Theo de Raadt (deraadt@) posted to tech@ a detailed message explaining the past and (potential) future of anti-ROP measures in OpenBSD.

It's well worth reading its entirety. Highlights include:

Years later, Todd Mortimer and I developed RETGUARD.  At the start of
that initiative he proposed we protect all functions, to try to guard
all the RET instructions, and therefore achieve a state we call
"ROP-free".  I felt this was impossible, but after a couple hurdles the
RETGUARD performance was vastly better than the stack protector and we
were able to protect all functions and get to ROP-free (on fixed-sized
instruction architecures).  Performance was acceptable to trade against
improved security.
[…]
We were able to enable RETGUARD on all functions because it was fast.
[…]
On the other hand the RETGUARD approach uses an illegal instruction (of
some sort), which is a speculation barrier. That prevents the cpu from
heading off into an alternative set of weeds.  It will go decode more
instructions along the post-RET execution path.

I filed that idea as interesting but did nothing with it.  Until now.

Like we said earlier, it is worth reading the whole thing! This points forward to some remarkable improvements on several architectures, and those changes could be a clear benefit for other systems too.

Frederic Cambus (fcambus@) wrote a blogpost about running OpenBSD on the arm64-based cloudservers provided by Hetzner. For now, only -current will work, because the new viogpu(4) driver [on which we reported earlier] is needed.

Head on over to Frederic's blog for the full story!

EuroBSDCon 2023 has now ended, and slides for many of the OpenBSD developer presentations are now available in the usual place.

Video of the presentations can be expected somewhat later.

Slides from the tutorial "Network Management with the OpenBSD Packet Filter Toolset" are also available.

Version 0.93 of Game of Trees has been released (and the port updated).

With the following commit(s), Theo de Raadt (deraadt@) moved -current to version 7.4-beta:

CVSROOT:	/cvs
Module name:	src
Changes by:	deraadt@cvs.openbsd.org	2023/09/18 07:16:13

Modified files:
	share/mk       : sys.mk 
	etc/root       : root.mail 
	sys/conf       : newvers.sh 
	sys/arch/macppc/stand/tbxidata: bsd.tbxi 
	usr.bin/signify: signify.1 

Log message:
crank to 7.4-beta

Snapshots are (already) available for several platforms. At the time of writing, there are a mixture of 7.3 and 7.4 files on at least some mirrors, so readers are advised that problems may occur.

(Regular readers will know what comes next…)

This serves as an excellent reminder to upgrade snapshots frequently, test both base and ports, and report problems [plus, of course, donate!].

We are pleased to have another p2k23 report, this time from Volker Schlecht (volker@) who writes:

"Ladies and Gentlemen, our plane is equipped with two engines, and I'm afraid I need to tell you that the one that you see to your right won't start right now…"
As with several other developers my trip to p2k23 didn't exactly start off as planned. Eventually the engine did start, though (and I'm glad to report it stayed on, too) and I made it to Dublin.

Can you really do 3D printing from OpenBSD? Cue suspenseful music whilst I formulate my answer, which is: Yes.

If you aren’t familiar with the 3D printing process, it’s divided into several steps, vaguely analogous to writing, compiling and running a program in a compiled language.

Next up in the series of p2k23 hackathon reports is this from Landry Breuil (landry@), who writes,

It's been a while since the last p2k19 in bucarest… and this time in a new place, city, country, lovely ireland with a lovely weather at this time of the year.

As usual, i wanted to play with things that were left on the side for a while (upgrading mail/stalwart stack to the new all-bundled-in-one layout to play with JMAP… or testing matthieu@'s work on wayland) - but i was of course mostly distracted from those interesting topics by …firefox, you guess it. Dammit, not again !

Next up in our reports from the p2k23 hackathon is one from Jeremy Evans (jeremy@). Jeremy writes:

My travel to Dublin started off not so great, with the airline figuring out they had to replace the copilot's chair in the cockpit after everyone had boarded, forcing everyone to deplane and then reboard an hour later. I ended up getting to Dublin a couple hours later than scheduled. This was the day before the hackathon started, so thankfully I didn't miss any hacking time. After I arrived, I took a brief nap, then found out where the hackroom was.