[PATCH v9 26/52] dyndbg: change __dynamic_func_call_cls* macros into expressions

Jim Cromie
2024-07-02T21:58:46Z

The Xe driver's XE_IOCTL_DBG macro calls drm_dbg() from inside an if
(expression). This breaks when CONFIG_DRM_USE_DYNAMIC_DEBUG=y because
the invoked macro has a do-while-0 wrapper.

if (cond && (drm_dbg("expr-form"),1)) {
... do some more stuff
}

Fix it by changing __dynamic_func_call_cls{,_no_desc} macros into
expressions, by replacing the do-while-0s with a ({ }) wrapper.

In C, all legal expressions are also legal statements, as converted by
the trailing semi-colon in a statement-style macro invocation:

drm_dbg("statement form");

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
include/linux/dynamic_debug.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 19f959f9a6b4..121a66b0ca25 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -287,20 +287,20 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* (|_cls): adds in _DPRINT_CLASS_DFLT as needed
* (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
*/
-#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) ({ \
DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
if (DYNAMIC_DEBUG_BRANCH(id)) \
func(&id, ##__VA_ARGS__); \
-} while (0)
+})
#define __dynamic_func_call(id, fmt, func, ...) \
__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \
func, ##__VA_ARGS__)

-#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) ({ \
DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
if (DYNAMIC_DEBUG_BRANCH(id)) \
func(__VA_ARGS__); \
-} while (0)
+})
#define __dynamic_func_call_no_desc(id, fmt, func, ...) \
__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \
fmt, func, ##__VA_ARGS__)
--
2.45.2