Re: [PATCH v2] mm: SLAB freelist randomization

[Thomas Garnier]

On Mon, Apr 25, 2016 at 2:38 PM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 25 Apr 2016 14:14:33 -0700 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:
>
>> >>> +     /* Get best entropy at this stage */
>> >>> +     get_random_bytes_arch(&seed, sizeof(seed));
>> >>
>> >> See concerns in other email - isn't this a no-op if CONFIG_ARCH_RANDOM=n?
>> >>
>>
>> The arch_* functions will return 0 which will break the loop in
>> get_random_bytes_arch and make it uses extract_entropy (as does
>> get_random_bytes).
>> (cf http://lxr.free-electrons.com/source/drivers/char/random.c#L1335)
>>
>
> oop, sorry, I misread the code.
>
> (and the get_random_bytes_arch() comment "This function will use the
> architecture-specific hardware random number generator if it is
> available" is misleading, so there)

No problem, better double check it. I agree it is misleading.

Thomas