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Date: Tue, 26 Jul 2022 14:08:48 +0200
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org, Florian Weimer <fweimer@redhat.com>,
 Cristian =?utf-8?Q?Rodr=C3=ADguez?= <crrodriguez@opensuse.org>,
 Paul Eggert <eggert@cs.ucla.edu>, linux-crypto@vger.kernel.org
Subject: Re: [PATCH v2] arc4random: simplify design for better safety
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Hey again,

On Tue, Jul 26, 2022 at 01:54:23PM +0200, Jason A. Donenfeld wrote:
> > As Florian said we will need a non cancellable poll here.  Since you are setting
> > the timeout as undefined, I think it would be simple to just add a non cancellable
> > wrapper as:
> > 
> >   int __ppoll_noncancel_notimeout (struct pollfd *fds, nfds_t nfds)
> >   {
> >   #ifndef __NR_ppoll_time64
> >   # define __NR_ppoll_time64 __NR_ppoll
> >   #endif
> >      return INLINE_SYSCALL_CALL (__NR_ppoll_time64, fds, nfds, NULL, NULL, 0);
> >   }
> > 
> > So we don't need to handle the timeout for 64-bit time_t wrappers.
> 
> Oh that sounds like a good solution to the time64 situation. I'll do
> that for v4... BUT, I already implemented possibly the wrong solution
> for v3. Could you take a look at what I did there and confirm that it's
> wrong? If so, then I'll do exactly what you suggested here.

Actually, forget my v3. What you're suggesting is also better because
it's ppoll, not poll, as poll isn't on all platforms. So I'll do things
exactly as you've described for v4.

Jason