Re: [PATCH] x86, AMD: Correct F15h IC aliasing issue

[Ingo Molnar <mingo@elte.hu>]

* Borislav Petkov <bp@amd64.org> wrote:

> > Was this done with a stock kernel, or with the simple patch 
> > applied?
> 
> with the simplest version of Linus' patch:
> 
> diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
> index 1dab519..6b1094d 100644
> --- a/arch/x86/mm/mmap.c
> +++ b/arch/x86/mm/mmap.c
> @@ -90,6 +90,8 @@ static unsigned long mmap_rnd(void)
>                         rnd = (long)get_random_int() % (1<<8);
>                 else
>                         rnd = (long)(get_random_int() % (1<<28));
> +
> +               rnd &= ~0x7;

So, unless i got the stats right, unmodified kernel has like a 75% 
mis-aligned rate, while with the simple fix this goes down to 30%?

Have you run the numbers on the stock, unmodified kernel by any 
chance, just to make sure the stats are ok?

Thanks,

	Ingo