Detect the situations in which the time after a resume from disk would
be earlier than the time before the suspend and prevent them from
happening on i386.
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
arch/i386/kernel/time.c | 24 ++++++++++++++++++------
1 files changed, 18 insertions(+), 6 deletions(-)
Index: linux-2.6.18-rc4-mm1/arch/i386/kernel/time.c
===================================================================
--- linux-2.6.18-rc4-mm1.orig/arch/i386/kernel/time.c
+++ linux-2.6.18-rc4-mm1/arch/i386/kernel/time.c
@@ -285,16 +285,19 @@ void notify_arch_cmos_timer(void)
mod_timer(&sync_cmos_timer, jiffies + 1);
}
-static long clock_cmos_diff, sleep_start;
+static long clock_cmos_diff;
+static unsigned long sleep_start;
static int timer_suspend(struct sys_device *dev, pm_message_t state)
{
/*
* Estimate time zone so that set_time can update the clock
*/
- clock_cmos_diff = -get_cmos_time();
+ unsigned long ctime = get_cmos_time();
+
+ clock_cmos_diff = -ctime;
clock_cmos_diff += get_seconds();
- sleep_start = get_cmos_time();
+ sleep_start = ctime;
return 0;
}
@@ -302,16 +305,25 @@ static int timer_resume(struct sys_devic
{
unsigned long flags;
unsigned long sec;
- unsigned long sleep_length;
+ unsigned long ctime = get_cmos_time();
+ long sleep_length = (ctime - sleep_start) * HZ;
struct timespec ts;
+
+ if (sleep_length < 0) {
+ printk(KERN_WARNING "Time skew detected in timer resume!\n");
+ /* The time after the resume must not be earlier than the time
+ * before the suspend or some nasty things will happen
+ */
+ sleep_length = 0;
+ ctime = sleep_start;
+ }
#ifdef CONFIG_HPET_TIMER
if (is_hpet_enabled())
hpet_reenable();
#endif
setup_pit_timer();
- sec = get_cmos_time() + clock_cmos_diff;
- sleep_length = (get_cmos_time() - sleep_start) * HZ;
+ sec = ctime + clock_cmos_diff;
ts.tv_sec = sec;
ts.tv_nsec = 0;
do_settimeofday(&ts);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
