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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 42D8EC43441 for ; Wed, 14 Nov 2018 15:58:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 026DA208E7 for ; Wed, 14 Nov 2018 15:58:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RNn+k9Z/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 026DA208E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727789AbeKOCCb (ORCPT ); Wed, 14 Nov 2018 21:02:31 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:40596 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725759AbeKOCCa (ORCPT ); Wed, 14 Nov 2018 21:02:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9A2QLYSk0TOBFpQjDm7Wf35crbq10uZKh8udoFHNxH0=; b=RNn+k9Z/p0Y9aW/mdJTqkQE++ llcN25O/jQuCSFeQxXm6nt8aAxik2KwA9ifI+lGU4XaXzRtcBwG2HM43aH/D4IecGMrgG5ggieIRk KvdT95XyT0YXprm0I0fpP/7AV7u7YfKdZKqSMk3BNSsZ+Ya9FFiva36fSYUds1uhCUgK6YK8pqTrY UqHNOsHcq4mQWc2RT6o55bW6TfrrZuXmFcsuHfZj+M5bSEb2OvhEHlwW5daF/UdgavIEbjFW+3KI6 H69SpMDfPnmeGUPv/jKUn881Qx7dLuqL2Tj4mNK8k1ee0nbSgrJYEXgnfnG5z7zsRqwsIIKsPSA2T CCLqDQRqQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gMxYw-0004Rf-OG; Wed, 14 Nov 2018 15:58:42 +0000 Date: Wed, 14 Nov 2018 07:58:42 -0800 From: Christoph Hellwig To: Jens Axboe Cc: Christoph Hellwig , linux-block@vger.kernel.org Subject: Re: [PATCH 3/6] blk-mq: embed blk_mq_ops directly in the request queue Message-ID: <20181114155842.GA16940@infradead.org> References: <20181110151317.3813-1-axboe@kernel.dk> <20181110151317.3813-4-axboe@kernel.dk> <20181114152053.GA22186@infradead.org> <130070cd-e0d1-e75e-4341-7c1b26d1531e@kernel.dk> <20181114153948.GA22811@infradead.org> <1bec98d9-c0b1-c14a-8717-59af2e746895@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1bec98d9-c0b1-c14a-8717-59af2e746895@kernel.dk> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Nov 14, 2018 at 08:47:58AM -0700, Jens Axboe wrote: > Are we really worried about this as an attack surface? I get it > for other types of ops, but for mq_ops, I'd be more worried about > callers changing it inadvertently, and they still can't do that. It isn't quite as bad as for thing like file ops, but for modern atacks finding some piece that is easily patchable is what starts it all. So the less functions pointers we have that are ever runtime writable, the better. > It's not a huge deal to me, I can drop this one for now and > revisit at a later time. Yes, I'd be much happier if we dropped this for now.