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=-9.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 3ED87C43387 for ; Wed, 16 Jan 2019 16:33:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03E9820675 for ; Wed, 16 Jan 2019 16:33:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547656406; bh=3OuHrXkXcoG9FPk0PC3yBBH5G+3Nlu+iVdEJD9ueGYo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=KWETzBkFEct9Akt6muQWRanLOlgRuR7Wm3rfJ+LFdG5FRbuZH0C2FLRnxmFb1oy8e GIlrUduyGGihLXRRMSatpO+6iex7xZEbi0xYot+05s6eEDxz3h2dBWIc89pGZFPdJM XFtR7B1/tZI0SnZvK4jvWBKY24Zg3WLEU9fjQx/I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405774AbfAPQdU (ORCPT ); Wed, 16 Jan 2019 11:33:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:37544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729410AbfAPQdS (ORCPT ); Wed, 16 Jan 2019 11:33:18 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4C4E420675; Wed, 16 Jan 2019 16:33:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547656397; bh=3OuHrXkXcoG9FPk0PC3yBBH5G+3Nlu+iVdEJD9ueGYo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E82caBty195AErNbakBj87gX6e3u8Y+d0ltbsY8oBninjY628Vs9BYZmHsBFTyEdh FJV8imlq8qA3OsOBwOGjj9abbUjxC5pKQILBQMLE8wbc34VEuaBwS2vbq3TZoz4HrT PawspyslPvtMp5BgnKNEmQ91AosB9qfqFJB9Wd9g= Date: Wed, 16 Jan 2019 17:33:14 +0100 From: Greg KH To: Mathieu Poirier Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Alexander Shishkin , schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, Will Deacon , Mark Rutland , Jiri Olsa , Namhyung Kim , Adrian Hunter , ast@kernel.org, "H. Peter Anvin" , "Suzuki K. Poulose" , linux-s390@vger.kernel.org, Linux Kernel Mailing List , linux-arm-kernel Subject: Re: [PATCH 2/7] coresight: perf: Add "sinks" group to PMU directory Message-ID: <20190116163314.GB5446@kroah.com> References: <20190115230742.13730-1-mathieu.poirier@linaro.org> <20190115230742.13730-3-mathieu.poirier@linaro.org> <20190116153948.GC871@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.2 (2019-01-07) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 16, 2019 at 09:14:33AM -0700, Mathieu Poirier wrote: > On Wed, 16 Jan 2019 at 08:39, Greg KH wrote: > > > > On Tue, Jan 15, 2019 at 04:07:37PM -0700, Mathieu Poirier wrote: > > > Add a "sinks" directory entry so that users can see all the sinks > > > available in the system in a single place. Individual sink are added > > > as they are registered with the coresight bus. > > > > > > Signed-off-by: Mathieu Poirier > > > --- > > > .../hwtracing/coresight/coresight-etm-perf.c | 43 +++++++++++++++++++ > > > .../hwtracing/coresight/coresight-etm-perf.h | 1 + > > > drivers/hwtracing/coresight/coresight.c | 17 ++++++++ > > > 3 files changed, 61 insertions(+) > > > > > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > > > index f21eb28b6782..292bd409a68c 100644 > > > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > > > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > > > @@ -14,6 +14,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > #include > > > #include > > > > > > @@ -43,8 +44,18 @@ static const struct attribute_group etm_pmu_format_group = { > > > .attrs = etm_config_formats_attr, > > > }; > > > > > > +static struct attribute *etm_config_sinks_attr[] = { > > > + NULL, > > > +}; > > > + > > > +static const struct attribute_group etm_pmu_sinks_group = { > > > + .name = "sinks", > > > + .attrs = etm_config_sinks_attr, > > > +}; > > > + > > > static const struct attribute_group *etm_pmu_attr_groups[] = { > > > &etm_pmu_format_group, > > > + &etm_pmu_sinks_group, > > > NULL, > > > }; > > > > > > @@ -479,6 +490,38 @@ int etm_perf_symlink(struct coresight_device *csdev, bool link) > > > return 0; > > > } > > > > > > +static ssize_t etm_perf_sink_name_show(struct device *dev, > > > + struct device_attribute *dattr, > > > + char *buf) > > > +{ > > > + /* See function coresight_sink_by_id() to know where this is used */ > > > + u32 hash = hashlen_hash(hashlen_string(NULL, dattr->attr.name)); > > > + > > > + return scnprintf(buf, PAGE_SIZE, "%x\n", hash); > > > +} > > > + > > > +int etm_perf_symlink_sink(struct coresight_device *csdev) > > > +{ > > > + struct device *pmu_dev = etm_pmu.dev; > > > + struct device *pdev = csdev->dev.parent; > > > + struct device_attribute *dev_attr; > > > + > > > + if (csdev->type != CORESIGHT_DEV_TYPE_SINK && > > > + csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) > > > + return -EINVAL; > > > + > > > + if (!etm_perf_up) > > > + return -EPROBE_DEFER; > > > + > > > + dev_attr = kzalloc(sizeof(*dev_attr), GFP_KERNEL); > > > + dev_attr->attr.name = kstrdup(dev_name(pdev), GFP_KERNEL); > > > + dev_attr->attr.mode = 0444; > > > + dev_attr->show = etm_perf_sink_name_show; > > > + > > > + return sysfs_add_file_to_group(&pmu_dev->kobj, > > > + &dev_attr->attr, "sinks"); > > > > What is so odd about this call that you needed me to review this? > > As far as I can tell nobody is feeding a dynamic struct attribute to > the function and I wasn't sure if it was because they were told not to > or simply because it wasn't needed, hence asking for a second opinion. Ah. Well, again, this is a good question to answer: > > And what happens if this call fails, do you leak memory? And also, what happens when you unload the device, who frees the attribute's memory? thanks, greg k-h