From patchwork Tue Nov 26 16:18:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 11262697 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 58AB914ED for ; Tue, 26 Nov 2019 16:18:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4410E20727 for ; Tue, 26 Nov 2019 16:18:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728744AbfKZQSn (ORCPT ); Tue, 26 Nov 2019 11:18:43 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:39427 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728250AbfKZQSk (ORCPT ); Tue, 26 Nov 2019 11:18:40 -0500 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue106 [212.227.15.145]) with ESMTPA (Nemesis) id 1MaIKJ-1iL14x2lz3-00WBEs; Tue, 26 Nov 2019 17:18:34 +0100 From: Arnd Bergmann To: linux-media@vger.kernel.org, Hans Verkuil , Mauro Carvalho Chehab Cc: y2038@lists.linaro.org, linux-kernel@vger.kernel.org, Arnd Bergmann Subject: [PATCH v5 4/8] media: v4l2-core: split out data copy from video_usercopy Date: Tue, 26 Nov 2019 17:18:20 +0100 Message-Id: <20191126161824.337724-5-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20191126161824.337724-1-arnd@arndb.de> References: <20191126161824.337724-1-arnd@arndb.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:r++WgAlr/NGAG5oOEEOa/W39DoBoyYcLns/mRUgxxpoktk06+ym 5xeohg1HW7rYPasW+z9VUJajRk+OLnFxeuCVTax2GwEsOcY4rGelk560Ro/n/jyS+lkXDPq Ilx8QVYx72Tz5qAK/RizIX+8hLDvqfNIZho0SByxH2KR02Wd7eeVxVOK9ZGMKK+gU/0GGhy GZkKeyy9I+NH8FS/hJe6w== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:wWBfceJaoWk=:WQemL2H/yF3X7qE+DDrrJj bCsQ//nqLfGQ6m/CYqhbqGF1XoM4xYMEteIjS/v4dfhx4V2I9Y5+C20EsKMr7qxMTKqauKO+/ O9SDc3AVJKKS0FlPrLptoObqW69ooCl6VCglGBHE3ZttrUJuN+TAf7buuwN/XJgr5Icvz3ekT s6EmEC6Y340iWOipAPTrlJgozryk0xpKDLF9k+wWaIbMP7YkNKq3oQ/t7ILft/aihtv98M3QP lRJZqq6ZLi3HgscdShxdvuBZxkGXOhsQWAghoJFlVvDNRYJevKQx4a75Cp/C3AN1O/zOleQVQ HgNuSxAMZY24BdFiGrvXBTIes7W8ZZLeDX65emvtm1B+5Pdj82g0RYYrNsJ5H/jeKNVOA5bBV xkVeazjhgBWzfHU78esr8+5OUEPyJt/Rh1tT5CR54AUpG9M3W9u92PLFcYl5dlLF3mCll9KXO OoFjfwfBKg4RWYM3qLe5RsMyt7akBVpETHcxE3Mj8b7f8IggrqaYfUgcWcQo7Q09EMtqIf0XL 7KTXeFcne9Vi2kah7VolsPnWWPHOs+ED+cIw/uFSyd944qn8qQ07RkavH9gsiFm25NNWG6hxC HnITohetp+AJuQ/2GCBLDfLH4ntTMbd2UBYK1dsd89gY7hSrzo0Ds9squxv4BLd80V8wROl4/ dc6NzuQdIbGKM8W9rarKd7Gx27zQpYNu+Zed5TWzcMobIzcs0GSwrBGXdTiJbYknv7gHefK7h rD9vncTnmPVucLn+Fwcv1L62Qvoqk6sBR+TuW/g+xoyrNTgFb9lc7r5Q3D1zOi8S7nspZJWXM U+HbZyIDAUdDU3IX1c7uwgtoE3ltsT9frlT254gsZE5rIHNUiIB7UuDdz9zZwByl2CbQ/0b3D +uaDnWrP756v6gNDPNAg== Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The copy-in/out portions of video_usercopy() are about to get more complex, so turn then into separate functions as a cleanup first. Signed-off-by: Arnd Bergmann --- drivers/media/v4l2-core/v4l2-ioctl.c | 107 +++++++++++++++++---------- 1 file changed, 68 insertions(+), 39 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 4e700583659b..2ce91f88369b 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3023,8 +3023,69 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, return ret; } +static unsigned int video_translate_cmd(unsigned int cmd) +{ + return cmd; +} + +static int video_get_user(void __user *arg, void *parg, unsigned int cmd, + bool *always_copy) +{ + unsigned int n = _IOC_SIZE(cmd); + + if (!(_IOC_DIR(cmd) & _IOC_WRITE)) { + /* read-only ioctl */ + memset(parg, 0, n); + return 0; + } + + switch (cmd) { + default: + /* + * In some cases, only a few fields are used as input, + * i.e. when the app sets "index" and then the driver + * fills in the rest of the structure for the thing + * with that index. We only need to copy up the first + * non-input field. + */ + if (v4l2_is_known_ioctl(cmd)) { + u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; + + if (flags & INFO_FL_CLEAR_MASK) + n = (flags & INFO_FL_CLEAR_MASK) >> 16; + *always_copy = flags & INFO_FL_ALWAYS_COPY; + } + + if (copy_from_user(parg, (void __user *)arg, n)) + return -EFAULT; + + /* zero out anything we don't copy from userspace */ + if (n < _IOC_SIZE(cmd)) + memset((u8 *)parg + n, 0, _IOC_SIZE(cmd) - n); + break; + } + + return 0; +} + +static int video_put_user(void __user *arg, void *parg, unsigned int cmd) +{ + if (!(_IOC_DIR(cmd) & _IOC_READ)) + return 0; + + switch (cmd) { + default: + /* Copy results into user buffer */ + if (copy_to_user(arg, parg, _IOC_SIZE(cmd))) + return -EFAULT; + break; + } + + return 0; +} + long -video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, +video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, v4l2_kioctl func) { char sbuf[128]; @@ -3036,6 +3097,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, size_t array_size = 0; void __user *user_ptr = NULL; void **kernel_ptr = NULL; + unsigned int cmd = video_translate_cmd(orig_cmd); const size_t ioc_size = _IOC_SIZE(cmd); /* Copy arguments into temp kernel buffer */ @@ -3050,37 +3112,12 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, parg = mbuf; } - err = -EFAULT; - if (_IOC_DIR(cmd) & _IOC_WRITE) { - unsigned int n = ioc_size; - - /* - * In some cases, only a few fields are used as input, - * i.e. when the app sets "index" and then the driver - * fills in the rest of the structure for the thing - * with that index. We only need to copy up the first - * non-input field. - */ - if (v4l2_is_known_ioctl(cmd)) { - u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; - - if (flags & INFO_FL_CLEAR_MASK) - n = (flags & INFO_FL_CLEAR_MASK) >> 16; - always_copy = flags & INFO_FL_ALWAYS_COPY; - } - - if (copy_from_user(parg, (void __user *)arg, n)) - goto out; - - /* zero out anything we don't copy from userspace */ - if (n < ioc_size) - memset((u8 *)parg + n, 0, ioc_size - n); - } else { - /* read-only ioctl */ - memset(parg, 0, ioc_size); - } } + err = video_get_user((void __user *)arg, parg, orig_cmd, &always_copy); + if (err) + goto out; + err = check_array_args(cmd, parg, &array_size, &user_ptr, &kernel_ptr); if (err < 0) goto out; @@ -3131,15 +3168,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, goto out; out_array_args: - /* Copy results into user buffer */ - switch (_IOC_DIR(cmd)) { - case _IOC_READ: - case (_IOC_WRITE | _IOC_READ): - if (copy_to_user((void __user *)arg, parg, ioc_size)) - err = -EFAULT; - break; - } - + err = video_put_user((void __user *)arg, parg, orig_cmd); out: kvfree(mbuf); return err;