tracing: Add trace_printk sample code

Add sample code to test trace_printk(). The trace_printk() functions should
never be used in production code. This makes testing it a bit more
difficult. Having a sample module that can test use cases of trace_printk()
can help out.

Currently it just tests trace_printk() where it will be converted into:

 trace_bputs()
 trace_puts()
 trace_bprintk()

as well as staying as the normal _trace_printk().

It also tests its use in interrupt context as that will test the auxilery
buffers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/samples/Kconfig b/samples/Kconfig
index 559a58baff6e..27a24571e96c 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -11,6 +11,13 @@ config SAMPLE_TRACE_EVENTS
         help
           This build trace event example modules.
 
+config SAMPLE_TRACE_PRINTK
+        tristate "Build trace_printk module - tests various trace_printk formats"
+        depends on EVENT_TRACING && m
+        help
+         This builds a module that calls trace_printk() and can be used to
+         test various trace_printk() calls from a module.
+
 config SAMPLE_KOBJECT
         tristate "Build kobject examples -- loadable modules only"
         depends on m