On 19/05/2017 at 22:18:55 +0530, Vaibhav Jain wrote: > In function __rtc_read_alarm() its possible for an alarm time-stamp to > be invalid even after replacing missing components with current > time-stamp. The condition 'alarm->time.tm_year < 70' will trigger this > case and will cause the call to 'rtc_tm_to_time64(&alarm->time)' > return a negative value for variable t_alm. > > While handling alarm rollover this negative t_alm (assumed to seconds > offset from '1970-01-01 00:00:00') is converted back to rtc_time via > rtc_time64_to_tm() which results in this error log with seemingly > garbage values: > > "rtc rtc0: invalid alarm value: -2-1--1041528741 > 2005511117:71582844:32" > > This error was generated when the rtc driver (rtc-opal in this case) > returned an alarm time-stamp of '00-00-00 00:00:00' to indicate that > the alarm is disabled. Though I have submitted a separate fix for the > rtc-opal driver, this issue may potentially impact other > existing/future rtc drivers. > > To fix this issue the patch validates the alarm time-stamp just after > filling up the missing datetime components and if rtc_valid_tm() still > reports it to be invalid then bails out of the function without > handling the rollover. > > Reported-by: Steve Best <sbest@xxxxxxxxxx> > Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxxxxxxx> > --- > drivers/rtc/interface.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > Applied, thanks. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
