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, 5 insertions, 0 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index 145a75528cc1..8cbec972d8e7 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -329,6 +329,11 @@ struct module
         unsigned int num_tracepoints;
 #endif
 
+#ifdef CONFIG_TRACE_BPRINTK
+        const char **trace_bprintk_fmt_start;
+        unsigned int num_trace_bprintk_fmt;
+#endif
+
 #ifdef CONFIG_MODULE_UNLOAD
         /* What modules depend on me? */
         struct list_head modules_which_use_me;