From mboxrd@z Thu Jan 1 00:00:00 1970 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 79F701CCAF for ; Sat, 12 Aug 2023 05:38:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8381C433C8; Sat, 12 Aug 2023 05:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691818696; bh=nAPla5bM8WSnDqOSNz1wS0JqUKaETcUf6cGd53WZP3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vIyseh5+5Iingx8OnLvN6kaJ7wrl4oBRajbwJKbZugplFLx7LonBLHuGJaNAidhln Qj456vP1yYN9RTIN1KuRcN1+7BD2igrXkl02vy+9zwYogTG1qgfV9HKHQjlGtrmyRk 7F3XE+M124rLYmw3dNQ+yLvjS+4/VIV0NVZmZYodOkndN7GRRi1pjqquI0UCwfICEA oMtY+DIpevdQU/qN/LntUD3J3ZAHzGhhrRsKDfHB2WpivcowDRu1nwtpEhigKlCUxd VbiOauyMb0KjEINJ82tB7NfWPNNOduLNqjb/NTr8azbs51dA96LmNmw/uL73Jlv6Lt WbQlYsCxikycQ== 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 Subject: [PATCH v3 8/8] Documentations: probes: Update fprobe document to use ftrace_regs Date: Sat, 12 Aug 2023 14:38:10 +0900 Message-Id: <169181869006.505132.4695602314698748304.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169181859570.505132.10136520092011157898.stgit@devnote2> References: <169181859570.505132.10136520092011157898.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit 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) --- 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 a6d682478147..8eee88eda4e6 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 of the traced function. 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 currect 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.