Re: [RFC PATCH PoC 01/11] x86/linkage: Add SYM_PI_ALIAS() macro helper to emit symbol aliases
From: Ard Biesheuvel
Date: Thu Apr 24 2025 - 14:17:45 EST
On Thu, 24 Apr 2025 at 20:05, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
>
> * Ard Biesheuvel <ardb+git@xxxxxxxxxx> wrote:
>
> > From: Ard Biesheuvel <ardb@xxxxxxxxxx>
> >
> > Startup code that may execute from the early 1:1 mapping of memory will
> > be confined into its own address space, and only be permitted to access
> > ordinary kernel symbols if this is known to be safe.
> >
> > Introduce a macro helper PI_ALIAS() that emits a __pi_ prefixed alias
> > for a symbol, which allows startup code to access it.
>
> s/PI_ALIAS
> /SYM_PI_ALIAS
>
> What does 'PI' stand for? 'Physical memory Identity' map?
>
'position independent' - it's what we ended up with on arm64, but I'm
not attached to it so happy to switch to something better.