Re: "[PATCH] selftests/ftrace: Correctly enable event in instance-event.tc"

[Steven Rostedt]

On Wed, 6 Sep 2023 14:50:00 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> BTW, when you ran these, did you apply:
> 
>   https://patchwork.kernel.org/project/linux-trace-kernel/patch/20230905183332.628d7cc0@xxxxxxxxxxxxxxxxxx/

Can you both try the above patch and this patch?

-- Steve

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 35783a7baf15..0827037ee3b8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4973,6 +4973,33 @@ int tracing_open_generic_tr(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+/*
+ * The private pointer of the inode is the trace_event_file.
+ * Update the tr ref count associated to it.
+ */
+int tracing_open_file_tr(struct inode *inode, struct file *filp)
+{
+	struct trace_event_file *file = inode->i_private;
+	int ret;
+
+	ret = tracing_check_open_get_tr(file->tr);
+	if (ret)
+		return ret;
+
+	filp->private_data = inode->i_private;
+
+	return 0;
+}
+
+int tracing_release_file_tr(struct inode *inode, struct file *filp)
+{
+	struct trace_event_file *file = inode->i_private;
+
+	trace_array_put(file->tr);
+
+	return 0;
+}
+
 static int tracing_mark_open(struct inode *inode, struct file *filp)
 {
 	stream_open(inode, filp);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5669dd1f90d9..77debe53f07c 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -610,6 +610,8 @@ void tracing_reset_all_online_cpus(void);
 void tracing_reset_all_online_cpus_unlocked(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
+int tracing_open_file_tr(struct inode *inode, struct file *filp);
+int tracing_release_file_tr(struct inode *inode, struct file *filp);
 bool tracing_is_disabled(void);
 bool tracer_tracing_is_on(struct trace_array *tr);
 void tracer_tracing_on(struct trace_array *tr);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index ed367d713be0..2af92177b765 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2103,9 +2103,10 @@ static const struct file_operations ftrace_set_event_notrace_pid_fops = {
 };
 
 static const struct file_operations ftrace_enable_fops = {
-	.open = tracing_open_generic,
+	.open = tracing_open_file_tr,
 	.read = event_enable_read,
 	.write = event_enable_write,
+	.release = tracing_release_file_tr,
 	.llseek = default_llseek,
 };
 
@@ -2122,9 +2123,10 @@ static const struct file_operations ftrace_event_id_fops = {
 };
 
 static const struct file_operations ftrace_event_filter_fops = {
-	.open = tracing_open_generic,
+	.open = tracing_open_file_tr,
 	.read = event_filter_read,
 	.write = event_filter_write,
+	.release = tracing_release_file_tr,
 	.llseek = default_llseek,
 };
 
-- 
2.40.1