BSD Now

GSoC 2018 Projects announced, tutorial FreeBSD jails with iocage, new Code of Conduct for FreeBSD, libhijack, and fancy monitoring for OpenSMTPD

You can join #freebsd-soc on the efnet IRC network to chat with FreeBSD developers interested in mentoring student proposals and projects, past FreeBSD/GSoC students, and other students applying to FreeBSD/GSoC this year.

You can get a stipend (paid for by Google) and spend a few months getting to know and improving the insides of NetBSD or pkgsrc.

These projects are suggestions; you can come up with your own. Suggestions for other suitable projects are welcome.

Feel free to contact, or chat around on IRC: irc.freenode.org #netbsd #netbsd-code #pkgsrc

FreeBSD jails allow users to run multiple, isolated instances of FreeBSD on a single server. Iocage simplifies the management of FreeBSD Jails. Following this tutorial, the jails will be configured to bind to an IP address on the jail host's internal network, and the host OS will pass traffic from the external network to the jail.

The jails will be managed with Iocage. Iocage uses ZFS properties to store configuration data for each jail, so a ZFS file system is required.

PF is full featured firewall, and can do more than just pass traffic to an internal network. Refer to the PF documentation for additional configuration options.

The best way to use ZFS on a VPS is to attach block storage as a new disk.

List the available disks.

geom disk list

zpool create jailstore /dev/vtbd1

Create the ZFS file.

dd if=/dev/zero of=/zfsfile bs=1M count=4096

zpool create jailstore /zfsfile

pkg install py36-iocage

Skip to "Using iocage"

Smaller servers may not have enough RAM to build iocage. If needed, create a swap file and reboot.

pkg install subversion python36 git-lite libgit2 py36-pip

svn checkout https://svn.freebsd.org/base/releng/11.1 /usr/src

Once you have a shell inside the jail, install and start Apache.

Port 80 on the jail will now be accessible on the hosts IP address.

Additional jails can be installed using the example above.

The FreeBSD Project is inclusive. We want the FreeBSD Project to be a venue where people of all backgrounds can work together to make the best operating system, built by a strong community. These values extend beyond just development to all aspects of the Project. All those given recognition as members of the Project in whatever form are seen as ambassadors of the Project.

Diversity is a huge strength and is critical to the long term success of the Project. To that end we have a few ground rules that we ask people to adhere to. This code applies equally to everyone representing the FreeBSD Project in any way, from new members, to committers, to the core team itself. These rules are intended to ensure a safe, harassment-free environment for all and to ensure that everyone feels welcome both working within, and interacting with, the Project.

This document is not an exhaustive list of things that you should not do. Rather, consider it a guide to make it easier to enrich all of us and the technical communities in which we participate.

This code of conduct applies to all spaces used by the FreeBSD Project, including our mailing lists, IRC channels, and social media, both online and off. Anyone who is found to violate this code of conduct may be sanctioned or expelled from FreeBSD Project controlled spaces at the discretion of the FreeBSD Code of Conduct Committee.

Some FreeBSD Project spaces may have additional rules in place, which will be made clearly available to participants. Participants are responsible for knowing and abiding by these rules.

Harassment includes but is not limited to:

In the land of red devils known as Beasties exists a system devoid of meaningful exploit mitigations. As we explore this vast land of opportunity, we will meet our ELFish friends, [p]tracing their very moves in order to hijack them. Since unprivileged process debugging is

Nothing presented here is technically new. However, this type of work has not been documented in this much detail, tying it all into one cohesive work. In Phrack 56, Silvio Cesare taught us ELF research enthusiasts how to hook the PLT/GOT. The Phrack 59 article on Runtime Process Infection briefly introduces the concept of injecting shared objects by injecting shellcode via PTrace that calls dlopen(). No other piece of research, however, has discovered the joys of forcing the application to create anonymous memory mappings in which to inject

This is only part one of a series of planned articles that will follow libhijack's development. The end goal is to be able to anonymously inject shared objects. The libhijack project is maintained by the SoldierX community.

All prior work injects code into the stack, the heap, or existing executable code. All three methods create issues on today's systems. On amd64 and arm64, the two architectures libhijack cares about, the stack is non-executable by default. jemalloc, the heap implementation

PLT/GOT hijacking requires parsing ELF headers. One would not be able to find the PLT/GOT without iterating through the Process Headers to find the Dynamic Headers, eventually ending up with the DT_PLTGOT entry.

With FreeBSD's libprocstat API, we don't have a need for parsing ELF headers until we get to the PLT/GOT stage, but doing so early makes it easier for the attacker using libhijack

Writing devious code in assembly is cumbersome. Assembly doesn't scale well to multiple architectures. Instead, we would like to write our devious code in C, compiling to a shared object that gets injected anonymously. This requires writing a remote RTLD within libhijack and

Additionally, creation of a general-purpose helper library that gets injected would be helpful. It could aid in PLT/GOT redirection attacks, possibly storing the addresses of functions we've previously hijacked. This work is dependent on the remote RTLD.

libhijack currently lacks documentation. Once the ABI and API stabilize, formal documentation will be written.

Using libhijack, we can easily create anonymous memory mappings, inject into them arbitrary code, and hijack the PLT/GOT on FreeBSD. On HardenedBSD, a hardened derivative of FreeBSD, libhijack is fully mitigated through PaX NOEXEC.

We've demonstrated that wrapper-style Capsicum is ineffective on FreeBSD. Through the use of libhijack, we emulate a control flow hijack in which the application is forced to call sandbox_open and fdlopen on the resulting file descriptor.

Further work to support anonymous injection of full shared objects, along with their dependencies, will be supported in the future. Imagine injecting libpcap into Apache to sniff traffic whenever "GET /pcap" is sent.

In order to prevent abuse of PTrace, FreeBSD should set the security.bsd.unprivileged_proc_debug to 0 by default. In order to prevent process manipulation, FreeBSD should implement PaX NOEXEC.

What the heck is the POSIX shell anyway? Well, the POSIX (the Portable Operating System Interface) shell is the standard Unix shell - standard meaning it was formally defined and shipped in a published standard. This makes shell scripts written for it portable, something no other shell can lay claim to. The POSIX shell is basically a formalized version of the venerable Bourne shell, and on your system it lives at /bin/sh, unless you’re one of the unlucky masses for whom this is a symlink to bash.

The “Bourne Again shell”, aka bash, is not standardized. Its grammar, features, and behavior aren’t formally written up anywhere, and only one implementation of bash exists. Without a standard, bash is defined by its implementation. POSIX shell, on the other hand, has many competing implementations on many different operating systems - all of which are compatible with each other because they conform to the standard.

Any shell that utilizes features specific to Bash are not portable, which means you cannot take them with you to any other system. Many Linux-based systems do not use Bash or GNU coreutils. Outside of Linux, pretty much everyone but Hurd does not ship GNU tools, including bash1. On any of these systems, scripts using “bashisms” will not work.

This is bad if your users wish to utilize your software anywhere other than GNU/Linux. If your build tooling utilizes bashisms, your software will not build on anything but GNU/Linux. If you ship runtime scripts that use bashisms, your software will not run on anything but GNU/Linux. The case for sticking to POSIX shell in shipping software is compelling, but I argue that you should stick to POSIX shell for your personal scripts, too. You might not care now, but when you feel like flirting with other Unicies you’ll thank me when all of your scripts work.

One place where POSIX shell does not shine is for interactive use - a place where I think bash sucks, too. Any shell you want to use for your day-to-day command line work is okay in my book. I use fish. Use whatever you like interactively, but stick to POSIX sh for your scripts.

At the top of your scripts, put #!/bin/sh. You don’t have to worry about using env here like you might have been trained to do with bash: /bin/sh is the standardized location for the POSIX shell, and any standards-conforming system will either put it there or make your script work anyway.

The next step is to avoid bashisms. There are many, but here are a few that might trip you up:

The easiest way to learn about POSIX shell is to read the standard - it’s not too dry and shorter than you think.

The last step to writing portable scripts is to use portable tools. Your system may have GNU coreutils installed, which provides tools like grep and cut. Unfortunately, GNU has extended these tools with its own non-portable flags and tools. It’s important that you avoid these.

One dead giveaway of a non-portable flag is long flags, e.g. grep --file=FILE as opposed to grep -f. The POSIX standard only defines the getopt function - not the proprietary GNU getopt_long function that’s used to interpret long options. As a result, no long flags are standardized. You might worry that this will make your scripts difficult to understand, but I think that on the whole it will not. Shell scripts are already pretty alien and require some knowledge to understand. Is knowledge of what the magic word grep means much different from knowledge of what grep -E means?

I also like that short flags allow you to make more concise command lines. Which is better: ps --all --format=user --without-tty, or ps -aux? If you are inclined to think the former, do you also prefer function(a, b, c) { return a + b + c; } over (a, b, c) => a + b + c? Conciseness matters, and POSIX shell supports comments if necessary!

A good reference for learning about standardized commands is, once again, the standard. From this page, search for the command you want, or navigate through “Shell & Utilities” -> “Utilities” for a list. If you have man-pages installed, you will also find POSIX man pages installed on your system with the p postfix, such as man 1p grep. Note: at the time of writing, the POSIX man pages do not use dashes if your locale is UTF-8, which makes searching for flags with / difficult. Use env LC_ALL=POSIX man 1p grep if you need to search for flags, and I’ll speak to the maintainer of man-pages about this.

Since 2015, I've been working on improving FreeBSD support for Broadcom Wi-Fi devices and SoCs, including authoring the bhnd(4) driver family, which provides a unified bus and driver programming interface for these devices.

First committed in early 2016, bhnd(4) allowed us to quickly bring up FreeBSD/MIPS on Broadcom SoCs, but it has taken much longer to implement the full set of features required to support modern Broadcom SoftMAC Wi-Fi hardware.

Thanks to the generosity of the FreeBSD Foundation, I've recently finished implementing the necessary improvements to the bhnd(4) driver family. With these changes in place, I was finally able to port the existing bwn(4) Broadcom SoftMAC Wi-Fi driver to the bhnd(4) bus, and implement initial support for the BCM43224 and BCM43225 chipsets, with additional hardware support to be forthcoming.

Now that my efforts on FreeBSD/Broadcom Wi-Fi support have progressed far enough to be generally useful, I wanted to take some time to provide a brief overview of Broadcom's Wi-Fi hardware, and explain how my work provides a foundation for further FreeBSD Broadcom Wi-Fi/SoC improvements.

Broadcom's Wi-Fi devices are members of the Broadcom Home Networking Division (BHND) device family; other BHND devices include MIPS/ARM SoCs (including Wi-Fi SoCs commonly found in consumer access points), as well as a large variety of related networking hardware.

When BHND hardware is used in a PCI Wi-Fi card, or a SDIO Wi-Fi module, the device's dual-mode peripheral controller is configured to operate as an endpoint device on the host's peripheral bus, bridging access to the SoC hardware:

The host is generally expected to provide drivers for the IP cores found on the SoC backplane; since these cores are found in both BHND SoCs and BHND Wi-Fi devices, it is advantageous to share driver and platform code between the two targets.

Prior to my work porting bwn(4) to bhnd(4), access to on-chip cores was mediated by siba_bwn, a PCI/WiFi-specific derivative of the legacy siba(4) SSB bus driver. There were two major limitations to siba_bwn that have long blocked adding support for newer SoftMAC Wi-Fi chipsets: the newer BCMA interconnect found in post-2009 hardware was not supported by siba(4), and siba_bwn assumed a PCI/PCIe bridge, preventing its use on FreeBSD/MIPS Broadcom SoCs with interconnect-attached D11 cores.

By porting bwn(4) to bhnd(4), we are now able to support existing BCMA devices with MAC/PHY/Radio combinations readily supported by bwn(4), as was the case with the BCM43224 and BCM43225 chipsets. This also opens the door to porting additional PHY support from Broadcom’s ISC-licensed Linux drivers, and will allow us to bring up bwn(4) on Broadcom WiSoCs supported by FreeBSD/MIPS.

Logs are usefull. Graphs are sexy. Here’s a way to get a view on what happens to your OpenSMTPD traffic, using Web v2.0 tools ; namely Logstash & Grafana.

OpenSMTPD deals with emails and logs its activity via Syslog.

We explain the physics behind ZFS, DTrace switching to the GPL, Emacs debugging, syncookies coming to PF & FreeBSD’s history on EC2.

64 bits would have been plenty ... but then you can't talk out of your ass about boiling oceans then, can you?

At Fosdem we had a talk on dtrace for linux in the Debugging Tools devroom.

Not explicitly mentioned in that talk, but certainly the most exciting thing, is that Oracle is doing a proper linux kernel port:

That is right, dtrace dropped the CDDL and switched to the GPL!

The user space code dtrace-utils and libdtrace-ctf (a combination of GPLv2 and UPL) can be found on the DTrace Project Source Control page. The NEWS file mentions the license switch (and that it is build upon elfutils, which I personally was pleased to find out).

The kernel sources (GPLv2+ for the core kernel and UPL for the uapi) are slightly harder to find because they are inside the uek kernel source tree, but following the above commit you can easily get at the whole linux kernel dtrace directory.

The UPL is the Universal Permissive License, which according to the FSF is a lax, non-copyleft license that is compatible with the GNU GPL.

Thank you Oracle for making everyone’s life easier by waving your magic relicensing wand!

Now there is lots of hard work to do to actually properly integrate this. And I am sure there are a lot of technical hurdles when trying to get this upstreamed into the mainline kernel. But that is just hard work. Which we can now start collaborating on in earnest.

Like systemtap and the Dynamic Probes (dprobes) before it, dtrace is a whole system observability tool combining tracing, profiling and probing/debugging techniques. Something the upstream linux kernel hackers don’t always appreciate when presented as one large system. They prefer having separate small tweaks for tracing, profiling and probing which are mostly separate from each other. It took years for the various hooks, kprobes, uprobes, markers, etc. from systemtap (and other systems) to get upstream. But these days they are. And there is now even a byte code interpreter (eBPF) in the mainline kernel as originally envisioned by dprobes, which systemtap can now target through stapbpf. So with all those techniques now available in the linux kernel it will be exciting to see if dtrace for linux can unite them all.

For some time Elfeed was experiencing a strange, spurious failure. Every so often users were seeing an error (spoiler warning) when updating feeds: “error in process sentinel: Search failed.” If you use Elfeed, you might have even seen this yourself. From the surface it appeared that curl, tasked with the responsibility for downloading feed data, was producing incomplete output despite reporting a successful run. Since the run was successful, Elfeed assumed certain data was in curl’s output buffer, but, since it wasn’t, it failed hard.

Unfortunately this issue was not reproducible. Manually running curl outside of Emacs never revealed any issues. Asking Elfeed to retry fetching the feeds would work fine. The issue would only randomly rear its head when Elfeed was fetching many feeds in parallel, under stress. By the time the error was discovered, the curl process had exited and vital debugging information was lost. Considering that this was likely to be a bug in Emacs itself, there really wasn’t a reliable way to capture the necessary debugging information from within Emacs Lisp. And, indeed, this later proved to be the case.

A quick-and-dirty work around is to use condition-case to catch and swallow the error. When the bizarre issue shows up, rather than fail badly in front of the user, Elfeed could attempt to swallow the error — assuming it can be reliably detected — and treat the fetch as simply a failure. That didn’t sit comfortably with me. Elfeed had done its due diligence checking for errors already. Someone was lying to Elfeed, and I intended to catch them with their pants on fire. Someday.

I’d just need to witness the bug on one of my own machines. Elfeed is part of my daily routine, so surely I’d have to experience this issue myself someday. My plan was, should that day come, to run a modified Elfeed, instrumented to capture extra data. I would have also routinely run Emacs under GDB so that I could inspect the failure more deeply.

For now I just had to wait to hunt that zebra.

Over the holidays I re-discovered Bryan Cantrill, a systems software engineer who worked for Sun between 1996 and 2010, and is most well known for DTrace. My first exposure to him was in a BSD Now interview in 2015. I had re-watched that interview and decided there was a lot more I had to learn from him. He’s become a personal hero to me. So I scoured the internet for more of his writing and talks.

Some interesting operating system technology came out of Sun during its final 15 or so years — most notably DTrace and ZFS — and Bryan speaks about it passionately. Almost as a matter of luck, most of it survived the Oracle acquisition thanks to Sun releasing it as open source in just the nick of time. Otherwise it would have been lost forever. The scattered ex-Sun employees, still passionate about their prior work at Sun, along with some of their old customers have since picked up the pieces and kept going as a community under the name illumos. It’s like an open source flotilla.

Naturally I wanted to get my hands on this stuff to try it out for myself. Is it really as good as they say? Normally I stick to Linux, but it (generally) doesn’t have these Sun technologies available. The main reason is license incompatibility. Sun released its code under the CDDL, which is incompatible with the GPL. Ubuntu does infamously include ZFS, but other distributions are unwilling to take that risk. Porting DTrace is a serious undertaking since it’s got its fingers throughout the kernel, which also makes the licensing issues even more complicated.

Linux has a reputation for Not Invented Here (NIH) syndrome, and these licensing issues certainly contribute to that. Rather than adopt ZFS and DTrace, they’ve been reinvented from scratch: btrfs instead of ZFS, and a slew of partial options instead of DTrace. Normally I’m most interested in system call tracing, and my go to is strace, though it certainly has its limitations — including this situation of debugging curl under Emacs. Another famous example of NIH is Linux’s epoll(2), which is a broken version of BSD kqueue(2).

So, if I want to try these for myself, I’ll need to install a different operating system. I’ve dabbled with OmniOS, an OS built on illumos, in virtual machines, using it as an alien environment to test some of my software (e.g. enchive). OmniOS has a philosophy called Keep Your Software To Yourself (KYSTY), which is really just code for “we don’t do packaging.” Honestly, you can’t blame them since they’re a tiny community. The best solution to this is probably pkgsrc, which is essentially a universal packaging system. Otherwise you’re on your own.

There’s also openindiana, which is a more friendly desktop-oriented illumos distribution. Still, the short of it is that you’re very much on your own when things don’t work. The situation is like running Linux a couple decades ago, when it was still difficult to do.

If you’re interested in trying DTrace, the easiest option these days is probably FreeBSD. It’s got a big, active community, thorough documentation, and a huge selection of packages. Its license (the BSD license, duh) is compatible with the CDDL, so both ZFS and DTrace have been ported to FreeBSD.

I’ve done all this talking but haven’t yet described what DTrace really is. I won’t pretend to write my own tutorial, but I’ll provide enough information to follow along. DTrace is a tracing framework for debugging production systems in real time, both for the kernel and for applications. The “production systems” part means it’s stable and safe — using DTrace won’t put your system at risk of crashing or damaging data. The “real time” part means it has little impact on performance. You can use DTrace on live, active systems with little impact. Both of these core design principles are vital for troubleshooting those really tricky bugs that only show up in production.

There are DTrace probes scattered all throughout the system: on system calls, scheduler events, networking events, process events, signals, virtual memory events, etc. Using a specialized language called D (unrelated to the general purpose programming language D), you can dynamically add behavior at these instrumentation points. Generally the behavior is to capture information, but it can also manipulate the event being traced.

Each probe is fully identified by a 4-tuple delimited by colons: provider, module, function, and probe name. An empty element denotes a sort of wildcard. For example, syscall::open:entry is a probe at the beginning (i.e. “entry”) of open(2). syscall:::entry matches all system call entry probes.

Unlike strace on Linux which monitors a specific process, DTrace applies to the entire system when active. To run curl under strace from Emacs, I’d have to modify Emacs’ behavior to do so. With DTrace I can instrument every curl process without making a single change to Emacs, and with negligible impact to Emacs. That’s a big deal.

So, when it comes to this Elfeed issue, FreeBSD is much better poised for debugging the problem. All I have to do is catch it in the act. However, it’s been months since that bug report and I’m not really making this connection yet. I’m just hoping I eventually find an interesting problem where I can apply DTrace.

As you may have heard, the a2k18 hackathon is in progress. As can be seen from the commit messages, several items of goodness are being worked on.

The first release to have this feature available will probably be the upcoming OpenBSD 6.3 if a sufficient number of people test this in their setups (hint, hint). More info is likely to emerge soon in post-hackathon writeups, so watch this space!

A couple years ago Jeff Barr published a blog post with a timeline of EC2 instances. I thought at the time that I should write up a timeline of the FreeBSD/EC2 platform, but I didn't get around to it; but last week, as I prepared to ask for sponsorship for my work I decided that it was time to sit down and collect together the long history of how the platform has evolved and improved over the years.

I was recently reading Mark Dominus's entry about some X keyboard problems, in which he said in passing (quoting himself):

I have been wondering for years if X's vaunted network transparency was as big a failure as it seemed: an interesting idea, worth trying out, but one that eventually turned out to be more trouble than it was worth. [...]

My first reaction was to bristle, because I use X's network transparency all of the time at work. I have several programs to make it work very smoothly, and some core portions of my environment would be basically impossible without it. But there's a big qualification on my use of X's network transparency, namely that it's essentially all for text. When I occasionally go outside of this all-text environment of xterms and emacs and so on, it doesn't go as well.

X's network transparency was not designed as 'it will run xterm well'; originally it was to be something that should let you run almost everything remotely, providing a full environment. Even apart from the practical issues covered in Daniel Stone's slide presentation, it's clear that it's been years since X could deliver a real first class environment over the network. You cannot operate with X over the network in the same way that you do locally. Trying to do so is painful and involves many things that either don't work at all or perform so badly that you don't want to use them.

In my view, there are two things that did in general X network transparency. The first is that networks turned out to not be fast enough even for ordinary things that people wanted to do, at least not the way that X used them. The obvious case is web browsers; once the web moved to lots of images and worse, video, that was pretty much it, especially with 24-bit colour.

(It's obviously not impossible to deliver video across the network with good performance, since YouTube and everyone else does it. But their video is highly encoded in specialized formats, not handled by any sort of general 'send successive images to the display' system.)

The second is that the communication facilities that X provided were too narrow and limited. This forced people to go outside of them in order to do all sorts of things, starting with audio and moving on to things like DBus and other ways of coordinating environments, handling sophisticated configuration systems, modern fonts, and so on. When people designed these additional communication protocols, the result generally wasn't something that could be used over the network (especially not without a bunch of setup work that you had to do in addition to remote X). Basic X clients that use X properties for everything may be genuinely network transparent, but there are very few of those left these days. (Not even xterm is any more, at least if you use XFT fonts. XFT fonts are rendered in the client, and so different hosts may have different renderings of the same thing, cf.)

< What remains of X's network transparency is still useful to some of us, but it's only a shadow of what the original design aimed for. I don't think it was a mistake for X to specifically design it in (to the extent that they did, which is less than you might think), and it did help X out pragmatically in the days of X terminals, but that's mostly it.

(I continue to think that remote display protocols are useful in general, but I'm in an usual situation. Most people only ever interact with remote machines with either text mode SSH or a browser talking to a web server on the remote machine.)

PS: The X protocol issues with synchronous requests that Daniel Stone talks about don't help the situation, but I think that even with those edges sanded off X's network transparency wouldn't be a success. Arguably X's protocol model committed a lesser version of part of the NeWS mistake.

I recently wrote an entry about how X's network transparency has wound up mostly being a failure for various reasons. However, there is an important flipside to the story of X's network transparency, and that is that X's network transparency was almost free at the time and in the context it was created. Unlike the situation today, in the beginning X did not have to give up lots of performance or other things in order to get network transparency.

X originated in the mid 1980s and it was explicitly created to be portable across various Unixes, especially BSD-derived ones (because those were what universities were mostly using at that time). In the mid to late 1980s, Unix had very few IPC methods, especially portable ones. In particular, BSD systems did not have shared memory (it was called 'System V IPC' for the obvious reasons). BSD had TCP and Unix sockets, some System V machines had TCP (and you could likely assume that more would get it), and in general your safest bet was to assume some sort of abstract stream protocol and then allow for switchable concrete backends. Unsurprisingly, this is exactly what X did; the core protocol is defined as a bidirectional stream of bytes over an abstracted channel. (And the concrete implementation of $DISPLAY has always let you specify the transport mechanism, as well as allowing your local system to pick the best mechanism it has.)

Once you've decided that your protocol has to run over abstracted streams, it's not that much more work to make it network transparent (TCP provides streams, after all). X could have refused to make the byte order of the stream clear or required the server and the client to have access to some shared files (eg for fonts), but I don't think either would have been a particularly big win. I'm sure that it took some extra effort and care to make X work across TCP from a different machine, but I don't think it took very much. (At the same time, my explanation here is probably a bit ahistorical. X's initial development seems relatively strongly tied to sometimes having clients on different machines than the display, which is not unreasonable for the era. But it doesn't hurt to get a feature that you want anyway for a low cost.)

I believe it's important here that X was intended to be portable across different Unixes. If you don't care about portability and can get changes made to your Unix, you can do better (for example, you can add some sort of shared memory or process to process virtual memory transfer). I'm not sure how the 1980s versions of SunView worked, but I believe they were very SunOS dependent. Wikipedia says SunView was partly implemented in the kernel, which is certainly one way to both share memory and speed things up.

PS: Sharing memory through mmap() and friends was years in the future at this point and required significant changes when it arrived.

We talk about our recent trip to FOSDEM, we discuss the pros and cons of permissive licensing, cover the installation of OpenBSD on a dedibox with full-disk encryption, the new Lumina guide repository, and we explain ZFS vs. OpenZFS.

I discovered this bug class during the InfoSect public code review session we ran looking specifically at the NetBSD kernel. I found a couple of these bugs and then after the session was complete, I went back and realised the same bug was scattered in other drivers. In total, 17 instances of this vulnerability and its variants were discovered.

Reporting of the bugs was easy. In less than a week from reporting the specific instances of each bug, patches were committed into the mainline kernel. Thanks to Luke Mewburn from NetBSD for coming to the code review session at InfoSect and coordinating with the NetBSD security team.

A few weeks ago I’ve been attacked by some GNU zealots on a German tech site after speaking in favor of permissive licenses. Unfortunately a discussion was not possible there because that would require the will to actually communicate instead of simply accusing the other side of vile motives. Since I actually do care about this topic and a reader asked for a post about it in comments a while ago, here we go.

This first part tries to sum up the most important things around the topic. I deliberately aim for an objective overview that tries not to be one-sided. The second part will then contain my points in defence of permissive licensing.

Licenses exist for reasons of protection. If you’re the author/inventor of some software, a story or whatever product, you get to decide what to do with it. You can keep it for yourself or you can give it away. If you decide for the latter, you have to decide who may use it and in which way(s). In case you intend to give it to a (potentially) large group of people, you may not want to be asked for permission to xyz by everybody. That’s when you decide to write a license which states what you are allowing and explicitly disallowing.

In short terms, permissive licensing usually goes like this: “Here you are, have fun. Oh, and don’t sue me if it does something else than what you expect!” Yes, it’s that easy and there’s little to dispute over.

The most popular copyleft license in use is the GPL (in various versions). It got more and more complex with each version – and to be fair, it had to, because it was necessary to react to new threats and loop holes that were found later. The GNU project states that they are committed to protect what they call the four freedoms of free software:

These are freedoms that every supporter of open source software should be able to agree with. So what’s the deal with all the hostility and fighting between the two camps? Let’s take a look at a permissive license, too.

Unlike the GPL, the BSD family of licenses begun with a rather simple license that span four rules (“original BSD license”). It was later revised and reduced to three (“modified BSD license”). And the modern BSD license that e.g. FreeBSD uses is even just two (“simplified BSD license”).

Did you read the GPLv3 that I linked to above? If you are using GPL’d code you really should. In case you don’t feel like reading all of it, at least take a look and grasp how long that text is. Now compare it to the complete modern BSD license.

There are essentially two problems that cause all the trouble. The first one is the question of what should be subject to the freedom that we’re talking about. And closely related, the second one is where that freedom needs to end.

Ironically both camps claim that freedom is the one important thing and it must not be restricted. The GPL is meant to protect the freedom of the software and enforces the availability of the source code, hence limiting the freedom of actual persons. BSD on the other hand is meant to protect the freedom of human beings who should be able to use the software as they see fit – even if that means closing down former open source code!

The GNU camp taunts permissive licenses as being “lax” for not providing the protection that they want. The other camp points out that the GPL is a complex monster and that it is virulent in nature: Since it’s very strict in a lot of areas, it’s incompatible with many other licenses. This makes it complicated to mix GPL and non-GPL code and in the cases where it’s legally possible, the GPL’s terms will take precedence and necessarily be in effect for the whole combined work.

That totally depends on what you want to achieve. There are pros and cons to both – and in fact we’re only looking at the big picture here. There’s also e.g. the Apache license which is often deemed as kind of middle ground. Then you may want to consider the difference between weak (e.g. LGPL) as well as strong copyleft (GPL). Licensing is a potentially huge topic. But let’s keep it simple here because the exact details are actually not necessary to understand the essence of our topic.

In the next post I’ll present my stance on why permissive licensing is a good thing and copyleft is more problematic than many people may think.

The previous post gave a short introduction into the topic of software licenses, focusing on the GPL vs. BSD discussion. This one is basically my response to some typical arguments I’ve seen from people who seem to loathe permissive licensing. I’ll write this in dialog style, hoping that this makes it a little lighter to read.

I run several "dedibox" servers at online.net, all powered by OpenBSD. OpenBSD is not officially supported so you have to work-around. Running full-disk encrypted OpenBSD there is a piece of cake. As a bonus, my first steps within a brand new booted machine ;-)

OpenBSD is not officially supported, I can’t guarantee that this will work for you on any kind of server online.net provides, however I’ve been running https://poolp.org on OpenBSD there since 2008, only switching machines as they were getting a bit old and new offers came up.

Currently, I’m running two SC 2016 (SATA) and one XC 2016 (SSD) boxes, all three running OpenBSD reliably ever since I installed them.

Recently I’ve been willing to reinstall the XC one after I did some experiments that turned it into a FrankenBSD, so this was the right occasion to document how I do it for future references.

I wrote an article similar to this a few years ago relying on qemu to install to the disk, since then online.net provided access to a virtual serial console accessed within the browser, making it much more convenient to install without the qemu indirection which hid the NIC devices and disks duid and required tricks.

The method I currently use is a mix and adaptation from the techniques described in https://www.2f30.org/guides/openbsd-dedibox.html to boot the installer, and the technique described in https://geekyschmidt.com/2011/01/19/configuring-openbsd-softraid-fo-encryption.html to setup the crypto slice.

Issues affecting most CPUs used in servers, desktops, laptops, and mobile devices are in the news. These hardware vulnerabilities, known by the code-names “Meltdown” and “Spectre”, allow malicious programs to read data to which they should not have access. This potentially includes credentials, cryptographic material, or other secrets. They were originally identified by a researcher from Google’s Project Zero, and were also independently discovered by researchers and academics from Cyberus Technology, Graz University of Technology, the University of Pennsylvania, the University of Maryland, Rambus, the University of Adelaide and Data61.

These vulnerabilities affect many CPU architectures supported by FreeBSD, but the 64-bit x86 family of processors from Intel and AMD are the most widely used, and are a high priority for software changes to mitigate the effects of Meltdown and Spectre. In particular, the Meltdown issue affects Intel CPUs and may be used to extract secret data from the running kernel, and therefore, is the most important issue to address.

The FreeBSD Foundation collaborates with Intel, and under this relationship participated in a briefing to understand the details of these issues and plan the mitigations to be applied to the x86 architectures supported by FreeBSD. We also made arrangements to have FreeBSD’s security officer join me in the briefing. It is through the generous support of the Foundation’s donors that we are able to dedicate resources to focus on these issues on demand as they arise.

Foundation staff member Konstantin (Kostik) Belousov is an expert on FreeBSD’s Virtual Memory (VM) system as well as low-level x86 details, and is developing the x86 kernel mitigations for FreeBSD.

The mitigation for Meltdown is known as Page Table Isolation (PTI). Kostik created a PTI implementation which was initially committed in mid-January and is available in the FreeBSD-CURRENT development repository. This is the same approach used by the Linux kernel to mitigate Meltdown.

One of the drawbacks of the PTI mitigation is that it incurs a performance regression. Kostik recently reworked FreeBSD’s use of Process-Context Identifiers (PCID) in order to regain some of the performance loss incurred by PTI. This change is also now available in FreeBSD-CURRENT.

The issue known as Spectre comes in two variants, and variant 2 is the more troubling and pressing one. It may be mitigated in one of two ways: by using a technique called “retpoline” in the compiler, or by making use of a CPU feature introduced in a processor microcode update. Both options are under active development. Kostik’s change to implement the CPU-based mitigation is currently in review. Unfortunately, it introduces a significant performance penalty and alternatives are preferred, if available.

For most cases, the compiler-based retpoline mitigation is likely to be the chosen mitigation. Having switched to the Clang compiler for the base system and most of the ports collection some years ago, FreeBSD is well-positioned to deploy Clang-based mitigations. FreeBSD developer Dimitry Andric is spearheading the update of Clang/LLVM in FreeBSD to version 6.0 in anticipation of its official release; FreeBSD-CURRENT now includes an interim snapshot. I have been assisting with the import, particularly with respect to LLVM’s lld linker, and will support the integration of retpoline. This support is expected to be merged into FreeBSD in the coming weeks.

The Foundation’s co-op students have also participated in the response to these vulnerabilities. Mitchell Horne developed the patch to control the PTI mitigation default setting, while Arshan Khanifar benchmarked the performance impact of the in-progress mitigation patches. In addition, Arshan and Mitchell each developed changes to FreeBSD’s tool chain to support the full set of mitigations that will be applied.

These mitigations will continue be tested, benchmarked, and refined in FreeBSD-CURRENT before being merged into stable branches and then being made available as updates to FreeBSD releases. Details on the timing of these merges and releases will be shared as they become available.

I would like to acknowledge all of those in the FreeBSD community who have participated in FreeBSD’s response to Meltdown and Spectre, for testing, reviewing, and coordinating x86 mitigations, for developing mitigations for other processor architectures and for the Bhyve hypervisor, and for working on the toolchain-based mitigations.

I am pleased to announce the beginning of a new sub-series of blog posts for the Lumina project: Guides!

The TrueOS/Lumina projects want to support our users as they use Lumina or experiment with TrueOS. To that end, we’ve recently set up a central repository for our users to share instructions or other “how-to” guides with each other! Project developers and contributors will also submit guides to the repository on occasion, but the overall goal is to provide a simple hub for instructions written by any Lumina or TrueOS user. This will make it easier for users to not only find a “how-to” for some procedure, but also a very easy way to “give back” to the community by writing simple instructions or more detailed guides.

Our first guide to get the whole thing started was created by the TrueOS Linebacker (with technical assistance from our own q5sys). In this guide, Terry Tate will walk you through the steps necessary to submit new wallpaper images to the Lumina Themes collection. This procedure is fully documented with screenshots every step of the way, walking you through a simple procedure that only requires a web browser and a Github account!

The end result of this guide was that Terry Tate was able to submit this cool new “Lunar-4K” wallpaper to the “lumina-nature” collection.

You’ve probably heard us say a mix of “ZFS” and “OpenZFS” and an explanation is long-overdue. Our Senior Analyst clears up what ZFS and OpenZFS refer to and how they differ.

We cover an interview about Unix Architecture Evolution, another vBSDcon trip report, how to teach an old Unix about backspace, new NUMA support coming to FreeBSD, and stack pointer checking in OpenBSD.

I’m a professor of software engineering, a programmer at heart, and a technology author. Currently I’m also the editor in chief of the IEEE Software magazine. I recently published the book Effective Debugging, where I detail 66 ways to debug software and systems.

I will describe how the architecture of the Unix operating system evolved over the past half century, starting from an unnamed system written in PDP-7 assembly language and ending with a modern FreeBSD system. My talk is based, first, on a GitHub repository where I tried to record the system’s history from 1970 until today and, second, on the evolution of documented facilities (user commands, system calls, library functions) across revisions. I will thus present the early system’s defining architectural features (layering, system calls, devices as files, an interpreter, and process management) and the important ones that followed in subsequent releases: the tree directory structure, user contributed code, I/O redirection, the shell as a user program, groups, pipes, scripting, and little languages.

Unix stands out as a major engineering breakthrough due to its exemplary design, its numerous technical contributions, its impact, its development model, and its widespread use. Furthermore, the design of the Unix programming environment has been characterized as one offering unusual simplicity, power, and elegance. Consequently, there are many lessons that we can learn by studying the evolution of the Unix architecture, which we can apply to the design of new systems. I often see modern systems that suffer from a bloat of architectural features and a lack of clear form on which functionality can be built. I believe that many of the modern Unix architecture defining features are excellent examples of what we should strive toward as system architects.

I’d like FOSDEM attendees to leave the talk with their mind full with architectural features of timeless quality. I want them to realize that architectural elegance isn’t derived by piling design patterns and does not need to be expensive in terms of resources. Rather, beautiful architecture can be achieved on an extremely modest scale. Furthermore, I want attendees to appreciate the importance of adopting flexible conventions rather than rigid enforcement mechanisms. Finally, I want to demonstrate through examples that the open source culture was part of Unix from its earliest days.

The architectural development of Unix follows a path of continuous evolution, albeit at a slowing pace, so I don’t see here the most important milestones. I would however define as significant milestones two key changes in the way Unix was developed. The first occurred in the late 1970s when significant activity shifted from a closely-knit team of researchers at the AT&T Bell Labs to the Computer Science Research Group in the University of California at Berkeley. This opened the system to academic contributions and growth through competitive research funding. The second took place in the late 1980s and the 1990s when Berkeley open-sourced the the code it had developed (by that time a large percentage of the system) and enthusiasts built on it to create complete open source operating system distributions: 386BSD, and then FreeBSD, NetBSD, OpenBSD, and others.

The data I will show demonstrate that there were in the past some long periods where the number of C library functions and system calls remained mostly stable. Nowadays there is significant growth in the number of all documented facilities with the exception of file formats. I’m looking forward to a discussion regarding the meaning of these growth patterns in the Q&A session after the talk.

Over the past half-century the Unix system has grown by four orders of magnitude from a few thousand lines of code to many millions. Nevertheless, looking at a 1970s architecture diagram and a current one reveals that the initial architectural blocks are still with us today. Furthermore, most system calls, user programs, and C library functions of that era have survived until today with essentially similar functionality. I’ve even found in modern FreeBSD some lines of code that have survived unchanged for 40 years.

There’s a saying that “form liberates”. So having available a time-tested form for developing operating system functionality allows you to innovate in areas that matter rather than reinventing the wheel.

Such concepts include having commands act as a filter, providing manual pages with a consistent structure, supplying build information in the form of a Makefile, installing files in a well-defined directory hierarchy, implementing filesystems with an standardized object-oriented interface, and packaging reusable functions as a library. Within this framework there’s ample space for both incremental additions (think of jq, the JSON query command) and radical innovations (consider the Solaris-derived ZFS and dtrace functionality). For this reason I think that BSD and Linux systems will always be recognizable as direct or intellectual descendants of the 1970s Research Unix editions.

Immensely! As an academic I need to attend many scientific conferences and meetings in order to present research results and interact with colleagues. This means too much time spent traveling and away from home, and a limited number of conferences I’m in the end able to attend. Nevertheless, attending FOSDEM is an easy decision due to the world-changing nature of its theme, the breadth of the topics presented, the participants’ enthusiasm and energy, as well as the exemplary, very efficient conference organization.

Recently I had the honor of co-presenting on the internals of FreeBSD’s Kernel RNG with John-Mark Gurney at the 3rd biennial vBSDCon, hosted in Reston, VA hosted by Verisign.

I’d also not had to do a stand-up presentation really since college before this. So, my first BSD con and my first time presenting rolled into one made for an interesting experience.

That said, it was amazing and invigorating experience. I got to meet a few big names in the FreeBSD community, discuss projects, ideas for FreeBSD, etc. I did seem to spend an unusual amount of time talking about FIPS and Common Criteria with folks, but to me that’s a good sign and indicative that there is interest in working to close gaps between FreeBSD and the current requirements so that we can start getting FreeBSD and more BSD-based products into the government and start whittling away the domination of Linux (especially since Oracle has cut Solaris, SPARC and the ZFS storage appliance business units).

I think the talk that really had the biggest impact on me, however, was Kyle Kneisl’s talk on BSD community dynamics. One of the key points he asked was whether the things that drew us to the BSD community in the first place would be able to happen today. Obviously, I’m not a 12 or 13 year old kid anymore, but it really got me thinking. That, combined with getting face time with people I’d previously only known as screen names has recently drawn me back into participating in IRC and rejoining mailing lists (wdf on freenode. be on the lookout!)

JMG and my talk seems to have been well received, with people paying lots of attention. I don’t know what a typical number of questions is for one of these things, but on day one there weren’t that many questions. We got about 5 during our question time and spent most of the rest of the day fielding questions from interested attendees. Getting a “great talk!” from GNN after coming down from the stage was probably one of the major highlights for me.

I think key to the interest in our presentation was that JMG did a good job framing a very complicated topic’s importance in terms everyone could understand. It also helped that we got to drop some serious truth bombs.

I met a lot of folks in person for the first time, and met some people I’d never known online before. It was a great community and I’m glad I got a chance to expand my network.

I have been messing with the UNIX® operating system, Seventh Edition (commonly known as UNIX V7 or just V7) for a while now. V7 dates from 1979, so it’s about 40 years old at this point. The last post was on V7/x86, but since I’ve run into various issues with it, I moved on to a proper installation of V7 on SIMH. The Internet has some really good resources on installing V7 in SIMH. Thus, I set out on my own journey on installing and using V7 a while ago, but that was remarkably uneventful.

One convenience that I have been dearly missing since the switch from V7/x86 is a functioning backspace key. There seem to be multiple different definitions of backspace:

BS, as in ASCII character 8 (010, 0x08, also represented as H), and

There is some debate on whether BS or DEL is the correct character for terminals to send when the user presses the backspace key. However, most programs have settled on DEL today. tmux forces DEL, even if the terminal emulator sends BS, so simply changing my terminal to send BS was not an option. The change from the defaults outlined here to today’s modern-day defaults occurred between 4.1BSD and 4.2BSD. enf on Hacker News has written a nice overview of the various conventions

For future generations as well as myself when I inevitably majorly break this installation of V7, I wanted to make a diff. However, my V7 is installed in SIMH. I am not a very intelligent man, I didn’t keep backup copies of the files I’d changed. Getting data out of this emulated machine is an exercise in frustration.

In the end, I printed everything on screen using cat(1) and copied that out. Then I performed a manual diff against the original source code tree because tabs got converted to spaces in the process. Then I applied the changes to clean copies that did have the tabs. And finally, I actually invoked diff(1).

Figuring all this out took me a few days. Penetrating how the system is put together was surprisingly fairly hard at first, but then the difficulty curve eased up. It was an interesting exercise in some kind of “reverse engineering” and I definitely learned something about tty handling. I was, however, not pleased with using ed(1), even if I do know the basics. vi(1) is a blessing that I did not appreciate enough until recently. Had I also been unable to access recursive grep(1) on my host and scroll through the code, I would’ve probably given up. Writing UNIX under those kinds of editing conditions is an amazing feat. I have nothing but the greatest respect for software developers of those days.

Hello folks,

I am working on merging improved NUMA support with policy implemented by cpuset(2) over the next week. This work has been supported by Dell/EMC's Isilon product division and Netflix. You can see some discussion of these changes here:

https://reviews.freebsd.org/D13403

The work has been done in user/jeff/numa if you want to look at svn history or experiment with the branch. It has been tested by Peter Holm on i386 and amd64 and it has been verified to work on arm at various points.

We are working towards compatibility with libnuma and linux mbind. These commits will bring in improved support for NUMA in the kernel. There are new domain specific allocation functions available to kernel for UMA, malloc, kmem_, and vm_page*. busdmamem consumers will automatically be placed in the correct domain, bringing automatic improvements to some

cpuset will be able to constrains processes, groups of processes, jails, etc. to subsets of the system memory domains, just as it can with sets of cpus. It can set default policy for any of the above. Threads can use cpusets to set policy that specifies a subset of their visible domains.

Available policies are first-touch (local in linux terms), round-robin (similar to linux interleave), and preferred. For now, the default is round-robin. You can achieve a fixed domain policy by using round-robin with a bitmask of a single domain. As the scheduler and VM become more

Currently these features are enabled with VM_NUMA_ALLOC and MAXMEMDOM. It will eventually be NUMA/MAXMEMDOM to match SMP/MAXCPU. The current NUMA syscalls and VM_NUMA_ALLOC code was 'experimental' and will be deprecated. numactl will continue to be supported although cpuset should be preferred going forward as it supports the full feature set of the new API.

Thank you for your patience as I deal with the inevitable fallout of such sweeping changes. If you do have bugs, please file them in bugzilla, or reach out to me directly. I don't always have time to catch up on all of my mailing list mail and regretfully things slip through the cracks when

Thanks,

Stefan (stefan@) and I have been working for a few months on this diff, with help from a few others.

At every trap and system call, it checks if the stack-pointer is on a page that is marked MAP_STACK. execve() is changed to create such mappings for the process stack. Also, libpthread is taught the new MAP_STACK flag to use with mmap().

There is no corresponding system call which can set MAP_FLAG on an existing page, you can only set the flag by mapping new memory into place. That is a piece of the security model.

The purpose of this change is to twart stack pivots, which apparently have gained some popularity in JIT ROP attacks. It makes it difficult to place the ROP stack in regular data memory, and then perform a system call from it. Workarounds are cumbersome, increasing the need for far more gadgetry. But also the trap case -- if any memory experiences a demand page fault, the same check will occur and potentially also kill the process.

We have experimented a little with performing this check during device interrupts, but there are some locking concerns and performance may then become a concern. It'll be best to gain experience from handle of syncronous trap cases first.

chrome and other applications I use run fine!

I'm asking for some feedback to discover what ports this breaks, we'd like to know. Those would be ports which try to (unconventionally) create their stacks in malloc()'d memory or inside another Data structure. Most of them are probably easily fixed ...

Tobias and Raphael have spent the past month or so hammering on the Qt 5.9 branch, which has (finally!) landed in the official FreeBSD ports tree. This brings FreeBSD back up-to-date with current Qt releases and, more importantly, up-to-date with the Qt release KDE software is increasingly expecting. With Qt 5.9, the Elisa music player works, for instance (where it has run-time errors with Qt 5.7, even if it compiles). The KDE-FreeBSD CI system has had Qt 5.9 for some time already, but that was hand-compiled and jimmied into the system, rather than being a “proper” ports build.

The new Qt version uses a new build system, which is one of the things that really slowed us down from a packaging perspective. Some modules have been reshuffled in the process. Some applications depending on Qt internal-private headers have been fixed along the way. The Telegram desktop client continues to be a pain in the butt that way.

Following on from Qt 5.9 there has been some work in getting ready for Clang 6 support; in general the KDE and Qt stack is clean and modern C++, so it’s more infrastructural tweaks than fixing code. Outside of our silo, I still see lots of wonky C++ code being fixed and plenty of confusion between pointers and integers and strings and chars and .. ugh. Speaking of ugh, I’m still planning to clean up Qt4 on ARM aarch64 for FreeBSD; this boils down to stealing suitable qatomic implementations from Arch Linux.

For regular users of Qt applications on FreeBSD, there should be few to no changes required outside the regular upgrade cycle. For KDE Plasma users, note that development of the ports has changed branches; as we get closer to actually landing modern KDE bits, things have been renamed and reshuffled and mulled over so often that the old plasma5 branch wasn’t really right anymore. The kde5-import branch is where it’s at nowadays, and the instructions are the same: the x11/kde5 metaport will give you all the KDE Frameworks 5, KDE Plasma Desktop and modern KDE Applications you need.

All of this took about 3 hours.

I expect some monitoring fallout from this change. I suspect some of my monitoring assumes IP4 and now that IPv6 is available, I need to monitor both IP addresses.

TrueOS was the first desktop operating system to fully implement the OpenZFS (Zettabyte File System or ZFS for short) enterprise file system in a stable production environment. To fully understand why we love ZFS, we will look back to the early days of TrueOS (formerly PC-BSD). The development team had been using the UFS file system in TrueOS because of its solid track record with FreeBSD-based computer systems and its ability to check file consistency with the built-in check utility fsck.

However, as computing demands increased, problems began to surface. Slow fsck file verification on large file systems, slow replication speeds, and inconsistency in data integrity while using UFS logging / journaling began to hinder users. It quickly became apparent that TrueOS users would need a file system that scales with evolving enterprise storage needs, offers the best data protection, and works just as well on a hobbyist system or desktop computer.

Kris Moore, the founder of the TrueOS project, first heard about OpenZFS in 2007 from chatter on the FreeBSD mailing lists. In 2008, the TrueOS development team was thrilled to learn that the FreeBSD Project had ported ZFS. At the time, ZFS was still unproven as a graphical desktop solution, but Kris saw a perfect opportunity to offer ZFS as a cutting-edge file system option in the TrueOS installer, allowing the TrueOS project to act as an indicator of how OpenZFS would fair in real-world production use.

The team was blown away by the reception and quality of OpenZFS on FreeBSD-based systems. By its nature, ZFS is a copy-on-write (CoW) file system that won’t move a block of data until it both writes the data and verifies its integrity. This is very different from most other file systems in use today. ZFS is able to assure that data stays consistent between writes by automatically comparing write checksums, which mitigates bit rot. ZFS also comes with native RaidZ functionality that allows for enterprise data management and redundancy without the need for expensive traditional RAID cards. ZFS snapshots allow for system configuration backups in a split-second. You read that right. TrueOS can backup or restore snapshots in less than a second using the ZFS file system.

Given these advantages, the TrueOS team decided to use ZFS as its exclusive file system starting in 2013, and we haven’t looked back since. ZFS offers TrueOS users the stable workstation experience they want, while simultaneously scaling to meet the increasing demands of the enterprise storage market. TrueOS users are frequently commenting on how easy it is to use ZFS snapshots with our built-in snapshot utility. This allows users the freedom to experiment with their system knowing they can restore it in seconds if anything goes wrong. If you haven’t had a chance to try ZFS with TrueOS, browse to our download page and make sure to grab a copy of TrueOS. You’ll be blown away by the ease of use, data protection functionality, and incredible flexibility of RaidZ.

We provide you with updates to Spectre and Meltdown from various BSD projects, a review of TrueOS from Linux, how to set up FreeBSD on ThinkPad x240, and a whole bunch of beastie bits.

I want to know when my girlfriend's passport expires, but she won't show me her passport (she complains that it has a horrible photo) and refuses to tell me the expiry date. I tell her that I'm going to take her to Europe on vacation in August and watch what happens: If she runs out to renew her passport, I know that it will expire before August; while if she doesn't get her passport renewed, I know that it will remain valid beyond that date. Her desire to ensure that her passport would be valid inadvertently revealed to me some information: Whether its expiry date was before or after August.

I tell my girlfriend that I'm going to take her on vacation in June, but I don't tell her where yet; however, she knows that it will either be somewhere within Canada (for which she doesn't need a passport, since we live in Vancouver) or somewhere in Europe. She knows that it takes time to get a passport renewed, so she checks her passport and (if it was about to expire) gets it renewed just in case I later reveal that I'm going to take her to Europe. If I tell her later that I'm only taking her to Ottawa — well, she didn't need to renew her passport after all, but in the meantime her behaviour has already revealed to me whether her passport was about to expire. This is what Google refers to "variant 1" of the Spectre vulnerability: Even though she didn't need her passport, she made sure it was still valid just in case she was going to need it.

I spend a week talking about how Oxford is a wonderful place to visit and I really enjoyed the years I spent there, and then I tell her that I want to take her on vacation. She very reasonably assumes that — since I've been talking about Oxford so much — I must be planning on taking her to England, and runs off to check her passport and potentially renew it... but in fact I tricked her and I'm only planning on taking her to Ottawa.

I tell my girlfriend that I want to take her to the Korean peninsula. She knows that her passport is valid for long enough; but she immediately runs off to check that her North Korean visa hasn't expired. Why does she have a North Korean visa, you ask? Good question. She doesn't — but she runs off to check its expiry date anyway! Because she doesn't have a North Korean visa, she (somehow) checks the expiry date on someone else's North Korean visa, and then (if it is about to expire) runs out to renew it — and so by telling her that I want to take her to Korea for a vacation I find out something she couldn't have told me even if she wanted to.

Patrick and others committed amd64 Intel cpu microcode update code over the last few days. The approach isn't perfect, but it is good enough for a start. I want to explain the situation.

I wasn’t going to write anything on the recently found x64 architecture – related bugs. I’m not a kernel developer nor even a programmer and I can’t say that I have a solid understanding of what Meltdown and Spectre attacks are. Also there already is a ton of articles and posts written by people who have no grasp of the subject.

Intel: as a *BSD user, I am fucking pissed!

Part of my work is UNIX-like systems administration – including BSDs and Linuces. As much as I am happy with Linux changes already made, I am beyond pissed about how the BSDs were handled by Intel – because they were not. FreeBSD Security Team received some heads-up just before Xmas, while OpenBSD, NetBSD and DragonflyBSD teams received no prior warnings.

Meltdown and Spectre attacks are hard to perform. It is a hard work to mitigate them in the software, as the bugs lay in the CPUs and are not fixable by microcode updates. Developers are trying to mitigate these bugs in a way that will deliver smallest performance losses. A lot of time consuming work is needed to fix CPU vendors’ mistakes. Linux developers had this time. BSD developers did not.

BSD user base is small in comparison to Linux. Seems that it’s too small for Intel. PlayStation4 consoles are FreeBSD-based (and use AMD CPUs) but I think it’s safe to say that gaming devices are not the most important systems to be fixed. Netflix serves their content off FreeBSD but the bugs are not remotely exploitable (possibly not including JavaScript, but it’s running someone’s code locally) so there’s probably not much harm to be done here either.

In March 2017, Intel promised “more timely support to FreeBSD”. They knew about flaws in their CPUs in June and decided that a timely manner is the end of December – short before the embargo was to be lifted.

Intel and Google (probably Intel more): it was your job to pick the correct people to whom the bugs can be disclosed. In my humble opinion you chose poorly by disclosing these issues with ONLY Apple, Microsoft, and the Linux Foundation, of OS vendors. You did much harm to the BSD community.

Intel: It’s your bugs. And you offered “more support” to the FreeBSD Foundation less than 3 months prior to being informed (my guess is that you knew much earlier) on the flaws in YOUR products. I don’t want to write more here as the wording would be too strong.

Trust me, the name TrueOS takes me back to 1990s when Tru64 UNIX operating system made its presence. TrueOS is PC-BSD’s new unified brand built upon FreeBSD-CURRENT code base. Note that TrueOS is not a Linux distro but is BSD Unix. FreeBSD is known for its cutting-edge features, security, scalability, and ability to work both as a server and desktop operating system. TrueOS aims at having user-friendliness with the power of FreeBSD OS. Let us start with going into details of different aspects of the TrueOS.

TrueOS was founded by Kris Moore in 2005 with name PC-BSD. Initial version focused to make FreeBSD easy to use starting with providing GUI based installer (to relatively complicated FreeBSD installer). In the year 2006, PC-BSD was acquired by iXsystems. Before rebranding as TrueOS in Sept 2016, PC-BSD reached a stage starting considering better than vanilla FreeBSD. Older PC-BSD version used to support both x86 and x86-64 architecture.

The startup is little longer; may be due to starting up of many services. The heavy KDE well suited to PC-BSD. The C++/Qt5 based Lumina desktop environment is light and fast. The Lumina offers an easy way to configure menu and panels. I did not face any problems for continuous use of two weeks on a virtual machine having the minimal configuration: 1 GB RAM, 20 GB hard disk and Intel 3.06 GHz i3 processor. The Lumina desktop is light and fast. The developers of Lumina know what they are doing and have a good idea of what makes a good IDE. As it happens with any new desktop environment, it needs some time to settle. Let us hope that they keep to the path they are on with it.

The TrueOS is impressive when consider it as relatively young. It is a daring step that TrueOS developers took FreeBSD Current rather than FreeBSD Stable code base. Overall it has created its own place from the legacy shadow of PC-BSD. Starting with easy installation TrueOS is a good combination of software and utilities that make the system ready to use. Go and get a TrueOS ISO to unleash the “bleeding edge” tag of FreeBSD

What follows is a record of how I set up FreeBSD to be my daily driver OS on the Lenovo Thinkpad X240. Everything seems to work great. Although, the touchpad needs some tweaking. I've tried several configurations, even recompiling Xorg with EVDEV support and all that, to no avail. Eventually I will figure it out. Do not sleep the laptop from the command line. Do it from within Xorg, or it will not wake up. I don't know why. You can do it from a terminal within Xorg, just not from the naked command line without Xorg started. It also will not sleep by closing the lid. I included a sudo config that allows you to run /usr/sbin/zzz without a password, so what I do is I have a key combo assigned within i3wm to run "sudo /usr/sbin/zzz". It works fine this way.

I go into detail when it comes to setting up Xorg with i3wm. You can skip this if you want, but if you've never used a tiling window manager, it will handle screen real estate very efficiently on a laptop with a 12.5-inch screen and a touchpad.

First, download the amd64 image for 11.1-RELEASE and flash it to a USB pen drive. For the Unices, use this:

# dd if=FreeBSD-11.1-RELEASE-amd64-memstick.img of=/dev/da0 bs=1M conv=sync

Obviously, you'll change /dev/da0 to whatever the USB pen drive is assigned. Plug it in, check dmesg.

Leave it plugged in, restart the laptop. When prompted, tap Enter to halt the boot process, then F12 to select a bootable device. Choose the USB drive.

I won't go through the actual install process, but it is pretty damn easy so just look at a guide or two and you'll be fine. If you can install Debian, you can install FreeBSD. I will, however, recommend ZFS if you have over 4GB of RAM (my particular variant of the X240 has 8GB of RAM, so yours should have at least 4GB), along with an encrypted disk, and an encrypted SWAP partition. When prompted to add an additional user, and you get to the question where it asks for additional groups, please make sure you add the user to "wheel". The rest should be self-explanatory during the install.

Now for the good shit. You just booted into a fresh FreeBSD install. Now what? Well, time to fire up vi and open some config files...

Walnut Creek CDROM sells a lot of CD-ROMs, but it gives away even more data. Specifically, anyone who has Internet access is free to log into wcarchive (ftp.cdrom.com) and start downloading bits.

Because FTP archives don't do a lot of thinking, wcarchive doesn't need a massive cluster of CPUs. In fact, it gets by with a single 200-MHz P6 Pentium Pro and a measly(!) 1 GB of RAM. The I/O support, however, is fairly impressive.

The system software is rather prosaic: a copy of FreeBSD, supplemented by home-grown FTP mirroring and server code. Because of the massive hardware support, the software "only" needs to keep the I/O going in an efficient and reliable manner.

Walnut Creek CDROM has been around for several years now, so you are likely to be familiar with its offerings. You may not realize, however, that it provides the major financial support for FreeBSD.

We review Meltdown and Spectre responses from various BSD projects, show you how to run CentOS with bhyve, GhostBSD 11.1 is out, and we look at the case against the fork syscall.

If new code is needed, Intel will need to get it right: the company already faces numerous class action lawsuits. Data centre operators already scrambling to conduct unplanned maintenance will not be happy about the fix reducing stability.

'Meltdown, aka "Dear Intel, you suck"'

With the addition of UEFI in FreeBSD (since version 11), users of bhyve can use the UEFI boot loader instead of the grub2-bhyve port for booting operating systems such as Microsoft Windows, Linux and OpenBSD. The following page provides information necessary for setting up bhyve with UEFI boot loader support:

# pkg install -y uefi-edk2-bhyve

With graphical support, you can use a vnc client like tigervnc, which can be installed with the following command:

# pkg install -y tigervnc

In the case of most corporate or government environments, the Linux of choice is RHEL, or CentOS. Utilizing bhyve, you can test and install CentOS in a bhyve VM the same way you would deploy a Linux VM in production. The first step is to download the CentOS iso (for this tutorial I used the CentOS minimal ISO): http://isoredirect.centos.org/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1708.iso

I normally use a ZFS Volume (zvol) when running bhyve VMs. Run the following commands to create a zvol (ensure you have enough disk space to perform these operations):

# zfs create -V20G -o volmode=dev zroot/centos0

Similar to my previous post about vmrun.sh, you need certain items to be configured on FreeBSD in order to use bhyve. The following commands are necessary to get things running:

There are a number of utilities that can be used to manage bhyve VMs, and I am sure there is a way to use vmrun.sh to run Linux VMs, but since all of the HowTos for running Linux use the bhyve command line, the following script is what I use for running CentOS with bhyve.

The variables at the top of the script can be adjusted to fit your own needs. With the addition of the graphics output protocol in UEFI (or UEFI-GOP), a VNC console is launched and hosted with the HOST and PORT setting. There is a password option available for the VNC service, but the connection should be treated as insecure. It is advised to only listen on localhost with the VNC console and tunnel into the host of the bhyve VM. Now with the ISO copied to /tmp/centos.iso, and the script saved as centos.sh you can run the following command to start the install:

# ./centos.sh install

At this point, using vncviewer (on the local machine, or over an SSH tunnel), you should be able to bring up the console and run the CentOS installer as normal. The absolutely most critical item is to resolve an issue with the booting of UEFI after the installation has completed. Because of the path used in bhyve, you need to run the following to be able to boot CentOS after the installation:

# cp -f /mnt/sysimage/boot/efi/EFI/centos/grubx64.efi /mnt/sysimage/boot/efi/EFI/BOOT

With this setting changed, the same script can be used to launch your CentOS VM as needed:

# ./centos.sh run

If you are interested in a better solution for managing your Linux VM, take a look at the various bhyve management ports in the FreeBSD ports tree.

GhostBSD is a desktop oriented operating system which is based on FreeBSD. The project takes the FreeBSD operating system and adds a desktop environment, some popular applications, a graphical package manager and Linux binary compatibility. GhostBSD is available in two flavours, MATE and Xfce, and is currently available for 64-bit x86 computers exclusively. I downloaded the MATE edition which is available as a 2.3GB ISO file.

GhostBSD's system installer is a graphical application which begins by asking us for our preferred language, which we can select from a list. We can then select our keyboard's layout and our time zone. When it comes to partitioning we have three main options: let GhostBSD take over the entire disk using UFS as the file system, create a custom UFS layout or take over the entire disk using ZFS as the file system. UFS is a classic file system and quite popular, it is more or less FreeBSD's equivalent to Linux's ext4. ZFS is a more advanced file system with snapshots, multi-disk volumes and optional deduplication of data. I decided to try the ZFS option.

Once I selected ZFS I didn't have many more options to go through. I was given the chance to set the size of my swap space and choose whether to set up ZFS as a plain volume, with a mirrored disk for backup or in a RAID arrangement with multiple disks. I stayed with the plain, single disk arrangement. We are then asked to create a password for the root account and create a username and password for a regular user account. The installer lets us pick our account's shell with the default being fish, which seemed unusual. Other shells, including bash, csh, tcsh, ksh and zsh are available. The installer goes to work copying files and offers to reboot our computer when it is done.

The newly installed copy of GhostBSD boots to a graphical login screen where we can sign into the account we created during the install process. Signing into our account loads the MATE 1.18 desktop environment. I found MATE to be responsive and applications were quick to open. Early on I noticed odd window behaviour where windows would continue to slide around after I moved them with the mouse, as if the windows were skidding on ice. Turning off compositing in the MATE settings panel corrected this behaviour. I also found the desktop's default font (Montserrat Alternates) to be hard on my eyes as the font is thin and, for lack of a better term, bubbly. Fonts can be easily adjusted in the settings panel.

A few minutes after I signed into my account, a notification appeared in the system tray letting me know software updates were available. Clicking the update icon brings up a small window showing us a list of package updates and, if any are available, updates to the base operating system. FreeBSD, and therefore GhostBSD, both separate the core operating system from the applications (packages) which run on the operating system. This means we can update the core of the system separately from the applications. GhostBSD's core remains relatively static and minimal while applications are updated using a semi-rolling schedule.

When we are updating the core operating system, the update manager will give us the option of rebooting the system to finish the process. We can dismiss this prompt to continue working, but the wording of the prompt may be confusing. When asked if we want to reboot to continue the update process, the options presented to us are "Continue" or "Restart". The Continue option closes the update manager and returns us to the MATE desktop.

The update manager worked well for me and the only issue I ran into was when I dismissed the update manager and then wanted to install updates later. There are two launchers for the update manager, one in MATE's System menu and one in the settings panel. Clicking either of these launchers didn't accomplish anything. Running the update manager from the command line simply caused the process to lock up until killed. I found if I had dismissed the update manager once, I'd have to wait until I logged in again to use it. Alternatively, I could use a command line tool or use the OctoPkg package manager to install package updates.

Most of my time with GhostBSD, I was impressed and happy with the operating system. GhostBSD builds on a solid, stable FreeBSD core. We benefit from FreeBSD's performance and its large collection of open source software packages. The MATE desktop was very responsive in my trial and the system is relatively light on memory, even when run on ZFS which has a reputation for taking up more memory than other file systems.

There's an active discussion this week about making Wayland support available by default on FreeBSD.

FreeBSD has working Wayland support -- well, assuming you have working Intel / Radeon graphics -- and do have Weston and some other Wayland components available via FreeBSD Ports. FreeBSD has offered working Wayland support that is "quite usable" for more than one year. But, it's not too easy to get going with Wayland on FreeBSD.

Right now those FreeBSD desktop users wanting to use/develop with Wayland currently need to rebuild the GTK3 tool-kit, Mesa, and other packages with Wayland support enabled. This call for action now is about allowing the wayland=on to be made the default.

This move would then allow these dependencies to be built with Wayland support by default, but for the foreseeable future FreeBSD will continue defaulting to X.Org-based sessions.

The FreeBSD developers mostly acknowledge that Wayland is the future and the cost of enabling Wayland support by default is just slightly larger packages, but that weight is still leaner than the size of the X.Org code-base and its dependencies.

This article has been on my to-write list for a while now. In my opinion, fork is one of the most questionable design choices of Unix. I don’t understand the circumstances that led to its creation, and I grieve over the legacy rationale that keeps it alive to this day.

Let’s set the scene. It’s 1971 and you’re a fly on the wall in Bell Labs, watching the first edition of Unix being designed for the PDP-11/20. This machine has a 16-bit address space with no more than 248 kilobytes of memory. They’re discussing how they’re going to support programs that spawn new programs, and someone has a brilliant idea. “What if we copied the entire address space of the program into a new process running from the same spot, then let them overwrite themselves with the new program?” This got a rousing laugh out of everyone present, then they moved on to a better design which would become immortalized in the most popular and influential operating system of all time.

At least, that’s the story I’d like to have been told. In actual fact, the laughter becomes consensus. There’s an obvious problem with this approach: every time you want to execute a new program, the entire process space is copied and promptly discarded when the new program begins. Usually when I complain about fork, this the point when its supporters play the virtual memory card, pointing out that modern operating systems don’t actually have to copy the whole address space. We’ll get to that, but first — First Edition Unix does copy the whole process space, so this excuse wouldn’t have held up at the time. By Fourth Edition Unix (the next one for which kernel sources survived), they had wisened up a bit, and started only copying segments when they faulted.

This model leads to a number of problems. One is that the new process inherits all of the parent’s process descriptors, so you have to close them all before you exec another process. However, unless you’re manually keeping tabs on your open file descriptors, there is no way to know what file handles you must close! The hack that solves this is CLOEXEC, the first of many hacks that deal with fork’s poor design choices. This file descriptors problem balloons a bit - consider for example if you want to set up a pipe. You have to establish a piped pair of file descriptors in the parent, then close every fd but the pipe in the child, then dup2 the pipe file descriptor over the (now recently closed) file descriptor 1. By this point you’ve probably had to do several non-trivial operations and utilize a handful of variables from the parent process space, which hopefully were on the stack so that we don’t end up copying segments into the new process space anyway.

These problems, however, pale in comparison to my number one complaint with the fork model. Fork is the direct cause of the stupidest component I’ve ever heard of in an operating system: the out-of-memory (aka OOM) killer. Say you have a process which is using half of the physical memory on your system, and wants to spawn a tiny program. Since fork “copies” the entire process, you might be inclined to think that this would make fork fail. But, on Linux and many other operating systems since, it does not fail! They agree that it’s stupid to copy the entire process just to exec something else, but because fork is Important for Backwards Compatibility, they just fake it and reuse the same memory map (except read-only), then trap the faults and actually copy later. The hope is that the child will get on with it and exec before this happens.

However, nothing prevents the child from doing something other than exec - it’s free to use the memory space however it desires! This approach now leads to memory overcommittment - Linux has promised memory it does not have. As a result, when it really does run out of physical memory, Linux will just kill off processes until it has some memory back. Linux makes an awfully big fuss about “never breaking userspace” for a kernel that will lie about memory it doesn’t have, then kill programs that try to use the back-alley memory they were given. That this nearly 50 year old crappy design choice has come to this astonishes me.

Alas, I cannot rant forever without discussing the alternatives. There are better process models that have been developed since Unix!

The first attempt I know of is BSD’s vfork syscall, which is, in a nutshell, the same as fork but with severe limitations on what you do in the child process (i.e. nothing other than calling exec straight away). There are loads of problems with vfork. It only handles the most basic of use cases: you cannot set up a pipe, cannot set up a pty, and can’t even close open file descriptors you inherited from the parent. Also, you couldn’t really be sure of what variables you were and weren’t editing or allowed to edit, considering the limitations of the C specification. Overall this syscall ended up being pretty useless.

Another model is posix_spawn, which is a hell of an interface. It’s far too complicated for me to detail here, and in my opinion far too complicated to ever consider using in practice. Even if it could be understood by mortals, it’s a really bad implementation of the spawn paradigm — it basically operates like fork backwards, and inherits many of the same flaws. You still have to deal with children inheriting your file descriptors, for example, only now you do it in the parent process. It’s also straight-up impossible to make a genuine pipe with posix_spawn. (Note: a reader corrected me - this is indeed possible via posix_spawn_file_actions_adddup2.)

Let’s talk about the good models - rfork and spawn (at least, if spawn is done right). rfork originated from plan9 and is a beautiful little coconut of a syscall, much like the rest of plan9. They also implement fork, but it’s a special case of rfork. plan9 does not distinguish between processes and threads - all threads are processes and vice versa. However, new processes in plan9 are not the everything-must-go fuckfest of your typical fork call. Instead, you specify exactly what the child should get from you. You can choose to include (or not include) your memory space, file descriptors, environment, or a number of other things specific to plan9. There’s a cool flag that makes it so you don’t have to reap the process, too, which is nice because reaping children is another really stupid idea. It still has some problems, mainly around creating pipes without tremendous file descriptor fuckery, but it’s basically as good as the fork model gets. Note: Linux offers this via the clone syscall now, but everyone just fork+execs anyway.

The other model is the spawn model, which I prefer. This is the approach I took in my own kernel for KnightOS, and I think it’s also used in NT (Microsoft’s kernel). I don’t really know much about NT, but I can tell you how it works in KnightOS. Basically, when you create a new process, it is kept in limbo until the parent consents to begin. You are given a handle with which you can configure the process - you can change its environment, load it up with file descriptors to your liking, and so on. When you’re ready for it to begin, you give the go-ahead and it’s off to the races. The spawn model has none of the flaws of fork.

Both fork and exec can be useful at times, but spawning is much better for 90% of their use-cases. If I were to write a new kernel today, I’d probably take a leaf from plan9’s book and find a happy medium between rfork and spawn, so you could use spawn to start new threads in your process space as well. To the brave OS designers of the future, ready to shrug off the weight of legacy: please reconsider fork.

For some time we have been planning to migrate to LLVM's lld linker.

This has been a long time in the making. On 2013-04-13 I submitted an

I'd like to express deep gratitude to upstream lld developers Rui

To revert to using ld.bfd as the bootstrap linker, in /etc/src.conf set

WITHOUT_LLD_BOOTSTRAP=yes

If you need to set this, please follow up with a PR or post to the

Note that GNU ld.bfd is still installed as /usr/bin/ld, and will still

A followup commit will set WITH_LLD_IS_LD by default, possibly after

Release notes: Yes

We review the information about Spectre & Meltdown thus far, we look at NetBSD memory sanitizer progress, Postgres on ZFS & show you a bit about NomadBSD.

...

$> pgbench -j 32 -c 32 -M prepared -T 10 pgbench

...

$> pgbench -j 32 -c 32 -M prepared -T 10 pgbench

tps = 10325.200812 (including connections establishing)

We walk through dumping a PS4 kernel in only 6 days, tell you the news that NetBSD 7.1.1 has been released, details on how to run FreeBSD on a Thinkpad T470, and there’s progress in OpenBSD’s pledge.

We read the FreeBSD Q3 status report, explore good and bad syscalls, list GOG Games for OpenBSD, and show you what devmatch can do.

devmatch(8) matchs up devices in the system device tree with drivers

In --unbound mode, devmatch can look for drivers that have attached to

In addition, the ability to dump out linker.hints is provided.

Future commits will add hooks to devd.conf and rc.d to fully automate

TrueOS stable 17.12 is out, we have an OpenBSD workstation guide for you, learnings from the PDP-11, FreeBSD 2017 Releng recap and Duo SSH.

We are pleased to announce a new release of the 6-month STABLE version of TrueOS!

TrueOS Version 17.12 (2017, December) is now available for download from the TrueOS website. Both the STABLE and UNSTABLE package repositories have also been updated in-sync with each other, so current users only need to follow the prompts about updating their system to run the new release.

To get the best hardware for the money I’m opting for a desktop computer. Haven’t had one since the early 2000s and it feels anachronistic, but it will outperform a laptop of similar cost. After much searching, I found the HP Z240 Tower Workstation. It’s no-nonsense and supports exactly the customizations I was looking for:

The Matias Ergo Pro uses mechanical switches for that old fashioned clicky sound. It also includes dedicated buttons along the side for copying and pasting. Why is that cool? Well, it improves secondary selection, a technique that Sun computers used but time forgot.

I know a lot of people enjoy surrounding themselves with a wall of monitors like they’re in the heart of NASA Mission Control, but I find multi-monitor setups slightly disorienting. It introduces an extra bit of cognitive overhead to determine which monitor is for what exactly. That’s why I’d go with a modest, crisp Dell UltraSharp 24" U2417H. It’s 1080p and yeah there are 4k monitors nowadays, but text and icons are small enough as it is for me!

We’re going dead simple and old-school, back to tapes. There are a set of tape standards called LTO-n. As n increases the tape capacity gets bigger, but the tape drive gets more expensive. In my opinion the best balance these days for the home user is LTO-3. You can usually find an HP Ultrium 960 LTO-3 on eBay for 150 dollars. The cartridges hold 800GB and are about 15 dollars apiece. Hard drives keep coming down in price, but these tapes are very cheap and simpler than keeping a bunch of disk drives. Also tape has proven longevity, and good recoverability.

You don’t want to generate and store secret keys on a general purpose network attached computer. The attack surface is a mile wide. Generating or manipulating “offline” secret keys needs to happen on a separate computer with no network access.

We take the beefed up hardware above and pair it with ninja-fast software written in C. Some text-based, others raw X11 graphical apps unencumbered by ties to any specific window manager.

The paper I have chosen tonight is a retrospective on a computer design. It is one of a series of papers by Gordon Bell, and various co-authors, spanning the design, growth, and eventual replacement of the companies iconic line of PDP-11 mini computers.

It is the nature of computer engineering to be goal-oriented, with pressure to produce deliverable products. It is therefore difficult to plan for an extensive lifetime.

A third weakness of minicomputers was their lack of hardware stack capability. In the PDP-11, this was solved with the autoincrement/autodecrement addressing mechanism. This solution is unique to the PDP-11 and has proven to be exceptionally useful. (In fact, it has been copied by other designers.)

A fourth weakness, limited interrupt capability and slow context switching, was essentially solved with the device of UNIBUS interrupt vectors, which direct device interrupts.

Although string instructions are not yet provided in the hardware, the common string operations (move, compare, concatenate) can be programmed with very short loops.

This setup uses an SSH key as the first factor of authentication. Please watch Part 1 on setting up SSH keys and how to scp it to your server.

pkg install -y duo

vi /usr/local/etc/pam_duo.conf

chmod 600 /usr/local/etc/pam_duo.conf

vi /etc/ssh/sshd_config

service sshd restart

ssh server.example.com

ssh server.example.com

This past year was undoubtedly a rather busy and successful year for the Release Engineering Team. Throughout the year, development snapshot builds for FreeBSD-CURRENT and supported FreeBSD-STABLE branches were continually provided. In addition, work to package the base system using pkg(8) continued throughout the year and remains ongoing.

A: When asked when the tag in the template was initially added, the answer would have been “no”, however in hindsight it is easier to sift through the false positives, than to comb through months or years of commit logs.

A: There were some rendering issues last time it was investigated, but it is really nothing more than taking the time to fix those issues. (Note, that since this talk, the migration of the documentation in question had moved.)

A: No. It would extend the length of the release cycle with no real benefit between milestones since as we draw nearer to the end of a given release cycle, the number of changes to that code base significantly reduce.

In 2014, when starting the Fuzzing Project, Hanno Böck did some primitive fuzzing on GIMP and reported two bugs. They weren't fixed and were forgotten in the public bug tracker.

It's a classic heap buffer overflow in the FLIC parser. FLIC is a file format for animations and was introduced by Autodesk Animator.

Tobias has created a detailed writeup.

We figured out it's unreliable and the memory addresses are depending on many circumstances. The exploit ZIP comes with two variations using different memory addresses.

There's a wide variety of graphics formats. GIMP tries to support many of them, including many legacy formats that nobody is using any more today.

The second bug (CVE-2017-17786), which is a simple overread, was in the TGA parser. Furthermore we found buffer overreads in the XCF parser (CVE-2017-17788), the Gimp Brush (GBR) parser (CVE-2017-17784) and the Paint Shop Pro (PSP) parser (CVE-2017-17789).

First of all obviously all known memory safety bugs should be fixed.

It seems just about everyone selling refurbished data centre kit has a load of Dell FS12-NV7’s to flog. Dell FS-what? You won’t find them in the Dell catalogue, that’s for sure. They look a bit like C2100s of some vintage, and they have a lot in common. But on closer inspection they’re obviously a “special” for an important customer. Given the number of them knocking around, it’s obviously a customer with big data, centres stuffed full of servers with a lot of processing to do. Here’s a hint: It’s not Google or Amazon.

As I’ve mentioned, the noise and SAS are easy and relatively cheap to fix, and thanks to BitCoin miners, even the PCI slot problem can be sorted. I’ll talk about this in a later post.