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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C9FB8C38A02 for ; Sun, 30 Oct 2022 08:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9GoifmaPbMlP/ysEVZeaFrCafk0+R6MPAiGoALFIevY=; b=1hM9h6SH39eZNM miZu2Jp1DrcxDDOjvmfwWblGGWeZNSfUPEesY4WoAuX9U5EUc8Hh39FKyl6TpogcQb1+ezvFUVhVG 4HJ7RMJt3O4ED0XcUQrfggxpPhG8D77lRaD9ovPAnk0RDfY1QrnYAB8VhzKlKxgC7KCyD0thBW/Bf YeiuNv/9woQJEWxiei2yWdH+7NMFLJ8FIwI5VsOLZ9Rx3zOxTH+KWctXvuSVJ5Sn37pfK+1caNtmJ DIIACMfyqv4TXh9lM9foPSAohpoPxIqzckGzyQPEYOF2vAUmeW+84L45ToyxVD952kekaC4aoiyz6 6Lm8zgQT6r6AEnyqOrjA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1op3yX-00EMzM-Sp; Sun, 30 Oct 2022 08:47:25 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1op3yT-00EMuK-KH for linux-arm-kernel@lists.infradead.org; Sun, 30 Oct 2022 08:47:23 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id DB72168AA6; Sun, 30 Oct 2022 09:47:18 +0100 (CET) Date: Sun, 30 Oct 2022 09:47:18 +0100 From: Christoph Hellwig To: Greg Kroah-Hartman Cc: Catalin Marinas , Linus Torvalds , Arnd Bergmann , Will Deacon , Marc Zyngier , Andrew Morton , Herbert Xu , Ard Biesheuvel , Christoph Hellwig , 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: <20221030084718.GC5278@lst.de> References: <20221025205247.3264568-1-catalin.marinas@arm.com> <20221025205247.3264568-3-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221030_014721_955727_FF46CDC6 X-CRM114-Status: GOOD ( 13.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 DD78FC38A02 for ; Sun, 30 Oct 2022 08:47:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7C5406B0078; Sun, 30 Oct 2022 04:47:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 774006B007B; Sun, 30 Oct 2022 04:47:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 663DB6B007D; Sun, 30 Oct 2022 04:47:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 538BB6B0078 for ; Sun, 30 Oct 2022 04:47:22 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 3550A1205E5 for ; Sun, 30 Oct 2022 08:47:22 +0000 (UTC) X-FDA: 80076986724.29.5137B59 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf20.hostedemail.com (Postfix) with ESMTP id AF3121C0011 for ; Sun, 30 Oct 2022 08:47:21 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id DB72168AA6; Sun, 30 Oct 2022 09:47:18 +0100 (CET) Date: Sun, 30 Oct 2022 09:47:18 +0100 From: Christoph Hellwig To: Greg Kroah-Hartman Cc: Catalin Marinas , Linus Torvalds , Arnd Bergmann , Will Deacon , Marc Zyngier , Andrew Morton , Herbert Xu , Ard Biesheuvel , Christoph Hellwig , 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: <20221030084718.GC5278@lst.de> References: <20221025205247.3264568-1-catalin.marinas@arm.com> <20221025205247.3264568-3-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=none; spf=none (imf20.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667119641; a=rsa-sha256; cv=none; b=KFOLwyMXdrl7b4I/71pHIHSm3+5H0ds9m90d1tKHc6JxQXelLmuujW8cYJgxvxYUECZ+mG kRCT4cdpAum/SYn5sjuHz6wIQF2sOqI892qlfq8GZbZJt02kZn88oWyVh+EveRK0U4HcUZ yWGqKCB6rs7obDHfmVKTEUgAwd6oavE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667119641; 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; bh=/d7i8q837qr59ysxtLsGR6L58G26LBMAACgvGiul+jY=; b=a3X79/Q2XGutElDLc2dVfX2jhdvCJTAAkW4i5TCDiYY/PO9ptsFPMntMubtZwES46Hzk80 zyALvRWdBKh9xKDbeZwcEC5a5q/qt2xM0ht5FgRmCVFW+K+3A6jri2kZd7KSxcwKtVoZGW KvvVd6XSA9ZjNmG+fRNM8wB6Z2Cm/KI= X-Rspam-User: Authentication-Results: imf20.hostedemail.com; dkim=none; spf=none (imf20.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none X-Rspamd-Server: rspam07 X-Stat-Signature: x6x9c3ki9eh586qbixkfb8p9g1xrqrfe X-Rspamd-Queue-Id: AF3121C0011 X-HE-Tag: 1667119641-40637 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 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.