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From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
Date:   Tue, 6 Sep 2022 12:16:56 +0200
Message-ID: <CAHmME9qBs0EpBBrragaXFJJ+yKEfBdWGkkZp7T60vq8m8x+RdA@mail.gmail.com>
Subject: Re: Inquiry about the removal of flag O_NONBLOCK on /dev/random
To:     "Guozihua (Scott)" <guozihua@huawei.com>
Cc:     Eric Biggers <ebiggers@kernel.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        Andrew Lutomirski <luto@kernel.org>,
        "Theodore Ts'o" <tytso@mit.edu>,
        zhongguohua <zhongguohua1@huawei.com>
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On Thu, Jul 28, 2022 at 10:25 AM Guozihua (Scott) <guozihua@huawei.com> wrote:
>
> On 2022/7/26 19:33, Guozihua (Scott) wrote:
> > On 2022/7/26 19:08, Jason A. Donenfeld wrote:
> >> Hi,
> >>
> >> On Tue, Jul 26, 2022 at 03:43:31PM +0800, Guozihua (Scott) wrote:
> >>> Thanks for all the comments on this inquiry. Does the community has any
> >>> channel to publishes changes like these? And will the man pages get
> >>> updated? If so, are there any time frame?
> >>
> >> I was under the impression you were ultimately okay with the status quo.
> >> Have I misunderstood you?
> >>
> >> Thanks,
> >> Jason
> >> .
> >
> > Hi Jason.
> >
> > To clarify, I does not have any issue with this change. I asked here
> > only because I would like some background knowledge on this flag, to
> > ensure I am on the same page as the community regarding this flag and
> > the change. And it seems that I understands it correctly.
> >
> > However I do think it's a good idea to update the document soon to avoid
> > any misunderstanding in the future.
> >
>
> Our colleague suggests that we should inform users clearly about the
> change on the flag by returning -EINVAL when /dev/random gets this flag
> during boot process. Otherwise programs might silently block for a long
> time, causing other issues. Do you think this is a good way to prevent
> similar issues on this flag?

I still don't really understand what you want. First you said this was
a problem and we should reintroduce the old behavior. Then you said no
big deal and the docs just needed to be updated. Now you're saying
this is a problem and we should reintroduce the old behavior?

I'm just a bit lost on where we were in the conversation.

Also, could you let me know whether this is affecting real things for
Huawei, or if this is just something you happened to notice but
doesn't have any practical impact?

Jason