diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ed7b5d1..2a22255 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4629,7 +4629,8 @@
 rb_simple_read(struct file *filp, char __user *ubuf,
 	       size_t cnt, loff_t *ppos)
 {
-	struct ring_buffer *buffer = filp->private_data;
+	struct trace_array *tr = filp->private_data;
+	struct ring_buffer *buffer = tr->buffer;
 	char buf[64];
 	int r;
 
@@ -4647,7 +4648,8 @@
 rb_simple_write(struct file *filp, const char __user *ubuf,
 		size_t cnt, loff_t *ppos)
 {
-	struct ring_buffer *buffer = filp->private_data;
+	struct trace_array *tr = filp->private_data;
+	struct ring_buffer *buffer = tr->buffer;
 	unsigned long val;
 	int ret;
 
@@ -4734,7 +4736,7 @@
 			  &trace_clock_fops);
 
 	trace_create_file("tracing_on", 0644, d_tracer,
-			    global_trace.buffer, &rb_simple_fops);
+			    &global_trace, &rb_simple_fops);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 	trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 95059f0..f95d65d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -836,11 +836,11 @@
 		     filter)
 #include "trace_entries.h"
 
-#ifdef CONFIG_FUNCTION_TRACER
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
 int perf_ftrace_event_register(struct ftrace_event_call *call,
 			       enum trace_reg type, void *data);
 #else
 #define perf_ftrace_event_register NULL
-#endif /* CONFIG_FUNCTION_TRACER */
+#endif
 
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 859fae6b..df611a0 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -652,6 +652,8 @@
 {
 	u64 next_ts;
 	int ret;
+	/* trace_find_next_entry will reset ent_size */
+	int ent_size = iter->ent_size;
 	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry = iter->ent,
 			   *next_entry = trace_find_next_entry(iter, NULL,
@@ -660,6 +662,9 @@
 	unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 	unsigned long rel_usecs;
 
+	/* Restore the original ent_size */
+	iter->ent_size = ent_size;
+
 	if (!next_entry)
 		next_ts = iter->ts;
 	rel_usecs = ns2usecs(next_ts - iter->ts);