Re: [PATCH 2/5] pidfd: add pidfd_wait()

From: Oleg Nesterov
Date: Thu Jul 25 2019 - 14:05:14 EST

On 07/24, Christian Brauner wrote:
> +SYSCALL_DEFINE6(pidfd_wait, int, pidfd, int __user *, stat_addr,
> + siginfo_t __user *, info, struct rusage __user *, ru,
> + unsigned int, states, unsigned int, flags)
> +{

Oh, I too think that P_PIDFD makes more sense.

and could you explain in the changelog why? I am not arguing and if
nothing else this is consistent with other pidfd features, but if you
are parent/debugger you can't hit the problem with pid-reuse, unless
you races with your sub-threads.