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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 0E1A0C04ABB for ; Tue, 11 Sep 2018 13:43:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C55F220833 for ; Tue, 11 Sep 2018 13:43:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C55F220833 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728099AbeIKSmR (ORCPT ); Tue, 11 Sep 2018 14:42:17 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57474 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727782AbeIKSln (ORCPT ); Tue, 11 Sep 2018 14:41:43 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1EA697721D; Tue, 11 Sep 2018 13:42:20 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-66.ams2.redhat.com [10.36.116.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id C1940D1CEE; Tue, 11 Sep 2018 13:42:19 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id DFE479AF2; Tue, 11 Sep 2018 15:42:16 +0200 (CEST) From: Gerd Hoffmann To: dri-devel@lists.freedesktop.org Cc: laurent.pinchart@ideasonboard.com, daniel@ffwll.ch, Gerd Hoffmann , Sumit Semwal , linux-media@vger.kernel.org (open list:DMA BUFFER SHARING FRAMEWORK), linaro-mm-sig@lists.linaro.org (moderated list:DMA BUFFER SHARING FRAMEWORK), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 07/13] udmabuf: rework limits Date: Tue, 11 Sep 2018 15:42:10 +0200 Message-Id: <20180911134216.9760-8-kraxel@redhat.com> In-Reply-To: <20180911134216.9760-1-kraxel@redhat.com> References: <20180911134216.9760-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 11 Sep 2018 13:42:20 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 11 Sep 2018 13:42:20 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kraxel@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Create variable for the list length limit. Serves as documentation, also allows to make it a module parameter if needed. Also add a total size limit. Signed-off-by: Gerd Hoffmann Acked-by: Daniel Vetter --- drivers/dma-buf/udmabuf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 4167da8141..a01fcf6a66 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -12,6 +12,9 @@ #include #include +static const u32 list_limit = 1024; /* udmabuf_create_list->count limit */ +static const size_t size_limit_mb = 64; /* total dmabuf size, in megabytes */ + struct udmabuf { pgoff_t pagecount; struct page **pages; @@ -123,7 +126,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head, struct file *memfd = NULL; struct udmabuf *ubuf; struct dma_buf *buf; - pgoff_t pgoff, pgcnt, pgidx, pgbuf; + pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit; struct page *page; int seals, ret = -EINVAL; u32 i, flags; @@ -132,12 +135,15 @@ static long udmabuf_create(const struct udmabuf_create_list *head, if (!ubuf) return -ENOMEM; + pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT; for (i = 0; i < head->count; i++) { if (!IS_ALIGNED(list[i].offset, PAGE_SIZE)) goto err_free_ubuf; if (!IS_ALIGNED(list[i].size, PAGE_SIZE)) goto err_free_ubuf; ubuf->pagecount += list[i].size >> PAGE_SHIFT; + if (ubuf->pagecount > pglimit) + goto err_free_ubuf; } ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *), GFP_KERNEL); @@ -227,7 +233,7 @@ static long udmabuf_ioctl_create_list(struct file *filp, unsigned long arg) if (copy_from_user(&head, (void __user *)arg, sizeof(head))) return -EFAULT; - if (head.count > 1024) + if (head.count > list_limit) return -EINVAL; lsize = sizeof(struct udmabuf_create_item) * head.count; list = memdup_user((void __user *)(arg + sizeof(head)), lsize); -- 2.9.3