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From: Yann Ylavic <ylavic.dev@gmail.com>
To: Willy Tarreau <w@1wt.eu>
Cc: linux-kernel@vger.kernel.org,
	Linux Kernel Network Developers <netdev@vger.kernel.org>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	George Spelvin <lkml@sdf.org>, Amit Klein <aksecurity@gmail.com>,
	Eric Dumazet <edumazet@google.com>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	Andy Lutomirski <luto@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	tytso@mit.edu, Florian Westphal <fw@strlen.de>,
	Marc Plumb <lkml.mplumb@gmail.com>
Subject: Re: [PATCH 1/2] random32: make prandom_u32() output unpredictable
Date: Tue, 1 Sep 2020 10:33:40 +0200	[thread overview]
Message-ID: <CAKQ1sVM9SMYVTSZYaGuPDhQHfyEOFSxBL8PNixyaN4pR2PWMxQ@mail.gmail.com> (raw)
In-Reply-To: <20200901064302.849-2-w@1wt.eu>

On Tue, Sep 1, 2020 at 8:45 AM Willy Tarreau <w@1wt.eu> wrote:
>
> +/*
> + *     Generate some initially weak seeding values to allow
> + *     the prandom_u32() engine to be started.
> + */
> +static int __init prandom_init_early(void)
> +{
> +       int i;
> +       unsigned long v0, v1, v2, v3;
> +
> +       if (!arch_get_random_long(&v0))
> +               v0 = jiffies;
> +       if (!arch_get_random_long(&v1))
> +               v0 = random_get_entropy();

Shouldn't the above be:
                  v1 = random_get_entropy();
?

> +       v2 = v0 ^ PRND_K0;
> +       v3 = v1 ^ PRND_K1;
> +
> +       for_each_possible_cpu(i) {
> +               struct siprand_state *state;
> +
> +               v3 ^= i;
> +               PRND_SIPROUND(v0, v1, v2, v3);
> +               PRND_SIPROUND(v0, v1, v2, v3);
> +               v0 ^= i;
> +
> +               state = per_cpu_ptr(&net_rand_state, i);
> +               state->v0 = v0;  state->v1 = v1;
> +               state->v2 = v2;  state->v3 = v3;
> +       }
> +
> +       return 0;
> +}
> +core_initcall(prandom_init_early);


Regards;
Yann.

  reply	other threads:[~2020-09-01  8:34 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-01  6:43 [PATCH 0/2] prandom_u32: make output less predictable Willy Tarreau
2020-09-01  6:43 ` [PATCH 1/2] random32: make prandom_u32() output unpredictable Willy Tarreau
2020-09-01  8:33   ` Yann Ylavic [this message]
2020-09-01  8:39     ` Willy Tarreau
2020-09-01  8:46       ` Sedat Dilek
2020-09-01  8:56         ` Willy Tarreau
2020-09-01  9:26           ` Sedat Dilek
2020-09-01 13:10   ` David Laight
2020-09-01 13:16     ` Willy Tarreau
     [not found]       ` <CANEQ_+Kuw6cxWRBE6NyXkr=8p3W-1f=o1q91ZESeueEnna9fvw@mail.gmail.com>
2020-09-14 16:16         ` Sedat Dilek
2020-09-14 16:29           ` Willy Tarreau
2020-09-14 16:48             ` Sedat Dilek
2020-09-01  6:43 ` [PATCH 2/2] random32: add noise from network and scheduling activity Willy Tarreau
2020-09-01 10:24   ` Eric Dumazet
2020-09-01 11:57     ` Willy Tarreau
2020-09-01 14:41 ` [PATCH 0/2] prandom_u32: make output less predictable Sedat Dilek
2020-09-01 14:55   ` Willy Tarreau
2020-09-01 15:19     ` Eric Dumazet

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