From patchwork Wed Jan 13 22:44:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 363273 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 59BC1C433E9 for ; Thu, 14 Jan 2021 01:51:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DF202074A for ; Thu, 14 Jan 2021 01:51:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729801AbhANAQy (ORCPT ); Wed, 13 Jan 2021 19:16:54 -0500 Received: from smtp.infotech.no ([82.134.31.41]:50172 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729830AbhANAQC (ORCPT ); Wed, 13 Jan 2021 19:16:02 -0500 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 86AFD2042A6; Wed, 13 Jan 2021 23:45:52 +0100 (CET) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rIjLkn9cZNgt; Wed, 13 Jan 2021 23:45:51 +0100 (CET) Received: from xtwo70.bingwo.ca (host-104-157-204-209.dyn.295.ca [104.157.204.209]) by smtp.infotech.no (Postfix) with ESMTPA id 1C1AA20426D; Wed, 13 Jan 2021 23:45:49 +0100 (CET) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de, kashyap.desai@broadcom.com Subject: [PATCH v13 16/45] sg: rework sg_mmap Date: Wed, 13 Jan 2021 17:44:57 -0500 Message-Id: <20210113224526.861000-17-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210113224526.861000-1-dgilbert@interlog.com> References: <20210113224526.861000-1-dgilbert@interlog.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Simple rework of the sg_mmap() function. Reviewed-by: Hannes Reinecke Signed-off-by: Douglas Gilbert --- drivers/scsi/sg.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 4d4e1c7b771c..fb04dc611506 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1489,14 +1489,15 @@ static const struct vm_operations_struct sg_mmap_vm_ops = { .fault = sg_vma_fault, }; +/* Entry point for mmap(2) system call */ static int sg_mmap(struct file *filp, struct vm_area_struct *vma) { - struct sg_fd *sfp; - unsigned long req_sz, len, sa; - struct sg_scatter_hold *rsv_schp; int k, length; int ret = 0; + unsigned long req_sz, len, sa; + struct sg_scatter_hold *rsv_schp; + struct sg_fd *sfp; if (!filp || !vma) return -ENXIO; @@ -1509,19 +1510,23 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__, (void *)vma->vm_start, (int)req_sz); if (vma->vm_pgoff) - return -EINVAL; /* want no offset */ - rsv_schp = &sfp->reserve; + return -EINVAL; /* only an offset of 0 accepted */ + /* Check reserve request is inactive and has large enough buffer */ mutex_lock(&sfp->f_mutex); - if (req_sz > rsv_schp->buflen) { - ret = -ENOMEM; /* cannot map more than reserved buffer */ + if (sfp->res_in_use) { + ret = -EBUSY; + goto out; + } + rsv_schp = &sfp->reserve; + if (req_sz > (unsigned long)rsv_schp->buflen) { + ret = -ENOMEM; goto out; } - sa = vma->vm_start; length = 1 << (PAGE_SHIFT + rsv_schp->page_order); - for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) { + for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) { len = vma->vm_end - sa; - len = (len < length) ? len : length; + len = min_t(unsigned long, len, (unsigned long)length); sa += len; }