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=-12.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 CF013C4727E for ; Wed, 30 Sep 2020 16:06:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 892C920B1F for ; Wed, 30 Sep 2020 16:06:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FdREMa9Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731121AbgI3QF6 (ORCPT ); Wed, 30 Sep 2020 12:05:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731093AbgI3QFv (ORCPT ); Wed, 30 Sep 2020 12:05:51 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C98FC0613D1 for ; Wed, 30 Sep 2020 09:05:51 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id lo4so3605992ejb.8 for ; Wed, 30 Sep 2020 09:05:51 -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=4nf8e6hIaPbRqntvQjCiPI17gKDQL3g6MdR3siKHn30=; b=FdREMa9YQ4gNRdQHURf/x/R8SmYVJ5gIkH9KpmlqeEAlOLeXAhaYjSC7VB4Y8/uoLl NpSU9flOBZMB2LnlrWowvIpCnct6WksL48hJ6hEvbeije9viNCjBJLNglsVPmK17McTE bQR932o1ftCv5I/jccydLYq37ELOk8HLaS5waUMw2Sl4+mDrlXBlbynVNtazEd8rcTZn oCfVkT2gQBFoWgRMv35xCS9XqXQ6DAZwYypy9P5mdyuszGukdvxnnn/AnzhUUV4OJTG3 jalYoYIzQjQOW6W2UeOKJ1wH4ANi3gdiXC8IiXeG+7KUsH9D9cVc5b9Ynx38GiIxo6v5 fQpQ== 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=4nf8e6hIaPbRqntvQjCiPI17gKDQL3g6MdR3siKHn30=; b=gvivPiVpjKCFKcHjsosm8WIvlsKoO1Cm/Qj6NAA1qdsxhBvbfsPiqgXRM5FKsLFvyH NfyYuzEXi4nvR2BRbM2KM365M4g/OMGuS/BNqAFrw1cx/5Q0V3r5CUqQl0SAkG3nIlxv 2HZcCVGpcv76XXIC3+tECiF8IeMDGIQKh9X3btuHKsp1sw/3pOrEAeVsKdzM+KeAAG87 AcL+4C9rHD68+UgXSNsxbtm/4TXaYgzvUmvSnhya0xtoADx3xN0Bsq9KtPEmqz9lIM5M ECJZcLexPPQ7OwZc05sj1zl6tuIf2T47pvTF7ZU83zYTz9P1QwZ2bg6VSPWWC2pFFosP XF6w== X-Gm-Message-State: AOAM533KFfnsAP+QXAgBGpQDvBzmtmFL0/mkkcF0l0WDcqXGTCWlvVju h2bADfUW0ZBunoH+ZYr7LQIamsJtPRvgRQ8xPmu29w== X-Google-Smtp-Source: ABdhPJzYVdbm3fjbvWcAsssxdkKlp1Qf8hBl3VmZLS0706h18aYEVSeaUqFy3XkT6TY1fv56XT82VdDVYI9SZJ5H+mA= X-Received: by 2002:a17:906:a256:: with SMTP id bi22mr3464394ejb.375.1601481949457; Wed, 30 Sep 2020 09:05:49 -0700 (PDT) MIME-Version: 1.0 References: <20200929214631.3516445-1-samitolvanen@google.com> <20200929214631.3516445-7-samitolvanen@google.com> <20200929201257.1570aadd@oasis.local.home> In-Reply-To: <20200929201257.1570aadd@oasis.local.home> From: Sami Tolvanen Date: Wed, 30 Sep 2020 09:05:38 -0700 Message-ID: Subject: Re: [PATCH v4 06/29] tracing: move function tracer options to Kconfig To: Steven Rostedt Cc: Masahiro Yamada , Will Deacon , Peter Zijlstra , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux , Kernel Hardening , linux-arch , linux-arm-kernel , linux-kbuild , LKML , linux-pci@vger.kernel.org, X86 ML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org On Tue, Sep 29, 2020 at 5:13 PM Steven Rostedt wrote: > > On Tue, 29 Sep 2020 14:46:08 -0700 > Sami Tolvanen wrote: > > > +++ b/kernel/trace/Kconfig > > @@ -595,6 +595,22 @@ config FTRACE_MCOUNT_RECORD > > depends on DYNAMIC_FTRACE > > depends on HAVE_FTRACE_MCOUNT_RECORD > > > > +config FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY > > + bool > > + depends on FTRACE_MCOUNT_RECORD > > + > > +config FTRACE_MCOUNT_USE_CC > > + def_bool y > > + depends on $(cc-option,-mrecord-mcount) > > Does the above get executed at every build? Or does a make *config need > to be done? If someone were to pass a .config to someone else that had > a compiler that didn't support this, would it be changed if the person > just did a make? Yes, it's updated if you copy a .config and just run make. For example, here's what happens when I create a config with gcc and then build it with Clang: $ make defconfig ... $ ./scripts/config -e FUNCTION_TRACER -e DYNAMIC_FTRACE $ make olddefconfig ... $ grep MCOUNT_USE .config CONFIG_FTRACE_MCOUNT_USE_CC=y $ make CC=clang scripts/kconfig/conf --syncconfig Kconfig ... ^C $ grep MCOUNT_USE .config CONFIG_FTRACE_MCOUNT_USE_OBJTOOL=y Sami