[PATCH 015/112] ACPI: /proc/acpi/alarm parsing: handle large numbers properly

Len Brown
2008-02-07T09:35:38Z

From: Yi Yang <yi.y.yang@intel.com>

In function acpi_system_write_alarm in file drivers/acpi/sleep/proc.c,
big sec, min, hr, mo, day and yr are counted twice to get reasonable
values, that is very superfluous, we can do that only once.

In additon, /proc/acpi/alarm can set a related value which can be
specified as YYYY years MM months DD days HH hours MM minutes SS
senconds, it isn't a date, so you can specify as +0000-00-00 96:00:00
, that means 3 days later, current code can't handle such a case.

This patch removes unnecessary code and does with the aforementioned
situation.

Before applying this patch:

[root@localhost /]# cat /proc/acpi/alarm
2007-12-00 00:00:00
[root@localhost /]# echo "0000-00-00 96:180:180" > /proc/acpi/alarm
[root@localhost /]# cat /proc/acpi/alarm
0007-12-02 **:**:**
[root@localhost /]#

After applying this patch:

[root@localhost ~]# echo "2007-12-00 00:00:00" > /proc/acpi/alarm
[root@localhost ~]# cat /proc/acpi/alarm
2007-12-00 00:00:00
[root@localhost ~]# echo "0000-00-00 96:180:180" > /proc/acpi/alarm
[root@localhost ~]# cat /proc/acpi/alarm
0007-12-04 03:03:00
[root@localhost ~]#

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/sleep/proc.c | 41 ++++++++++-------------------------------
1 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index 1538355..e19eb0c 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -251,27 +251,6 @@ acpi_system_write_alarm(struct file *file,
if ((result = get_date_field(&p, &sec)))
goto end;

- if (sec > 59) {
- min += 1;
- sec -= 60;
- }
- if (min > 59) {
- hr += 1;
- min -= 60;
- }
- if (hr > 23) {
- day += 1;
- hr -= 24;
- }
- if (day > 31) {
- mo += 1;
- day -= 31;
- }
- if (mo > 12) {
- yr += 1;
- mo -= 12;
- }
-
spin_lock_irq(&rtc_lock);

rtc_control = CMOS_READ(RTC_CONTROL);
@@ -288,24 +267,24 @@ acpi_system_write_alarm(struct file *file,
spin_unlock_irq(&rtc_lock);

if (sec > 59) {
- min++;
- sec -= 60;
+ min += sec/60;
+ sec = sec%60;
}
if (min > 59) {
- hr++;
- min -= 60;
+ hr += min/60;
+ min = min%60;
}
if (hr > 23) {
- day++;
- hr -= 24;
+ day += hr/24;
+ hr = hr%24;
}
if (day > 31) {
- mo++;
- day -= 31;
+ mo += day/32;
+ day = day%32;
}
if (mo > 12) {
- yr++;
- mo -= 12;
+ yr += mo/13;
+ mo = mo%13;
}

spin_lock_irq(&rtc_lock);
--
1.5.4.23.gef5b9