Re: [RFC] New codectl(2) system call for sframe registration

[Mathieu Desnoyers]

On 2025-07-22 17:13, Steven Rostedt wrote:
> On Tue, 22 Jul 2025 14:04:37 -0700
> Indu Bhagat <indu.bhagat@xxxxxxxxxx> wrote:
>
> > Yes and No.  The offset at which the text is loaded is _one_ part of the
> > information to "fill in the blanks".  The other part is what to do with
> > that information (text_vma) or how to relocate the SFrame section itself
> > a.k.a. the relocation entries.  To know the relocations, one will need
> > to get access to the respective relocation section, and hence access to
> > the ELF section headers.
>
> You mean to find where in the sframe section itself that needs to be update?
>
> OK, that makes sense. So sframes does need to still be in an ELF file for
> its own relocations and such.
>
> It will be interesting on how to do compression and on-demand page loading.
>
> There would need to be a table as well that will denote where in the
> decompressed pages that relocations need to be performed.

If we can find a way to express all sframe "pointers" as offsets from a
text_vma base, then there is no need for relocations. This would
minimize complexity.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com