Re: [evlog-dev] [BUG] time stamp of kernel event increases improperly when timezo ne is not UTC

Hi Yi,

CURRENT_TIME is not always be UTC. When the system first starts up,
CURRENT_TIME = 0, little later CURRENT_TIME = CMOS time and finally
CURRENT_TIME = UTC (this happens after the kernel knows the TZ).

So what you see in evlogd.c around lines 1260-1277, basically addresses
the case when CURRENT_TIME=0 (flagged by EVL_INITIAL_BOOT_EVENT) and
CURRENT_TIME=CMOS (flagged by  EVL_KERNTIME_LOCAL, by the way I should
name this flag EVL_KERNTIME_CMOS). As you can see this code should be
around.

 The code at 2794-2796 is actual problematic and should not be there at
all (because time now should be already adjusted). It's probably a merge
error, since I did a pretty big merge for 1.5.0 version. I will fix this
  problem and do more testing on this.

Thanks, Hien.

Zhu, Yi wrote:
> Hi,
> 
> When I ran the kernel test script test1.sh I got a failure. I traced the
> code and found there are two pieces of code trying to adjust the kernel
> message time stamp to local time in file evlogd.c lines 1275~1277 and
> 2794~2796.
> 
> /* Adjust timestamp to local time for kernel event */
> if (logrec->rechdr.log_flags & EVL_KERNEL_EVENT) {
>         logrec->rechdr.log_time.tv_sec = logrec->rechdr.log_time.tv_sec +
> (tz.tz_minuteswest * 60) ;
> }
> 
> But I think the entry rechdr->log_time has been set to the kernel variable
> CURRENT_TIME before. CURRENT_TIME will always be the UTC time (in linux-2.4.
> 19/kernel/time.c line 134). In my redhat 8.0, it will set the kernel time to
> UTC in /etc/rc.sysinit with /sbin/hwclock if the CMOS time is local time.
> And in glibc-2.2.93-5, function localtime_r() will use tzset(3) to get the
> current time zone. So I think there is no need to do this in evlogd.
> 
> Test1.sh passed after I removed those lines.
> 
> Thanks,
> ----------------------------------------------------------------------------
> ----------------------------------------------------
> Opinions expressed are those of the author and do not represent Intel Corp.
> 
> Zhu Yi (Chuyee)
> Intel China Software Lab (ICSL)
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