Re: [RFC][PATCH 07/11] signal: Deliver group signals via PIDTYPE_TGID not PIDTYPE_PID

[Linus Torvalds]

On Mon, Jul 16, 2018 at 7:50 AM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
>
> In practice since glibc does not make thread id's available I don't
> expect anyone relies on this behavior.  Since no one relies on it we
> can change it without creating a regression.

Actually, there's a really obvious case where this simply isn't true.

Just imagine you're a MIS person or a developer, doing "ps -eLf" to
see what's going on, and want to kill one thread. Either because you
see that one thread using all CPU, or because you are the developer
and you know what's up.

Those thread ID's are exported trivially.

               Linus