Re: [PATCH 2/2] xen/arm: Mitigate straight-line speculation for SMC call

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 17 Jun 2020, Andrew Cooper wrote:
> On 16/06/2020 22:57, Julien Grall wrote:
> > On Tue, 16 Jun 2020 at 22:34, Stefano Stabellini <sstabellini@xxxxxxxxxx> 
> > wrote:
> >> On Tue, 16 Jun 2020, Julien Grall wrote:
> >>> From: Julien Grall <jgrall@xxxxxxxxxx>
> >>>
> >>> SMC call will update some of registers (typically only x0) depending on
> >>   ^a SMC call
> 
> An SMC call.
> 
> >>
> >>> the arguments provided.
> >>>
> >>> Some CPUs can speculate past a SMC instruction and potentially perform
> >>> speculative access to emrmoy using the pre-call values before executing
> >>                         ^ memory
> >>
> >>> the SMC.
> >>>
> >>> There is no known gadget available after the SMC call today. However
> >>> some of the registers may contain values from the guest and are expected
> >>> to be updated by the SMC call.
> >>>
> >>> In order to harden the code, it would be better to prevent straight-line
> >>> speculation from an SMC. Architecturally executing the speculation
> >>                    ^ a? any?
> > "any" might be better.
> 
> "an SMC" is correct, but "any" is also fine.
> 
> 'a' vs 'an' is based on the sound of the following.  S in "S-M-C" as an
> abbreviation starts with an 'e' vowel sound, unlike 's' in secure, so
> the correct grammar is "an SMC" and "a secure monitor call".

LOL! English sometimes... damn.

Anyway, many thanks for the correction :-)