Re: [RFC PATCH 0/3] introduce PIDFD_SELF

[Florian Weimer <fweimer@redhat.com>]

* Lorenzo Stoakes:

> If you wish to utilise a pidfd interface to refer to the current process
> (from the point of view of userland - from the kernel point of view - the
> thread group leader), it is rather cumbersome, requiring something like:
>
> 	int pidfd = pidfd_open(getpid(), 0);
>
> 	...
>
> 	close(pidfd);
>
> Or the equivalent call opening /proc/self. It is more convenient to use a
> sentinel value to indicate to an interface that accepts a pidfd that we
> simply wish to refer to the current process.

The descriptor will refer to the current thread, not process, right?

The distinction matters for pidfd_getfd if a process contains multiple
threads with different file descriptor tables, and probably for
pidfd_send_signal as well.

Thanks,
Florian