From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35568 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726587AbeIKL5R (ORCPT ); Tue, 11 Sep 2018 07:57:17 -0400 From: Gerd Hoffmann To: dri-devel@lists.freedesktop.org Cc: laurent.pinchart@ideasonboard.com, 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 07/10] udmabuf: rework limits Date: Tue, 11 Sep 2018 08:59:18 +0200 Message-Id: <20180911065921.23818-8-kraxel@redhat.com> In-Reply-To: <20180911065921.23818-1-kraxel@redhat.com> References: <20180911065921.23818-1-kraxel@redhat.com> Sender: linux-media-owner@vger.kernel.org List-ID: 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 --- 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 0cf7e85585..cb99a7886a 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -12,6 +12,9 @@ #include #include +static int list_limit = 1024; /* udmabuf_create_list->count limit */ +static int 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(struct const 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(struct const 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