From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B862DC33CB7 for ; Fri, 31 Jan 2020 16:54:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9412F2173E for ; Fri, 31 Jan 2020 16:54:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726722AbgAaQyV (ORCPT ); Fri, 31 Jan 2020 11:54:21 -0500 Received: from mga09.intel.com ([134.134.136.24]:23682 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726330AbgAaQyV (ORCPT ); Fri, 31 Jan 2020 11:54:21 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jan 2020 08:54:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,386,1574150400"; d="scan'208";a="377393441" Received: from unknown (HELO [134.134.177.86]) ([134.134.177.86]) by orsmga004.jf.intel.com with ESMTP; 31 Jan 2020 08:54:19 -0800 Subject: Re: [Intel PMC TGPIO Driver 1/5] drivers/ptp: Add Enhanced handling of reserve fields To: christopher.s.hall@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, mingo@redhat.com, x86@kernel.org, richardcochran@gmail.com, davem@davemloft.net, sean.v.kelley@intel.com References: <20191211214852.26317-1-christopher.s.hall@intel.com> <20191211214852.26317-2-christopher.s.hall@intel.com> From: Jacob Keller Organization: Intel Corporation Message-ID: <0f868a7e-5806-4976-80b5-0185a64b42a0@intel.com> Date: Fri, 31 Jan 2020 08:54:19 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20191211214852.26317-2-christopher.s.hall@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 12/11/2019 1:48 PM, christopher.s.hall@intel.com wrote: > From: Christopher Hall > > Add functions that parameterize checking and zeroing of reserve fields in > ioctl arguments. Eliminates need to change this code when repurposing > reserve fields. > Nice! > Signed-off-by: Christopher Hall > --- > drivers/ptp/ptp_chardev.c | 60 +++++++++++++++++++++------------------ > 1 file changed, 33 insertions(+), 27 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 9d72ab593f13..f9ad6df57fa5 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -12,6 +12,7 @@ > #include > > #include > +#include > > #include "ptp_private.h" > > @@ -106,6 +107,28 @@ int ptp_open(struct posix_clock *pc, fmode_t fmode) > return 0; > } > > +/* Returns -1 if any reserved fields are non-zero */ > +static inline int _check_rsv_field(unsigned int *field, size_t size) > +{ > + unsigned int *iter; > + int ret = 0; > + > + for (iter = field; iter < field+size && ret == 0; ++iter) > + ret = *iter == 0 ? 0 : -1; > + > + return ret; > +} > +#define check_rsv_field(field) _check_rsv_field(field, ARRAY_SIZE(field)) > + This assumes that reserved fields will always be arrays. Seems like a reasonable restriction to me. Are the reserved fields always integers? Seems so. Ok. > +static inline void _zero_rsv_field(unsigned int *field, size_t size) > +{ > + unsigned int *iter; > + > + for (iter = field; iter < field+size; ++iter) > + *iter = 0; > +} > +#define zero_rsv_field(field) _zero_rsv_field(field, ARRAY_SIZE(field)) > + > long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > { > struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); > @@ -154,7 +177,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > req.extts.flags |= PTP_STRICT_FLAGS; > /* Make sure no reserved bit is set. */ > if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) || > - req.extts.rsv[0] || req.extts.rsv[1]) { > + check_rsv_field(req.extts.rsv)) { > err = -EINVAL; > break; > } > @@ -166,8 +189,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > } > } else if (cmd == PTP_EXTTS_REQUEST) { > req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS; > - req.extts.rsv[0] = 0; > - req.extts.rsv[1] = 0; > + zero_rsv_field(req.extts.rsv); > } > if (req.extts.index >= ops->n_ext_ts) { > err = -EINVAL; > @@ -188,17 +210,13 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > break; > } > if (((req.perout.flags & ~PTP_PEROUT_VALID_FLAGS) || > - req.perout.rsv[0] || req.perout.rsv[1] || > - req.perout.rsv[2] || req.perout.rsv[3]) && > - cmd == PTP_PEROUT_REQUEST2) { > + check_rsv_field(req.perout.rsv)) && > + cmd == PTP_PEROUT_REQUEST2) { > err = -EINVAL; > break; > } else if (cmd == PTP_PEROUT_REQUEST) { > req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS; > - req.perout.rsv[0] = 0; > - req.perout.rsv[1] = 0; > - req.perout.rsv[2] = 0; > - req.perout.rsv[3] = 0; > + zero_rsv_field(req.perout.rsv); > } > if (req.perout.index >= ops->n_per_out) { > err = -EINVAL; > @@ -258,7 +276,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > break; > } > if (extoff->n_samples > PTP_MAX_SAMPLES > - || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) { > + || check_rsv_field(extoff->rsv)) { > err = -EINVAL; > break; > } > @@ -318,17 +336,11 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > err = -EFAULT; > break; > } > - if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2] > - || pd.rsv[3] || pd.rsv[4]) > - && cmd == PTP_PIN_GETFUNC2) { > + if (check_rsv_field(pd.rsv) && cmd == PTP_PIN_GETFUNC2) { Not that it's a big deal, but I think this might read more clearly if this was "cmd == PTP_PIN_GETFUNC2 && check_rsv_field(pd.rsv)" Thanks, Jake