linux-kernel - Re: [PATCH v6 10/17] arm: use fallback for random_get

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Message-ID: <YmawarJUQoOeVzVt@shell.armlinux.org.uk>
Date:   Mon, 25 Apr 2022 15:30:02 +0100
From:   "Russell King (Oracle)" <linux@...linux.org.uk>
To:     "Jason A. Donenfeld" <Jason@...c4.com>
Cc:     linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
        tglx@...utronix.de, arnd@...db.de
Subject: Re: [PATCH v6 10/17] arm: use fallback for random_get_entropy()
 instead of zero

On Sat, Apr 23, 2022 at 11:26:16PM +0200, Jason A. Donenfeld wrote:
> In the event that random_get_entropy() can't access a cycle counter or
> similar, falling back to returning 0 is really not the best we can do.
> Instead, at least calling random_get_entropy_fallback() would be
> preferable, because that always needs to return _something_, even
> falling back to jiffies eventually. It's not as though
> random_get_entropy_fallback() is super high precision or guaranteed to
> be entropic, but basically anything that's not zero all the time is
> better than returning zero all the time.
> 
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Arnd Bergmann <arnd@...db.de>
> Cc: Russell King <linux@...linux.org.uk>

Reviewed-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>

Thanks.

-- 
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