Re: [musl] Incorrect thread TID caching

[Rich Felker <dalias@libc.org>]

On Wed, Feb 17, 2021 at 02:49:45PM -0500, Dominic Chen wrote:
> On 2/15/2021 11:56 AM, Rich Felker wrote:
> >Following up on this now, the code in _Fork is something I really
> >don't want to duplicate for clone() for risk of forgetting there's a
> >copy in the latter and letting it bitrot there. I'd rather refactor
> >things so the same logic can be shared...
> 
> Thanks for the update. Can you use something like
> __attribute__((always_inline)) to just write the logic once but
> force it to be inlined into both library functions?

Whether it's inlined isn't really a big deal; this is not a hot path.
It's more just a matter of how it needs to be split up at the source
level, and it seems to be messy whichever way we choose.

Trying to avoid calling __clone doesn't seem like such a good idea,
since the child has to run on a new stack -- if we did avoid it we'd
need a new way to switch stacks. The generic __unmapself has a hack
to do this already that we could reuse without needing new
arch-specific glue though.

I'll keep trying things and see if I come up with something not too
unreasonable.

Rich