Re: [LPC] pkeys ABI

On 17/06/2026 15:59, James Bottomley wrote:
> On Wed, 2026-06-17 at 15:45 +0200, Kevin Brodsky wrote:
>> On 17/06/2026 15:06, James Bottomley wrote:
>>> On Wed, 2026-06-17 at 14:57 +0200, Kevin Brodsky wrote:
>>>> Hi,
>>>>
>>>> I am considering submitting a Refereed presentation proposal for
>>>> LPC, but I would first like to check if it makes sense to
>>>> everyone in To/Cc.
>>>>
>>>> The pkeys ABI is heavily underspecified when it comes to
>>>> asynchronous kernel interactions, such as signal delivery [1],
>>>> rseq [2], io_uring worker threads, etc. Depending on the
>>>> situation, we might reset the pkey register to "allow all", or
>>>> "allow acess to pkey 0 only", or use the interrupted context's
>>>> register (even though it is arguably unrelated). It isn't always
>>>> consistent across architectures either. 
>>>>
>>>> As Thomas put it, "that's all broken". LPC feels like the right
>>>> occasion to summarise where we are, and explore potential
>>>> solutions. Unfortunately this topic isn't an obvious fit for any
>>>> MC, so a Refereed presentation seems like the least bad option.
>>>  
>>> That's not necessarily true, especially if you want a group
>>> discussion. If all of your attendees are going to plumbers anyway
>>> you might consider a BoF ... or possibly a workshop like the Nova
>>> GPU people did last year if you need more than an hour.  The
>>> downside of BoF or Workshop is that you have to run your own A/V
>>> connections (we'll have at least USB speaker/Mic's to provide you
>>> at reception and might have one of the owl camera things)
>> Right, a BoF session would indeed be a good fit (1h should be more
>> than enough). According to [3] the Refereed track also accepts BoFs
>> so I suppose that it's the right place to make the submission
>> regardless?
> Well, we have one URL to submit everything, yes.  Right at the bottom
> it has a Track selector and you need to click on "Birds of a Feather
> (BoF)" rather than "LPC Refereed Track".
>
> We'll do the BoF acceptances in two phases.  We have some track room
> slots we use for BoFs, which get full A/V and get notified early.  The
> rest of the BoFs we assign to hack rooms with run your own A/V.  If you
> prefer the latter it would be helpful to say so in the submission.

Got it, thanks. I do think the visibility of a track slot + A/V would be
useful (not sure if Florian and other folks are planning to attend in
person), so that'd be my preference but I'm sure we can also make a hack
room work.

- Kevin