From patchwork Wed Apr 7 20:21:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12189351 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,URIBL_BLOCKED,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 B3635C433B4 for ; Wed, 7 Apr 2021 20:36:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8606D611CC for ; Wed, 7 Apr 2021 20:36:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229685AbhDGUgw (ORCPT ); Wed, 7 Apr 2021 16:36:52 -0400 Received: from ex13-edg-ou-002.vmware.com ([208.91.0.190]:53808 "EHLO EX13-EDG-OU-002.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233158AbhDGUgw (ORCPT ); Wed, 7 Apr 2021 16:36:52 -0400 Received: from sc9-mailhost1.vmware.com (10.113.161.71) by EX13-EDG-OU-002.vmware.com (10.113.208.156) with Microsoft SMTP Server id 15.0.1156.6; Wed, 7 Apr 2021 13:21:34 -0700 Received: from vypre.com (unknown [10.21.255.158]) by sc9-mailhost1.vmware.com (Postfix) with ESMTP id 5CD3B211A8; Wed, 7 Apr 2021 13:21:36 -0700 (PDT) From: Steven Rostedt To: CC: Sameeruddin shaik , "Steven Rostedt (VMware)" Subject: [PATCH 2/3] libtracefs: Add tracefs_function_notrace() API Date: Wed, 7 Apr 2021 16:21:25 -0400 Message-ID: <20210407202126.1870994-3-rostedt@goodmis.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210407202126.1870994-1-rostedt@goodmis.org> References: <20210407202126.1870994-1-rostedt@goodmis.org> MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-002.vmware.com: rostedt@goodmis.org does not designate permitted sender hosts) Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (VMware)" Add the API of tracefs_function_notrace() that is identical to how tracefs_function_filter() works, but will work with the set_ftrace_notrace filter file. Signed-off-by: Steven Rostedt (VMware) --- Documentation/libtracefs-function-filter.txt | 19 ++++++++--- include/tracefs-local.h | 1 + include/tracefs.h | 3 ++ src/tracefs-instance.c | 1 + src/tracefs-tools.c | 33 ++++++++++++++++++++ 5 files changed, 53 insertions(+), 4 deletions(-) diff --git a/Documentation/libtracefs-function-filter.txt b/Documentation/libtracefs-function-filter.txt index ccf20e9..746be37 100644 --- a/Documentation/libtracefs-function-filter.txt +++ b/Documentation/libtracefs-function-filter.txt @@ -4,6 +4,7 @@ libtracefs(3) NAME ---- tracefs_function_filter - Function to limit kernel functions that are traced +tracefs_function_notrace - Function to filter kernel functions that not to be traced SYNOPSIS -------- @@ -12,15 +13,18 @@ SYNOPSIS *#include * int *tracefs_function_filter*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_filter_, const char pass:[*]_module_, int _flags_); +int *tracefs_function_notrace*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_filter_, const char pass:[*]_module_, int _flags_); -- DESCRIPTION ----------- -This function can be used to limit the Linux kernel functions that would be -traced by the function and function-graph tracers +*tracefs_function_filter* and *tracefs_function_notrace* can be used to limit the +Linux kernel functions that would be traced by the function and function-graph tracers. +The *tracefs_function_filter* defines a list of functions that can be traced. +The *tracefs_function_notrace* defines a list of functions that will not be traced. +If a function is in both lists, it will not be traced. -It will take an -_instance_ , that can be NULL for the top level tracing, +They take an _instance_ , that can be NULL for the top level tracing, _filter_, a string that represents a filter that should be applied to define what functions are to be traced, _module_, to limit the filtering on a specific module (or NULL to filter on all functions), @@ -125,6 +129,13 @@ int main(int argc, char *argv[]) /* Error creating new trace instance */ } + /* Do not trace any function with the word "lock" in it */ + ret = tracefs_function_notrace(inst, "*lock*", NULL, TRACEFS_FL_RESET); + if (ret) { + printf("Failed to set the notrace filter\n"); + goto out; + } + /* First reset the filter */ ret = tracefs_function_filter(inst, NULL, NULL, TRACEFS_FL_RESET | TRACEFS_FL_CONTINUE); diff --git a/include/tracefs-local.h b/include/tracefs-local.h index 73ec113..060de7e 100644 --- a/include/tracefs-local.h +++ b/include/tracefs-local.h @@ -19,6 +19,7 @@ struct tracefs_instance { char *name; int flags; int ftrace_filter_fd; + int ftrace_notrace_fd; }; /* Can be overridden */ diff --git a/include/tracefs.h b/include/tracefs.h index befcc48..70b7ebe 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -160,4 +160,7 @@ enum { int tracefs_function_filter(struct tracefs_instance *instance, const char *filter, const char *module, unsigned int flags); +int tracefs_function_notrace(struct tracefs_instance *instance, const char *filter, + const char *module, unsigned int flags); + #endif /* _TRACE_FS_H */ diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c index bf2fabf..9f45624 100644 --- a/src/tracefs-instance.c +++ b/src/tracefs-instance.c @@ -44,6 +44,7 @@ static struct tracefs_instance *instance_alloc(const char *trace_dir, const char } instance->ftrace_filter_fd = -1; + instance->ftrace_notrace_fd = -1; return instance; diff --git a/src/tracefs-tools.c b/src/tracefs-tools.c index 21a9bd3..b41806b 100644 --- a/src/tracefs-tools.c +++ b/src/tracefs-tools.c @@ -21,10 +21,12 @@ #define TRACE_CTRL "tracing_on" #define TRACE_FILTER "set_ftrace_filter" +#define TRACE_NOTRACE "set_ftrace_notrace" #define TRACE_FILTER_LIST "available_filter_functions" /* File descriptor for Top level set_ftrace_filter */ static int ftrace_filter_fd = -1; +static int ftrace_notrace_fd = -1; static pthread_mutex_t filter_lock = PTHREAD_MUTEX_INITIALIZER; static const char * const options_map[] = { @@ -898,3 +900,34 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char *filte tracefs_put_tracing_file(filter_path); return ret; } + +/** + * tracefs_function_notrace - filter the functions that are not to be traced + * @instance: ftrace instance, can be NULL for top tracing instance. + * @filter: The filter to filter what functions are not to be traced + * @module: Module to be traced or NULL if all functions are to be examined. + * @flags: flags on modifying the filter file + * + * See tracefs_function_filter, as this has the same functionality but + * for adding to the "notrace" filter. + */ +int tracefs_function_notrace(struct tracefs_instance *instance, const char *filter, + const char *module, unsigned int flags) +{ + char *filter_path; + int *fd; + int ret; + + filter_path = tracefs_instance_get_file(instance, TRACE_NOTRACE); + if (!filter_path) + return -1; + + if (instance) + fd = &instance->ftrace_notrace_fd; + else + fd = &ftrace_notrace_fd; + + ret = update_filter(filter_path, fd, instance, filter, module, flags); + tracefs_put_tracing_file(filter_path); + return ret; +}