[PATCH v2] dyndbg: Ignore additional arguments from pr_fmt

[Philipp Hahn]

pr_fmt can be used to add a common prefix to any output from a module:
	#define pr_fmt(fmt) KBUILD_MODNAME ".%s " fmt, __func__

But adding additional arguments breaks dynamic debug:
> error: macro "DEFINE_DYNAMIC_DEBUG_METADATA_CLS" passed 4 arguments, but takes just 3
> |         pr_debug_ratelimited("%s", "Hello world!");
> |                                                  ^
> note: macro "DEFINE_DYNAMIC_DEBUG_METADATA_CLS" defined here
> | #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)       \
> |
> error: ‘DEFINE_DYNAMIC_DEBUG_METADATA_CLS’ undeclared (first use in this function)
> |         DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt)
> |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> note: in expansion of macro ‘DEFINE_DYNAMIC_DEBUG_METADATA’
> |         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
> |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> note: in expansion of macro ‘pr_debug_ratelimited’
> |         pr_debug_ratelimited("%s", "Hello world!");
> |         ^~~~~~~~~~~~~~~~~~~~

Add an additional ', ...' to DEFINE_DYNAMIC_DEBUG_METADATA_CLS to slurp
any additional argument, which `pr_fmt` might add.

Signed-off-by: Philipp Hahn <phahn-oss@xxxxxx>
Acked-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
 include/linux/dynamic_debug.h | 2 +-
 lib/test_dynamic_debug.c      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 05743900a1169..0ac0df04bac00 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -167,7 +167,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 		dump_stack();					\
 }
 
-#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
+#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt, ...)	\
 	static struct _ddebug  __aligned(8)			\
 	__section("__dyndbg") name = {				\
 		.modname = KBUILD_MODNAME,			\
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 77c2a669b6afd..cf1e3b5f6f0f8 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -6,7 +6,7 @@
  *      Jim Cromie	<jim.cromie@xxxxxxxxx>
  */
 
-#define pr_fmt(fmt) "test_dd: " fmt
+#define pr_fmt(fmt) "test_dd: %s " fmt, __func__
 
 #include <linux/module.h>
 
@@ -155,7 +155,7 @@ static int __init test_dynamic_debug_init(void)
 
 static void __exit test_dynamic_debug_exit(void)
 {
-	pr_debug("exited\n");
+	pr_debug_ratelimited("exited\n");
 }
 
 module_init(test_dynamic_debug_init);
-- 
2.43.0