Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 2A74CC433C9
From:   Tingwei Zhang <tingwei@codeaurora.org>
To:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>
Cc:     Tingwei Zhang <tingwei@codeaurora.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        tsoni@codeaurora.org,
        Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
        Mao Jinlong <jinlmao@codeaurora.org>,
        linux-kernel@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 4/6] tracing: add trace_export support for trace_marker
Date:   Thu,  3 Sep 2020 08:17:04 +0800
Message-Id: <20200903001706.28147-5-tingwei@codeaurora.org>
In-Reply-To: <20200903001706.28147-1-tingwei@codeaurora.org>
References: <20200903001706.28147-1-tingwei@codeaurora.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add the support to route trace_marker buffer to other destination
via trace_export.

Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/trace.h | 1 +
 kernel/trace/trace.c  | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/include/linux/trace.h b/include/linux/trace.h
index 5a01eeffb254..80b7df68bc0f 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -6,6 +6,7 @@
 
 #define TRACE_EXPORT_FUNCTION	BIT(0)
 #define TRACE_EXPORT_EVENT	BIT(1)
+#define TRACE_EXPORT_MARKER	BIT(2)
 
 /*
  * The trace export - an export of Ftrace output. The trace_export
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2f9302a8b322..67993abda394 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -271,6 +271,7 @@ static struct trace_export __rcu *ftrace_exports_list __read_mostly;
 
 static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
 static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled);
 
 static inline void ftrace_exports_enable(struct trace_export *export)
 {
@@ -279,6 +280,9 @@ static inline void ftrace_exports_enable(struct trace_export *export)
 
 	if (export->flags & TRACE_EXPORT_EVENT)
 		static_branch_inc(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_inc(&trace_marker_exports_enabled);
 }
 
 static inline void ftrace_exports_disable(struct trace_export *export)
@@ -288,6 +292,9 @@ static inline void ftrace_exports_disable(struct trace_export *export)
 
 	if (export->flags & TRACE_EXPORT_EVENT)
 		static_branch_dec(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_dec(&trace_marker_exports_enabled);
 }
 
 static void ftrace_exports(struct ring_buffer_event *event, int flag)
@@ -6648,6 +6655,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	} else
 		entry->buf[cnt] = '\0';
 
+	if (static_branch_unlikely(&trace_marker_exports_enabled))
+		ftrace_exports(event, TRACE_EXPORT_MARKER);
 	__buffer_unlock_commit(buffer, event);
 
 	if (tt)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project