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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 88239C74A35 for ; Thu, 11 Jul 2019 13:03:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D8F221019 for ; Thu, 11 Jul 2019 13:03:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HHLxh+6I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728597AbfGKNDV (ORCPT ); Thu, 11 Jul 2019 09:03:21 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:38626 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728645AbfGKNDV (ORCPT ); Thu, 11 Jul 2019 09:03:21 -0400 Received: by mail-wr1-f68.google.com with SMTP id g17so6220742wrr.5 for ; Thu, 11 Jul 2019 06:03:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bQBV9G+B2hAmMg3gfg98ZAsN206h3AQ53nVV5eoKMtE=; b=HHLxh+6Io3qO4btvPodOmQncqO+eeN6uA/mMbJiujPBgbzlp5nKM6ybvwtf+x3TPNc hmzmIzECXeRQiYPR6wfjMoqcREJCrijQSJFj/ULyyN6RqXorBKcODopPlQjAZKbCy+Pv I71c+we1Zxrf16AOt5sJVCaEVpz970Vo1596UyfByhORaGf4mUag7HVbOXybHAsdoOzE 17ZzMN+VRpaFR4BXob4dXOOqbctnFCeU/VZOC2TU6XxDp7Q+ei10BpKKYyD2qQL2J6k3 zB6zBvSGkW9DAjyjzoeOf1UG1rXzwRuE0HR609R9avSz3xiBg8li/Ycr1ahoclfihFIL 3i+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bQBV9G+B2hAmMg3gfg98ZAsN206h3AQ53nVV5eoKMtE=; b=A5eoxzQWcwFkpsWygh+QHp8GTWHgi1m/W5GZ8btVaGVGU1CJGhfTgsRKxl74L1Mq6/ bKBW9JFL2QNn3vS64/vpl0oq5UNCwQvNZru/9wnfK3PQl0TzYkbQ6M2mNm3EhjtESN7R A8m08Vt80262woMKKSyO3mZ+OYHI4Sufoj7unOQmCjlhEqhqJXyGf3Vb7emmOWPM6vXI JlFa8Ll/475T0hWg9ak9aO4tCSDf/EU2LLTXjr9+1suNPRKxh8UIjbyXjOE6NJ8UKvAu xTbsGtO4i0Z0ZZ0cWAt+/pq/2Y+FgBxrRcOenzsUoBeqGey8Yr+VT5vhK8Y1Fxo7iI7U JUzA== X-Gm-Message-State: APjAAAVi/WT7YugitqBviLlNrKo8grU296DPo/EDFt8Cb4xHGjR4ZobJ AHQyZG7bbxMBlb9/4k81AoSISBbX X-Google-Smtp-Source: APXvYqwLa3fD/lX4K8dQSoYtE1P5rSPbIAmQigEcj5MiTFlR8VW3HIf7DQt7xHfDIYIWMo4cGyzOyQ== X-Received: by 2002:a5d:53c2:: with SMTP id a2mr5385856wrw.8.1562850198654; Thu, 11 Jul 2019 06:03:18 -0700 (PDT) Received: from oberon.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id h6sm4642590wre.82.2019.07.11.06.03.17 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 11 Jul 2019 06:03:17 -0700 (PDT) From: "Tzvetomir Stoyanov (VMware)" To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH 7/7] trace-cmd: Move tracecmd_stack_tracer_status() function to libtracecmd Date: Thu, 11 Jul 2019 16:03:07 +0300 Message-Id: <20190711130307.25041-8-tz.stoyanov@gmail.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190711130307.25041-1-tz.stoyanov@gmail.com> References: <20190711130307.25041-1-tz.stoyanov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org tracecmd_stack_tracer_status() function reads the stack tracer status from the proc file system. It does not depend on trace-cmd context and can be used standalone. The function is moved from trace-cmd application into libtracecmd. Signed-off-by: Tzvetomir Stoyanov (VMware) --- lib/trace-cmd/trace-util.c | 49 +++++++++++++++++++++++++++++++++ tracecmd/trace-stack.c | 56 ++------------------------------------ 2 files changed, 51 insertions(+), 54 deletions(-) diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c index 8c1a0a0..d16a018 100644 --- a/lib/trace-cmd/trace-util.c +++ b/lib/trace-cmd/trace-util.c @@ -25,6 +25,7 @@ #define LOCAL_PLUGIN_DIR ".trace-cmd/plugins" #define TRACEFS_PATH "/sys/kernel/tracing" #define DEBUGFS_PATH "/sys/kernel/debug" +#define PROC_STACK_FILE "/proc/sys/kernel/stack_tracer_enabled" int tracecmd_disable_sys_plugins; int tracecmd_disable_plugins; @@ -1787,3 +1788,51 @@ int trace_set_log_file(char *logfile) return 0; } +/** + * tracecmd_stack_tracer_status - Check stack trace status + * @status: Returned stack trace status: + * 0 - not configured, disabled + * non 0 - enabled + * + * Returns -1 in case of an error, 0 if file does not exist + * (stack tracer not enabled) or 1 on successful completion. + */ +int tracecmd_stack_tracer_status(int *status) +{ + struct stat stat_buf; + char buf[64]; + long num; + int fd; + int n; + + if (stat(PROC_STACK_FILE, &stat_buf) < 0) { + /* stack tracer not configured on running kernel */ + *status = 0; /* not configured means disabled */ + return 0; + } + + fd = open(PROC_STACK_FILE, O_RDONLY); + + if (fd < 0) + return -1; + + n = read(fd, buf, sizeof(buf)); + close(fd); + + if (n <= 0) + return -1; + + if (n >= sizeof(buf)) + return -1; + + buf[n] = 0; + errno = 0; + num = strtol(buf, NULL, 10); + + /* Check for various possible errors */ + if (num > INT_MAX || num < INT_MIN || (!num && errno)) + return -1; + + *status = num; + return 1; /* full success */ +} diff --git a/tracecmd/trace-stack.c b/tracecmd/trace-stack.c index 34b3b58..bb002c0 100644 --- a/tracecmd/trace-stack.c +++ b/tracecmd/trace-stack.c @@ -36,58 +36,6 @@ static void test_available(void) die("stack tracer not configured on running kernel"); } -/* - * Returns: - * -1 - Something went wrong - * 0 - File does not exist (stack tracer not enabled) - * 1 - Success - */ -static int read_proc(int *status) -{ - struct stat stat_buf; - char buf[64]; - long num; - int fd; - int n; - - if (stat(PROC_FILE, &stat_buf) < 0) { - /* stack tracer not configured on running kernel */ - *status = 0; /* not configured means disabled */ - return 0; - } - - fd = open(PROC_FILE, O_RDONLY); - - if (fd < 0) - return -1; - - n = read(fd, buf, sizeof(buf)); - close(fd); - - if (n <= 0) - return -1; - - if (n >= sizeof(buf)) - return -1; - - buf[n] = 0; - errno = 0; - num = strtol(buf, NULL, 10); - - /* Check for various possible errors */ - if (num > INT_MAX || num < INT_MIN || (!num && errno)) - return -1; - - *status = num; - return 1; /* full success */ -} - -/* Public wrapper of read_proc() */ -int tracecmd_stack_tracer_status(int *status) -{ - return read_proc(status); -} - /* NOTE: this implementation only accepts new_status in the range [0..9]. */ static void change_stack_tracer_status(unsigned new_status) { @@ -102,7 +50,7 @@ static void change_stack_tracer_status(unsigned new_status) return; } - ret = read_proc(&status); + ret = tracecmd_stack_tracer_status(&status); if (ret < 0) die("error reading %s", PROC_FILE); @@ -160,7 +108,7 @@ static void read_trace(void) size_t n; int r; - if (read_proc(&status) <= 0) + if (tracecmd_stack_tracer_status(&status) <= 0) die("Invalid stack tracer state"); if (status > 0) -- 2.21.0