Re: [RFC PATCH v1 18/28] prctl: arch-agnostic prtcl for indirect branch tracking

[Deepak Gupta]

On Tue, Feb 06, 2024 at 04:13:39PM +0000, Mark Brown wrote:
> On Wed, Jan 24, 2024 at 10:21:43PM -0800, debug@xxxxxxxxxxxx wrote:
>
> > To allow userspace to enable this feature for itself, following prtcls are
> > defined:
> >  - PR_GET_INDIR_BR_LP_STATUS: Gets current configured status for indirect branch
> >    tracking.
> >  - PR_SET_INDIR_BR_LP_STATUS: Sets a configuration for indirect branch tracking
> >    Following status options are allowed
> >            - PR_INDIR_BR_LP_ENABLE: Enables indirect branch tracking on user
> >              thread.
> >            - PR_INDIR_BR_LP_DISABLE; Disables indirect branch tracking on user
> >              thread.
> >  - PR_LOCK_INDIR_BR_LP_STATUS: Locks configured status for indirect branch
> >    tracking for user thread.
>
> FWIW the arm64 BTI feature is enabled per page of executable memory
> rather than in CPU state so it'd be hard for us to adopt this interface.
> I don't think that's a blocker, just noting it.

Got it, makes sense.