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Date:   Wed, 8 Sep 2021 20:43:04 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     Sandy Harris <sandyinchina@gmail.com>
Cc:     Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        Ted Ts'o <tytso@mit.edu>,
        Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH] In _extract-crng mix in 64 bits if possible
Message-ID: <YTmCyOTFADDSTdQm@sol.localdomain>
References: <CACXcFmm798P6mPErh9B4thz7uvBG1sUO-eJpa1MB+7ayDyTCvw@mail.gmail.com>
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On Thu, Sep 09, 2021 at 10:49:20AM +0800, Sandy Harris wrote:
> On some machines arch_get_random_long() gives 64 bits.
> XORing it into a 32-bit state word uses only half of it.
> This change makes it use it all instead.
> 
> Signed-off-by: Sandy Harris <sandyinchina@gmail.com>
> 
> ---
>  drivers/char/random.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

This patch is corrupted and doesn't apply.

> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 57fe011fb5e4..fe7f3366b934 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -988,7 +988,8 @@ static void crng_reseed(struct crng_state *crng,
> struct entropy_store *r)
>  static void _extract_crng(struct crng_state *crng,
>                __u8 out[CHACHA_BLOCK_SIZE])
>  {
> -    unsigned long v, flags;
> +    unsigned long v, flags, *last;
> +    last = (unsigned long *) &crng->state[14] ;

How do you know that this has the right alignment for an unsigned long?

- Eric