Le 03/04/2026 à 23:15, Tom via Dng a écrit :
> On 4/4/2026 00:35, Didier Kryn wrote:
>> Le 03/04/2026 à 11:23, Kevin Chadwick via Dng a écrit :
>>>
>>> -------- Original Message --------
>>>
>>>> which uses assert for invarant checks in the context of the init
>>>> process. Should these asserts ever trigger, they'll stop the
>>>> program via
>>>> abort which will cause a kernel panic because init is special can just
>>>> exit in case of a runtime error. But why would people programming
>>>> in the
>>>> context of init take that into account?
>>> Ada SPARK would be a great choice of language for pid 1 actually. As
>>> you could I
>>> guess quite easily prove it to Silver level and be sure it could
>>> never crash
>>> (AORE; absence of runtime errors).
>>>
>>      Ada is really made for large or complex applications. OTOH, I
>> don't think pid 1 should be complex. There are versions of init
>> written in C which are so tiny that almost everybody with a basic
>> knowledge of the language can review, and of course the most
>> brilliant programmers do. This makes a lot of reviewers. This is the
>> main problem with systemd: the size and the complexity; of course it
>> is worsened because it is written in C, and , why not C++.
>>
>> --     Didier
>
> Indeed, there are tiny init systems designed for containers that are
> less than 1000 lines of code:
>
> https://github.com/krallin/tini - 688 LOC
>
> https://github.com/Yelp/dumb-init - 340 LOC
>
> You can go even further still with this minimal example by Rich
> Felker, the musl libc developer:
>
> https://ewontfix.com/14/ - 22 LOC


    This version is for systems which implement the fork() and execve()
system calls, like Unix and Linux.

>
> Or his improved version:
>
> https://github.com/richfelker/minimal-init - 50 LOC

    This other version is OK for Unix-like systems, but also for those
which lack the fork() and execve() system-calls.

    posix_spawn() is implemented in Linux (and I guess other Unixes) by
the mean of fork() and execve().

    This leads to note that a lot of the program is hidden because it
resides in the C system library. But we assume we can trust the library
more that any other part of the system.

--     Didier