From patchwork Tue Feb 25 22:26:04 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13991104 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 F2D98215F44; Tue, 25 Feb 2025 22:26:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740522375; cv=none; b=YVD3vMIMQNMkcPK1warUUIdAGK8gV9+ccEoDivr3XGy8wixpuCUd6csuHHj53FRAAfowTY9mTLbO0ii3QzWwewB/ZoSKdnJ8HlVO5tYiwRLvtVO42tGAh/xICnGAv4iEtXnGlEpCR9f0vMoYCBIZgkCiTrVjpsFrqNVSx7WZS4c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740522375; c=relaxed/simple; bh=V6yqo14s8VZnghlNKFkP7GDMB8LaMpi+LaJvcGP8TW8=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=VSEme1+mvK/y3nL+8JnyxdTmDExFKHclpJjLD5HX5GNmwkinj8Ns6zid6mBNnhWUhgDtnIoTVLRa1wQ86kMlmi4QzVxPKZ9ZLr5COSa/GgJHa+ZeMyfUyBKGOzf4nBcQnhroZTvRqDaV6IwOOQqtJE3qh7KYjp4DCtmy4F5wTmg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F94DC4CEEE; Tue, 25 Feb 2025 22:26:14 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1tn3OA-00000009CJg-0CN1; Tue, 25 Feb 2025 17:26:54 -0500 Message-ID: <20250225222653.895547257@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 25 Feb 2025 17:26:04 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Sven Schnelle , Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , Donglin Peng , Zheng Yejian , bpf@vger.kernel.org Subject: [PATCH v3 3/4] ftrace: Have funcgraph-args take affect during tracing References: <20250225222601.423129938@goodmis.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt Currently, when function_graph is started, it looks at the option funcgraph-args, and if it is set, it will enable tracing of the arguments. But if tracing is already running, and the user enables funcgraph-args, it will have no effect. Instead, it should enable argument tracing when it is enabled, even if it means disabling the function graph tracing for a short time in order to do the transition. Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Sven Schnelle Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Guo Ren Cc: Donglin Peng Cc: Zheng Yejian Link: https://lore.kernel.org/20241223201542.240760965@goodmis.org Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_functions_graph.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 406b21472bde..49fcf665cb58 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -462,7 +462,7 @@ static int graph_trace_init(struct trace_array *tr) else tr->gops->retfunc = trace_graph_return; - /* Make gops functions are visible before we start tracing */ + /* Make gops functions visible before we start tracing */ smp_mb(); ret = register_ftrace_graph(tr->gops); @@ -473,6 +473,28 @@ static int graph_trace_init(struct trace_array *tr) return 0; } +static int ftrace_graph_trace_args(struct trace_array *tr, int set) +{ + trace_func_graph_ent_t entry; + + if (set) + entry = trace_graph_entry_args; + else + entry = trace_graph_entry; + + /* See if there's any changes */ + if (tr->gops->entryfunc == entry) + return 0; + + unregister_ftrace_graph(tr->gops); + + tr->gops->entryfunc = entry; + + /* Make gops functions visible before we start tracing */ + smp_mb(); + return register_ftrace_graph(tr->gops); +} + static void graph_trace_reset(struct trace_array *tr) { tracing_stop_cmdline_record(); @@ -1605,6 +1627,9 @@ func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) if (bit == TRACE_GRAPH_GRAPH_TIME) ftrace_graph_graph_time_control(set); + if (bit == TRACE_GRAPH_ARGS) + return ftrace_graph_trace_args(tr, set); + return 0; }