From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 60A7E7DE7B for ; Tue, 11 Sep 2018 21:13:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727534AbeILCOm (ORCPT ); Tue, 11 Sep 2018 22:14:42 -0400 Received: from ou.quest-ce.net ([195.154.187.82]:43360 "EHLO ou.quest-ce.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726909AbeILCOm (ORCPT ); Tue, 11 Sep 2018 22:14:42 -0400 X-Greylist: delayed 1565 seconds by postgrey-1.27 at vger.kernel.org; Tue, 11 Sep 2018 22:14:40 EDT Received: from [2a01:e35:2e9f:6cb0:857c:11e6:3194:d53d] (helo=test.quest-ce.net) by ou.quest-ce.net with esmtpsa (TLS1.1:RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1fzpZ8-000FMY-9v; Tue, 11 Sep 2018 22:47:21 +0200 Message-ID: From: Yann Droneaud To: Gerd Hoffmann , dri-devel@lists.freedesktop.org Cc: "open list:KERNEL SELFTEST FRAMEWORK" , Tomeu Vizoso , Jonathan Corbet , David Airlie , "open list:DOCUMENTATION" , open list , "moderated list:DMA BUFFER SHARING FRAMEWORK" , "open list:DMA BUFFER SHARING FRAMEWORK" , Shuah Khan , Laurent Pinchart , linux-api@vger.kernel.org Date: Tue, 11 Sep 2018 22:47:17 +0200 In-Reply-To: <20180827093444.23623-1-kraxel@redhat.com> References: <20180827093444.23623-1-kraxel@redhat.com> Organization: OPTEYA Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2a01:e35:2e9f:6cb0:857c:11e6:3194:d53d X-SA-Exim-Mail-From: ydroneaud@opteya.com Subject: Re: [v7] Add udmabuf misc device X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ou.quest-ce.net) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi, Le lundi 27 août 2018 à 11:34 +0200, Gerd Hoffmann a écrit : > A driver to let userspace turn memfd regions into dma-bufs. > > Use case: Allows qemu create dmabufs for the vga framebuffer or > virtio-gpu ressources. Then they can be passed around to display > those guest things on the host. To spice client for classic full > framebuffer display, and hopefully some day to wayland server for > seamless guest window display. > > qemu test branch: > https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf > > Cc: David Airlie > Cc: Tomeu Vizoso > Cc: Laurent Pinchart > Cc: Daniel Vetter > Signed-off-by: Gerd Hoffmann > Acked-by: Daniel Vetter > --- > Documentation/ioctl/ioctl-number.txt | 1 + > include/uapi/linux/udmabuf.h | 33 +++ > drivers/dma-buf/udmabuf.c | 287 > ++++++++++++++++++++++ > tools/testing/selftests/drivers/dma-buf/udmabuf.c | 96 ++++++++ > MAINTAINERS | 16 ++ > drivers/dma-buf/Kconfig | 8 + > drivers/dma-buf/Makefile | 1 + > tools/testing/selftests/drivers/dma-buf/Makefile | 5 + > 8 files changed, 447 insertions(+) > create mode 100644 include/uapi/linux/udmabuf.h > create mode 100644 drivers/dma-buf/udmabuf.c > create mode 100644 tools/testing/selftests/drivers/dma-buf/udmabuf.c > create mode 100644 tools/testing/selftests/drivers/dma-buf/Makefile > > diff --git a/include/uapi/linux/udmabuf.h > b/include/uapi/linux/udmabuf.h > new file mode 100644 > index 0000000000..46b6532ed8 > --- /dev/null > +++ b/include/uapi/linux/udmabuf.h > @@ -0,0 +1,33 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +#ifndef _UAPI_LINUX_UDMABUF_H > +#define _UAPI_LINUX_UDMABUF_H > + > +#include > +#include > + > +#define UDMABUF_FLAGS_CLOEXEC 0x01 > + > +struct udmabuf_create { > + __u32 memfd; > + __u32 flags; > + __u64 offset; > + __u64 size; > +}; > + > +struct udmabuf_create_item { > + __u32 memfd; > + __u32 __pad; > + __u64 offset; > + __u64 size; > +}; > + > +struct udmabuf_create_list { > + __u32 flags; > + __u32 count; > + struct udmabuf_create_item list[]; > +}; > + > +#define UDMABUF_CREATE _IOW('u', 0x42, struct udmabuf_create) > +#define UDMABUF_CREATE_LIST _IOW('u', 0x43, struct > udmabuf_create_list) > + > +#endif /* _UAPI_LINUX_UDMABUF_H */ > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c > new file mode 100644 > index 0000000000..8e24204526 > --- /dev/null > +++ b/drivers/dma-buf/udmabuf.c > +static long udmabuf_create(struct udmabuf_create_list *head, > + struct udmabuf_create_item *list) > +{ > + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); > + struct file *memfd = NULL; > + struct udmabuf *ubuf; > + struct dma_buf *buf; > + pgoff_t pgoff, pgcnt, pgidx, pgbuf; > + struct page *page; > + int seals, ret = -EINVAL; > + u32 i, flags; > + > + ubuf = kzalloc(sizeof(struct udmabuf), GFP_KERNEL); > + if (!ubuf) > + return -ENOMEM; > + > + for (i = 0; i < head->count; i++) { You need to check .__pad for unsupported value: if (list[i].__pad) { ret = -EINVAL; goto err_free_ubuf; } > + 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; > + } > + ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page > *), > + GFP_KERNEL); > + if (!ubuf->pages) { > + ret = -ENOMEM; > + goto err_free_ubuf; > + } > + > + pgbuf = 0; > + for (i = 0; i < head->count; i++) { > + memfd = fget(list[i].memfd); > + if (!memfd) > + goto err_put_pages; > + if (!shmem_mapping(file_inode(memfd)->i_mapping)) > + goto err_put_pages; > + seals = memfd_fcntl(memfd, F_GET_SEALS, 0); > + if (seals == -EINVAL || > + (seals & SEALS_WANTED) != SEALS_WANTED || > + (seals & SEALS_DENIED) != 0) > + goto err_put_pages; > + pgoff = list[i].offset >> PAGE_SHIFT; > + pgcnt = list[i].size >> PAGE_SHIFT; > + for (pgidx = 0; pgidx < pgcnt; pgidx++) { > + page = shmem_read_mapping_page( > + file_inode(memfd)->i_mapping, pgoff + > pgidx); > + if (IS_ERR(page)) { > + ret = PTR_ERR(page); > + goto err_put_pages; > + } > + ubuf->pages[pgbuf++] = page; > + } > + fput(memfd); > + } > + memfd = NULL; > + > + exp_info.ops = &udmabuf_ops; > + exp_info.size = ubuf->pagecount << PAGE_SHIFT; > + exp_info.priv = ubuf; > + > + buf = dma_buf_export(&exp_info); > + if (IS_ERR(buf)) { > + ret = PTR_ERR(buf); > + goto err_put_pages; > + } > + > + flags = 0; You need to check .flags for unsupported value: if (head->flags & ~UDMABUF_FLAGS_CLOEXEC) return -EINVAL; (at the beginning of the function, of course). > + if (head->flags & UDMABUF_FLAGS_CLOEXEC) > + flags |= O_CLOEXEC; > + return dma_buf_fd(buf, flags); > + > +err_put_pages: > + while (pgbuf > 0) > + put_page(ubuf->pages[--pgbuf]); > +err_free_ubuf: > + fput(memfd); > + kfree(ubuf->pages); > + kfree(ubuf); > + return ret; > +} > + Regards -- Yann Droneaud OPTEYA