Re: [PATCH v4] signal: add taskfd_send_signal() syscall

Eric W. Biederman
2018-12-06T14:46:57Z

Florian Weimer <fweimer@redhat.com> writes:

> * Eric W. Biederman:
>
>> Floriam are you seeing a problem with this behavior or the way Christian
>> was describing it?
>
> My hope is that you could use taskfd_send_signal one day to send a
> signal to a process which you *known* (based on how you've written your
> application) should be running and not in a zombie state, and get back
> an error if it has exited.
>
> If you get this error, only then you wait on the process, using the file
> descriptor you have, and run some recovery code.
>
> Wouldn't that be a reasonable approach once we've got task descriptors?

Getting an error back if the target was a zombie does seem reasonable,
as in principle it is an easy thing to notice, and post zombie once the
process has been reaped we definitely get an error back.

I also agree that it sounds like an extension, as changing the default
would violate the princile of least surprise.

Eric