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Date:   Wed, 06 Jul 2022 09:42:49 -0700
From:   "H. Peter Anvin" <hpa@zytor.com>
To:     Borislav Petkov <bp@alien8.de>
CC:     "Jason A. Donenfeld" <Jason@zx2c4.com>,
        linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Heiko Carstens <hca@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] random: remove CONFIG_ARCH_RANDOM and "nordrand"
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On July 6, 2022 5:23:31 AM PDT, Borislav Petkov <bp@alien8=2Ede> wrote:
>On Tue, Jul 05, 2022 at 04:11:45PM -0700, H=2E Peter Anvin wrote:
>> What I'm wondering is if we shouldn't be simply instrument *every*
>> invocation, and set the trust to zero if we ever trip it=2E
>
>I guess you can add some logic to rdrand_long() to sanity-check what it
>returns=2E=2E=2E
>
>But would that be worth the effort?
>

I think doing it centrally, as non-arch-specific code, and letting it subs=
ume ad hoc checks for known failure conditions could be a win=2E