Re: [PATCH] mm: SLAB freelist randomization

From: Andrew Morton
Date: Mon Apr 25 2016 - 17:04:26 EST


On Mon, 18 Apr 2016 12:52:30 -0700 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:

> I agree, if we had a generic way to pass entropy across boots on all
> architecture that would be amazing. I will let the SLAB maintainers to
> decide on requiring CONFIG_ARCH_RANDOM or documenting it.

In our world, requiring that sort of attention from maintainers
requires a pretty active level of pinging, poking and harrassing ;)

I do think that if you stick with get_random_bytes_arch() then it need
a comment explaining why.

And I (still) don't think that get_random_bytes_arch() actually does
what you want - if CONFIG_ARCH_RANDOM isn't implemented then
get_random_bytes_arch() just fails. IOW your statement "the arch
version that will fallback on get_random_bytes sub API in the worse
case" is a misconception? There is no fallback.