From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 09508383; Wed, 6 Nov 2024 23:42:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730936526; cv=none; b=qKToZjfEAlpkQ1ovQjBOxeh2zpcm0DlW6Y3KqwPCMYM8aNZoTjdeLpVNUGIi/3JSCHankiu20j4Nyf9+Pro3ZM5z94HNDPVl62agy216JDW0B73+KxCtLTwz9ExHxQWM0PXd68iMzX2s27JTHOkDdzsHxSSi8berExnverkRHIc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730936526; c=relaxed/simple; bh=kwrvRtpnL9wQxwLPaB3tUfEYfC0qsi4v9251ehrqVeQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PD4xv17BXDghJNDpHEr8L5ZO64hlZ0NhL99jb9lB5mJL3rPcbCHI9behQkA06L2Lui110aue4O7BpGu+/lMKdFSzSgT+VFINgdYKd4FHU0Rs41LnCqMRQyvQwmX5hq+vJQfbQMJVjKO+YwFAlfoxNYTUdEm8ensbd7OLzwtNck4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XNcDhYDU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XNcDhYDU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B36CC4CEC6; Wed, 6 Nov 2024 23:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730936525; bh=kwrvRtpnL9wQxwLPaB3tUfEYfC0qsi4v9251ehrqVeQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XNcDhYDUdSPyfOdgNO8jvSiKfDe8h+ARB1B6QxdNU03dkrPGlTLnzCvdRheiGYXx1 B0fy/y+1nCzSja3bozoUAkxbMghhz24mKLBCO4D+eUvdFDm7T9bDj+0ttPwPCxyXbe XI75HpGg+mXySsz+X8F+xGdbTewJAyk8FcjC3aEeB/cv2I1xb1XZaiA53EWRr/Et9H 1UA2V4JDnDklDyVod1sHvdZnBvd+Z3qRDqKsyhqblgtYa7iBUPbr4uz8fFxZi5m3gX yKEr18QDqBxO3Kj4sWi0BdvCsFTzEmoCDVWPgn9ptfS0Mchoikhs3uTgGYj0RsbjPQ DAXgeyF+NcTpA== Date: Wed, 6 Nov 2024 15:42:03 -0800 From: Luis Chamberlain To: Peter Zijlstra Cc: x86@kernel.org, hpa@zytor.com, petr.pavlu@suse.com, samitolvanen@google.com, da.gomez@samsung.com, masahiroy@kernel.org, nathan@kernel.org, nicolas@fjasle.eu, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, hch@infradead.org, gregkh@linuxfoundation.org Subject: Re: [RFC] module: Strict per-modname namespaces Message-ID: References: <20241106190240.GR10375@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-modules@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: <20241106190240.GR10375@noisy.programming.kicks-ass.net> On Wed, Nov 06, 2024 at 08:02:40PM +0100, Peter Zijlstra wrote: > Hi, > > I've been wanting $topic for a while, and having just stumbled into the > whole namespace thing by accident, I figured I'd give it a go, most if > the hard parts seem to have already been done. Neat, hch suggested something similar a while back https://lore.kernel.org/all/ZCIiBHyrzDoTJPXT@bombadil.infradead.org/ > It reserves and disallows imports on any "MODULE_${name}" namespace, > while it implicitly adds the same namespace to every module. That's simple enough, I like it. > This allows exports targeted at specific modules and no others -- one > random example included. I've hated the various kvm exports we've had > for a while, and strictly limiting them to the kvm module helps > alleviate some abuse potential. Yeah we also want: EXPORT_SYMBOL_NS_GPL(bdev_disk_changed, MODULE_loop); EXPORT_SYMBOL_NS_GPL(bdev_disk_changed, MODULE_dasd_kmod); But we might as well have EXPORT_SYMBOL_GPL_FOR() with the implied module list. We could then add just: EXPORT_SYMBOL_GPL_FOR(bdev_disk_changed, loop); But it would be nice to just also support this as well: EXPORT_SYMBOL_GPL_FOR(bdev_disk_changed, loop, dasd_kmod); That's possible perhaps something grotesque like this: #define _EXPORT_SYMBOL_GPL_FOR_EACH(name, module) EXPORT_SYMBOL_NS_GPL(name, MODULE_##module); #define _GET_MACRO(_1, _2, _3, _4, _5, NAME, ...) NAME #define _EXPORT_SYMBOL_GPL_FOR1(name, a) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, a) #define _EXPORT_SYMBOL_GPL_FOR2(name, a, b) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, a) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, b) #define _EXPORT_SYMBOL_GPL_FOR3(name, a, b, c) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, a) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, b) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, c) #define _EXPORT_SYMBOL_GPL_FOR4(name, a, b, c, d) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, a) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, b) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, c) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, d) #define _EXPORT_SYMBOL_GPL_FOR5(name, a, b, c, d, e) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, a) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, b) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, c) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, d) \ _EXPORT_SYMBOL_GPL_FOR_EACH(name, e) #define EXPORT_SYMBOL_GPL_FOR(name, ...) \ _GET_MACRO(__VA_ARGS__, \ _EXPORT_SYMBOL_GPL_FOR5, \ _EXPORT_SYMBOL_GPL_FOR4, \ _EXPORT_SYMBOL_GPL_FOR3, \ _EXPORT_SYMBOL_GPL_FOR2, \ _EXPORT_SYMBOL_GPL_FOR1)(name, __VA_ARGS__) Luis