Commit 34464a5b8937b79801776dfb6970c1b949fed4be
Committed by
Andi Kleen
Andi Kleen
1 parent
a549b86dd0
Exists in
master
and in
4 other branches
[PATCH] Detect clock skew during suspend
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 x86_64. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@suse.de>
Showing 1 changed file with 9 additions and 1 deletions Side-by-side Diff
arch/x86_64/kernel/time.c
| ... | ... | @@ -1039,8 +1039,16 @@ |
| 1039 | 1039 | unsigned long flags; |
| 1040 | 1040 | unsigned long sec; |
| 1041 | 1041 | unsigned long ctime = get_cmos_time(); |
| 1042 | - unsigned long sleep_length = (ctime - sleep_start) * HZ; | |
| 1042 | + long sleep_length = (ctime - sleep_start) * HZ; | |
| 1043 | 1043 | |
| 1044 | + if (sleep_length < 0) { | |
| 1045 | + printk(KERN_WARNING "Time skew detected in timer resume!\n"); | |
| 1046 | + /* The time after the resume must not be earlier than the time | |
| 1047 | + * before the suspend or some nasty things will happen | |
| 1048 | + */ | |
| 1049 | + sleep_length = 0; | |
| 1050 | + ctime = sleep_start; | |
| 1051 | + } | |
| 1044 | 1052 | if (vxtime.hpet_address) |
| 1045 | 1053 | hpet_reenable(); |
| 1046 | 1054 | else |