From patchwork Mon Nov 11 20:38:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 11237693 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 89863159A for ; Mon, 11 Nov 2019 20:38:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 639E12184C for ; Mon, 11 Nov 2019 20:38:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727543AbfKKUir (ORCPT ); Mon, 11 Nov 2019 15:38:47 -0500 Received: from mout.kundenserver.de ([212.227.126.133]:50135 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727170AbfKKUiq (ORCPT ); Mon, 11 Nov 2019 15:38:46 -0500 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue012 [212.227.15.129]) with ESMTPA (Nemesis) id 1MlL5x-1i2OQc4Am5-00lqC9; Mon, 11 Nov 2019 21:38:40 +0100 From: Arnd Bergmann To: Mauro Carvalho Chehab , linux-media@vger.kernel.org Cc: Hans Verkuil , linux-kernel@vger.kernel.org, y2038@lists.linaro.org, Arnd Bergmann Subject: [PATCH v4 4/8] media: v4l2-core: split out data copy from video_usercopy Date: Mon, 11 Nov 2019 21:38:31 +0100 Message-Id: <20191111203835.2260382-5-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20191111203835.2260382-1-arnd@arndb.de> References: <20191111203835.2260382-1-arnd@arndb.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:XYSYE4CP2TXV0A5SoFgD7xC90DDcVn86gtgneJ99KiQ7zVJ2UsL 5d1PhMLzTTi9pJ4MJwArMpXoh5E3LJe1xXvzLtuPEcbxxajp6CjgvYc6nR1geKrcyAVARiw eMfP9R9Jer1sIbQQQ0qZDue60m5rAaQQo9/V+TtRE6czNZPGAfKtv/1qxGxliCkYmywgOMj NlkiM7jdlkkrluJoFjPSw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:WbYCTQEH2I8=:XkR8BsI9YP60yyNEnM2ClU nK+0BFpzUx0clF0GWFYdPaByYz+bzyfp5aXOtWq83abKAdHNBj7y5NueZNSAnGFMNz9pG1P2l TSgX7XWTSoDVMQ5GWHIlr3ZP2hRLB0xJsdwgnWUALTUxUBwVEj1Hk9p26evebkNYJaiqShyH9 VcrNd+0UnEv2Yw4FZ8+znwkkbVbIIbPxQuZBXoEr4/lNET72lj9x3akCG3/p4SDYJiq63NGC6 fGZ3BuLp7v64IwDBntNUsOs/h7ymFG7CTAeGqbZw+NakzX8Tum5qcB27j9d14K7MyJ0DssPJ/ qx+csRUtyK/Lva9PRxXbzO9CGkp/FKfD4taU+PltZNAI4keRnyY3OQ5+KUs324xx/7iYbZ5ki LokA4uZdYqqOg7lhCIZEaJZFBTW76D4EHS+wlqkcRp31FX9Y6NupaSEbmaHnmH7zFWrKLzifO d9aUJc+FhKMLv+iJx77esxSN+32ss+e+fs4t4TgY+8yoGg2jcKpG7La45GdROjQDtOeDC67Cj SPV0oML6LPPRR5uD54hWnQ23JWDa18JV0sGBL59opmnmf+Tn3qkqbeMXUJGulv2bUaXqHkVo+ LxZzVjYgBkYHVtC1DVXy++1r2KD6QAcOS4qv7w8G4uaRnEmN2soLHI9bqLJADWcxskq8uG79N H/U8BI6WwaUE32HZ9YLo6cRbvBfk3Xzpn9o4BO2N+8PRoFZuE5hn5ypz8/zRoJbbRIbwrKwKU 6mXd1WcCj5urjX1kmmORaCXk9/ux5w6X3TT7+VXkIpwlSBs5HLXpo8TjMAFoBZM0a5tjSZBGg 5c31W7QK5Ik6PlUScx1rDk1nhYQSbJY51HfXkr0KAEiZ12dWSWJMZUmocQ9sT6ctAJ62p5Dd/ 5EbDFinEmK2zRUqo20Ig== 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 51b912743f0f..693f9eb8e01b 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3008,8 +3008,69 @@ 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]; @@ -3021,6 +3082,7 @@ 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 */ @@ -3035,37 +3097,12 @@ 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; @@ -3116,15 +3153,7 @@ 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;