0fdu2VbNCqei TFIcpr++LXSUf5khJ+knt4Et0a+bb/kxE6kmTms= X-Google-Smtp-Source: APiQypKAatSudP8aUlQtpECyiIhS5dMTJTbNMrIUHmJFtKEtt151ryEXaQP5JMg42FXgb88XoxDiySGwQlzjdXW+i50= X-Received: by 2002:a37:aa82:: with SMTP id t124mr3905009qke.3.1588692552175; Tue, 05 May 2020 08:29:12 -0700 (PDT) MIME-Version: 1.0 References: <20200505142341.1096942-1-arnd@arndb.de> In-Reply-To: From: Arnd Bergmann Date: Tue, 5 May 2020 17:28:55 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] ubsan, kcsan: don't combine sanitizer with kcov To: Marco Elver Cc: Dmitry Vyukov , Andrey Ryabinin , Kees Cook , Andrey Konovalov , "Paul E. McKenney" , Ingo Molnar , Andrew Morton , Greg Kroah-Hartman , Stephen Rothwell , Thomas Gleixner , kasan-dev , LKML , clang-built-linux Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:Smh/UD1h+RCatZUNh5fAt4NdOdRLO2xoRL8DVAvW2SR5yA27ihp wd95R9B7Q4grRRSt57pSWM2839NHsjnDFKpgd5/wTvqlL8XZf58ymUDUyEe97Jz1gFaYn3b z1s+pwCeuaMq4lEjCJl1/vMhP0ZoQcOuz0WQ07/VuZg74q+4skF35iutbiBsWL3Zp445nZ+ iEbMi61YGB6k4/RcQveoQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:BsAAcAL5tts=:ZQhyVcdDkNSCeAYivkFOPj m089480LrJwsc2an4TYFDqh3Ujfa7EkEoRj7UlP/IXnHG8tMiCDxKk5cbHWKvNNZvIGrElk1a imQzrgu+311UKTjyaH9N6GCMKm48iyQAt0eD8vvhA1D/c76ZN3guwtUDiNmmPgcH2Nhw2LlDv xp7v2Yyxb4+CokhXrX1kTyBsOs46axbWG3UecsRUxRVV4PZg81Ncgy0pl6pXfS4RsDtXES1Am JP3Q7zN9Rgk5nMFVwPLzc7EZe8DXKNikhwcF9ncHCDirbMQPkrSlsox/U1L48f/pFFgFof+oO P26BuWp3h5lzkjsYz5mcIVI9ja5EoHwFLGVepwdcxrdx3LWfXze9iUPZLwHIrxiV9KUmk7dLC 5FJc+IxAwXRuZ4UKI2zkHeCIU5I/Naaro0XfOeCOEeLe9ZEx8bLcUHnF6sriUxrK0wPu5Itf7 xZpYX4TS+jaHmaIN/R5h1ZtBRlsGeyzh71PFXxI3NeKDSMLyRb06YiSLDEUsiJj7Fn4uDzOIS owOKD96k85Oo4p1lBhkYe6LXmf/nwKfeerGarm7GCMcQOnIBb6/PIaA0cI3V6TYcNSFIgj97y Vbqz+8UpSrYFyKLvXJUMGBkGc3MQoYf/tdag4U4a4duG6NlKr8o9OZIsaAtJTU2SoTf7AnkN6 aqj44Dta+LOPZqvE1FWfZrqr4kQu+AIKXvFxFECYowXwZeiy7HtYYLm9/XGg2jTYL4jDYeGfb BvP/M8NdhTzvY36b5paw4CDBm9UL3ZAfE9MQiP1Cv3QGBOVMm+IoLb5N8JNvNPzC/ub3ERHMy uTHHzaHVfr1oGMo+0DyocY0EPUQt0DJrLfuVhkVLe+ORAcBpvE= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 5, 2020 at 5:20 PM 'Marco Elver' via Clang Built Linux wrote: > > --- a/lib/Kconfig.kcsan > > +++ b/lib/Kconfig.kcsan > > @@ -5,7 +5,7 @@ config HAVE_ARCH_KCSAN > > > > menuconfig KCSAN > > bool "KCSAN: dynamic data race detector" > > - depends on HAVE_ARCH_KCSAN && DEBUG_KERNEL && !KASAN && !KCOV > > + depends on HAVE_ARCH_KCSAN && DEBUG_KERNEL && !KASAN && !(KCOV > > && CC_IS_CLANG) > > I wonder if we can just add this: depends on !(KCOV && > !$(cc-option,-Werror -fsanitize=thread -fsanitize-coverage=trace-pc)) > > Similarly for UBSAN. > > That way, once Clang supports this combination, we don't need another > patch to fix it. Good idea. It probably get a little more complicated because kcov uses different flags depending on other options: kcov-flags-$(CONFIG_CC_HAS_SANCOV_TRACE_PC) += -fsanitize-coverage=trace-pc kcov-flags-$(CONFIG_KCOV_ENABLE_COMPARISONS) += -fsanitize-coverage=trace-cmp kcov-flags-$(CONFIG_GCC_PLUGIN_SANCOV) += -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so Do you have any preference on whether we should make KCSAN or KCOV conditional in this case? It may be easier to move the compiletime check into CONFIG_KCOV_ENABLE_COMPARISONS and CONFIG_CC_HAS_SANCOV_TRACE_PC. Arnd