From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 480B036B910; Fri, 9 Oct 2026 06:56:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791528975; cv=none; b=icV9tbuBsiBLG+hcrWVqAovhB+yoylYtPxn/d+yjwjeH5yWtw9MwFdlyh0vYXINff4S8L2zLQ6JsijpyDRhgnKOTwY9Xms09f6CV+pW/69M3WJnpwTDTQ9tHBzPlvIKAXyVxeZesfTFU8zZrGU6qC+0EbQaCfO27E49FqhLPkUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791528975; c=relaxed/simple; bh=0iCbDi61UpmcCHXdfg/G61aSFZzT/N51dKZO3m1YycM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PVF8+hteu4/8q9nijMEZGF0A96NvVXNRrrzkhNqtvwMB4Q8Q+VJ8Y+UZfF2nyEUKB5jT/AB2UuUtv77Dj3F25ygNbDRkOGmCSPS9lC1OTK0DKGxiNbrPnpR3aStTd9vcxflwkydiSprW5P4u57xJ5tlgG+97pWfWkToSVGMJHAk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VlzrlOj4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VlzrlOj4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B8F11F000FF; Fri, 9 Oct 2026 06:56:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791528974; bh=kqzy6vEz0RfryQ6x1GPlflYy3LT5Qzbfi9fT1N1rBz4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VlzrlOj4yjeCjQFmjvNduRQOQr2Dp+5OM+Gxqdjv38vAnEHixCgCtyGZw2hWBMswg hDnXP5OyOdPh83hWNe9Xu5s02CoxdYLcjLZ3TjNmbqrrZ0mHBisRV+OpnIKRPfnVgY ByO7cFfFKV7MjFP9krDXQ1G9yxadG9ulRYthKC40T0GOexBu7n7ZbXs8x/iV1+Klkq dZ3dWmwGpVgRL1+Wcl9OshwGOU14kJQV8XF3yHswqQ9ZoMqdm+7Sjo0bJyNldCpy/+ PpAh/6Dr4UMko77NPR/A9QG9IgIa2TtAZeYTPLku19e7bD7MJrHih34uwyKDndoDHQ aOptluwE98khQ== Date: Thu, 8 Oct 2026 23:56:13 -0700 From: Kees Cook To: Nicolas Schier Cc: Nathan Chancellor , Julian Braha , Lorenzo Stoakes , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Initial ergonomic improvements to scripts/Kconfig.toolchain Message-ID: <202610082355.D904DA02@keescook> References: <20261007-scripts-kconfig-toolchain-improvements-v1-0-1e524178da11@kernel.org> <179139172076.154975.7876331914722818497.b4-review@b4> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <179139172076.154975.7876331914722818497.b4-review@b4> On Wed, Oct 07, 2026 at 06:48:40PM +0200, Nicolas Schier wrote: > When I look into the resulting .config, I'd wish, these empty string > kconfig symbols could be unset, e.g. > > # CONFIG_CC_OPT_WNO_FORMAT_TRUNCATION_NON_KPRINTF is not set > # CONFIG_CC_OPT_WNO_DEFAULT_CONST_INIT_UNSAFE is not set > CONFIG_CC_OPT_WNO_DANGLING_POINTER="-Wno-dangling-pointer" > CONFIG_CC_OPT_WVLA_LARGER_THAN="-Wvla-larger-than=1" > CONFIG_CC_HAS_WSTRINGOP_OVERFLOW=y > > instead of the current: > > CONFIG_CC_OPT_WNO_FORMAT_TRUNCATION_NON_KPRINTF="" > CONFIG_CC_OPT_WNO_DEFAULT_CONST_INIT_UNSAFE="" > CONFIG_CC_OPT_WNO_DANGLING_POINTER="-Wno-dangling-pointer" > CONFIG_CC_OPT_WVLA_LARGER_THAN="-Wvla-larger-than=1" > CONFIG_CC_HAS_WSTRINGOP_OVERFLOW=y > > but that would make things unneccessary more complicated, right now. Yeah, it may be worth documenting somewhere that "CONFIG_CC_OPT_..." will have empty strings, and if someone wants to test _availability_ of a feature, they need to still create and use CONFIG_CC_HAS_... ? -- Kees Cook