rtc_time_to_tm: fix signed/unsigned arithmetic

73442daf · Jan Altenberg <[email protected]> · 2008-09-02 14:36:05 -07:00

commit 945185a69daa457c4c5e46e47f4afad7dcea734f ("rtc: rtc_time_to_tm: use
unsigned arithmetic") 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.

Signed-off-by: Jan Altenberg <[email protected]>
Cc: Maciej W. Rozycki <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: David Brownell <[email protected]>
Cc: Dmitri Vorobiev <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 73442daf2ea85e2a779396b76b1a39b10188ecb5
Parents: b4a49b12

Changes

1 files changed · +3 −2

File	Status	Add	Del	Content
drivers/rtc/rtc-lib.c	modified	+3	−2	View file

drivers/rtc/rtc-lib.c

View file

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;