diff options
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index f53b975e32f..018af16bce5 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -157,7 +157,24 @@ static inline void __ftrace_enabled_restore(int enabled) #ifdef CONFIG_TRACING extern void ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); -# define ftrace_printk(x...) __ftrace_printk(_THIS_IP_, x) + +/** + * ftrace_printk - printf formatting in the ftrace buffer + * @fmt: the printf format for printing + * + * Note: __ftrace_printk is an internal function for ftrace_printk and + * the @ip is passed in via the ftrace_printk macro. + * + * This function allows a kernel developer to debug fast path sections + * that printk is not appropriate for. By scattering in various + * printk like tracing in the code, a developer can quickly see + * where problems are occurring. + * + * This is intended as a debugging tool for the developer only. + * Please refrain from leaving ftrace_printks scattered around in + * your code. + */ +# define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt) extern int __ftrace_printk(unsigned long ip, const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); |