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Re: [PATCH] randomize_range: use random long instead of int

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Hi William, Kees,

On Mon, Jul 25, 2016 at 11:25:41AM -0700, william.c.roberts@intel.com wrote:
> From: William Roberts <william.c.roberts@intel.com>
> 
> Use a long when generating the random range rather than
> an int. This will produce better random distributions as
> well as matching all the types at hand.
> 
> Signed-off-by: William Roberts <william.c.roberts@intel.com>
> ---
>  drivers/char/random.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Upon further review, I think we should dig into this a little bit
deeper.  Standby, I'll post an RFC series shortly.

thx,

Jason.

> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 0158d3b..bbf11b5 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -1837,7 +1837,8 @@ randomize_range(unsigned long start, unsigned long end, unsigned long len)
>  
>  	if (end <= start + len)
>  		return 0;
> -	return PAGE_ALIGN(get_random_int() % range + start);
> +
> +	return PAGE_ALIGN(get_random_long() % range + start);
>  }
>  
>  /* Interface for in-kernel drivers of true hardware RNGs.
> -- 
> 1.9.1
> 

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Thread

[PATCH] randomize_range: use random long instead of int william.c.roberts@intel.com - 2016-07-25 20:30 +0200
  Re: [PATCH] randomize_range: use random long instead of int Kees Cook <keescook@chromium.org> - 2016-07-25 21:00 +0200
  Re: [PATCH] randomize_range: use random long instead of int Jason Cooper <jason@lakedaemon.net> - 2016-07-26 04:20 +0200
  [RFC patch 6/6] unicore32: Use simpler API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
  [RFC patch 4/6] arm64: Use simpler API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
  [RFC patch 3/6] ARM: Use simpler API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
  [RFC patch 2/6] x86: Use simpler API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
  [RFC patch 5/6] tile: Use simpler API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
  [RFC patch 1/6] random: Simplify API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:10 +0200
    Re: [RFC patch 1/6] random: Simplify API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 05:40 +0200
      Re: [RFC patch 1/6] random: Simplify API for random address requests Kees Cook <keescook@chromium.org> - 2016-07-26 06:50 +0200
        Re: [RFC patch 1/6] random: Simplify API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 19:10 +0200
          Re: [RFC patch 1/6] random: Simplify API for random address requests Kees Cook <keescook@chromium.org> - 2016-07-26 19:10 +0200
            Re: [RFC patch 1/6] random: Simplify API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-28 21:10 +0200
      RE: [RFC patch 1/6] random: Simplify API for random address requests "Roberts, William C" <william.c.roberts@intel.com> - 2016-07-26 19:40 +0200
    Re: [RFC patch 1/6] random: Simplify API for random address requests Kees Cook <keescook@chromium.org> - 2016-07-26 06:50 +0200
      Re: [RFC patch 1/6] random: Simplify API for random address requests Jason Cooper <jason@lakedaemon.net> - 2016-07-26 18:00 +0200
        Re: [RFC patch 1/6] random: Simplify API for random address requests Kees Cook <keescook@chromium.org> - 2016-07-26 18:50 +0200
    Re: [kernel-hardening] [RFC patch 1/6] random: Simplify API for  random address requests Yann Droneaud <ydroneaud@opteya.com> - 2016-07-27 16:30 +0200

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