Re: [RFC PATCH PoC 01/11] x86/linkage: Add SYM_PI_ALIAS() macro helper to emit symbol aliases

Ingo Molnar
2025-04-24T18:23:23Z

* Ard Biesheuvel <ardb@kernel.org> wrote:

> On Thu, 24 Apr 2025 at 20:05, Ingo Molnar <mingo@kernel.org> wrote:
> >
> >
> > * Ard Biesheuvel <ardb+git@google.com> wrote:
> >
> > > From: Ard Biesheuvel <ardb@kernel.org>
> > >
> > > 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'

/facepalm

Clearly it's getting late here :)

> - it's what we ended up with on arm64, but I'm
> not attached to it so happy to switch to something better.

Could we make it something like SYM_PIC_ALIAS() at least? Because 'PIC'
is something most people will recognize in this context. PI goes for
3.1415. ;-)

Thanks,

Ingo