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=-14.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 7039AC433E0 for ; Mon, 15 Jun 2020 19:04:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B37E2067B for ; Mon, 15 Jun 2020 19:04:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lMnXpMZZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731409AbgFOTE3 (ORCPT ); Mon, 15 Jun 2020 15:04:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731249AbgFOTE0 (ORCPT ); Mon, 15 Jun 2020 15:04:26 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02CD5C061A0E for ; Mon, 15 Jun 2020 12:04:25 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id i4so262585pjd.0 for ; Mon, 15 Jun 2020 12:04:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9aW2TqrBLH8LeFdcz9gJFpsSwBcZN5ImxsbMz/APSqI=; b=lMnXpMZZ28eB1AUnoYs0tMCcfdx9eomDMjAwwW3tQo1QWecVxMGf4Z9oaZqZ0DSC9J 2kdu8TS9YCnn3/TZaRoxoLXK308sh0TkEM2S9r1iOsf5XFgv1gHIODJ2b1KSLoDQU2gr 2GkTorHfQSznZssJuKgKDyKM2FHoLNgGsjtxAaSGs39xQuzdBO8oFjHZRCA1vzJmkHuE FrP7hVmxLNMjj55B8KoaF5Zzn5gLiy03derdrZFzbR+UtzN3f/tpmNXR7KuPoQQBbFB2 zD6DWqxILh+69QkSkIQYbHTSGhmqUbWK5DPPtTDnPrfIO6PmhLpzTNAl2BoKwml1HovC CzTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9aW2TqrBLH8LeFdcz9gJFpsSwBcZN5ImxsbMz/APSqI=; b=YLsTz7OnjXL+/vF42BKFwlxXP58N0X75Za4xGMPdnRene/GiJeaVWBhs0DOnqQpWKB dhBNlko+WgsBx/Hj7fOCtwyt1Tn4yXhv10/0mL3UkaTHbcjg1aENnm63lup2fnOWaUoa EU+KRp8yLaOc1FBBay8ulfXNEu4XJvq7mcLknh52QhK1MWPrTDSWI1fW9zq1FNzEJyCg bTugk9Er8E53cpaxoD6HE0s3VICeMFEHZ40xxf5uC69UDsmwF7FbcGBq/jxhkEBOJAra WbK9u5zNu9mroYRJu90xQlpnkmLZpRA0fg7R9op4xV7FeOakrzYRAo6x1X44tLJyPhCg pDeg== X-Gm-Message-State: AOAM530Aj6fiNSMNpzB6qbHNZlN2tqSX2ipk7TReFG6EmoBJZfGsAl9k mSEXmLIcvELTMNr1F6ISz3j1U+RkGiJ53XOibe4Si530EHQ= X-Google-Smtp-Source: ABdhPJylLhumge3iLMOwdrqKasfZc2kbu7Zpnn7izPXUiTo/OOS+izBX7wRfEj0QlmWA813ZcGQ3QUzhmD/VSOhu3wk= X-Received: by 2002:a17:90b:1244:: with SMTP id gx4mr707505pjb.136.1592247864399; Mon, 15 Jun 2020 12:04:24 -0700 (PDT) MIME-Version: 1.0 References: <20200615184302.7591-1-elver@google.com> In-Reply-To: <20200615184302.7591-1-elver@google.com> From: Andrey Konovalov Date: Mon, 15 Jun 2020 21:04:13 +0200 Message-ID: Subject: Re: [PATCH] kcov: Unconditionally add -fno-stack-protector to compiler options To: Marco Elver Cc: Andrew Morton , Dmitry Vyukov , Alexander Potapenko , LKML , kasan-dev , Nick Desaulniers Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 15, 2020 at 8:43 PM Marco Elver wrote: > > Unconditionally add -fno-stack-protector to KCOV's compiler options, as > all supported compilers support the option. This saves a compiler > invocation to determine if the option is supported. > > Because Clang does not support -fno-conserve-stack, and > -fno-stack-protector was wrapped in the same cc-option, we were missing > -fno-stack-protector with Clang. Unconditionally adding this option > fixes this for Clang. > > Suggested-by: Nick Desaulniers > Reviewed-by: Nick Desaulniers > Signed-off-by: Marco Elver > --- > Split out from series: > https://lkml.kernel.org/r/20200605082839.226418-2-elver@google.com > as there is no dependency on the preceding patch (which will be dropped). > --- > kernel/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/Makefile b/kernel/Makefile > index f3218bc5ec69..592cb549dcb8 100644 > --- a/kernel/Makefile > +++ b/kernel/Makefile > @@ -35,7 +35,7 @@ KCOV_INSTRUMENT_stacktrace.o := n > KCOV_INSTRUMENT_kcov.o := n > KASAN_SANITIZE_kcov.o := n > KCSAN_SANITIZE_kcov.o := n > -CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) > +CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector > > # cond_syscall is currently not LTO compatible > CFLAGS_sys_ni.o = $(DISABLE_LTO) > -- > 2.27.0.290.gba653c62da-goog > Reviewed-by: Andrey Konovalov