On Tue, 2018-02-20 at 23:43 +0200, Andy Shevchenko wrote: > There are users which print time and date represented by content of > struct rtc_time in human readable format. > > Instead of open coding that each time introduce %ptR[dt][rv] specifier. > > Note, users have to select PRINTK_PEXT_TIMEDATE option in a Kconfig. Not sure this is a great option. Not just the name, the need to select it. > diff --git a/lib/vsprintf.c b/lib/vsprintf.c [] > +static noinline_for_stack > +char *date_str(char *buf, char *end, const struct rtc_time *tm, bool v, bool r) > +{ > + int year = tm->tm_year + (r ? 0 : 1900); > + int mon = tm->tm_mon + (r ? 0 : 1); What happens with negative values? Perhaps these temporaries should be unsigned int. > + > + if (unlikely(v && (unsigned int)tm->tm_year > 200)) > + buf = string(buf, end, "****", default_str_spec); > + else > + buf = number(buf, end, year, default_dec04_spec); > + > + if (buf < end) > + *buf = '-'; > + buf++; > + > + if (unlikely(v && (unsigned int)tm->tm_mon > 11)) > + buf = string(buf, end, "**", default_str_spec); > + else > + buf = number(buf, end, mon, default_dec02_spec); > + > + if (buf < end) > + *buf = '-'; > + buf++; > + > + if (unlikely(v && (unsigned int)tm->tm_mday > 31)) > + buf = string(buf, end, "**", default_str_spec); > + else > + buf = number(buf, end, tm->tm_mday, default_dec02_spec); > + > + return buf; > +} > + > +static noinline_for_stack > +char *time_str(char *buf, char *end, const struct rtc_time *tm, bool v, bool r) > +{ Maybe use unsigned int temporaries here too for hour, min, sec > + if (unlikely(v && (unsigned int)tm->tm_hour > 24)) > + buf = string(buf, end, "**", default_str_spec); > + else > + buf = number(buf, end, tm->tm_hour, default_dec02_spec); > + > + if (buf < end) > + *buf = ':'; > + buf++; > + > + if (unlikely(v && (unsigned int)tm->tm_min > 59)) leap seconds are allowed in the struct > + buf = string(buf, end, "**", default_str_spec); > + else > + buf = number(buf, end, tm->tm_min, default_dec02_spec); > + > + if (buf < end) > + *buf = ':'; > + buf++; > + > + if (unlikely(v && (unsigned int)tm->tm_sec > 59)) > + buf = string(buf, end, "**", default_str_spec); > + else > + buf = number(buf, end, tm->tm_sec, default_dec02_spec); > + > + return buf; > +} >