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=-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 5A623C07E9A for ; Fri, 2 Jul 2021 20:17:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46EF66142C for ; Fri, 2 Jul 2021 20:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232744AbhGBUUE (ORCPT ); Fri, 2 Jul 2021 16:20:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:42720 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232749AbhGBUUD (ORCPT ); Fri, 2 Jul 2021 16:20:03 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E360B6140E; Fri, 2 Jul 2021 20:17:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1lzPbN-000i0Q-Pg; Fri, 02 Jul 2021 16:17:29 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Steven Rostedt (VMware)" Subject: [PATCH v7 04/10] libtracefs: Implement tracefs_get_kprobes() Date: Fri, 2 Jul 2021 16:17:21 -0400 Message-Id: <20210702201727.169080-5-rostedt@goodmis.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210702201727.169080-1-rostedt@goodmis.org> References: <20210702201727.169080-1-rostedt@goodmis.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (VMware)" Add the function tracefs_get_kprobes() that returns a list of kprobes that are registered. The list contains strings that are of the format "group/event" (i.e. "kprobes/open"). The last element in the list is a NULL pointer. In the case that there are no kprobes, the list will return a single entry of a NULL pointer. tracefs_get_kprobes() takes a type parameter to determine which kprobes to return: TRACEFS_ALL_KPROBES - return all that are found TRACEFS_KPROBE - return only normal kprobes ("p:") TRACEFS_KRETPROBE - return only kretprobes ("r:") NULL is returned in the case of error (mainly a memory issue, or bad parsing). Signed-off-by: Steven Rostedt (VMware) --- include/tracefs.h | 7 ++++ src/tracefs-kprobes.c | 93 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+) diff --git a/include/tracefs.h b/include/tracefs.h index 64164c8c2b20..e8a2008d9714 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -215,8 +215,15 @@ ssize_t tracefs_trace_pipe_stream(int fd, struct tracefs_instance *instance, int ssize_t tracefs_trace_pipe_print(struct tracefs_instance *instance, int flags); void tracefs_trace_pipe_stop(struct tracefs_instance *instance); +enum tracefs_kprobe_type { + TRACEFS_ALL_KPROBES, + TRACEFS_KPROBE, + TRACEFS_KRETPROBE, +}; + int tracefs_kprobe_raw(const char *system, const char *event, const char *addr, const char *format); int tracefs_kretprobe_raw(const char *system, const char *event, const char *addr, const char *format); +char **tracefs_get_kprobes(enum tracefs_kprobe_type type); #endif /* _TRACE_FS_H */ diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c index 4970620b28f2..3bba3683f29b 100644 --- a/src/tracefs-kprobes.c +++ b/src/tracefs-kprobes.c @@ -103,3 +103,96 @@ int tracefs_kretprobe_raw(const char *system, const char *event, { return insert_kprobe("r", system, event, addr, format); } + +/** + * tracefs_get_kprobes - return a list kprobes (by group/event name) + * @type: The type of kprobes to return. + * + * If @type is TRACEFS_ALL_KPROBES all kprobes in the kprobe_events + * are returned. Otherwise if it is TRACEFS_KPROBE, then only + * normal kprobes (p:) are returned, or if type is TRACEFS_KRETPROBE + * then only kretprobes (r:) are returned. + * + * Returns a list of strings that contain the kprobes that exist + * in the kprobe_events files. The strings returned are in the + * "group/event" format. + * The list must be freed with tracefs_list_free(). + * If there are no kprobes, a list is still returned, but it contains + * only a NULL pointer. + * On error, NULL is returned. + */ +char **tracefs_get_kprobes(enum tracefs_kprobe_type type) +{ + char **list = NULL; + char *content; + char *saveptr; + char *event; + char *p; + int cnt = 0; + + errno = 0; + content = tracefs_instance_file_read(NULL, KPROBE_EVENTS, NULL); + if (!content) { + if (errno) + return NULL; + /* content is NULL on empty file, return an empty list */ + list = calloc(1, sizeof(*list)); + return list; + } + + p = strtok_r(content, ":", &saveptr); + + while (p) { + char **tmp; + + if (type != TRACEFS_ALL_KPROBES) { + switch (*p) { + case 'p': + if (type != TRACEFS_KPROBE) + goto next; + break; + case 'r': + if (type != TRACEFS_KRETPROBE) + goto next; + break; + default: + goto next; + } + } + + /* Failed parsing always return a failure */ + p = strtok_r(NULL, " ", &saveptr); + if (!p) + break; + + event = strdup(p); + if (!event) + goto fail; + + tmp = realloc(list, sizeof(*list) * (cnt + 2)); + if (!tmp) + goto fail; + + list = tmp; + list[cnt++] = event; + list[cnt] = NULL; + next: + p = strtok_r(NULL, "\n", &saveptr); + /* Could be end of content */ + if (!p) + break; + + /* p is NULL on end of content */ + p = strtok_r(NULL, ":", &saveptr); + } + + if (!list) + list = calloc(1, sizeof(*list)); + out: + free(content); + return list; + fail: + free(list); + list = NULL; + goto out; +} -- 2.30.2