Messages in this thread | | | Date | Wed, 25 Oct 2023 10:02:13 +0200 | From | Peter Zijlstra <> | Subject | Re: [RESEND][PATCH 1/6] x86/bugs: Add asm helpers for executing VERW |
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On Wed, Oct 25, 2023 at 08:52:50AM +0100, Andrew Cooper wrote:
> > +.pushsection .entry.text, "ax" > > + > > +.align 64 > > +SYM_CODE_START_NOALIGN(mds_verw_sel) > > + UNWIND_HINT_UNDEFINED > > + ANNOTATE_NOENDBR > > +1: > > + .word __KERNEL_DS > > + .skip 64 - (. - 1b), 0xcc > > The 1 label aliases mds_verw_sel and this must remain like this for the > construct to work. > > So instead of .skip, why not simply .align 64, 0xcc and get rid of the > 1: label?
Because I forgot you can add a filler byte to .align :/ Yes, that's much saner.
> Do we have a suitably named constant cacheline size, rather than > opencoding 64?
L1_CACHE_BYTES probably.
> > > +SYM_CODE_END(mds_verw_sel); > > Given that KVM needs it, this probably needs an EXPORT_SYMBOL_GPL() on it.
localyesconfig ftw ;-)
/me runs
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