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,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 CDD09C11F68 for ; Tue, 29 Jun 2021 20:53:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFABF61D62 for ; Tue, 29 Jun 2021 20:53:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235573AbhF2U4K (ORCPT ); Tue, 29 Jun 2021 16:56:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:50514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235559AbhF2U4J (ORCPT ); Tue, 29 Jun 2021 16:56:09 -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 E306F6128B; Tue, 29 Jun 2021 20:53:41 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1lyKjj-000UT9-UJ; Tue, 29 Jun 2021 16:53:39 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Steven Rostedt (VMware)" Subject: [PATCH 2/3] libtracefs: Implement tracefs_kprobe_clear() to remove all kprobes Date: Tue, 29 Jun 2021 16:53:25 -0400 Message-Id: <20210629205326.117059-3-rostedt@goodmis.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210629205326.117059-1-rostedt@goodmis.org> References: <20210629205326.117059-1-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)" A call to tracefs_kprobe_clear() will attempt to disable all kprobes. If any kprobe is set, and the @force parameter is set, it will fail with errno set to EBUSY. If @force is set, then it will attempt to disable all the defined kprobe events and then clear it. Signed-off-by: Steven Rostedt (VMware) --- include/tracefs.h | 2 +- src/tracefs-kprobes.c | 136 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 137 insertions(+), 1 deletion(-) diff --git a/include/tracefs.h b/include/tracefs.h index 47b05b3f55e7..54c461e85a2b 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -212,5 +212,5 @@ void tracefs_trace_pipe_stop(struct tracefs_instance *instance); int tracefs_kprobe_raw(const char *system, const char *event, const char *addr, const char *format); - +int tracefs_kprobe_clear(bool force); #endif /* _TRACE_FS_H */ diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c index e4b28cff9f08..48a4f090f041 100644 --- a/src/tracefs-kprobes.c +++ b/src/tracefs-kprobes.c @@ -68,3 +68,139 @@ int tracefs_kprobe_raw(const char *system, const char *event, return ret < 0 ? ret : 0; } + +struct instance_list { + struct instance_list *next; + struct tracefs_instance *instance; +}; + +static int disable_events(const char *system, const char *event, + struct instance_list *list) +{ + int ret; + + ret = tracefs_event_disable(NULL, system, event); + if (ret < 0) + return ret; + + while (list) { + ret = tracefs_event_disable(list->instance, system, event); + if (ret < 0) + return ret; + list = list->next; + } + + return 0; +} + +static int build_instances(const char *name, void *data) +{ + struct instance_list ***ptr_next = (struct instance_list ***)data; + struct instance_list **next = *ptr_next; + struct tracefs_instance *instance; + struct instance_list *list; + + instance = tracefs_instance_alloc(NULL, name); + if (!instance) + return -1; + + list = malloc(sizeof(*list)); + if (!list) { + tracefs_instance_free(instance); + return -1; + } + + list->instance = instance; + list->next = *next; + *next = list; + *ptr_next = &list->next; + return 0; +} + +static void free_instance_list(struct instance_list *list) +{ + struct instance_list *n; + + while (list) { + n = list->next; + tracefs_instance_free(list->instance); + free(list); + list = n; + } +} + +/** + * tracefs_kprobe_clear - clear kprobe events + * @force: Will attempt to disable all kprobe events and clear them + * + * Will remove all defined kprobe events. If any of them are enabled, + * and @force is not set, then it will error with -1 and errno to be + * EBUSY. If @force is set, then it will attempt to disable all the kprobe + * events in all instances, and try again. + * + * Returns zero on success, -1 otherwise. + */ +int tracefs_kprobe_clear(bool force) +{ + struct instance_list *list = NULL; + struct instance_list **plist = &list; + char *content; + char *saveptr; + char *system; + char *event; + char *p; + int ret; + + ret = tracefs_instance_file_clear(NULL, KPROBE_EVENTS); + if (!ret) + return 0; + + if (!force) + return -1; + + /* Attempt to disable all kprobe events */ + content = tracefs_instance_file_read(NULL, KPROBE_EVENTS, NULL); + if (!content) + return -1; + + ret = tracefs_instances_walk(build_instances, &plist); + if (ret < 0) + goto out; + + ret = -1; + p = strtok_r(content, ":", &saveptr); + if (!p) + goto out; + + for (;;) { + p = strtok_r(NULL, "/", &saveptr); + if (!p) + goto out; + + system = p; + + p = strtok_r(NULL," ", &saveptr); + if (!p) + goto out; + event = p; + + if (disable_events(system, event, list) < 0) + goto out; + + ret = tracefs_instance_file_clear(NULL, KPROBE_EVENTS); + /* On success stop the loop */ + if (!ret) + goto out; + + ret = -1; + p = strtok_r(NULL, "\n", &saveptr); + if (!p) + goto out; + + p = strtok_r(NULL, ":", &saveptr); + } + out: + free(content); + free_instance_list(list); + return ret; +} -- 2.30.2