[PATCH v2 23/24] dyndbg: change __dynamic_func_call_cls* macros into expressions
From: Jim Cromie <jim.cromie@gmail.com>
Date: 2026-05-23 07:15:42
Also in:
linux-arch, linux-doc, linux-kselftest, lkml
Subsystem:
dynamic debug, the rest · Maintainers:
Jason Baron, Jim Cromie, Linus Torvalds
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, and is not an expression.
if (cond && (drm_dbg("expr-form"),1)) {
... do some more stuff
}
Fix for this usage by changing __dynamic_func_call_cls{,_no_desc}
macros into expressions, by replacing the do-while-0s with a ({ })
wrapper. In the common usage, the trailing ';' converts the
expression into a statement.
drm_dbg("statement form");
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
fix statement-expressions to return 0 (not void) like their respective fallbacks
1. Add 0; to __dynamic_func_call_cls
2. Add 0; to __dynamic_func_call_cls_no_desc
3. Convert the disabled fallback of dynamic_hex_dump from do { ... } while(0) to ({ ... 0; })
move RvB after SoB
---
include/linux/dynamic_debug.h | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 11ec40f488f3..fe73aa27b350 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h@@ -224,24 +224,26 @@ 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__); \ __dynamic_dump_stack(id); \ } \ -} while (0) + 0; /* match no_printk return value */ \ +}) #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__); \ __dynamic_dump_stack(id); \ } \ -} while (0) + 0; /* match no_printk return value */ \ +}) #define __dynamic_func_call_no_desc(id, fmt, func, ...) \ __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \ fmt, func, ##__VA_ARGS__)
@@ -321,10 +323,12 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__) #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ groupsize, buf, len, ascii) \ - do { if (0) \ +({ \ + if (0) \ print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \ - rowsize, groupsize, buf, len, ascii); \ - } while (0) + rowsize, groupsize, buf, len, ascii); \ + 0; \ +}) #endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */
--
2.54.0