Re: [PATCH] pidfd: getfd should always report ESRCH if a task is exiting

[Christian Brauner]

On Tue, Feb 06, 2024 at 08:25:54PM +0100, Oleg Nesterov wrote:
> On 02/06, Tycho Andersen wrote:
> 
> > On Tue, Feb 06, 2024 at 07:06:07PM +0100, Oleg Nesterov wrote:
> > > Or we can check task->files != NULL rather than PF_EXITING.
> > >
> > > To me this looks even better, but looks more confusing without a comment.
> > > OTOH, imo this needs a comment anyway ;)
> >
> > I thought about this, but I didn't really understand the null check in
> > exit_files();
> 
> I guess task->files can be NULL at least if it was cloned with
> kernel_clone_args->no_files == T

Won't this give false positives for vhost workers which do set
->no_files but are user workers? IOW, return -ESRCH even though -EBADF
would be correct in this scenario?