From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932679AbcGHPVn (ORCPT ); Fri, 8 Jul 2016 11:21:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53977 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932371AbcGHPVf (ORCPT ); Fri, 8 Jul 2016 11:21:35 -0400 Date: Fri, 8 Jul 2016 17:21:33 +0200 From: Jiri Olsa To: Song Shan Gong Cc: acme@kernel.org, jolsa@kernel.org, dsahern@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [RFC V1]s390/perf: fix 'start' address of module's map Message-ID: <20160708152133.GK31763@krava> References: <1467856176-8712-1-git-send-email-gongss@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1467856176-8712-1-git-send-email-gongss@linux.vnet.ibm.com> User-Agent: Mutt/1.6.1 (2016-04-27) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 08 Jul 2016 15:21:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 07, 2016 at 09:49:36AM +0800, Song Shan Gong wrote: SNIP > + char *line = NULL; > + size_t n; > + char *sep; > + > + module_name[len - 1] = '\0'; > + module_name += 1; > + snprintf(path, PATH_MAX, "%s/sys/module/%s/sections/.text", > + machine->root_dir, module_name); > + file = fopen(path, "r"); > + if (file == NULL) > + return -1; > + > + len = getline(&line, &n, file); > + if (len < 0) { > + err = -1; > + goto out; > + } > + line[--len] = '\0'; /* \n */ > + sep = strrchr(line, 'x'); > + if (sep == NULL) { > + err = -1; > + goto out; > + } > + hex2u64(sep + 1, &text_start); we have following functions in tools/lib/api/fs to read single number from file, which I assume you do above: int sysfs__read_int(const char *entry, int *value); int sysfs__read_ull(const char *entry, unsigned long long *value); please check if you could use some of them, we could add some more generic one if needed thanks, jirka