On Tue, 21 Aug 2018, Jiri Kosina wrote:
> On Thu, 2 Aug 2018, Jiri Kosina wrote:
>
> > as in previous years (and as discussed with quite a few of you in person),
> > I've just submitted LPC2018 miniconf proposal for live patching.
>
> For those of you who are planning to attend, please send either me or Josh
> (and CC the list) the topic you'd like to get discussed, and your
> preliminary statement / confirmation whether you'd be making best effort
> to participate.
First, yes, I'd like to participate.
As for the topics. Hopefully, the atomic replace and basic selftests will
have been merged by then, so that is one topic less.
1. Architecture support.
x86_64 is complete.
powerpc perhaps too. If I remember correctly, Michael (mpe) said it would
nice to have objtool even for powerpc, but it is not strictly
necessary.
arm64 is being discussed. I haven't seen Torsten's patchset yet, but from
a quick look we need ftrace with regs support, we need to find out
if objtool is necessary and then implement the reliable stack traces
detection.
s390x has ftrace with regs support and klp_arch_set_pc() implemented.
objtool and reliable stack traces need to be discussed. Reportedly
some of SUSE's customers have been asking about s390x support
recently.
So, it'd nice to talk about objtool and archs' peculiarities. Especially
if arch maintainers attend the event.
2. GCC optimizations. Recurrent topic. We talked about a GCC option to
disable all IPA optimizations affecting livepatching. I wanted to measure
the performance impact on the kernel first. This was done months ago, but
we haven't processed the results in detail yet (because of other seemingly
more important things).
3. Userspace tool for live patches creation ("better kpatch-build").
Nothing new here I'm afraid, but Joao may have some input. Also Nicolai
has been working on the first steps to generate live patches from the
source code approach. It'd interesting to hear about that and discuss its
viability.
4. Small things here and there. I remember Josh's idea to rewrite module
livepatching somehow.
That is all for now. I may come up with more.
Thanks,
Miroslav
