From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 00E3F2568 for ; Thu, 5 May 2022 16:25:40 +0000 (UTC) Received: by mail-pj1-f48.google.com with SMTP id w5-20020a17090aaf8500b001d74c754128so8491253pjq.0 for ; Thu, 05 May 2022 09:25:40 -0700 (PDT) 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=AMszwqVGUUkRlqT3bH9KZgvoJEDUJqYcdmFvwR43CTQ=; b=nqkUAGbObnsBEq0E+RdFzEBv9xuAOfg+/oONK+DfcjkFJ+Lqbk1Lxsyuf4E2dI9W0p wL4xpitBmfFa56MgN1186scmSSm3YB/7qrUEctUAW/Fk6aTk2AAkifz9WkeNpn+XaQUH SdP5hM0JRdmsjkaCO7o5uz9TiBKRdlWD+/Djg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=AMszwqVGUUkRlqT3bH9KZgvoJEDUJqYcdmFvwR43CTQ=; b=czuL1bv9kAd2dVhpgk71b1BtMILU+U534Cz7/Vf/oZcV6ssROHHPx847GqMf1z+CpC Hb/OPQR7o+Wk4oor2MOYHrj8AmRI+8USYZZtYNE/JzDGDpKFPcHFjLEbnmM4nj7jdzIT iH7I1kEbRQ/VPFP8QGkU/vBMe/5x+F8odT1ia1qeqhz+UAUxO3QHatCCrT3mkeJvhB1u ySQhgY78/4AC/DD/7SoohrkY+l2SXvafHIDRLYXNoa+40g/0wEBl2NoYxkkOSnDeBSmQ la4DXFSAWUZ2qdZgy10sF+o8mVj9mFcoqPFbc220cV865pOrQmTXemNnzAHimRCw6TvM TvFw== X-Gm-Message-State: AOAM531D5dgd4HkZ64QV1HziefGnnHBYBmcfCusBdtrjfn96KyENPHuh 0te27QFL+qYUKj3MpQz+vsyJLg== X-Google-Smtp-Source: ABdhPJx6wPVrYHxsa68KRgQKpBYm+86c0ZSHTSAAubzPSZ9HEe2FvIzxPyT8mlJ1clOyQ1w2FcrXkQ== X-Received: by 2002:a17:903:2312:b0:15e:a6c8:a313 with SMTP id d18-20020a170903231200b0015ea6c8a313mr20672636plh.122.1651767940456; Thu, 05 May 2022 09:25:40 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id c23-20020a170902849700b0015e8d4eb287sm1749040plo.209.2022.05.05.09.25.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 May 2022 09:25:40 -0700 (PDT) Date: Thu, 5 May 2022 09:25:39 -0700 From: Kees Cook To: Mark Rutland Cc: kernel test robot , llvm@lists.linux.dev, kbuild-all@lists.01.org, linux-kernel@vger.kernel.org Subject: Re: [kees:for-next/kspp 21/25] drivers/misc/lkdtm/stackleak.c:17:39: error: call to undeclared function 'stackleak_task_low_bound'; ISO C99 and later do not support implicit function declarations Message-ID: <202205050924.7D219E774@keescook> References: <202205050943.HDgeO9iV-lkp@intel.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, May 05, 2022 at 01:45:37PM +0100, Mark Rutland wrote: > Hi Kees, > > I hadn't realised the LKDTM STACKLEAK test could be built with > CONFIG_STACKLEAK=n, and my rework of that depends upon helpers that only exist > when CONFIG_STACKLEAK=y. > > IMO the test is nonsensical for CONFIG_STACKLEAK=n, and I reckon we should > either: > > a) Not build the stackleak test at all when CONFIG_STACKLEAK=n > > b) Have a small stub that just logs that CONFIG_STACKLEAK=n and the test is > being skipped. > > Do you have any preference between the two? Since it's looking for a specific poison, it doesn't make sense to look for this property as magically appearing (where as this kind of thing sometimes exists for other tests: did the hypervisor block it instead of the kernel, etc) So, yeah, I'd wrap it in an ifdef with an else: XFAIL. -- Kees Cook