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=-13.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 387A8C433E6 for ; Tue, 1 Sep 2020 21:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E24592078B for ; Tue, 1 Sep 2020 21:30:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="fliXsxSN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728789AbgIAVaW (ORCPT ); Tue, 1 Sep 2020 17:30:22 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:7168 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726521AbgIAVaT (ORCPT ); Tue, 1 Sep 2020 17:30:19 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 01 Sep 2020 14:28:12 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 01 Sep 2020 14:30:19 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 01 Sep 2020 14:30:19 -0700 Received: from [10.2.63.6] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 1 Sep 2020 21:30:18 +0000 Subject: Re: [linux-next PATCH v4] drivers/virt/fsl_hypervisor: Fix error handling path To: Souptick Joarder , CC: , , , , , References: <1598995271-6755-1-git-send-email-jrdr.linux@gmail.com> From: John Hubbard Message-ID: Date: Tue, 1 Sep 2020 14:30:18 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1598995271-6755-1-git-send-email-jrdr.linux@gmail.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1598995692; bh=bJ0AvRFOeKaBU0OzseOoDtmXAo41HBvW7nwl0IHgiTM=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=fliXsxSNeIMqSZY5YVw5jSsPl3+0/o5IRA+9EANbQp/zIWqN7jXavd/VGcgfvvkxY 96SNMi66eENkdctZA7PsGz9omeatFHMhYWr75tqs10szH1gVscU+98pz7KU2gyHubo +GURvE4r+FL3gzEJ8/Qk8smFSd8Jg93BHC5NkcyD00g4+EeskX++jCc/pHNu/LxKR0 u1rdcpHsqZEL8/yW/c0or76mxgBQqYYL4KhiU7F/3eIpSQsh4bc2f91YFuiCQHyREn bamDRByrNDWAnfF+tqYb43UVsy76hNCcqZalzNXlyVeiAjRu5rfovf2WywQnTegb3d 4XHqWpjhWzXhA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/1/20 2:21 PM, Souptick Joarder wrote: > First, when memory allocation for sg_list_unaligned failed, there > is a bug of calling put_pages() as we haven't pinned any pages. > > Second, if get_user_pages_fast() failed we should unpin num_pinned > pages. > > This will address both. > > As part of these changes, minor update in documentation. > > Fixes: 6db7199407ca ("drivers/virt: introduce Freescale hypervisor > management driver") > Signed-off-by: Souptick Joarder > Reviewed-by: Dan Carpenter > Reviewed-by: John Hubbard > --- This looks good to me. thanks, -- John Hubbard NVIDIA > v2: > Added review tag. > > v3: > Address review comment on v2 from John. > Added review tag. > > v4: > Address another set of review comments from John. > > drivers/virt/fsl_hypervisor.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c > index 1b0b11b..46ee0a0 100644 > --- a/drivers/virt/fsl_hypervisor.c > +++ b/drivers/virt/fsl_hypervisor.c > @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > > unsigned int i; > long ret = 0; > - int num_pinned; /* return value from get_user_pages() */ > + int num_pinned = 0; /* return value from get_user_pages_fast() */ > phys_addr_t remote_paddr; /* The next address in the remote buffer */ > uint32_t count; /* The number of bytes left to copy */ > > @@ -174,7 +174,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > return -EINVAL; > > /* > - * The array of pages returned by get_user_pages() covers only > + * The array of pages returned by get_user_pages_fast() covers only > * page-aligned memory. Since the user buffer is probably not > * page-aligned, we need to handle the discrepancy. > * > @@ -224,7 +224,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > > /* > * 'pages' is an array of struct page pointers that's initialized by > - * get_user_pages(). > + * get_user_pages_fast(). > */ > pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); > if (!pages) { > @@ -241,7 +241,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > if (!sg_list_unaligned) { > pr_debug("fsl-hv: could not allocate S/G list\n"); > ret = -ENOMEM; > - goto exit; > + goto free_pages; > } > sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list)); > > @@ -250,7 +250,6 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > num_pages, param.source != -1 ? FOLL_WRITE : 0, pages); > > if (num_pinned != num_pages) { > - /* get_user_pages() failed */ > pr_debug("fsl-hv: could not lock source buffer\n"); > ret = (num_pinned < 0) ? num_pinned : -EFAULT; > goto exit; > @@ -292,13 +291,13 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > virt_to_phys(sg_list), num_pages); > > exit: > - if (pages) { > - for (i = 0; i < num_pages; i++) > - if (pages[i]) > - put_page(pages[i]); > + if (pages && (num_pinned > 0)) { > + for (i = 0; i < num_pinned; i++) > + put_page(pages[i]); > } > > kfree(sg_list_unaligned); > +free_pages: > kfree(pages); > > if (!ret) >