Re: [PATCH v9 23/42] Documentation/x86: Add CET shadow stack description

[szabolcs.nagy@xxxxxxx]

The 07/05/2023 20:29, Mark Brown wrote:
> On Wed, Jul 05, 2023 at 07:17:25PM +0000, Edgecombe, Rick P wrote:
> 
> > Ah, interesting, thanks for the extra info. So which features is glibc
> > planning to use? (probably more of a question for Szabolcs). Are push
> > and pop controllable separately?
> 
> Push and pop are one control, you get both or neither.
> 
> I'll defer to Szabolcs on glibc plans.

gcspopm is always available (esentially *ssp++, this is used
for longjmp).

i haven't planned anything yet for other modes (i dont know
anything where writable shadow stack is better than just
turning the feature off, so i expect we at most have a
glibc tunable env var to enable it but it will not affect
glibc behaviour otherwise).