From patchwork Mon Jun 17 11:16:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 10998787 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8E9EE76 for ; Mon, 17 Jun 2019 11:17:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7F5BE286D0 for ; Mon, 17 Jun 2019 11:17:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7409E28846; Mon, 17 Jun 2019 11:17:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D9A832882F for ; Mon, 17 Jun 2019 11:17:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728122AbfFQLRt (ORCPT ); Mon, 17 Jun 2019 07:17:49 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:44427 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727599AbfFQLRt (ORCPT ); Mon, 17 Jun 2019 07:17:49 -0400 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue108 [212.227.15.145]) with ESMTPA (Nemesis) id 1N79ly-1ihwra0FNk-017V4f; Mon, 17 Jun 2019 13:17:42 +0200 From: Arnd Bergmann To: Mauro Carvalho Chehab Cc: Arnd Bergmann , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] media: dvb_frontend: split dvb_frontend_handle_ioctl function Date: Mon, 17 Jun 2019 13:16:52 +0200 Message-Id: <20190617111718.2277220-2-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20190617111718.2277220-1-arnd@arndb.de> References: <20190617111718.2277220-1-arnd@arndb.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:upYYRH6KMdTm/jl5OCVbNn4KgWGMZDIcmATiaGhDYQZpRr1yWLe cExWHNCIc+WiciBqTGaHGtsNzeKYFnRGQXM1n+t2V0sPoi2cx0gHKHR+wIfGxSMQRP75+Cb DSwAzAAOZj+UrMZ9D+IPi2M8mNcxrFUNVRXO5yAxIA7DD8xrDSkA720vL3s+Ce0Z6JNakLn 7jOrSnR7fPf2xpYFH5F/w== X-UI-Out-Filterresults: notjunk:1;V03:K0:cvJgTMyJlFg=:j7TS26qQq+OSl8j4ep4vij YZ4DK4MHAAK1cmCwV/9myYnPQ957JMFhOldsDcAqRN9dwgCFF4UK4iDds3C3q9MJnBGnS2fCc zYOUyYn6wobLlF5KdDWx4Ych0pUDhbO+SStug1rpnSO8RDzD9hhjzQ0K7Wg/8jdfJ9XjSq9QO mPsh4urMy5GHU9r5YPsulwjhuIZEn0J/GdSppGdF54d6CN1Qh7NVA2U2l1xPGo4kZmoy1Ejgl j/Qm9yPAISmyYdChX3lxqZUJGKi0i0f3s49Jf5dB6sA16TfTHKEOSOt6UhvqqndJ310iFc7Yj on4+pDnWRsY0/8hx91VfxfXmSOku9+NUYgKuXHvqi2yPUWl7vDxcbHt8FDIT2hpTpqMQOZvyU qqXuaolr9yIYz3g51QThsqK8ojE0+9U8pgw0ldFQR7afbRgX3+MECT9+OAWeUYBQ0eDuKBZpx ajLnFg2dJHjgxV9p+ciLLh+peoz3+X82CV7PT4Ebw3/fqgZZZlna+ZZVhyw5vamDvQQe1Vxfd IIw2D96aICFN+pvpgwgwmh4zCdB0j+/OXdsDwFNn58GQL/ZdxwEsKsTFS/oDlztpV2jhVL+3a XE0svIiKHz8LS1uVOi3TXT/EX3p8qv1imrR4wJ9zrxsOlmjM/57d6gQxuN8ey4WUHEtrtrPil dPqnuxtpvRkjA0Ox008ChRu5TEPL/SUQOXDIyiF5KIKljfduUUf+A7a/YBU18S3NLvk1NpKFL rijPEPYMZWVvtBoIFCV+bSwUgyIAOisk/5E8pA== Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Over time, dvb_frontend_handle_ioctl() has grown to the point where we now get a warning from the compiler about excessive stack usage: drivers/media/dvb-core/dvb_frontend.c: In function 'dvb_frontend_handle_ioctl': drivers/media/dvb-core/dvb_frontend.c:2692:1: error: the frame size of 1048 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] Almost all of this is used by the dtv_frontend_properties structure in the FE_GET_PROPERTY and FE_GET_FRONTEND commands. Splitting those into separate function reduces the stack usage of the main function to just 136 bytes, the others are under 500 each. Signed-off-by: Arnd Bergmann --- drivers/media/dvb-core/dvb_frontend.c | 140 ++++++++++++++------------ 1 file changed, 77 insertions(+), 63 deletions(-) diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index 2dc7761a3680..202f0ba5819c 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -2314,6 +2314,78 @@ static int dtv_set_frontend(struct dvb_frontend *fe) return 0; } +static int dvb_get_property(struct dvb_frontend *fe, struct file *file, + struct dtv_properties *tvps) +{ + struct dvb_frontend_private *fepriv = fe->frontend_priv; + struct dtv_property *tvp = NULL; + struct dtv_frontend_properties getp; + int i, err; + + memcpy(&getp, &fe->dtv_property_cache, sizeof(getp)); + + dev_dbg(fe->dvb->device, "%s: properties.num = %d\n", + __func__, tvps->num); + dev_dbg(fe->dvb->device, "%s: properties.props = %p\n", + __func__, tvps->props); + + /* + * Put an arbitrary limit on the number of messages that can + * be sent at once + */ + if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS)) + return -EINVAL; + + tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp)); + if (IS_ERR(tvp)) + return PTR_ERR(tvp); + + /* + * Let's use our own copy of property cache, in order to + * avoid mangling with DTV zigzag logic, as drivers might + * return crap, if they don't check if the data is available + * before updating the properties cache. + */ + if (fepriv->state != FESTATE_IDLE) { + err = dtv_get_frontend(fe, &getp, NULL); + if (err < 0) + goto out; + } + for (i = 0; i < tvps->num; i++) { + err = dtv_property_process_get(fe, &getp, + tvp + i, file); + if (err < 0) + goto out; + } + + if (copy_to_user((void __user *)tvps->props, tvp, + tvps->num * sizeof(struct dtv_property))) { + err = -EFAULT; + goto out; + } + + err = 0; +out: + kfree(tvp); + return err; +} + +static int dvb_get_frontend(struct dvb_frontend *fe, + struct dvb_frontend_parameters *p_out) +{ + struct dtv_frontend_properties getp; + + /* + * Let's use our own copy of property cache, in order to + * avoid mangling with DTV zigzag logic, as drivers might + * return crap, if they don't check if the data is available + * before updating the properties cache. + */ + memcpy(&getp, &fe->dtv_property_cache, sizeof(getp)); + + return dtv_get_frontend(fe, &getp, p_out); +} + static int dvb_frontend_handle_ioctl(struct file *file, unsigned int cmd, void *parg) { @@ -2359,58 +2431,9 @@ static int dvb_frontend_handle_ioctl(struct file *file, err = 0; break; } - case FE_GET_PROPERTY: { - struct dtv_properties *tvps = parg; - struct dtv_property *tvp = NULL; - struct dtv_frontend_properties getp = fe->dtv_property_cache; - - dev_dbg(fe->dvb->device, "%s: properties.num = %d\n", - __func__, tvps->num); - dev_dbg(fe->dvb->device, "%s: properties.props = %p\n", - __func__, tvps->props); - - /* - * Put an arbitrary limit on the number of messages that can - * be sent at once - */ - if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS)) - return -EINVAL; - - tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp)); - if (IS_ERR(tvp)) - return PTR_ERR(tvp); - - /* - * Let's use our own copy of property cache, in order to - * avoid mangling with DTV zigzag logic, as drivers might - * return crap, if they don't check if the data is available - * before updating the properties cache. - */ - if (fepriv->state != FESTATE_IDLE) { - err = dtv_get_frontend(fe, &getp, NULL); - if (err < 0) { - kfree(tvp); - return err; - } - } - for (i = 0; i < tvps->num; i++) { - err = dtv_property_process_get(fe, &getp, - tvp + i, file); - if (err < 0) { - kfree(tvp); - return err; - } - } - - if (copy_to_user((void __user *)tvps->props, tvp, - tvps->num * sizeof(struct dtv_property))) { - kfree(tvp); - return -EFAULT; - } - kfree(tvp); - err = 0; + case FE_GET_PROPERTY: + err = dvb_get_property(fe, file, parg); break; - } case FE_GET_INFO: { struct dvb_frontend_info *info = parg; @@ -2548,7 +2571,6 @@ static int dvb_frontend_handle_ioctl(struct file *file, fepriv->tune_mode_flags = (unsigned long)parg; err = 0; break; - /* DEPRECATED dish control ioctls */ case FE_DISHNETWORK_SEND_LEGACY_CMD: @@ -2667,22 +2689,14 @@ static int dvb_frontend_handle_ioctl(struct file *file, break; err = dtv_set_frontend(fe); break; + case FE_GET_EVENT: err = dvb_frontend_get_event(fe, parg, file->f_flags); break; - case FE_GET_FRONTEND: { - struct dtv_frontend_properties getp = fe->dtv_property_cache; - - /* - * Let's use our own copy of property cache, in order to - * avoid mangling with DTV zigzag logic, as drivers might - * return crap, if they don't check if the data is available - * before updating the properties cache. - */ - err = dtv_get_frontend(fe, &getp, parg); + case FE_GET_FRONTEND: + err = dvb_get_frontend(fe, parg); break; - } default: return -ENOTSUPP;