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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4958AFA373D for ; Sun, 30 Oct 2022 09:02:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A9FC06B0080; Sun, 30 Oct 2022 05:02:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A4E9E6B0081; Sun, 30 Oct 2022 05:02:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 916F76B0082; Sun, 30 Oct 2022 05:02:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 7FE3A6B0080 for ; Sun, 30 Oct 2022 05:02:01 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 4FE7DA08F7 for ; Sun, 30 Oct 2022 09:02:01 +0000 (UTC) X-FDA: 80077023642.18.0F08442 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf21.hostedemail.com (Postfix) with ESMTP id C4E6E1C002E for ; Sun, 30 Oct 2022 09:02:00 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 511DD60E95; Sun, 30 Oct 2022 09:01:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30DA7C433C1; Sun, 30 Oct 2022 09:01:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667120517; bh=sas7Li8v8Fy8iS/StTY7RBsjDeKY9mn9FYsPpc0Ypyo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Xxud9PzOQ2g3QEKoQyGgd189RK9wsEM9nTW272qdtcSux+Hf4uwwYkRXXfWdYj0O5 Z1k4UWQKpVVkTL/2/B/s9eDUwziWDqa4uxIZsF5c5F3Zxh5p5HadVqgOSHXjhf4+L1 ENhUECTHvE+yTG4OVaRvbpnnRISMbVS0wMK0wJYk= Date: Sun, 30 Oct 2022 10:02:53 +0100 From: Greg Kroah-Hartman To: Christoph Hellwig Cc: Catalin Marinas , Linus Torvalds , Arnd Bergmann , Will Deacon , Marc Zyngier , Andrew Morton , Herbert Xu , Ard Biesheuvel , Isaac Manjarres , Saravana Kannan , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/2] treewide: Add the __GFP_PACKED flag to several non-DMA kmalloc() allocations Message-ID: References: <20221025205247.3264568-1-catalin.marinas@arm.com> <20221025205247.3264568-3-catalin.marinas@arm.com> <20221030084718.GC5278@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221030084718.GC5278@lst.de> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667120520; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0YPkpuBwtMRm+70Ok7vh5HZUkE0bjX1u1JLfjquBzIc=; b=Dk5zftz7DtDYrrhGsBJYy54Yxom2TUIYFldgJArjydYlCwcM7fW9c1OkCBzdsazVHdM/uz mItIPUldYTmv5pusMRZ2TNbOjf4ZyS91+S71xUgZs8vZiJ4oeeHmHQElze7MJwjaxWqzN0 ZsVvz+L+bsZjO3Lk+5NwraSrCsE7gEc= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=Xxud9PzO; spf=pass (imf21.hostedemail.com: domain of gregkh@linuxfoundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667120520; a=rsa-sha256; cv=none; b=fmFDuX4g/0kwCGzsUfrEaWNnu7aSi+454AlUl2j1dBCJCwj5jZ98LDhivjTh/yjYlZiVB3 U9gFiGq8/EhZc+G7b5iCxyShOI30msxE/oOgT4KQPT8GesDYO2Tbs+zisFw+sM/QFd8d2B xl6XBZStmKigE5hCea1KDg6ZkRFmuag= Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=Xxud9PzO; spf=pass (imf21.hostedemail.com: domain of gregkh@linuxfoundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org X-Rspam-User: X-Rspamd-Queue-Id: C4E6E1C002E X-Rspamd-Server: rspam03 X-Stat-Signature: 69rzxc4e8cznhrcw5njphri731uowotq X-HE-Tag: 1667120520-756481 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Oct 30, 2022 at 09:47:18AM +0100, Christoph Hellwig wrote: > On Fri, Oct 28, 2022 at 11:37:52AM +0200, Greg Kroah-Hartman wrote: > > And here's actually the patch... > > How is this supposed to work? noderef means any dereference of it will > now make sparse complain. And the whole point of the DMA is to get > data into and out of the system, so except for corner cases like direct > DMA to userspace (which won't use kmalloc) we absolutely do want to > derference it to generate or consume the information. Ah, my fault, sorry, you are right. Is there a sparse tag that just means "enforce this void * type?" I guess we could do that with something like: typedef void *dmaptr; but that feels icky.