[PATCH v3 1/6] nptl: Make pthread_kill async-signal-safe

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> Changes from v2:
> * Rebase against master.
>
> Changes from v1:
> * Move __libc_signal_block_all prior TID read.
>
> ---
>
> Simiar to raise (BZ #15368), pthread_kill is also defined as
> async-signal-safe (POSIX.1-2008 TC1).  However, similar to raise
> it has the same issues relating to signal handling.
>
> Different than raise, all the signal are blocked so it would be
> possible to implement pthread_cancel (which also should be
> async-cancel safe).

I think it would make sense to spell out what the actual bug fix is.

It's hard to tell whether pthread_kill is now truly async-signal-safe,
given that there is still a race with regards to thread exit and TID
reuse.

Thanks,
Florian