linux-kernel - Re: [PATCH 1/5] Renaming weak prng invocations - prandom_bytes_state, prandom_u32

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Date:   Mon, 12 Dec 2022 15:35:20 +0100
From:   "Jason A. Donenfeld" <Jason@...c4.com>
To:     david.keisarschm@...l.huji.ac.il
Cc:     Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
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        x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>,
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Subject: Re: [PATCH 1/5] Renaming weak prng invocations -
 prandom_bytes_state, prandom_u32_state

Please CC me on future revisions.

As of 6.2, the prandom namespace is *only* for predictable randomness.
There's no need to rename anything. So nack on this patch 1/5.

With regards to the remaining patches in this series, if you want to
move prandom_u32_state callers over to get_random_bytes() and
get_random_u32(), that's fine from my perspective, but last I looked,
there was much usage in places where being repeatable was actually the
goal - test suites and such, where you want to be able to redo your
tests with the same seed. So you'll have to look at each instance case
by case and convince whoever maintains that code that they don't need
predictability. However, if you do that, the right functions to use are
get_random_bytes() and get_random_u32().

Jason