From: Noah Goldstein <goldstein.w.n@gmail.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>,
GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH v9 6/9] x86: Add AVX2 optimized chacha20
Date: Wed, 13 Jul 2022 13:23:04 -0700 [thread overview]
Message-ID: <CAFUsyfKjnFdsLHzQ24dVohdY53qPhxqXQ7YtzN1sDRCsAtnnMA@mail.gmail.com> (raw)
In-Reply-To: <87cze8zs3j.fsf@oldenburg.str.redhat.com>
On Wed, Jul 13, 2022 at 1:16 PM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Noah Goldstein:
>
> > Since `arc4random ()` might need to read from /dev/urandom I don't
> > think this function could ever truly be RTM safe so we may not care.
> >
> > If im missing something we do want to support RTM, should there be a
> > '!CPU_FEATURE_USABLE_P (cpu_features, RTM)' check for the avx2
> > implementation?
>
> Calling arc4random from a transaction is potentially unsafe anyway
> because it may act as an oracle that reveals the internal PRNG state.
> The application needs to avoid that. I think we can use the AVX2
> implementation even with RTM enabled.
Agreed.
>
> Thanks,
> Florian
>
next prev parent reply other threads:[~2022-07-13 20:23 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 17:36 [PATCH v9 0/9] Add arc4random support Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 1/9] stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417) Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 2/9] stdlib: Add arc4random tests Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 3/9] benchtests: Add arc4random benchtest Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 4/9] aarch64: Add optimized chacha20 Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 5/9] x86: Add SSE2 " Adhemerval Zanella
2022-07-13 18:12 ` Noah Goldstein
2022-07-13 18:20 ` Adhemerval Zanella Netto
2022-07-13 18:22 ` Noah Goldstein
2022-07-13 18:27 ` Noah Goldstein
2022-07-13 18:29 ` Adhemerval Zanella Netto
2022-07-13 18:53 ` Noah Goldstein
2022-07-13 17:36 ` [PATCH v9 6/9] x86: Add AVX2 " Adhemerval Zanella
2022-07-13 18:07 ` Noah Goldstein
2022-07-13 19:31 ` Adhemerval Zanella Netto
2022-07-13 20:24 ` Noah Goldstein
2022-07-13 20:16 ` Florian Weimer
2022-07-13 20:23 ` Noah Goldstein [this message]
2022-07-13 17:36 ` [PATCH v9 7/9] powerpc64: Add " Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 8/9] s390x: " Adhemerval Zanella
2022-07-13 17:36 ` [PATCH v9 9/9] manual: Add documentation for arc4random functions Adhemerval Zanella
2022-07-14 10:03 ` Mark Harris
2022-07-14 11:08 ` Adhemerval Zanella Netto
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