tracing: add trace_array_printk for internal tracers to use

This patch adds a trace_array_printk to allow a tracer to use the
trace_printk on its own trace array.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -1201,7 +1201,23 @@ out:
 }
 EXPORT_SYMBOL_GPL(trace_vbprintk);
 
-int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+int trace_array_printk(struct trace_array *tr,
+		       unsigned long ip, const char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	if (!(trace_flags & TRACE_ITER_PRINTK))
+		return 0;
+
+	va_start(ap, fmt);
+	ret = trace_array_vprintk(tr, ip, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+int trace_array_vprintk(struct trace_array *tr,
+			unsigned long ip, const char *fmt, va_list args)
 {
 	static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
 	static char trace_buf[TRACE_BUF_SIZE];
@@ -1209,7 +1225,6 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 	struct ftrace_event_call *call = &event_print;
 	struct ring_buffer_event *event;
 	struct ring_buffer *buffer;
-	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
 	int cpu, len = 0, size, pc;
 	struct print_entry *entry;
@@ -1260,6 +1275,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 
 	return len;
 }
+
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+{
+	return trace_array_printk(&global_trace, ip, fmt, args);
+}
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
 enum trace_file_type {

kernel/trace/trace.h

@@ -566,6 +566,11 @@ extern int
 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
+extern int
+trace_array_vprintk(struct trace_array *tr,
+		    unsigned long ip, const char *fmt, va_list args);
+int trace_array_printk(struct trace_array *tr,
+		       unsigned long ip, const char *fmt, ...);
 
 extern unsigned long trace_flags;