From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 4DF0EA05D3 for ; Fri, 29 Mar 2019 17:25:53 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 1B4184CC7; Fri, 29 Mar 2019 17:25:53 +0100 (CET) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 428F14C99; Fri, 29 Mar 2019 17:25:51 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Mar 2019 09:25:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,284,1549958400"; d="scan'208";a="157000629" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.103]) ([10.237.220.103]) by fmsmga004.fm.intel.com with ESMTP; 29 Mar 2019 09:25:48 -0700 To: David Hunt , dev@dpdk.org Cc: stable@dpdk.org References: <20190329161142.39787-1-david.hunt@intel.com> From: "Burakov, Anatoly" Message-ID: Date: Fri, 29 Mar 2019 16:25:47 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <20190329161142.39787-1-david.hunt@intel.com> Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] lib/power: fix governor storage to trim newlines X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190329162547.Xbkr3_tvoYdSZ8sdk0naX2wikZ4VfqWMh1vahXVpkVg@z> On 29-Mar-19 4:11 PM, David Hunt wrote: > Currently the Power Libray stores the governor name with an embedded > newline read from the scaling_governor sysfs file. This patch strips > it out. > > Fixes: 445c6528b55f ("power: common interface for guest and host") > Cc: stable@dpdk.org > > Signed-off-by: David Hunt > --- > lib/librte_power/power_acpi_cpufreq.c | 4 ++++ > lib/librte_power/power_pstate_cpufreq.c | 4 ++++ > 2 files changed, 8 insertions(+) > > diff --git a/lib/librte_power/power_acpi_cpufreq.c b/lib/librte_power/power_acpi_cpufreq.c > index 45412f0b9..c2febdf06 100644 > --- a/lib/librte_power/power_acpi_cpufreq.c > +++ b/lib/librte_power/power_acpi_cpufreq.c > @@ -147,6 +147,10 @@ power_set_governor_userspace(struct rte_power_info *pi) > > s = fgets(buf, sizeof(buf), f); > FOPS_OR_NULL_GOTO(s, out); > + buf[BUFSIZ-1] = '\0'; > + if (strlen(buf)) > + /* Strip off terminating '\n' */ > + strtok(buf, "\n"); I have a feeling that either strlen or strtok here is unnecessary. If it's always terminating - you can just use strlen return value and overwrite the '\n' without going over the string the second time - you know where the string ends! You have already written null-terminator to the end of the buffer, so it can't overflow on strtok, so you don't really need strlen either, because the string will either: 1) be empty (in which case strtok does nothing) 2) contain text + newline (in which case you cut off the newline and leave the text - no need for strlen), or 3) contain just a newline (which would make it empty after strtok) Did you mean to only cut off the newline off the strings that have stuff other than newline? That would be the only case where using strlen would make sense - in which case, not only the check is wrong, but you could also replace it with a simple 'if (buf[0] != '\n')' check instead of strlen. -- Thanks, Anatoly