From patchwork Sun Sep 24 13:38:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13396975 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF416CA4C; Sun, 24 Sep 2023 13:38:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80C1CC433C9; Sun, 24 Sep 2023 13:38:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695562688; bh=CLUahLECFFMThaMlg6kBR2ihukQ2SmAsdwcA4AdH8rk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pV93df4UU5q1m05W20xMqKCAie39MI7vyF8y2HIqDTWOsxFBvDzv2eP9xz/EzI0oF e0r4Iuz1rqZhPm2sX88w62J6AMOUShFxf9hVU3p8esqhejBVuWBiqvGfDkIsyv8cdz V02/uAiHnmVFhuk0yj086D+g54+ycpHy3bAB3VryqWXWYY/mxSa66sxl400CIEnKNH tHNbC2rokwrO5AowIFkrUaC4WenWq9wlV/3DYfIR5XkbfMCb0g0IcWm9n45dsLd5Mb 4bF04iwvGb3sWZPighPuFFn7s7wBq6B5nrMjhIYKf1I0uJ+RR6vuiW51e7xhy4OvoC ghBfS8cf5aNOA== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v5 11/12] Documentation: probes: Update fprobe document to use ftrace_regs Date: Sun, 24 Sep 2023 22:38:01 +0900 Message-Id: <169556268150.146934.2968626447452628416.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169556254640.146934.5654329452696494756.stgit@devnote2> References: <169556254640.146934.5654329452696494756.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Update fprobe document so that the entry/exit handler uses ftrace_regs instead of pt_regs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest --- Documentation/trace/fprobe.rst | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/Documentation/trace/fprobe.rst b/Documentation/trace/fprobe.rst index 196f52386aaa..64ef522f7a64 100644 --- a/Documentation/trace/fprobe.rst +++ b/Documentation/trace/fprobe.rst @@ -91,9 +91,9 @@ The prototype of the entry/exit callback function are as follows: .. code-block:: c - int entry_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data); + int entry_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct ftrace_regs *fregs, void *entry_data); - void exit_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data); + void exit_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct ftrace_regs *fregs, 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. @@ -112,12 +112,10 @@ If the entry callback function returns !0, the corresponding exit callback will This is the return address that the traced function will return to, somewhere in the caller. This can be used at both entry and exit. -@regs - This is the `pt_regs` data structure at the entry and exit. Note that - the instruction pointer of @regs may be different from the @entry_ip - in the entry_handler. If you need traced instruction pointer, you need - to use @entry_ip. On the other hand, in the exit_handler, the instruction - pointer of @regs is set to the current return address. +@fregs + This is the `ftrace_regs` data structure at the entry and exit. Note that + the instruction pointer of @fregs may be incorrect in entry handler and + exit handler, so you have to use @entry_ip and @ret_ip instead. @entry_data This is a local storage to share the data between entry and exit handlers.