On Tue, Oct 29, 2024 at 05:48:58PM +0900, Gyeyoung Baek wrote:
if CONFIG_DRM_USE_DYNAMIC_DEBUG is set,
'drm_dbg' function is replaced with '__dynamic_func_call_cls',
which is replaced with a do while statement.
so in the previous code, there are the following build errors.
include/linux/dynamic_debug.h:221:58: error: expected expression before ‘do’
221 | #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
| ^~
include/linux/dynamic_debug.h:248:9: note: in expansion of macro ‘__dynamic_func_call_cls’
248 | __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~~~~~~
include/drm/drm_print.h:425:9: note: in expansion of macro ‘_dynamic_func_call_cls’
425 | _dynamic_func_call_cls(cat, fmt, __drm_dev_dbg, \
| ^~~~~~~~~~~~~~~~~~~~~~
include/drm/drm_print.h:504:9: note: in expansion of macro ‘drm_dev_dbg’
504 | drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
| ^~~~~~~~~~~
include/drm/drm_print.h:522:33: note: in expansion of macro ‘drm_dbg_driver’
522 | #define drm_dbg(drm, fmt, ...) drm_dbg_driver(drm, fmt, ##__VA_ARGS__)
| ^~~~~~~~~~~~~~
drivers/gpu/drm/xe/xe_macros.h:14:21: note: in expansion of macro ‘drm_dbg’
14 | ((cond) && (drm_dbg(&(xe)->drm, \
| ^~~~~~~
drivers/gpu/drm/xe/xe_bo.c:2029:13: note: in expansion of macro ‘XE_IOCTL_DBG’
2029 | if (XE_IOCTL_DBG(xe, !gem_obj))
the problem is that,
XE_IOCTL_DBG uses this function for conditional expr.
so I fix the expr to be compatible with the do while statement,
by referring to "https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html";.
v2: I modified this to print when only cond is true.
Signed-off-by: Gyeyoung Baek <gye976@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_macros.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_macros.h b/drivers/gpu/drm/xe/xe_macros.h
index daf56c846d03..ac2bd103bb22 100644
--- a/drivers/gpu/drm/xe/xe_macros.h
+++ b/drivers/gpu/drm/xe/xe_macros.h
@@ -11,8 +11,12 @@
#define XE_WARN_ON WARN_ON
#define XE_IOCTL_DBG(xe, cond) \
- ((cond) && (drm_dbg(&(xe)->drm, \
- "Ioctl argument check failed at %s:%d: %s", \
- __FILE__, __LINE__, #cond), 1))
+({ \
+ if ((cond)) \
+ drm_dbg(&(xe)->drm, \
+ "Ioctl argument check failed at %s:%d: %s", \
+ __FILE__, __LINE__, #cond); \
+ (cond); \
there's a double cond evaluation here and given any expression can be
given to XE_IOCTL_DBG(), this doens't look very safe. I think this would
be safer as:
#define XE_IOCTL_DBG(xe, cond) ({ \
int cond__ = !!(cond); \
if (cond__) \
drm_dbg(&(xe)->drm, \
"Ioctl argument check failed at %s:%d: %s", \
__FILE__, __LINE__, #cond); \
cond__; \
})
as it then evaluates cond just once. Also the generated code seems to be
sane compared to what we had before too.
And I also needed this to build-test:
| diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
| index 08cfea04e22bd..82585d442f017 100644
| --- a/drivers/gpu/drm/drm_print.c
| +++ b/drivers/gpu/drm/drm_print.c
| @@ -215,9 +215,8 @@ void __drm_printfn_dbg(struct drm_printer *p, struct va_format *vaf)
| {
| const struct drm_device *drm = p->arg;
| const struct device *dev = drm ? drm->dev : NULL;
| - enum drm_debug_category category = p->category;
|
| - if (!__drm_debug_enabled(category))
| + if (!__drm_debug_enabled(p->category))
| return;
|
| __drm_dev_vprintk(dev, KERN_DEBUG, p->origin, p->prefix, vaf);
as otherwise it complains category is unused.
Lucas De Marchi
