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 A4344C07E95 for ; Fri, 2 Jul 2021 20:17:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DC6761422 for ; Fri, 2 Jul 2021 20:17:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232759AbhGBUUD (ORCPT ); Fri, 2 Jul 2021 16:20:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:42680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232733AbhGBUUD (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 DE3836135C; 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-000i0O-Oo; 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 03/10] libtracefs: Implement tracefs_kretprobe_raw() Date: Fri, 2 Jul 2021 16:17:20 -0400 Message-Id: <20210702201727.169080-4-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 an interface that is similar to tracefs_kprobe_raw() but creates a "kretprobe". The difference between a kprobe and a kretprobe is that a kretprobe comes at the end of a function. See Documentation/trace/kprobetrace.rst in the Linux kernel source code for more information. Note, kprobes are started with "p" and kretprobe lines start with an "r". Signed-off-by: Steven Rostedt (VMware) --- include/tracefs.h | 3 +- src/tracefs-kprobes.c | 85 ++++++++++++++++++++++++++++++------------- 2 files changed, 61 insertions(+), 27 deletions(-) diff --git a/include/tracefs.h b/include/tracefs.h index bc504bcb0188..64164c8c2b20 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -217,5 +217,6 @@ 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_kretprobe_raw(const char *system, const char *event, + const char *addr, const char *format); #endif /* _TRACE_FS_H */ diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c index d50191d55181..4970620b28f2 100644 --- a/src/tracefs-kprobes.c +++ b/src/tracefs-kprobes.c @@ -19,28 +19,9 @@ #define KPROBE_EVENTS "kprobe_events" -/** - * tracefs_kprobe_raw - Create a kprobe using raw format - * @system: The system name (NULL for the default kprobes) - * @event: The event to create (NULL to use @addr for the event) - * @addr: The function and offset (or address) to insert the probe - * @format: The raw format string to define the probe. - * - * Create a kprobe that will be in the @system group (or kprobes if - * @system is NULL). Have the name of @event (or @addr if @event is - * NULL). Will be inserted to @addr (function name, with or without - * offset, or a address). And the @format will define the raw format - * of the kprobe. See the Linux documentation file under: - * Documentation/trace/kprobetrace.rst - * - * Return 0 on success, or -1 on error. - * If the syntex of @format was incorrect, running - * tracefs_error_last(NULL) may show what went wrong. - * - * errno will be set to EBADMSG if addr or format is NULL. - */ -int tracefs_kprobe_raw(const char *system, const char *event, - const char *addr, const char *format) +static int insert_kprobe(const char *type, const char *system, + const char *event, const char *addr, + const char *format) { char *str; int ret; @@ -56,11 +37,11 @@ int tracefs_kprobe_raw(const char *system, const char *event, event = addr; if (system) - ret = asprintf(&str, "p:%s/%s %s %s\n", - system, event, addr, format); + ret = asprintf(&str, "%s:%s/%s %s %s\n", + type, system, event, addr, format); else - ret = asprintf(&str, "p:%s %s %s\n", - event, addr, format); + ret = asprintf(&str, "%s:%s %s %s\n", + type, event, addr, format); if (ret < 0) return -1; @@ -70,3 +51,55 @@ int tracefs_kprobe_raw(const char *system, const char *event, return ret < 0 ? ret : 0; } + +/** + * tracefs_kprobe_raw - Create a kprobe using raw format + * @system: The system name (NULL for the default kprobes) + * @event: The event to create (NULL to use @addr for the event) + * @addr: The function and offset (or address) to insert the probe + * @format: The raw format string to define the probe. + * + * Create a kprobe that will be in the @system group (or kprobes if + * @system is NULL). Have the name of @event (or @addr if @event is + * NULL). Will be inserted to @addr (function name, with or without + * offset, or a address). And the @format will define the raw format + * of the kprobe. See the Linux documentation file under: + * Documentation/trace/kprobetrace.rst + * + * Return 0 on success, or -1 on error. + * If the syntex of @format was incorrect, running + * tracefs_error_last(NULL) may show what went wrong. + * + * errno will be set to EBADMSG if addr or format is NULL. + */ +int tracefs_kprobe_raw(const char *system, const char *event, + const char *addr, const char *format) +{ + return insert_kprobe("p", system, event, addr, format); +} + +/** + * tracefs_kretprobe_raw - Create a kretprobe using raw format + * @system: The system name (NULL for the default kprobes) + * @event: The event to create (NULL to use @addr for the event) + * @addr: The function and offset (or address) to insert the retprobe + * @format: The raw format string to define the retprobe. + * + * Create a kretprobe that will be in the @system group (or kprobes if + * @system is NULL). Have the name of @event (or @addr if @event is + * NULL). Will be inserted to @addr (function name, with or without + * offset, or a address). And the @format will define the raw format + * of the kprobe. See the Linux documentation file under: + * Documentation/trace/kprobetrace.rst + * + * Return 0 on success, or -1 on error. + * If the syntex of @format was incorrect, running + * tracefs_error_last(NULL) may show what went wrong. + * + * errno will be set to EBADMSG if addr or format is NULL. + */ +int tracefs_kretprobe_raw(const char *system, const char *event, + const char *addr, const char *format) +{ + return insert_kprobe("r", system, event, addr, format); +} -- 2.30.2