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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 CDD2DC32753 for ; Wed, 14 Aug 2019 17:56:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C75720651 for ; Wed, 14 Aug 2019 17:56:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="qZU7rubJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729097AbfHNR4R (ORCPT ); Wed, 14 Aug 2019 13:56:17 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:43434 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729083AbfHNR4O (ORCPT ); Wed, 14 Aug 2019 13:56:14 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7EHrsli098539; Wed, 14 Aug 2019 17:55:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2019-08-05; bh=StjhRVJT5STPBomYiyWxppKH50oyW+XPLSWOY/dHgAU=; b=qZU7rubJNquYxFICZT7Dte85s1QWM2rXTiUNxVub/7BvS49t+FtiaPpCEJzV2P4Bauhn FJSAi7cfi2lS1gyDHYARDXh5zqtX5PUEdD5J73+IY3fezYStAla/KeFpNLq0KDKZV5ba +AsA0GVoAQOMDZybPI5LLK0MEdK8IzgWfHWEwDxgkVY0yQDcoO9y6YoOC2i2mbtrFC6h XlaL4QV4ZgpRI3DU/a1ysRcs4emV4UcusAYIrNm8y9r01tYE8yGCZ/wZ/ukM7SydCJPu Wg/X3cGpasJfFFCErgD8VMegQRqXEaq3Pjnv2ZpSc6CDIyfTkgf1tpNAGMWWD+h/3ky8 0Q== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2u9pjqp84r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Aug 2019 17:55:45 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7EHqwDn114053; Wed, 14 Aug 2019 17:55:44 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2ucmwhprep-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Aug 2019 17:55:44 +0000 Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x7EHthGj025390; Wed, 14 Aug 2019 17:55:43 GMT Received: from ca-common-hq.us.oracle.com (/10.211.9.209) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 14 Aug 2019 10:55:42 -0700 From: Divya Indi To: Steven Rostedt , linux-kernel@vger.kernel.org Cc: Divya Indi , Joe Jin , Srinivas Eeda , Aruna Ramakrishna Subject: [PATCH 5/5] tracing: New functions for kernel access to Ftrace instances Date: Wed, 14 Aug 2019 10:55:27 -0700 Message-Id: <1565805327-579-6-git-send-email-divya.indi@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1565805327-579-1-git-send-email-divya.indi@oracle.com> References: <1565805327-579-1-git-send-email-divya.indi@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9349 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908140160 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9349 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908140161 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding 2 new functions - 1) trace_array_lookup : Look up and return a trace array, given its name. 2) trace_array_set_clr_event : Enable/disable event recording to the given trace array. NOTE: trace_array_lookup returns a trace array and also increments the reference counter associated with the returned trace array. Make sure to call trace_array_put() once the use is done so that the instance can be removed at a later time. Example use: tr = trace_array_lookup("foo-bar"); if (!tr) tr = trace_array_create("foo-bar"); // Log to tr // Enable/disable events to tr trace_array_set_clr_event(tr, _THIS_IP,"system","event",1); // Done using tr trace_array_put(tr); .. Also, use trace_array_set_clr_event to enable/disable events to a trace array. So now we no longer need to have ftrace_set_clr_event as an exported API. Signed-off-by: Divya Indi --- include/linux/trace.h | 2 ++ include/linux/trace_events.h | 3 ++- kernel/trace/trace.c | 28 ++++++++++++++++++++++++++++ kernel/trace/trace_events.c | 23 ++++++++++++++++++++++- 4 files changed, 54 insertions(+), 2 deletions(-) diff --git a/include/linux/trace.h b/include/linux/trace.h index 2c782d5..05164bb 100644 --- a/include/linux/trace.h +++ b/include/linux/trace.h @@ -32,6 +32,8 @@ int trace_array_printk(struct trace_array *tr, unsigned long ip, struct trace_array *trace_array_create(const char *name); int trace_array_destroy(struct trace_array *tr); void trace_array_put(struct trace_array *tr); +struct trace_array *trace_array_lookup(const char *name); + #endif /* CONFIG_TRACING */ #endif /* _LINUX_TRACE_H */ diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 8a62731..05a7514 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -540,7 +540,8 @@ extern int trace_define_field(struct trace_event_call *call, const char *type, #define is_signed_type(type) (((type)(-1)) < (type)1) int trace_set_clr_event(const char *system, const char *event, int set); - +int trace_array_set_clr_event(struct trace_array *tr, const char *system, + const char *event, int set); /* * The double __builtin_constant_p is because gcc will give us an error * if we try to allocate the static variable to fmt if it is not a diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7b6a37a..e394d55 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8514,6 +8514,34 @@ static int instance_rmdir(const char *name) return ret; } +/** + * trace_array_lookup - Lookup the trace array, given its name. + * @name: The name of the trace array to be looked up. + * + * Lookup and return the trace array associated with @name. + * + * NOTE: The reference counter associated with the returned trace array is + * incremented to ensure it is not freed when in use. Make sure to call + * "trace_array_put" for this trace array when its use is done. + */ +struct trace_array *trace_array_lookup(const char *name) +{ + struct trace_array *tr; + + mutex_lock(&trace_types_lock); + + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr->name && strcmp(tr->name, name) == 0) { + tr->ref++; + mutex_unlock(&trace_types_lock); + return tr; + } + } + mutex_unlock(&trace_types_lock); + return NULL; +} +EXPORT_SYMBOL_GPL(trace_array_lookup); + static __init void create_trace_instances(struct dentry *d_tracer) { trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 2621995..96dd997 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -834,7 +834,6 @@ static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) return ret; } -EXPORT_SYMBOL_GPL(ftrace_set_clr_event); /** * trace_set_clr_event - enable or disable an event @@ -859,6 +858,28 @@ int trace_set_clr_event(const char *system, const char *event, int set) } EXPORT_SYMBOL_GPL(trace_set_clr_event); +/** + * trace_array_set_clr_event - enable or disable an event for a trace array + * @system: system name to match (NULL for any system) + * @event: event name to match (NULL for all events, within system) + * @set: 1 to enable, 0 to disable + * + * This is a way for other parts of the kernel to enable or disable + * event recording to instances. + * + * Returns 0 on success, -EINVAL if the parameters do not match any + * registered events. + */ +int trace_array_set_clr_event(struct trace_array *tr, const char *system, + const char *event, int set) +{ + if (!tr) + return -ENOENT; + + return __ftrace_set_clr_event(tr, NULL, system, event, set); +} +EXPORT_SYMBOL_GPL(trace_array_set_clr_event); + /* 128 should be much more than enough */ #define EVENT_BUF_SIZE 127 -- 1.8.3.1