Re: [RFC PATCH 0/4] rseq: Introduce extensible struct rseq

[Florian Weimer <fweimer@redhat.com>]

* Carlos O'Donell:

> On 7/13/20 11:03 PM, Mathieu Desnoyers wrote:
>> Recent discussion led to a solution for extending struct rseq. This is
>> an implementation of the proposed solution.
>> 
>> Now is a good time to agree on this scheme before the release of glibc
>> 2.32, just in case there are small details to fix on the user-space
>> side in order to allow extending struct rseq.
>
> Adding extensibility to the rseq registration process would be great,
> but we are out of time for the glibc 2.32 release.
>
> Should we revert rseq for glibc 2.32 and spend quality time discussing
> the implications of an extensible design, something that Google already
> says they are doing?
>
> We can, with a clear head, and an agreed upon extension mechanism
> include rseq in glibc 2.33 (release scheduled for Feburary 1st 2021).
> We release time boxed every 6 months, no deviation, so you know when
> your next merge window will be.
>
> We have already done the hard work of fixing the nesting signal
> handler issues, and glibc integration. If we revert today that will 
> also give time for Firefox and Chrome to adjust their sandboxes.
>
> Do you wish to go forward with rseq as we have it in glibc 2.32,
> or do you wish to revert rseq from glibc 2.32, discuss the extension
> mechanism, and put it back into glibc 2.33 with adjustments?

I posted the glibc revert:

  <https://sourceware.org/pipermail/libc-alpha/2020-July/116368.html>

I do not think we have any other choice at this point.

Thanks,
Florian