[Buildroot] date command

[Buildroot] date command

[shy]

Hi:


I have a question and need your help.


The linux epoch time is 1970-01-01 00:00:00,  I set the UTC  time, but it has error with "date: cannot set date: Invalid argument".
I'm confused with it.




Best regards!






 
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[Buildroot] date command

[Peter Seiderer]

Hello,

On Mon, 23 Mar 2020 22:47:07 +0800 (CST), shy  <mail_hysong@163.com> wrote:

> Hi:
>
>
> I have a question and need your help.
>
>
> The linux epoch time is 1970-01-01 00:00:00,  I set the UTC  time, but it has error with "date: cannot set date: Invalid argument".
> I'm confused with it.

Please show the exact commands (including options) your use...

Regards,
Peter

>
>
>
>
> Best regards!
>
>
>
>
>
>
>

[Buildroot] date command

[shy]

Hi all:


I test in buildroot and ubuntu, it all can't set time "1970-01-01 00:00:00", there is error message "date: can't set date: Invalid argument".
I don't know why and how to solve the problem. It's UTC time and no timezone.


1. I use buildroot-2013.05, the busybox is in 1.21.1, the linux kernel is in version 4.4.39.


# date -s "1970-01-20 00:00:00"
Tue Jan 20 00:00:00 UTC 1970
# date -R
Tue, 20 Jan 1970 00:00:03 +0000
# date -s "1970-01-01 00:00:00"
date: can't set date: Invalid argument
Thu Jan  1 00:00:00 UTC 1970




2. I test in ubuntu version 14.04.1.
shy at ubuntu:/etc$ sudo date -s "2020-03-01 00:00:00"
Sun Mar  1 00:00:00 UTC 2020
shy at ubuntu:/etc$ date -R
Sun, 01 Mar 2020 00:00:03 +0000

shy at ubuntu:/etc$ sudo date -s "1970-01-01 00:00:00"

date: cannot set date: Invalid argument

Thu Jan  1 00:00:00 UTC 1970

shy at ubuntu:/etc$ uname -a

Linux ubuntu 4.4.0-142-generic #168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux







Best regards!








At 2020-03-24 00:05:49, "Peter Seiderer" <ps.report@gmx.net> wrote:
>Hello,
>
>On Mon, 23 Mar 2020 22:47:07 +0800 (CST), shy  <mail_hysong@163.com> wrote:
>
>> Hi:
>>
>>
>> I have a question and need your help.
>>
>>
>> The linux epoch time is 1970-01-01 00:00:00,  I set the UTC  time, but it has error with "date: cannot set date: Invalid argument".
>> I'm confused with it.
>
>Please show the exact commands (including options) your use...
>
>Regards,
>Peter
>
>>
>>
>>
>>
>> Best regards!
>>
>>
>>
>>
>>
>>
>>
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[Buildroot] date command

[Peter Korsgaard]

>>>>> "shy" == shy  <mail_hysong@163.com> writes:

 > Hi all:
 > I test in buildroot and ubuntu, it all can't set time "1970-01-01 00:00:00", there is error message "date: can't set date: Invalid argument".
 > I don't know why and how to solve the problem. It's UTC time and no timezone.


 > 1. I use buildroot-2013.05, the busybox is in 1.21.1, the linux kernel is in version 4.4.39.


 > # date -s "1970-01-20 00:00:00"
 > Tue Jan 20 00:00:00 UTC 1970
 > # date -R
 > Tue, 20 Jan 1970 00:00:03 +0000
 > # date -s "1970-01-01 00:00:00"
 > date: can't set date: Invalid argument
 > Thu Jan  1 00:00:00 UTC 1970

 > 2. I test in ubuntu version 14.04.1.
 > shy at ubuntu:/etc$ sudo date -s "2020-03-01 00:00:00"
 > Sun Mar  1 00:00:00 UTC 2020
 > shy at ubuntu:/etc$ date -R
 > Sun, 01 Mar 2020 00:00:03 +0000

 > shy at ubuntu:/etc$ sudo date -s "1970-01-01 00:00:00"

 > date: cannot set date: Invalid argument

 > Thu Jan  1 00:00:00 UTC 1970

 > shy at ubuntu:/etc$ uname -a

 > Linux ubuntu 4.4.0-142-generic #168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

This looks to be a kernel regression, presumably introduced by the year
2038 work.

Specifically, it seems to reject settimeofday with a tv_sec value less
than 1171500:

# strace -e settimeofday date -s '1970-01-14 13:24'
settimeofday({tv_sec=1171440, tv_usec=0}, NULL) = -1 EINVAL (Invalid argument)
date: can't set date: Invalid argument

# strace -e settimeofday date -s '1970-01-14 13:25'
settimeofday({tv_sec=1171500, tv_usec=0}, NULL) = 0
Wed Jan 14 13:25:00 UTC 1970

(here on 5.4.18).


On an ancient 2.6.37 kernel it does work:

strace -e settimeofday date -s '1970-01-14 13:24'
settimeofday({tv_sec=1171440, tv_usec=0}, NULL) = 0
Wed Jan 14 13:24:00 UTC 1970
+++ exited with 0 +++
uname -r
2.6.37.6

Arnd, any ideas?

-- 
Bye, Peter Korsgaard

[Buildroot] date command

[Peter Korsgaard]

>>>>> "Arnd" == Arnd Bergmann <arnd@arndb.de> writes:

Hi,

 >> > Linux ubuntu 4.4.0-142-generic #168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
 >> 
 >> This looks to be a kernel regression, presumably introduced by the year
 >> 2038 work.
 >> 
 >> Specifically, it seems to reject settimeofday with a tv_sec value less
 >> than 1171500:
 >> 
 >> # strace -e settimeofday date -s '1970-01-14 13:24'
 >> settimeofday({tv_sec=1171440, tv_usec=0}, NULL) = -1 EINVAL (Invalid argument)
 >> date: can't set date: Invalid argument
 >> 
 >> # strace -e settimeofday date -s '1970-01-14 13:25'
 >> settimeofday({tv_sec=1171500, tv_usec=0}, NULL) = 0
 >> Wed Jan 14 13:25:00 UTC 1970
 >> 
 >> (here on 5.4.18).

 > I think this is a result of commit e1d7ba873555 ("time: Always make sure
 > wall_to_monotonic isn't positive") that enforces CLOCK_REALTIME to return a
 > number greater than CLOCK_MONOTONIC, meaning you cannot set the current
 > time to anything less than the number of seconds since booting the system.
 > This has been the case since linux-4.3, and is unrelated to the y2038 work.

Ahh yes, thanks - And sorry for pointing fingers in the wrong
direction. I did see the check, but didn't connect the dots.

-- 
Bye, Peter Korsgaard