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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 1FD10C4361B for ; Wed, 16 Dec 2020 04:47:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E73F52333E for ; Wed, 16 Dec 2020 04:47:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725985AbgLPEr2 (ORCPT ); Tue, 15 Dec 2020 23:47:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:52568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725889AbgLPEr2 (ORCPT ); Tue, 15 Dec 2020 23:47:28 -0500 Date: Tue, 15 Dec 2020 20:46:46 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1608094008; bh=69KPAPmxp1MLi2Zi0yovgGENLPqn3QImq48kiupQaJI=; h=From:To:Subject:In-Reply-To:From; b=WEeuIzjl47igNbKlbjJzbnQ60YTqr+5qGUBrk1tQmQHAYypj335i1CFy249NH6742 gqFUAY//1+i4Z5/BkNaZh9gL0ZjRcU9L1qsqNCdG1Ofifky89k3xBLB1Fsj2wur2jp SkjvJGeHMNM53EV7LzjPdbxeltgKMnPCP5V+WDvY= From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, dvyukov@google.com, elver@google.com, keescook@chromium.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, sfr@canb.auug.org.au, torvalds@linux-foundation.org Subject: [patch 81/95] kcov: don't instrument with UBSAN Message-ID: <20201216044646.UfdxttgTd%akpm@linux-foundation.org> In-Reply-To: <20201215204156.f05ec694b907845bcfab5c44@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Dmitry Vyukov Subject: kcov: don't instrument with UBSAN Both KCOV and UBSAN use compiler instrumentation. If UBSAN detects a bug in KCOV, it may cause infinite recursion via printk and other common functions. We already don't instrument KCOV with KASAN/KCSAN for this reason, don't instrument it with UBSAN as well. As a side effect this also resolves the following gcc warning: conflicting types for built-in function '__sanitizer_cov_trace_switch'; expected 'void(long unsigned int, void *)' [-Wbuiltin-declaration-mismatch] It's only reported when kcov.c is compiled with any of the sanitizers enabled. Size of the arguments is correct, it's just that gcc uses 'long' on 64-bit arches and 'long long' on 32-bit arches, while kernel type is always 'long long'. Link: https://lkml.kernel.org/r/20201209100152.2492072-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov Reported-by: Stephen Rothwell Suggested-by: Marco Elver Acked-by: Marco Elver Reviewed-by: Andrey Konovalov Reviewed-by: Kees Cook Signed-off-by: Andrew Morton --- kernel/Makefile | 3 +++ 1 file changed, 3 insertions(+) --- a/kernel/Makefile~kcov-dont-instrument-with-ubsan +++ a/kernel/Makefile @@ -34,8 +34,11 @@ KCOV_INSTRUMENT_extable.o := n KCOV_INSTRUMENT_stacktrace.o := n # Don't self-instrument. KCOV_INSTRUMENT_kcov.o := n +# If sanitizers detect any issues in kcov, it may lead to recursion +# via printk, etc. KASAN_SANITIZE_kcov.o := n KCSAN_SANITIZE_kcov.o := n +UBSAN_SANITIZE_kcov.o := n CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector obj-y += sched/ _