tracing: add trace_bprintk()

Impact: add a generic printk() for tracing, like trace_printk()

trace_bprintk() uses the infrastructure to record events on ring_buffer.

[ fweisbec@gmail.com: ported to latest -tip, made it work if
  !CONFIG_MODULES, never free the format strings from modules
  because we can't keep track of them and conditionnaly create
  the ftrace format strings section (reported by Steven Rostedt) ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 15 insertions, 0 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ff53509e19f8..46b3cd7a5752 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3848,6 +3848,21 @@ out:
 }
 EXPORT_SYMBOL_GPL(trace_vbprintk);
 
+int __trace_bprintk(unsigned long ip, const char *fmt, ...)
+{
+        int ret;
+        va_list ap;
+
+        if (!fmt)
+                return 0;
+
+        va_start(ap, fmt);
+        ret = trace_vbprintk(ip, fmt, ap);
+        va_end(ap);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(__trace_bprintk);
+
 static int trace_panic_handler(struct notifier_block *this,
                                unsigned long event, void *unused)
 {