Messages in this thread Patch in this message | | | Date | Tue, 26 Jul 2011 20:39:35 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86, AMD: Correct F15h IC aliasing issue |
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On Tue, Jul 26, 2011 at 02:34:30PM -0400, Ingo Molnar wrote: > > * Borislav Petkov <bp@amd64.org> wrote: > > > Ok, I went and installed a Debian wheezy with gnome and started > > almost everything I could find in the startup menu. Kernel is 3.0 > > with Linus' simpler fix. > > > > The attached file shows all libraries which would create aliases > > (i.e. 2 or more unique values for bits [14:12] along with the > > respective count) in the total of: > > > > Total r-xp mappings: 831, aliasing: 240 (0.289%) > > 28.9%, right?
Yessir.
> > For example, libc gets mapped into all possible slots for [14:12] > > > > Library [14:12] count > > ======= ======= ===== > > /lib/libc-2.11.2.so > > 0 12 > > 1 12 > > 2 11 > > 3 12 > > 4 13 > > 5 16 > > 6 13 > > 7 9 > > > > > > and so on. > > 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; } return rnd << PAGE_SHIFT; } -- Regards/Gruss, Boris.
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