Messages in this thread Patch in this message | | | Subject | [PATCH] rtc_time_to_tm: Fix signed / unsigned arithmetic | From | Jan Altenberg <> | Date | Sat, 02 Aug 2008 16:34:40 +0200 |
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Hi all,
commit 945185a69daa457c4c5e46e47f4afad7dcea734f changed the some types in rtc_time_to_tm() to unsigned:
void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) { - register int days, month, year; + unsigned int days, month, year;
This doesn't work for all cases, because days is checked for < 0 later on:
if (days < 0) { year -= 1; days += 365 + LEAP_YEAR(year); }
I think the correct fix would be to keep days signed and do an appropriate cast later on. See attached patch.
Signed-off-by: Jan Altenberg <jan.altenberg@linutronix.de>
--- diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c index 9f996ec..dd70bf7 100644 --- a/drivers/rtc/rtc-lib.c +++ b/drivers/rtc/rtc-lib.c @@ -51,10 +51,11 @@ EXPORT_SYMBOL(rtc_year_days); */ void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) { - unsigned int days, month, year; + unsigned int month, year; + int days; days = time / 86400; - time -= days * 86400; + time -= (unsigned int) days * 86400; /* day of the week, 1970-01-01 was a Thursday */ tm->tm_wday = (days + 4) % 7;
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