If the RTC HW returns an invalid time, the rtc_year_days() call would crash. This patch adds error logging in this situation, and removes the tm_yday and tm_wday calculations. These fields should not be relied upon by userspace according to man rtc, and thus we don't need to calculate them.
Signed-off-by: Nick Crews <[email protected]> --- drivers/rtc/rtc-wilco-ec.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c index 8ad4c4e6d557..ff46066a68a4 100644 --- a/drivers/rtc/rtc-wilco-ec.c +++ b/drivers/rtc/rtc-wilco-ec.c @@ -110,10 +110,12 @@ static int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) tm->tm_mday = rtc.day; tm->tm_mon = rtc.month - 1; tm->tm_year = rtc.year + (rtc.century * 100) - 1900; - tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); + /* Ignore other tm fields, man rtc says userspace shouldn't use them. */ - /* Don't compute day of week, we don't need it. */ - tm->tm_wday = -1; + if (rtc_valid_tm(tm)) { + dev_err(dev, "Time from RTC is invalid: %ptRr\n", tm); + return -EIO; + } return 0; } -- 2.21.0
