Re: [PATCH v2] mm: SLAB freelist randomization

[Andrew Morton]

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)