X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace_printk.c;h=1c2b28536feb8113a408b2335c38fb0a0c4272e1;hb=7dac7102afbeb99daa454f555f1ea1f42fad2f78;hp=36c1455b7567ee11f2305cc71b2aa9f48c2a0ae1;hpb=2e455c27bddbf8cf6d1039daea40de8e6865c453;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 36c1455b7567..1c2b28536feb 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -178,6 +178,12 @@ static inline void format_mod_start(void) { }
 static inline void format_mod_stop(void) { }
 #endif /* CONFIG_MODULES */
 
+static bool __read_mostly trace_printk_enabled = true;
+
+void trace_printk_control(bool enabled)
+{
+	trace_printk_enabled = enabled;
+}
 
 __initdata_or_module static
 struct notifier_block module_trace_bprintk_format_nb = {
@@ -192,7 +198,7 @@ int __trace_bprintk(unsigned long ip, const char *fmt, ...)
 	if (unlikely(!fmt))
 		return 0;
 
-	if (!(trace_flags & TRACE_ITER_PRINTK))
+	if (!trace_printk_enabled)
 		return 0;
 
 	va_start(ap, fmt);
@@ -207,7 +213,7 @@ int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap)
 	if (unlikely(!fmt))
 		return 0;
 
-	if (!(trace_flags & TRACE_ITER_PRINTK))
+	if (!trace_printk_enabled)
 		return 0;
 
 	return trace_vbprintk(ip, fmt, ap);
@@ -219,7 +225,7 @@ int __trace_printk(unsigned long ip, const char *fmt, ...)
 	int ret;
 	va_list ap;
 
-	if (!(trace_flags & TRACE_ITER_PRINTK))
+	if (!trace_printk_enabled)
 		return 0;
 
 	va_start(ap, fmt);
@@ -231,7 +237,7 @@ EXPORT_SYMBOL_GPL(__trace_printk);
 
 int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
 {
-	if (!(trace_flags & TRACE_ITER_PRINTK))
+	if (!trace_printk_enabled)
 		return 0;
 
 	return trace_vprintk(ip, fmt, ap);