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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 02458C432C3 for ; Wed, 27 Nov 2019 18:40:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D228620835 for ; Wed, 27 Nov 2019 18:40:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726947AbfK0SkU (ORCPT ); Wed, 27 Nov 2019 13:40:20 -0500 Received: from foss.arm.com ([217.140.110.172]:51658 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726593AbfK0SkU (ORCPT ); Wed, 27 Nov 2019 13:40:20 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 72E0F31B; Wed, 27 Nov 2019 10:40:19 -0800 (PST) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A46543F6C4; Wed, 27 Nov 2019 10:40:18 -0800 (PST) Subject: Re: [PATCH v5 04/14] coresight: cti: Add sysfs trigger / channel programming API To: Mike Leach , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org Cc: mathieu.poirier@linaro.org References: <20191119231912.12768-1-mike.leach@linaro.org> <20191119231912.12768-5-mike.leach@linaro.org> From: Suzuki Kuruppassery Poulose Message-ID: Date: Wed, 27 Nov 2019 18:40:17 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191119231912.12768-5-mike.leach@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 19/11/2019 23:19, Mike Leach wrote: > Adds a user API to allow programming of CTI by trigger ID and > channel number. This will take the channel and trigger ID supplied > by the user and program the appropriate register values. > > Signed-off-by: Mike Leach > --- > + > +static ssize_t chan_xtrigs_view_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent); > + struct cti_config *cfg = &drvdata->config; > + int used = 0, reg_idx; > + int buf_sz = PAGE_SIZE; > + u32 chan_mask = BIT(cfg->xtrig_rchan_sel); > + > + used += scnprintf(buf, buf_sz, "[%d] IN: ", cfg->xtrig_rchan_sel); > + for (reg_idx = 0; > + reg_idx < drvdata->config.nr_trig_max; > + reg_idx++) { > + if (chan_mask & cfg->ctiinen[reg_idx]) { > + used += scnprintf(buf + used, buf_sz - used, "%d ", > + reg_idx); > + } > + } As a security measure, we must make sure that we have space left in the buffer. We could end up passing "negative" numbers for the size argument, in the worst case. > + > + used += scnprintf(buf + used, buf_sz - used, "OUT: "); > + for (reg_idx = 0; > + reg_idx < drvdata->config.nr_trig_max; > + reg_idx++) { > + if (chan_mask & cfg->ctiouten[reg_idx]) { > + used += scnprintf(buf + used, buf_sz - used, "%d ", > + reg_idx); > + } > + } > + used += scnprintf(buf + used, buf_sz - used, "\n"); > + return used; > +} > +static DEVICE_ATTR_RW(chan_xtrigs_view); The rest looks fine to me. Suzuki