Le 03/08/2025 à 05:57, Jim Cromie a écrit :
> 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>
> ---
> ---
> 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 769f02456c8e0..1785ef5b93b15 100644
> --- a/include/linux/dynamic_debug.h
> +++ b/include/linux/dynamic_debug.h
> @@ -217,20 +217,20 @@ 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__)
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com