On Mon, Nov 27, 2017 at 07:36:40PM -0800, Andy Lutomirski wrote: > On Mon, Nov 27, 2017 at 2:31 PM, Peter Zijlstra <[email protected]> wrote: > > So we can more easily see if the shiny got enabled. > > > > Signed-off-by: Peter Zijlstra (Intel) <[email protected]> > > --- > > arch/x86/mm/kaiser.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > --- a/arch/x86/mm/kaiser.c > > +++ b/arch/x86/mm/kaiser.c > > @@ -425,6 +425,8 @@ void __init kaiser_init(void) > > if (!kaiser_enabled) > > return; > > > > + printk("All your KAISER are belong to us\n"); > > + > > All your incomprehensible academic names are belong to us. > > On a serious note, can we please banish the name KAISER from all the > user-facing bits? No one should be setting a boot option that has a > name based on an academic project called "Kernel Address Isolation to > have Side-channels Efficiently Removed". We're not efficiently > removing side channels. The side channels are still very much there. > Heck, the series as currently presented doesn't even rescue kASLR. It > could*, if we were to finish the work that I mostly started and > completely banish all the normal kernel mappings from the shadow** > tables. We're rather inefficiently (and partially!) mitigating the > fact that certain CPU designers have had their heads up their > collective arses for *years* and have failed to pay attention to > numerous academic papers documenting that fact. > > Let's call the user facing bits "separate user pagetables". If we > want to make it conditioned on a future cpu cap called > X86_BUG_REALLY_DUMB_SIDE_CHANNELS, great, assuming a better CPU ever > shows up. But please let's not make users look up WTF "KAISER" means. > > * No one ever documented the %*!& side channels AFAIK, so everything > we're talking about here is mostly speculation. > > ** The word "shadow" needs to die, too. I know what shadow page > tables are, and they have *nothing* to do with KAISER.
+1. Somebody please rename KAISER and shadow page tables for more clarity. To fix KASLR I think we need to move (at least parts of) .entry.text, .irqentry.text, and .entry_trampoline into their own fixed section(s). Is there anything else missing? -- Josh
