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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 7BDF4C33CB7 for ; Wed, 29 Jan 2020 17:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 528ED2071E for ; Wed, 29 Jan 2020 17:09:47 +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="NhFKnxuo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727270AbgA2RJq (ORCPT ); Wed, 29 Jan 2020 12:09:46 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:49012 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727192AbgA2RJp (ORCPT ); Wed, 29 Jan 2020 12:09:45 -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=JBGzCaUSC9Lw4zwXSBacb958kBHmLwh4j+E2NT3N+w8=; b=NhFKnxuoL1ybWnVtBKPDIWMBP kobcIUhcIWOiLiG3PhNd1ELyerpA31rPbS6Kk+/rNcGNtdvIwl3PWmij/a9xM6voX6vcQ34B/13tb 4sU+kkNa7lo/b+1DVlDczi63ra5N/m9v+y0mgHUBdkQYpbYHvL4MFcrF2hKLGtE/SDpRurYO/ZJMU 3fNEzYX6iMsOEDNCuxNq+MS6nvqCnrBj9PFGyavXJ3LfiH3BOipeubAWMl/VM2NN+GdAtadT2jDC1 ZhsY2KS8Q6r+OuKBSd1ZSOIe6r+EBoMmmCU1+Zeo7KcL47ocsUHq4SR16gYSJMGUFtfahEHuJSMCK tP90C6XjA==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iwqqR-00019P-Ug; Wed, 29 Jan 2020 17:09:39 +0000 Date: Wed, 29 Jan 2020 09:09:39 -0800 From: Christoph Hellwig To: Christian Borntraeger Cc: Christopher Lameter , Kees Cook , Jiri Slaby , Julian Wiedmann , Ursula Braun , Alexander Viro , linux-kernel@vger.kernel.org, David Windsor , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, linux-xfs@vger.kernel.org, Linus Torvalds , Andy Lutomirski , Christoph Hellwig , "David S. Miller" , Laura Abbott , Mark Rutland , "Martin K. Petersen" , Paolo Bonzini , Christoffer Dall , Dave Kleikamp , Jan Kara , Luis de Bethencourt , Marc Zyngier , Rik van Riel , Matthew Garrett , linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, kernel-hardening@lists.openwall.com, Vlastimil Babka , Michal Kubecek Subject: Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches Message-ID: <20200129170939.GA4277@infradead.org> References: <1515636190-24061-10-git-send-email-keescook@chromium.org> <9519edb7-456a-a2fa-659e-3e5a1ff89466@suse.cz> <201911121313.1097D6EE@keescook> <201911141327.4DE6510@keescook> <202001271519.AA6ADEACF0@keescook> <5861936c-1fe1-4c44-d012-26efa0c8b6e7@de.ibm.com> <202001281457.FA11CC313A@keescook> <6844ea47-8e0e-4fb7-d86f-68046995a749@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6844ea47-8e0e-4fb7-d86f-68046995a749@de.ibm.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jan 29, 2020 at 06:07:14PM +0100, Christian Borntraeger wrote: > > DMA can be done to NORMAL memory as well. > > Exactly. > I think iucv uses GFP_DMA because z/VM needs those buffers to reside below 2GB (which is ZONA_DMA for s390). The normal way to allocate memory with addressing limits would be to use dma_alloc_coherent and friends. Any chance to switch iucv over to that? Or is there no device associated with it?