Commit 08798029 authored Dec 27, 2007 by Yi Yang Committed by Len Brown Dec 27, 2007

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>

parent c68cb23d

drivers/acpi/sleep/proc.c

+10 −31

Original line number	Diff line number	Diff line
		@@ -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);