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=-8.8 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 153C6C31E46 for ; Wed, 12 Jun 2019 16:35:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5BE8215EA for ; Wed, 12 Jun 2019 16:35:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="3i9BlIkA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438224AbfFLQfd (ORCPT ); Wed, 12 Jun 2019 12:35:33 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:38890 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438250AbfFLQfZ (ORCPT ); Wed, 12 Jun 2019 12:35:25 -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 x5CGXeL1180963; Wed, 12 Jun 2019 16:34:58 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-2018-07-02; bh=OZ07ptOy2B80GlbT6lz5k/wWg5JkWZcAoOSiGptgXoI=; b=3i9BlIkAgbpRW4KMrJFF9FVpB9aV6hrBUlUPolA2nBEAg5/HXhH0kpu9dzfwmo6/P9FQ uagMawXS8M+FkxYw/3Gfjg53hn3zq83vDGnx1EykNKBX5I4Z1QOwTa4r2z4BVOKKKbYT aar1NwqtxnMXMGVNJdgwBwTo+OU0YdwqcCS1ZNzkxrIRjVIUx88X1iUvxnCTb8d3edMK e3m7snvEwDXYyi5GjtFw05DWVUzpIXv0wj7hTBxaFKcK2PgSiduLNOZeAh5MfXL5L7s8 yee+jPe7u5snkCX1+uya0zCp6gdh60fc3Mf/aQOtmh98x3c1lvoya2Ht7yWa+WTUbzrn cQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2t05nqvn9v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Jun 2019 16:34:57 +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 x5CGXJ5H113164; Wed, 12 Jun 2019 16:34:57 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2t024v2urq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Jun 2019 16:34:57 +0000 Received: from abhmp0001.oracle.com (abhmp0001.oracle.com [141.146.116.7]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5CGYukW025982; Wed, 12 Jun 2019 16:34:56 GMT Received: from ca-common-hq.us.oracle.com (/10.211.9.209) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 12 Jun 2019 09:34:56 -0700 From: Divya Indi To: linux-kernel@vger.kernel.org, Steven Rostedt Cc: Divya Indi , Srinivas Eeda , Aruna Ramakrishna Subject: [PATCH 3/3] tracing: Add 2 new funcs. for kernel access to Ftrace instances. Date: Wed, 12 Jun 2019 09:34:19 -0700 Message-Id: <1560357259-3497-4-git-send-email-divya.indi@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1560357259-3497-3-git-send-email-divya.indi@oracle.com> References: <1560357259-3497-1-git-send-email-divya.indi@oracle.com> <1560357259-3497-2-git-send-email-divya.indi@oracle.com> <1560357259-3497-3-git-send-email-divya.indi@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9286 signatures=668687 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=8.0.1-1810050000 definitions=main-1906120112 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9286 signatures=668687 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=8.0.1-1810050000 definitions=main-1906120112 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. Newly added functions trace_array_lookup and trace_array_create also need to increment the reference counter associated with the trace array they return. This is to ensure the trace array does not get freed while in use by the newly introduced APIs. The reference ctr is decremented in the trace_array_destroy. Signed-off-by: Divya Indi --- include/linux/trace_events.h | 3 +++ kernel/trace/trace.c | 30 +++++++++++++++++++++++++++++- kernel/trace/trace_events.c | 22 ++++++++++++++++++++++ 3 files changed, 54 insertions(+), 1 deletion(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index d7b7d85..0cc99a8 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -545,7 +545,10 @@ 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); int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); +struct trace_array *trace_array_lookup(const char *name); 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 diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a60dc13..fb70ccc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8364,6 +8364,8 @@ struct trace_array *trace_array_create(const char *name) list_add(&tr->list, &ftrace_trace_arrays); + tr->ref++; + mutex_unlock(&trace_types_lock); mutex_unlock(&event_mutex); @@ -8385,7 +8387,14 @@ struct trace_array *trace_array_create(const char *name) static int instance_mkdir(const char *name) { - return PTR_ERR_OR_ZERO(trace_array_create(name)); + struct trace_array *tr; + + tr = trace_array_create(name); + if (IS_ERR(tr)) + return PTR_ERR(tr); + trace_array_put(tr); + + return 0; } static int __remove_instance(struct trace_array *tr) @@ -8434,6 +8443,7 @@ int trace_array_destroy(struct trace_array *tr) mutex_lock(&event_mutex); mutex_lock(&trace_types_lock); + tr->ref--; ret = __remove_instance(tr); mutex_unlock(&trace_types_lock); @@ -8465,6 +8475,24 @@ static int instance_rmdir(const char *name) return ret; } +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 445b059..c126d2c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -859,6 +859,28 @@ 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 -ENODEV; + + 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