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=-2.2 required=3.0 tests=BAYES_00,DATE_IN_PAST_06_12, 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 A86F2C433E0 for ; Wed, 17 Feb 2021 01:43:02 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1E71E64DFF for ; Wed, 17 Feb 2021 01:43:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E71E64DFF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id E20CC100F2240; Tue, 16 Feb 2021 17:43:01 -0800 (PST) Received-SPF: None (mailfrom) identity=mailfrom; client-ip=2607:5300:60:148a::1; helo=zeniv-ca.linux.org.uk; envelope-from=viro@ftp.linux.org.uk; receiver= Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id AFA5A100EC1D7 for ; Tue, 16 Feb 2021 17:42:59 -0800 (PST) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94 #2 (Red Hat Linux)) id 1lC4pR-00Egds-Ey; Tue, 16 Feb 2021 18:12:05 +0000 Date: Tue, 16 Feb 2021 18:12:05 +0000 From: Al Viro To: Ben Widawsky Subject: Re: [PATCH v4 4/9] cxl/mem: Add basic IOCTL interface Message-ID: References: <20210216014538.268106-1-ben.widawsky@intel.com> <20210216014538.268106-5-ben.widawsky@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210216014538.268106-5-ben.widawsky@intel.com> Sender: Al Viro Message-ID-Hash: QAIFY4OW3QRWT53U7EXQ4C76V2N6XD3I X-Message-ID-Hash: QAIFY4OW3QRWT53U7EXQ4C76V2N6XD3I X-MailFrom: viro@ftp.linux.org.uk X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, Bjorn Helgaas , Chris Browy , Christoph Hellwig , David Hildenbrand , David Rientjes , Jon Masters , Jonathan Cameron , Rafael Wysocki , Randy Dunlap , "John Groves (jgroves)" , "Kelley, Sean V" , kernel test robot X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, Feb 15, 2021 at 05:45:33PM -0800, Ben Widawsky wrote: > + if (cmd->info.size_in) { > + mbox_cmd.payload_in = kvzalloc(cmd->info.size_in, GFP_KERNEL); > + if (!mbox_cmd.payload_in) { > + rc = -ENOMEM; > + goto out; > + } > + > + if (copy_from_user(mbox_cmd.payload_in, > + u64_to_user_ptr(in_payload), > + cmd->info.size_in)) { > + rc = -EFAULT; > + goto out; > + } Umm... Do you need to open-code vmemdup_user()? The only difference is GFP_KERNEL allocation instead of GFP_USER one, and the latter is arguably saner here... Zeroing is definitely pointless - you either overwrite the entire buffer with copy_from_user(), or you fail and free the damn thing. _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org 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=-3.8 required=3.0 tests=BAYES_00, 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 41F42C433E0 for ; Tue, 16 Feb 2021 18:12:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18139614A7 for ; Tue, 16 Feb 2021 18:12:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229780AbhBPSM5 (ORCPT ); Tue, 16 Feb 2021 13:12:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbhBPSM4 (ORCPT ); Tue, 16 Feb 2021 13:12:56 -0500 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54D58C061574; Tue, 16 Feb 2021 10:12:16 -0800 (PST) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94 #2 (Red Hat Linux)) id 1lC4pR-00Egds-Ey; Tue, 16 Feb 2021 18:12:05 +0000 Date: Tue, 16 Feb 2021 18:12:05 +0000 From: Al Viro To: Ben Widawsky Cc: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, Bjorn Helgaas , Chris Browy , Christoph Hellwig , Dan Williams , David Hildenbrand , David Rientjes , Ira Weiny , Jon Masters , Jonathan Cameron , Rafael Wysocki , Randy Dunlap , Vishal Verma , "John Groves (jgroves)" , "Kelley, Sean V" , kernel test robot Subject: Re: [PATCH v4 4/9] cxl/mem: Add basic IOCTL interface Message-ID: References: <20210216014538.268106-1-ben.widawsky@intel.com> <20210216014538.268106-5-ben.widawsky@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210216014538.268106-5-ben.widawsky@intel.com> Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Feb 15, 2021 at 05:45:33PM -0800, Ben Widawsky wrote: > + if (cmd->info.size_in) { > + mbox_cmd.payload_in = kvzalloc(cmd->info.size_in, GFP_KERNEL); > + if (!mbox_cmd.payload_in) { > + rc = -ENOMEM; > + goto out; > + } > + > + if (copy_from_user(mbox_cmd.payload_in, > + u64_to_user_ptr(in_payload), > + cmd->info.size_in)) { > + rc = -EFAULT; > + goto out; > + } Umm... Do you need to open-code vmemdup_user()? The only difference is GFP_KERNEL allocation instead of GFP_USER one, and the latter is arguably saner here... Zeroing is definitely pointless - you either overwrite the entire buffer with copy_from_user(), or you fail and free the damn thing.