ARM64 Livepatch based on SFrame

ARM64 Livepatch based on SFrame

[Praveen Kumar]

Hi Mark,

Hope you are doing great.

I am interested to work on ARM64 livepatching using SFrame, and thus, reinitiating the old thread (Link: https://lore.kernel.org/all/ZXxO43Xwn5GHsrO8@FVFF77S0Q05N/).

Please do let me know if there anything which I can help with, in developing this feature. Thanks.

Regards,

~Praveen.

Re: ARM64 Livepatch based on SFrame

[Weinan Liu]

We from Google are working on implementing SFrame unwinder for the Linux kernel, 
And we will be happy to collaborate with others for adding arm64 livepatch support

Weinan

Re: ARM64 Livepatch based on SFrame

[Praveen Kumar]

On 27-09-2024 13:11, Weinan Liu wrote:
> We from Google are working on implementing SFrame unwinder for the Linux kernel, 
> And we will be happy to collaborate with others for adding arm64 livepatch support
> 

Good to know Weinan!

Happy to collaborate, please let me know what I can focus on and help here. Thanks.

Regards,

~Praveen.

Re: ARM64 Livepatch based on SFrame

[Madhavan T. Venkataraman]

On 12/15/23 07:04, Mark Rutland wrote:
> On Thu, Dec 14, 2023 at 02:49:29PM -0600, Madhavan T. Venkataraman wrote:
>> Hi Mark,
> 
> Hi Madhavan,
> 
>> I attended your presentation in the LPC. You mentioned that you could use
>> some help with some pre-requisites for the Livepatch feature.
>> I would like to lend a hand.
> 
> Cool!
> 
> I've been meaning to send a mail round with a summary of the current state of
> things, and what needs to be done going forward, but I haven't had the time
> since LPC to put that together (as e.g. that requires learning some more about
> SFrame).  I'll be disappearing for the holiday shortly, and I intend to pick
> that up in the new year.
> 
>> What would you like me to implement?
> 
> I'm not currently sure exactly what we need/want to implement, and as above I
> think that needs to wait until the new year.
> 

OK.

> However, one thing that you can do that would be very useful is to write up and
> report the GCC DWARF issues that you mentioned in:
> 
>   https://lore.kernel.org/linux-arm-kernel/20230202074036.507249-1-madvenka@linux.microsoft.com/
> 
> ... as (depending on exactly what those are) those could also affect SFrame
> generation (and thus we'll need to get those fixed in GCC), and regardless it
> would be useful information to know.
> 
> I understood that you planned to do that from:
> 
>   https://lore.kernel.org/linux-arm-kernel/054ce0d6-70f0-b834-d4e5-1049c8df7492@linux.microsoft.com/
> 
> ... but I couldn't spot any relevant mails or issues in the GCC bugzilla, so
> either I'm failing to search hard enough, or did that get forgotten about?
> 

Yeah. I had notes on that. But I seem to have lost them. I need to reproduce the
problems and analyze them again which is not trivial. So, I have been procrastinating.

I am also disappearing for the rest of this year. I will try to look at it in the
new year.

>> I would also like to implement Unwind Hints for the feature. If you want a
>> specific format for the hints, let me know.
> 
> I will get back to you on that in the new year; I think the specifics we want
> are going to depend on other details above we need to analyse first.
> 

OK.

For now, I will implement something and send it out just for reference. We can revisit
this topic next year sometime.

Thanks.

Madhavan

Re: ARM64 Livepatch based on SFrame

[Mark Rutland]

On Thu, Dec 14, 2023 at 02:49:29PM -0600, Madhavan T. Venkataraman wrote:
> Hi Mark,

Hi Madhavan,

> I attended your presentation in the LPC. You mentioned that you could use
> some help with some pre-requisites for the Livepatch feature.
> I would like to lend a hand.

Cool!

I've been meaning to send a mail round with a summary of the current state of
things, and what needs to be done going forward, but I haven't had the time
since LPC to put that together (as e.g. that requires learning some more about
SFrame).  I'll be disappearing for the holiday shortly, and I intend to pick
that up in the new year.

> What would you like me to implement?

I'm not currently sure exactly what we need/want to implement, and as above I
think that needs to wait until the new year.

However, one thing that you can do that would be very useful is to write up and
report the GCC DWARF issues that you mentioned in:

  https://lore.kernel.org/linux-arm-kernel/20230202074036.507249-1-madvenka@linux.microsoft.com/

... as (depending on exactly what those are) those could also affect SFrame
generation (and thus we'll need to get those fixed in GCC), and regardless it
would be useful information to know.

I understood that you planned to do that from:

  https://lore.kernel.org/linux-arm-kernel/054ce0d6-70f0-b834-d4e5-1049c8df7492@linux.microsoft.com/

... but I couldn't spot any relevant mails or issues in the GCC bugzilla, so
either I'm failing to search hard enough, or did that get forgotten about?

> I would also like to implement Unwind Hints for the feature. If you want a
> specific format for the hints, let me know.

I will get back to you on that in the new year; I think the specifics we want
are going to depend on other details above we need to analyse first.

Thanks,
Mark.

ARM64 Livepatch based on SFrame

[Madhavan T. Venkataraman]

Hi Mark,

I attended your presentation in the LPC. You mentioned that you could use some help with some pre-requisites for the Livepatch feature.
I would like to lend a hand.

What would you like me to implement?

I would also like to implement Unwind Hints for the feature. If you want a specific format for the hints, let me know.

Looking forward to help out with the feature.

Madhavan