Re: [PATCH v10 04/40] arm64: Document boot requirements for Guarded Control Stacks

2024-08-15 Thread Mark Brown
On Thu, Aug 15, 2024 at 06:00:15PM +0100, Catalin Marinas wrote: > On Thu, Aug 01, 2024 at 01:06:31PM +0100, Mark Brown wrote: > > + - If EL2 is present: > > +- GCSCR_EL2 must be initialised to 0. > > + - If the kernel is entered at EL1 and EL2 is present: > > + > > +- GCSCR_EL1 must be

Re: [PATCH v10 04/40] arm64: Document boot requirements for Guarded Control Stacks

2024-08-15 Thread Catalin Marinas
On Thu, Aug 01, 2024 at 01:06:31PM +0100, Mark Brown wrote: > + - If EL2 is present: > + > +- GCSCR_EL2 must be initialised to 0. > + > + - If the kernel is entered at EL1 and EL2 is present: > + > +- GCSCR_EL1 must be initialised to 0. > + > +- GCSCRE0_EL1 must be initialised to 0. C

[PATCH v10 04/40] arm64: Document boot requirements for Guarded Control Stacks

2024-08-01 Thread Mark Brown
FEAT_GCS introduces a number of new system registers, we require that access to these registers is not trapped when we identify that the feature is detected. Since if GCS is enabled any function call instruction will be checked we also require that the feature be specifically disabled. Signed-off