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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 86E43C43461 for ; Thu, 3 Sep 2020 21:58:49 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id CD91320678 for ; Thu, 3 Sep 2020 21:58:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="cfK1czkM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD91320678 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-19755-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16146 invoked by uid 550); 3 Sep 2020 21:58:43 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 16107 invoked from network); 3 Sep 2020 21:58:42 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=zwlTSlngv7hk/k8joOBYJecRtutX3pQhWGRYHaQfHNc=; b=cfK1czkMgexKgeV+AniPDaw2RXSPRTJErK03aD3KyKL4Fgd4NeDHwP5V8Xl/FfVKCS 6F+iqqs9u11jyJ00qYjcMmLzcZHnV9wHK2dvI7ZXa7ITGd9X9E1vU0dh9lPkAo/o/+N9 ZlfpNW1hK+/ISGP4OP8u8wm5pAhXJBxxqUlTY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=zwlTSlngv7hk/k8joOBYJecRtutX3pQhWGRYHaQfHNc=; b=Jg3vh02uTCMbGTe1qdJTDPVVoLo061yO0Ql0Y9aMASCgEDQht3qyJk9EDTLDkDvkrE GZ5A9ec42XL2Mh15QQ88M50MvXr8a0yJER5/la5WvfYhiLAhCZJHfk5xNwvyV17eo0Ub EaxYFYHBKUlByVA8yWh0utP00+mt7uh7L02nymwNjL8GrcZiv/xDQ7lG/4d2z3d3wPwl la8ZWD481W0S0oBeZbkP1z12qMrgSsATUriY5hBaQrb97xNpnFU4Uxb4emRj0Dz8KHOQ k2wH8aZev4c/KucImFZQf0Cmq8UkVQPxMPDOuKf4gRmmQiEqaSbMNAZQON02/CRbVRuQ loAQ== X-Gm-Message-State: AOAM533YOgg4exSZMCmfc29G+/VCG6oQy+Lp1AKzfiBmizVo91pTRuSh UmsplCLJwUH9vJCVn2SccrB2Jw== X-Google-Smtp-Source: ABdhPJxsSBaVqKQu0Depn8jVU89HVsiUUr1gbeyokvUp0RXsPEsXdBRA9MTk7ZF9gX6Cd/pjcZAmmw== X-Received: by 2002:a63:d70f:: with SMTP id d15mr4658855pgg.354.1599170310450; Thu, 03 Sep 2020 14:58:30 -0700 (PDT) Date: Thu, 3 Sep 2020 14:58:28 -0700 From: Kees Cook To: Sami Tolvanen Cc: Masahiro Yamada , Will Deacon , Peter Zijlstra , Steven Rostedt , Greg Kroah-Hartman , "Paul E. McKenney" , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v2 08/28] x86, build: use objtool mcount Message-ID: <202009031456.C058EC4@keescook> References: <20200624203200.78870-1-samitolvanen@google.com> <20200903203053.3411268-1-samitolvanen@google.com> <20200903203053.3411268-9-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903203053.3411268-9-samitolvanen@google.com> On Thu, Sep 03, 2020 at 01:30:33PM -0700, Sami Tolvanen wrote: > Select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION is selected to use > objtool to generate __mcount_loc sections for dynamic ftrace with > Clang and gcc <5. > > Signed-off-by: Sami Tolvanen Am I right to understand that this fixes mcount for Clang generally (i.e. it's not _strictly_ related to LTO, though LTO depends on this change)? And does this mean mcount was working for gcc < 5? Reviewed-by: Kees Cook -- Kees Cook