arc4random weakness

Xin LI
Thu, 16 Mar 2017 17:24:48 -0000

On Wed, Mar 15, 2017 at 1:13 PM, Andrey Chernov <ache at freebsd.org>
wrote:
> On 15.03.2017 16:06, Steven Chamberlain wrote:
>> Also it is great to see INHERIT_ZERO was added to mmap(2)!
>
> It is not so great. For a program which forks very often zeroing even
> one page will be slowdown. It will be better and faster to implement it
> as fork syscall wrapper setting single variable, as it already done for
> threaded lib.

I think it's exactly what it was done (and unlike a fork wrapper, the
zeroing only happens on-demand, i.e. when the page is first touched).

Cheers,