From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 A8F9F1D0BB0 for ; Wed, 2 Oct 2024 14:51:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880676; cv=none; b=RUSDvPn8SaRRq8e5r1BhWFkypy+PSTEa0qOqG8CJatzJcMCLOxNnF66CcTs/pLM+jRFcTxoqzDmqNLDo2vU5HborFZzFwNYAxhIBk8I0POcgFunRARH0wx5afx1eGoQebkrOq6NMnUStC34ZVfaOnzAxXLl+c9KpkhaARnkorb0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880676; c=relaxed/simple; bh=NlCN07NBCbK+Nekm7+SqexVSiuiW3p9UhLnBlxmV2UM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=MyqF0hVCB4rpHbFyjefyRslhCeEoMhb7sgl4cZCsXOwOwqrFpvo6dn6pK65CNoJBOj+fprn3qw+/oZNMCdRhWDr76bk53zFkVHu/zT7mfrfFqiH52Zk4HzxoRwW3ncq5rq9e1OcU619m95iReAgoXZz/w3LSLtusCvcB7BDVxoU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=giS3x0+g; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="giS3x0+g" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net E508F42BFD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1727880667; bh=dv2c4uQQw9Jrf51Rjg0ifhhbGMu1TSlUbiUdqfpC2fs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=giS3x0+glSIeNOmHDqOTGmly11dKSYlXwtd5JyZkl30AzBaBJprdU3b24Sp2xhPOI JzXIT567r82/mKqT0ape86ouB2j+h7cjLfc4ba051W5SzXrR1RlBWUyrPKYLTps4Kc BiH1fw8dv1ugcj5bQWR6t9170NxfWZuIVSmST09nvlIkR6drKi+F0KlUG+2FOxLVqQ M9d8CyfQbRxx3PmeaquFCU4dPm4y6iSgt+k0nxZlXJYtGibzVlGE9S0Rk+RnOkQU+Z GOw361Jb04LzF4M7gw1nr8D5GE0atesFyTRUMUJMBsbFgChGzGM+hjU1GsaFjKn07C mPzSRsKGTTrUw== Received: from localhost (mdns.lwn.net [45.79.72.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id E508F42BFD; Wed, 2 Oct 2024 14:51:06 +0000 (UTC) From: Jonathan Corbet To: Tetsuo Handa , Linus Torvalds Cc: LKML , Paul Moore Subject: Re: [GIT PULL] tomoyo update for v6.12 In-Reply-To: <7dce903c-2f76-43b2-bb6f-808cb50d0696@I-love.SAKURA.ne.jp> References: <0c4b443a-9c72-4800-97e8-a3816b6a9ae2@I-love.SAKURA.ne.jp> <877cavdgsu.fsf@trenco.lwn.net> <7dce903c-2f76-43b2-bb6f-808cb50d0696@I-love.SAKURA.ne.jp> Date: Wed, 02 Oct 2024 08:51:02 -0600 Message-ID: <87ikua4kyx.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Tetsuo Handa writes: >> Even stranger, to me at least, is the backdoor symbol-export mechanism. >> That seems like ... not the way we do things. Was the need for this so >> urgent that you couldn't try to get those symbols exported properly? > > Yes. This is a chicken-and-egg problem. Symbols not used by in-tree kernel > code cannot be justified for export, but I can't prove that loadable LSM > can work unless I export symbols. Honestly, this is the part that concerns me the most. The normal way to deal with this is to create a series with both the exports and the users so that they can be evaluated together. Instead you seem to have created just the sort of shim layer that we have not allowed in other settings, then pushed it upstream without review. What will you do if, for any reason, one or more of those symbols cannot be exported? Either you will circumvent that decision indefinitely with your "temporary hack", or you will remove the hack, regressing things for your users. Neither seems like a good outcome; that is why we normally want to actually review things like symbol exports before pushing them into the mainline. jon