Re: [PATCH] remaining steps for time64 switchover

[Matias Fonzo <selk@dragora.org>]

Hello Rich,

El 2019-10-27 18:14, Rich Felker escribió:
> On Sun, Oct 27, 2019 at 05:12:59PM -0300, Matias Fonzo wrote:
>> Hello Laurent,
>> 
>> Can utmps work without s6?.  I mean, independently of the init
>> system or distribution...
> 
> Laurent could answer in better detail, but as a quick answer, there's
> no requirement from having s6 installed that you use it as your init
> system.
> 

I thought so, but there could be a configuration-side requirement or 
daemon (setup) to work properly, I don't know.  We are using perp for 
Dragora.

> 
> 
>> El 2019-10-27 05:32, Laurent Bercot escribió:
>> >>Or here. So, the story on utmpx: we can either
>> >>
>> >>1. match the current size on 32-bit archs, but move the timeval to
>> >>   unused space at the end where a time64 version fits, or
>> >>
>> >>2. match the current size and layout of the 64-bit struct, making it
>> >>   possible to share records between 32- and 64-bit processes on the
>> >>   same machine.
>> >>
>> >>Keep in mind that this struct is not used anywhere in libc presently,
>> >>but normally it's used as a format for on-disk records.
>> >>
>> >>I'm kinda leaning towards option 2, but being that I don't use (and
>> >>hate) utmp, I'd rather hear opinions from people who do use it. Either
>> >>way time fields in existing data will break, so it's a question of
>> >>whether that one-time breakage is already sufficient to go a bit
>> >>further and get 32/64 compat afterwards.
>> >
>> >I don't use the libc's utmpx, but I maintain utmps, which is a secure
>> >implementation of utmp, including the definition of struct utmpx.
>> >I haven't been following the time64 thing closely. The current struct
>> >utmpx definition includes a struct timeval. Will it need to change,
>> >or will musl's struct timeval change be enough and naturally propagate
>> >so the struct utmpx will become time64-compatible?
>> >
>> >On-disk data is not a problem. On the distro that I know uses utmps
>> >(Adélie), the utmp/wtmp records, by design, do not survive a reboot,
>> >so a reboot will fix everything - and will be mandatory anyway on
>> >arches where the musl ABI changes.
>> >
>> >I'm not aware of any distribution that uses musl, doesn't use utmps,
>> >and still keeps on-disk utmpx records.
>> >
>> >--
>> >Laurent