Re: [musl] [PATCH 2/2] man/man2/fork.2: Document glibc and musl relaxed fork->exec AS requirements

[Florian Weimer <fweimer@redhat.com>]

* Rich Felker:

>> +On glibc and musl libc, this is relaxed;
>> +it is safe to call non-async-signal-safe functions in the time between
>> +.BR fork ()
>> +and
>> +.BR exec ()
>> +\&.

> While glibc has taken measures to make this mostly work, especially
> malloc-after-fork, I don't think glibc has an intentional model for
> ensuring that arbitrary libc functions work right in the child of a
> multithreaded fork. Before accepting such a man page patch, we should
> at least get an official position from glibc on whether they claim
> this property or at least aim for it.

Far from everything in glibc is fork-protected, so the statement is not
true today as far as glibc is concerned.  We try to maintain
compatibility with existing application requirements, but the precise
goals have not been written down.

Thanks,
Florian