On 2016/08/18 at 18:36, Oliver Neukum wrote:
> On Thu, 2016-08-18 at 18:43 +0800, Chen Yu wrote:
>> Previously we encountered some memory overflow issues due to
>> the bogus sleep time brought by inconsistent rtc, which is
>> triggered when pm_trace is enabled, please refer to:
>> https://patchwork.kernel.org/patch/9286365/
>> It's improper in the first place to call __timekeeping_inject_sleeptime()
>> in case that pm_trace is enabled simply because that "hash" time value
>> will wreckage the timekeeping subsystem.
> Hi,
>
> do you know since when this bug exists?
Hi Oliver,
I think it should be since __timekeeping_inject_sleeptime() was updated to use
@delta
of timespec64 type, which lets it survive the former timespec_valid_strict()
check and
then results in an index larger than 31 into sleep_time_bin[] in subsequent
call.
Regards,
Xunlei
>
>> /**
>> @@ -1662,6 +1668,12 @@ void timekeeping_resume(void)
>> } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
>> ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time);
>> sleeptime_injected = true;
>> + /*
>> + * If rtc is used as persist clock thus it
>> + * would be bogus when pm_trace is enabled.
>> + */
>> + if (!persistent_clock_is_usable())
>> + sleeptime_injected = false;
>> }
>>
>> if (sleeptime_injected)
> How about
>
> sleeptime_injected = persistent_clock_is_usable();
>
> Regards
> Oliver
>
>
