From patchwork Wed Mar 17 02:22:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 403516 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 820B6C2BA83 for ; Wed, 17 Mar 2021 02:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51D7964F40 for ; Wed, 17 Mar 2021 02:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231189AbhCQCZI (ORCPT ); Tue, 16 Mar 2021 22:25:08 -0400 Received: from mga01.intel.com ([192.55.52.88]:55651 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230473AbhCQCYh (ORCPT ); Tue, 16 Mar 2021 22:24:37 -0400 IronPort-SDR: Mg3cQk5YX/m+Fp/NTDaQqb+6WZJk/3wP1PbESv0nEf27FD5RSEky81/EBBoS/11Vc7DUimhPw4 fWZdaRXnQ0OA== X-IronPort-AV: E=McAfee;i="6000,8403,9925"; a="209328723" X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="209328723" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 19:24:34 -0700 IronPort-SDR: N8Ph0fm6O1SYs14tyyvo67YPGtFxvE31MOFKCKc+KWMH8hF+pxo24EQlPK6EkmQZzte+OZDzAs oM5PsfRDqH5w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="440290300" Received: from otcwcpicx3.sc.intel.com ([172.25.55.73]) by FMSMGA003.fm.intel.com with ESMTP; 16 Mar 2021 19:24:34 -0700 From: Fenghua Yu To: "Shuah Khan" , "Tony Luck" , "Reinette Chatre" , "Babu Moger" , "Ravi V Shankar" Cc: "linux-kselftest" , "linux-kernel" , Fenghua Yu , Dan Carpenter Subject: [PATCH v6 20/21] selftests/resctrl: Fix checking for < 0 for unsigned values Date: Wed, 17 Mar 2021 02:22:54 +0000 Message-Id: <20210317022255.2536745-21-fenghua.yu@intel.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210317022255.2536745-1-fenghua.yu@intel.com> References: <20210317022255.2536745-1-fenghua.yu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Dan reported following static checker warnings tools/testing/selftests/resctrl/resctrl_val.c:545 measure_vals() warn: 'bw_imc' unsigned <= 0 tools/testing/selftests/resctrl/resctrl_val.c:549 measure_vals() warn: 'bw_resc_end' unsigned <= 0 These warnings are reported because 1. measure_vals() declares 'bw_imc' and 'bw_resc_end' as unsigned long variables 2. Return value of get_mem_bw_imc() and get_mem_bw_resctrl() are assigned to 'bw_imc' and 'bw_resc_end' respectively 3. The returned values are checked for <= 0 to see if the calls failed Checking for < 0 for an unsigned value doesn't make any sense. Fix this issue by changing the implementation of get_mem_bw_imc() and get_mem_bw_resctrl() such that they now accept reference to a variable and set the variable appropriately upon success and return 0, else return < 0 on error. Reported-by: Dan Carpenter Tested-by: Babu Moger Signed-off-by: Fenghua Yu --- tools/testing/selftests/resctrl/resctrl_val.c | 41 +++++++++++-------- 1 file changed, 23 insertions(+), 18 deletions(-) diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c index 20d457c47ded..95224345c78e 100644 --- a/tools/testing/selftests/resctrl/resctrl_val.c +++ b/tools/testing/selftests/resctrl/resctrl_val.c @@ -300,9 +300,9 @@ static int initialize_mem_bw_imc(void) * Memory B/W utilized by a process on a socket can be calculated using * iMC counters. Perf events are used to read these counters. * - * Return: >= 0 on success. < 0 on failure. + * Return: = 0 on success. < 0 on failure. */ -static float get_mem_bw_imc(int cpu_no, char *bw_report) +static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc) { float reads, writes, of_mul_read, of_mul_write; int imc, j, ret; @@ -373,13 +373,18 @@ static float get_mem_bw_imc(int cpu_no, char *bw_report) close(imc_counters_config[imc][WRITE].fd); } - if (strcmp(bw_report, "reads") == 0) - return reads; + if (strcmp(bw_report, "reads") == 0) { + *bw_imc = reads; + return 0; + } - if (strcmp(bw_report, "writes") == 0) - return writes; + if (strcmp(bw_report, "writes") == 0) { + *bw_imc = writes; + return 0; + } - return (reads + writes); + *bw_imc = reads + writes; + return 0; } void set_mbm_path(const char *ctrlgrp, const char *mongrp, int resource_id) @@ -438,9 +443,8 @@ static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp, * 1. If con_mon grp is given, then read from it * 2. If con_mon grp is not given, then read from root con_mon grp */ -static unsigned long get_mem_bw_resctrl(void) +static int get_mem_bw_resctrl(unsigned long *mbm_total) { - unsigned long mbm_total = 0; FILE *fp; fp = fopen(mbm_total_path, "r"); @@ -449,7 +453,7 @@ static unsigned long get_mem_bw_resctrl(void) return -1; } - if (fscanf(fp, "%lu", &mbm_total) <= 0) { + if (fscanf(fp, "%lu", mbm_total) <= 0) { perror("Could not get mbm local bytes"); fclose(fp); @@ -457,7 +461,7 @@ static unsigned long get_mem_bw_resctrl(void) } fclose(fp); - return mbm_total; + return 0; } pid_t bm_pid, ppid; @@ -549,7 +553,8 @@ static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp, static int measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start) { - unsigned long bw_imc, bw_resc, bw_resc_end; + unsigned long bw_resc, bw_resc_end; + float bw_imc; int ret; /* @@ -559,13 +564,13 @@ measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start) * Compare the two values to validate resctrl value. * It takes 1sec to measure the data. */ - bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report); - if (bw_imc <= 0) - return bw_imc; + ret = get_mem_bw_imc(param->cpu_no, param->bw_report, &bw_imc); + if (ret < 0) + return ret; - bw_resc_end = get_mem_bw_resctrl(); - if (bw_resc_end <= 0) - return bw_resc_end; + ret = get_mem_bw_resctrl(&bw_resc_end); + if (ret < 0) + return ret; bw_resc = (bw_resc_end - *bw_resc_start) / MB; ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);