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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8016CC6FD18 for ; Wed, 29 Mar 2023 19:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230307AbjC2TqU (ORCPT ); Wed, 29 Mar 2023 15:46:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229940AbjC2Tpx (ORCPT ); Wed, 29 Mar 2023 15:45:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A240CA2 for ; Wed, 29 Mar 2023 12:45:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0F9BA61E21 for ; Wed, 29 Mar 2023 19:45:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 787B0C43442; Wed, 29 Mar 2023 19:45:51 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1phbjy-002Ri3-1x; Wed, 29 Mar 2023 15:45:50 -0400 Message-ID: <20230329194550.418276586@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 29 Mar 2023 15:45:23 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Florent Revest , Will Deacon Subject: [for-next][PATCH 07/25] docs: tracing: Update fprobe documentation References: <20230329194516.146147554@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Masami Hiramatsu (Google)" Update fprobe.rst for - the private entry_data argument - the return value of the entry handler - the nr_rethook_node field. Link: https://lkml.kernel.org/r/167526701579.433354.3057889264263546659.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest Cc: Mark Rutland Cc: Will Deacon Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- Documentation/trace/fprobe.rst | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/Documentation/trace/fprobe.rst b/Documentation/trace/fprobe.rst index b64bec1ce144..40dd2fbce861 100644 --- a/Documentation/trace/fprobe.rst +++ b/Documentation/trace/fprobe.rst @@ -87,14 +87,16 @@ returns as same as unregister_ftrace_function(). The fprobe entry/exit handler ============================= -The prototype of the entry/exit callback function is as follows: +The prototype of the entry/exit callback function are as follows: .. code-block:: c - void callback_func(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs); + int entry_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data); -Note that both entry and exit callbacks have same ptototype. The @entry_ip is -saved at function entry and passed to exit handler. + void exit_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data); + +Note that the @entry_ip is saved at function entry and passed to exit handler. +If the entry callback function returns !0, the corresponding exit callback will be cancelled. @fp This is the address of `fprobe` data structure related to this handler. @@ -113,6 +115,12 @@ saved at function entry and passed to exit handler. to use @entry_ip. On the other hand, in the exit_handler, the instruction pointer of @regs is set to the currect return address. +@entry_data + This is a local storage to share the data between entry and exit handlers. + This storage is NULL by default. If the user specify `exit_handler` field + and `entry_data_size` field when registering the fprobe, the storage is + allocated and passed to both `entry_handler` and `exit_handler`. + Share the callbacks with kprobes ================================ -- 2.39.1