From patchwork Wed Apr 7 20:21:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12189349 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 6E287C433ED 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 49317611CC for ; Wed, 7 Apr 2021 20:36:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234869AbhDGUgw (ORCPT ); Wed, 7 Apr 2021 16:36:52 -0400 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:46601 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229685AbhDGUgw (ORCPT ); Wed, 7 Apr 2021 16:36:52 -0400 X-Greylist: delayed 906 seconds by postgrey-1.27 at vger.kernel.org; Wed, 07 Apr 2021 16:36:52 EDT Received: from sc9-mailhost1.vmware.com (10.113.161.71) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Wed, 7 Apr 2021 13:21:33 -0700 Received: from vypre.com (unknown [10.21.255.158]) by sc9-mailhost1.vmware.com (Postfix) with ESMTP id 8B8E0211A7; Wed, 7 Apr 2021 13:21:35 -0700 (PDT) From: Steven Rostedt To: CC: Sameeruddin shaik , "Steven Rostedt (VMware)" Subject: [PATCH 1/3] libtracefs: Move most functionality into helper function for tracefs_function_filter() Date: Wed, 7 Apr 2021 16:21:24 -0400 Message-ID: <20210407202126.1870994-2-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-001.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)" In order to share the code of tracefs_function_filter() for tracefs_function_notrace(), move all its functionality out of tracefs_function_filter() and into a new helper function called update_filter(). Then pass in the filter file and the pointer to the file descriptor to the set_ftrace_filter, such that tracefs_function_notrace() could do the same with set_ftrace_notrace file. Signed-off-by: Steven Rostedt (VMware) --- src/tracefs-tools.c | 111 ++++++++++++++++++++++++-------------------- 1 file changed, 61 insertions(+), 50 deletions(-) diff --git a/src/tracefs-tools.c b/src/tracefs-tools.c index cb07b6f..21a9bd3 100644 --- a/src/tracefs-tools.c +++ b/src/tracefs-tools.c @@ -744,54 +744,17 @@ static int write_func_list(int fd, struct func_list *list) return 0; } -/** - * tracefs_function_filter - filter the functions that are traced - * @instance: ftrace instance, can be NULL for top tracing instance. - * @filter: The filter to filter what functions are to be traced - * @module: Module to be traced or NULL if all functions are to be examined. - * @flags: flags on modifying the filter file - * - * @filter may be a full function name, a glob, or a regex. It will be - * considered a regex, if there's any characters that are not normally in - * function names or "*" or "?" for a glob. - * - * @flags: - * TRACEFS_FL_RESET - will clear the functions in the filter file - * before applying the @filter. This will error with -1 - * and errno of EBUSY if this flag is set and a previous - * call had the same instance and TRACEFS_FL_CONTINUE set. - * TRACEFS_FL_CONTINUE - will keep the filter file open on return. - * The filter is updated on closing of the filter file. - * With this flag set, the file is not closed, and more filters - * may be added before they take effect. The last call of this - * function must be called without this flag for the filter - * to take effect. - * TRACEFS_FL_FUTURE - only applicable if "module" is set. If no match - * is made, and the module is not yet loaded, it will still attempt - * to write the filter plus the module; ":mod:" - * to the filter file. Starting with Linux kernels 4.13, it is possible - * to load the filter file with module functions for a module that - * is not yet loaded, and when the module is loaded, it will then - * activate the module. - * - * Returns 0 on success, 1 if there was an error but the filtering has not - * yet started, -1 if there was an error but the filtering has started. - * If -1 is returned and TRACEFS_FL_CONTINUE was set, then this function - * needs to be called again without the TRACEFS_FL_CONTINUE flag to commit - * the changes and close the filter file. - */ -int tracefs_function_filter(struct tracefs_instance *instance, const char *filter, - const char *module, unsigned int flags) +static int update_filter(const char *filter_path, int *fd, + struct tracefs_instance *instance, const char *filter, + const char *module, unsigned int flags) { struct func_filter func_filter; struct func_list *func_list = NULL; - char *ftrace_filter_path; bool reset = flags & TRACEFS_FL_RESET; bool cont = flags & TRACEFS_FL_CONTINUE; bool future = flags & TRACEFS_FL_FUTURE; int open_flags; int ret = 1; - int *fd; /* future flag is only applicable to modules */ if (future && !module) { @@ -800,10 +763,6 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char *filte } pthread_mutex_lock(&filter_lock); - if (instance) - fd = &instance->ftrace_filter_fd; - else - fd = &ftrace_filter_fd; /* RESET is only allowed if the file is not opened yet */ if (reset && *fd >= 0) { @@ -846,20 +805,15 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char *filte open_file: ret = 1; - ftrace_filter_path = tracefs_instance_get_file(instance, TRACE_FILTER); - if (!ftrace_filter_path) - goto out_free; open_flags = reset ? O_TRUNC : O_APPEND; if (*fd < 0) - *fd = open(ftrace_filter_path, O_WRONLY | open_flags); - tracefs_put_tracing_file(ftrace_filter_path); + *fd = open(filter_path, O_WRONLY | open_flags); if (*fd < 0) goto out_free; errno = 0; - ret = 0; if (filter) { @@ -887,3 +841,60 @@ int tracefs_function_filter(struct tracefs_instance *instance, const char *filte return ret; } + +/** + * tracefs_function_filter - filter the functions that are traced + * @instance: ftrace instance, can be NULL for top tracing instance. + * @filter: The filter to filter what functions are to be traced + * @module: Module to be traced or NULL if all functions are to be examined. + * @flags: flags on modifying the filter file + * + * @filter may be a full function name, a glob, or a regex. It will be + * considered a regex, if there's any characters that are not normally in + * function names or "*" or "?" for a glob. + * + * @flags: + * TRACEFS_FL_RESET - will clear the functions in the filter file + * before applying the @filter. This will error with -1 + * and errno of EBUSY if this flag is set and a previous + * call had the same instance and TRACEFS_FL_CONTINUE set. + * TRACEFS_FL_CONTINUE - will keep the filter file open on return. + * The filter is updated on closing of the filter file. + * With this flag set, the file is not closed, and more filters + * may be added before they take effect. The last call of this + * function must be called without this flag for the filter + * to take effect. + * TRACEFS_FL_FUTURE - only applicable if "module" is set. If no match + * is made, and the module is not yet loaded, it will still attempt + * to write the filter plus the module; ":mod:" + * to the filter file. Starting with Linux kernels 4.13, it is possible + * to load the filter file with module functions for a module that + * is not yet loaded, and when the module is loaded, it will then + * activate the module. + * + * Returns 0 on success, 1 if there was an error but the filtering has not + * yet started, -1 if there was an error but the filtering has started. + * If -1 is returned and TRACEFS_FL_CONTINUE was set, then this function + * needs to be called again without the TRACEFS_FL_CONTINUE flag to commit + * the changes and close the filter file. + */ +int tracefs_function_filter(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_FILTER); + if (!filter_path) + return -1; + + if (instance) + fd = &instance->ftrace_filter_fd; + else + fd = &ftrace_filter_fd; + + ret = update_filter(filter_path, fd, instance, filter, module, flags); + tracefs_put_tracing_file(filter_path); + return ret; +} 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; +} From patchwork Wed Apr 7 20:21:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12189355 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 C6387C433B4 for ; Wed, 7 Apr 2021 20:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E33C6108B for ; Wed, 7 Apr 2021 20:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235298AbhDGUhA (ORCPT ); Wed, 7 Apr 2021 16:37:00 -0400 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:46603 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234141AbhDGUg5 (ORCPT ); Wed, 7 Apr 2021 16:36:57 -0400 Received: from sc9-mailhost1.vmware.com (10.113.161.71) by EX13-EDG-OU-001.vmware.com (10.113.208.155) 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 2D74C211A7; Wed, 7 Apr 2021 13:21:37 -0700 (PDT) From: Steven Rostedt To: CC: Sameeruddin shaik , "Steven Rostedt (VMware)" Subject: [PATCH 3/3] libtracefs: Add a pthread_mutex per instance Date: Wed, 7 Apr 2021 16:21:26 -0400 Message-ID: <20210407202126.1870994-4-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-001.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 a pthread_mutex per instance such that modifications being done on specific instances do not interfere with each other. This also includes a new "toplevel_lock" that is to be used when modifying the toplevel instance. Convert the filter_mutex over to the toplevel/instance locking. Signed-off-by: Steven Rostedt (VMware) --- include/tracefs-local.h | 13 ++++++++----- src/tracefs-instance.c | 5 +++++ src/tracefs-tools.c | 8 +++++--- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/include/tracefs-local.h b/include/tracefs-local.h index 060de7e..6865611 100644 --- a/include/tracefs-local.h +++ b/include/tracefs-local.h @@ -15,13 +15,16 @@ do { if (!(1/!(cond))) { } } while (0) struct tracefs_instance { - char *trace_dir; - char *name; - int flags; - int ftrace_filter_fd; - int ftrace_notrace_fd; + char *trace_dir; + char *name; + pthread_mutex_t lock; + int flags; + int ftrace_filter_fd; + int ftrace_notrace_fd; }; +extern pthread_mutex_t toplevel_lock; + /* Can be overridden */ void warning(const char *fmt, ...); diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c index 9f45624..599c3a7 100644 --- a/src/tracefs-instance.c +++ b/src/tracefs-instance.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "tracefs.h" #include "tracefs-local.h" @@ -43,6 +44,9 @@ static struct tracefs_instance *instance_alloc(const char *trace_dir, const char goto error; } + if (pthread_mutex_init(&instance->lock, NULL) < 0) + goto error; + instance->ftrace_filter_fd = -1; instance->ftrace_notrace_fd = -1; @@ -69,6 +73,7 @@ void tracefs_instance_free(struct tracefs_instance *instance) return; free(instance->trace_dir); free(instance->name); + pthread_mutex_destroy(&instance->lock); free(instance); } diff --git a/src/tracefs-tools.c b/src/tracefs-tools.c index b41806b..d48062c 100644 --- a/src/tracefs-tools.c +++ b/src/tracefs-tools.c @@ -19,6 +19,8 @@ #include "tracefs.h" #include "tracefs-local.h" +__hidden pthread_mutex_t toplevel_lock = PTHREAD_MUTEX_INITIALIZER; + #define TRACE_CTRL "tracing_on" #define TRACE_FILTER "set_ftrace_filter" #define TRACE_NOTRACE "set_ftrace_notrace" @@ -27,7 +29,6 @@ /* 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[] = { "unknown", @@ -755,6 +756,7 @@ static int update_filter(const char *filter_path, int *fd, bool reset = flags & TRACEFS_FL_RESET; bool cont = flags & TRACEFS_FL_CONTINUE; bool future = flags & TRACEFS_FL_FUTURE; + pthread_mutex_t *lock = instance ? &instance->lock : &toplevel_lock; int open_flags; int ret = 1; @@ -764,7 +766,7 @@ static int update_filter(const char *filter_path, int *fd, return 1; } - pthread_mutex_lock(&filter_lock); + pthread_mutex_lock(lock); /* RESET is only allowed if the file is not opened yet */ if (reset && *fd >= 0) { @@ -839,7 +841,7 @@ static int update_filter(const char *filter_path, int *fd, out_free: free_func_list(func_list); out: - pthread_mutex_unlock(&filter_lock); + pthread_mutex_unlock(lock); return ret; }