From: Zach Brown check pr_debug() arguments When DEBUG isn't defined pr_debug() is defined away as an empty macro. By throwing away the arguments we allow completely incorrect code to build. Instead let's make it an empty inline which checks arguments and mark it so gcc can check the format specification. This results in a seemingly insignificant code size increase. A x86-64 allyesconfig: text data bss dec hex filename 25354768 7191098 4854720 37400586 23ab00a vmlinux.before 25354945 7191138 4854720 37400803 23ab0e3 vmlinux Signed-off-by: Zach Brown Signed-off-by: Andrew Morton --- include/linux/kernel.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff -puN include/linux/kernel.h~pr_debug-check-pr_debug-arguments include/linux/kernel.h --- a/include/linux/kernel.h~pr_debug-check-pr_debug-arguments +++ a/include/linux/kernel.h @@ -203,8 +203,10 @@ extern void dump_stack(void); #define pr_debug(fmt,arg...) \ printk(KERN_DEBUG fmt,##arg) #else -#define pr_debug(fmt,arg...) \ - do { } while (0) +static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...) +{ + return 0; +} #endif #define pr_info(fmt,arg...) \ _