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ACPI: /proc/acpi/alarm parsing: handle large numbers properly 

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>
This commit is contained in:
Yi Yang 2007-12-27 22:04:26 -05:00 committed by Len Brown
parent c68cb23dde
commit 0879802950
1 changed files with 10 additions and 31 deletions
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41
drivers/acpi/sleep/proc.c
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@ -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);