This weekend Toby Churchill kindly hosted a hacking weekend for OpenTAC myself, Michael Grzeschik, Steve McIntyre and Andy Simpkins got together to bring up the remaining bits of the hardware on the current board revision and get some of the low level tooling like production flashing for the FTDI serial ports on the board up and running. It was a very productive weekend, we verified that everything was working with only few small mods needed for the board . Personally the main thing I worked on was getting most of an initial driver for the EMC1701 written. That was the one component without Linux support and allowed us to verify that the power switching and measurement for the systems under test was working well. There s still at least one more board revision and quite a bit of software work to do (I m hoping to get the EMC1701 upstream for v4.8) but it was great to finally see all the physical components of the system working well and see it managing a system under test, this board revision should support all the software development that s going to be needed for the final board. Thanks to all who attended, Pengutronix for sponsoring Michael s attendance and Toby Churchill for hosting!

I apologize to all potential readers of this blog for not writing a comprehensive Introduction post with details of the project I am taking part in during my internship, as well as some story about how I ended up there. Let me just say that I was a Debian user for years when I discovered it is taking part in Outreachy as one of organisations. Their Reproducible Builds effort has a noble goal and a bunch of great people behind it - I had no chances not to get excited by it. Looking for a place where my skills could be of any use, I discovered diffoscope - the tool for in-depth comparassion of files, archives etc. My mentor, Mattia Rizzolo, supported my decision to work on it, so now I am concentrating my efforts on improving diffoscope. As my first steps, I am doing small (but hopefully still somewhat important) job of fixing existing bugs. It helps me to better understand how diffoscope works, as well as introduces me to the workflow of opensource development. During December, I have done several small contributions, mostly fixing bugs.

Test data and jessie-backports First of them could be somewhat called cleaning up after my own mistake, although that mistake wasn t trivial. During the application period, I have fixed a bug with diffoscope failing while comparing symlinks to directory. That was a small change, but I included some tests for that case anyway. And that actually caused problems. With these tests, I included test data: two folders with symlinks. All was good in unstable version of Debian, but in jessie-backports, that commit caused build to fail. After some digging, I discovered the problem was caused by build process including copying that data. That was done using shutils Python module, and older version of that module, included in jessie, could not handle copying symlinks to directory properly. Thanks to my mentor for giving me a hint on how to resolve this: using temporary folders and creating these symlinks at runtime. That way, we ensured tests run without problems during build process on jessie. What have I learned: A great deal, actually. I spent too much time on that one, but I learned how to build packages, what happens during dpkg-buildpackage run and what debhelper tools are for. I also learned a bit about what chroot is and how to use it for testing.

ICC profile files and file type recognizing regexp Another one was also about failing tests and, therefore, failing build. Failing tests were all due to ICC files were not recognized by diffoscope. Turned out libmagic got an update which changed the description of ICC profile files. Diffoscope was relying on regexp applied to file type description to recognize the file, so I changed regexp to reflect the changes in libmagic. What have I learned: How diffoscope recognizes file types. Got me thinking: maybe there is a better way? That regexp-based approach is doomed to cause problems with every file type description change. I have this question still lingering in my mind - maybe I will come up with an idea later.

Order-like difference in text files Next, I decided to do something a bit bigger and fullfilled a feature request. That request was for detecting order-like difference in text files (when files has the same lines, but in different order). I did it by collecting added and removed lines in diff output in lists, sorting and then comparing them. Sadly, I forgot about one particular case - when one of the files is missing the newline at the end of file. I was kindly reminded of that quite soon in comments on the bug-tracker (thanks danielsh!) and have already fixed that. I also recieved feedback on how better implement it deeper in the diffoscope - not using the results of diff, but rather comparing sum of hashes of the lines directly in the difference module. I am yet to try that. What have I learned: That a call to diff is actually the slowest part of the diffoscope run when done on two big text files. Could it help somehow in speeding it up? I don t know yet. I also learned to comment on bugs in Debian bugtracker and was surprised by how much feedback I got. Thanks to my mentor for pushing me to do that - I definetely need to overcome my fear of communications to be more effective!

Random FTBFS There was also a very nasty bug that caused diffoscope to fail to be built from source randomly, failing with non-informative Fatal Python error: deallocated None. It already seemed strange when it was first reported; It got only more strange when suddenly that bug ceased to be reproducible. We hoped that would mean that bug was caused by some external tool, and was fixed there. Turns out it was not that easy. I tested this on two separate computers and on virtual machine; I used different versions of diffoscope. Well. Seems like that bug is still somehow tied to diffoscope version and not some external tool version - I still can do git checkout 64 and be able to reproduce the bug (still randomly, though). Although I spent quite a lot of time on that one, the only result was the information about connection between bug apperances and diffoscope version. I still wasn t able to get to the root of the problem - hopefully, someone else will be able to, given the information I found. What have I learned: git-bisect! Thanks to my friend for pointing me to it, that tool came handy in that situation. Also, got some experience in catching nasty bugs like that (pity that no experience in squashing them). I had some extra time commitements in December, one of them (Reproducible Builds Summit II) connected to my internship and one (my exam session in university) not. In January, I should be able to allocate more time to that work - I hope it will help me achieve more significant results. Many thanks to Mattia Rizzolo, Chris Lamb, Holger Levsen and all other folks of Reproducible Builds project - I cannot stress enough how important your support is to me. Wish you all a great 2017!

I am sad (but feel my duty) to inform the world that we will not be providing a Drupal 8 package in Debian. I filed an Intent To Package bug a very long time ago, intending to ship it with Jessie; Drupal 8 was so deep a change that it took their community overly long to achieve and stabilize. Still, Drupal 8 was released over a year ago today. I started working on debianizing the package shortly afterwards. There is also some online evidence As my call for help sent through this same blog. I have been too busy this last year. I let the packaging process lay dormant for too long, without even touching it for even half a year. Then, around September, I started working with the very nice guys of Indava, David and Enrique, and did very good advances. They clearly understood Debian's needs when it comes to full source inclusion (as D8 ships many minified Javascript libraries), attribution (as additionally to all those, many third-party PHP projects are bundled in the infamous vendor/ directory), and system-wide dependency management (as Drupal builds on some frameworks and libraries already available within Debian, chiefly Symfony, Doctrine, Twig... Even more, most of them appeared to work at the version levels we will be shipping, so all was dandy and for some weeks, I was quite optimistic on finishing the package on time and with the needed quality and testing. Yay! But... Reality bites. When I started testing my precious package... It broke in horrible ways. Uncomprehensible PHP errors (and I have to add here, I am a PHP newbie and am reluctant to learn better a language that strikes me as so inconsistent, so ugly), which we spent some time tackling... Of course, configuration changes are more than expected... But, just as we Debianers learnt some important lessons after the way-too-long Sarge freeze (ten years ago, many among you won't remember those frustrating days), Drupal learnt as well. They changed their release strategy Instead of describing it, those interested can read it at its source. What it meant for me, sadly, is that this process does not align with the Debian maintenance model. This means: The Drupal API stays mostly-stable between 8.0.x, 8.1.x, 8.2.x, etc. However, Drupal will incorporate new versions of their bundled libraries. I understood the new versions would be incorporated at minor-level branches, but if I read correctly some of my errors, some dependencies change even at patch-level updates. And... Well, if you update a PHP library, and the invoking PHP code (that is, Drupal) relies in this new version... Sadly, it makes it unmaintainable for Debian. So, long story short: I have decided to drop Drupal8 support in Debian. Of course, if somebody wants to pick up the pieces, the Git repository is still there (although I do plan on erasing it in a couple of weeks, as it means useless waste of project resources otherwise), and you could probably even target unstable+backports in a weird way (as it's software that, given our constraints, shouldn't enter testing, at least during a freeze). So... Sigh, a tear is dropped for every lost hour of work, and my depeest regrets to David and Enrique who put their work as well to make D8 happen in Debian. I will soon be closing the ITP and... Forgetting about the whole issue?

I used to rely on ifupdown to bring up my iptables firewall automatically using a config like this in /etc/network/interfaces:

allow-hotplug eth0
iface eth0 inet dhcp
    pre-up /sbin/iptables-restore /etc/network/iptables.up.rules
    pre-up /sbin/ip6tables-restore /etc/network/ip6tables.up.rules
allow-hotplug wlan0
iface wlan0 inet dhcp
    pre-up /sbin/iptables-restore /etc/network/iptables.up.rules
    pre-up /sbin/ip6tables-restore /etc/network/ip6tables.up.rules

but that doesn't seem to work very well in the brave new NetworkManager world. What does work reliably is a "pre-up" NetworkManager script, something that gets run before a network interface is brought up. However, despite what the documentation says, a dispatcher script in /etc/NetworkManager/dispatched.d/ won't work on my Debian and Ubuntu machines. Instead, I had to create a new iptables script in /etc/NetworkManager/dispatcher.d/pre-up.d/:

#!/bin/sh
LOGFILE=/var/log/iptables.log
if [ "$1" = lo ]; then
    echo "$0: ignoring $1 for \ $2'" >> $LOGFILE
    exit 0
fi
case "$2" in
    pre-up)
        echo "$0: restoring iptables rules for $1" >> $LOGFILE
        /sbin/iptables-restore /etc/network/iptables.up.rules >> $LOGFILE 2>&1
        /sbin/ip6tables-restore /etc/network/ip6tables.up.rules >> $LOGFILE 2>&1
        ;;
    *)
        echo "$0: nothing to do with $1 for \ $2'" >> $LOGFILE
        ;;
esac
exit 0

and then make that script executable:

chmod a+x /etc/NetworkManager/dispatcher.d/pre-up.d/iptables

With this in place, I can put my iptables rules in the usual place (/etc/network/iptables.up.rules and /etc/network/ip6tables.up.rules) and use the handy iptables-apply and ip6tables-apply commands to test any changes to my firewall rules.

Previously: v4.8. Here are a bunch of security things I m excited about in the newly released Linux v4.9: Latent Entropy GCC plugin Building on her earlier work to bring GCC plugin support to the Linux kernel, Emese Revfy ported PaX s Latent Entropy GCC plugin to upstream. This plugin is significantly more complex than the others that have already been ported, and performs extensive instrumentation of functions marked with __latent_entropy. These functions have their branches and loops adjusted to mix random values (selected at build time) into a global entropy gathering variable. Since the branch and loop ordering is very specific to boot conditions, CPU quirks, memory layout, etc, this provides some additional uncertainty to the kernel s entropy pool. Since the entropy actually gathered is hard to measure, no entropy is credited , but rather used to mix the existing pool further. Probably the best place to enable this plugin is on small devices without other strong sources of entropy. vmapped kernel stack and thread_info relocation on x86 Normally, kernel stacks are mapped together in memory. This meant that attackers could use forms of stack exhaustion (or stack buffer overflows) to reach past the end of a stack and start writing over another process s stack. This is bad, and one way to stop it is to provide guard pages between stacks, which is provided by vmalloced memory. Andy Lutomirski did a bunch of work to move to vmapped kernel stack via CONFIG_VMAP_STACK on x86_64. Now when writing past the end of the stack, the kernel will immediately fault instead of just continuing to blindly write. Related to this, the kernel was storing thread_info (which contained sensitive values like addr_limit) at the bottom of the kernel stack, which was an easy target for attackers to hit. Between a combination of explicitly moving targets out of thread_info, removing needless fields, and entirely moving thread_info off the stack, Andy Lutomirski and Linus Torvalds created CONFIG_THREAD_INFO_IN_TASK for x86. CONFIG_DEBUG_RODATA mandatory on arm64 As recently done for x86, Mark Rutland made CONFIG_DEBUG_RODATA mandatory on arm64. This feature controls whether the kernel enforces proper memory protections on its own memory regions (code memory is executable and read-only, read-only data is actually read-only and non-executable, and writable data is non-executable). This protection is a fundamental security primitive for kernel self-protection, so there s no reason to make the protection optional. random_page() cleanup Cleaning up the code around the userspace ASLR implementations makes them easier to reason about. This has been happening for things like the recent consolidation on arch_mmap_rnd() for ET_DYN and during the addition of the entropy sysctl. Both uncovered some awkward uses of get_random_int() (or similar) in and around arch_mmap_rnd() (which is used for mmap (and therefore shared library) and PIE ASLR), as well as in randomize_stack_top() (which is used for stack ASLR). Jason Cooper cleaned things up further by doing away with randomize_range() entirely and replacing it with the saner random_page(), making the per-architecture arch_randomize_brk() (responsible for brk ASLR) much easier to understand. That s it for now! Let me know if there are other fun things to call attention to in v4.9.

2016, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.

Disclaimer This is an attempt at humor and hence entirely fictional in nature. While some incidents depicted are true, the context and the story woven around them are by yours truly. None of the Mascots of Debian were hurt during the blog post. I also disavow any responsibility for any hurt (real or imagined) to any past, current and future mascots. The attempt should not be looked upon as demeaning people who are accused of false crimes, tortured and confessions eked out of them as this happens quite a lot (In India for sure, but guess it s the same world over in various degrees). The idea is loosely inspired by Chocolate:Deep Dark Secrets. (2005) On a more positive note, let s start Being a Sunday morning woke up late to find incessant knocking on the door, incidentally mum was not at home. Opening the door, found two official looking gentleman. They asked my name, asked my credentials, tortured and arrested me for Group conspiracy of Malicious Mischief in second and third degrees . The torture was done by means of making me forcefully watch endless reruns of Norbit . While I do love Eddie Murphy, this was one of his movies he could have done without. I guess for many people watching it once was torture enough. I *think* they were nominated for razzie awards dunno if they won it or not, but this is beside the point. Unlike the 20 years it takes for a typical case to reach to its conclusion even in the smallest court in India, due to the torture, I was made to confess (due to endless torture) and was given summary judgement. The judgement was/is as follows a. Do 100 hours of Community service in Debian in 2017. This could be done via blog posts, raising tickets in the Debian BTS or in whichever way I could be helpful to Debian. b. Write a confessional with some photographic evidence sharing/detailing some of the other members who were part of the conspiracy in view of the reduced sentence. So now, have been forced to write this confession As you all know, I won a bursary this year for debconf16. What is not known by most people is that I also got an innocuous looking e-mail titled Pollito for DPL . While I can t name all the names as investigation is still ongoing about how far-reaching the conspiracy is . The email was purportedly written by members of cabal within cabal which are in Debian. I looked at the email header to see if this was genuine and I could trace the origin but was left none the wiser, as obviously these people are far more technically advanced than to fall in simple tricks like this Anyways, secretly happy that I have been invited to be part of these elites, I did the visa thing, packed my bags and came to Debconf16. At this point in juncture, I had no idea whether it was real or I had imagined the whole thing. Then to my surprise saw this Just like the Illuminati the conspiracy was for all to see those who knew about it. Most people were thinking of it as a joke, but those like me who had got e-mails knew better. I knew that the thing is real, now I only needed to bide my time and knew that the opportunity would present itself. And few days later, sure enough, there was a trip planned for Table Mountain, Cape Town . Few people planned to hike to the mountain, while few chose to take the cable car till up the mountain. Quite a few people came along with us and bought tickets for the to and fro to the mountain and back. Incidentally, I was thinking if the South African Govt. were getting the tax or not. If you look at the ticket, there is just a bar-code. In India as well as the U.S. there is TIN Tax Identification Number Few links to share what it is all about . While these should be on all invoices, need to specially check when taking high-value items. In India as shared in the article the awareness, knowledge leaves a bit to be desired. While I m drifting from the incident, it would be nice if somebody from SA could share how things work there. Moving on, we boarded the cable car. It was quite spacious cable car with I guess around 30-40 people or some more who were able to see everything along with the controller. It was a pleasant cacophony of almost two dozen or more nationalities on this 360 degrees moving chamber. I was a little worried though as it essentially is a bucket and there is always a possibility that a severe wind could damage it. Later somebody did share that some frightful incidents had occurred not too long ago on the cable car. It took about 20-25 odd minutes to get to the top of table mountain and we were presented with views such as below The picture I am sharing is actually when we were going down as all the pictures of going up via the cable car were over-exposed. Also, it was pretty crowded on the way up then on the way down so handling the mobile camera was not so comfortable. Once we reached up, the wind was blowing at incredible speeds. Even with my jacket and everything I was feeling cold. Most of the group around 10-12 people looked around if we could find a place to have some refreshments and get some of the energy in the body. So we all ventured to a place and placed our orders I was introduced to Irish Coffee few years back and have had some incredible Irish Coffees in Pune and elsewhere. I do hope to be able to make Irish Coffee at home if and when I have my own house. This is hotter than brandy and is perfect if you are suffering from cold etc if done right, really needs some skills. This is the only drink which I wanted in SA which I never got right . As South Africa was freezing for me, this would have been the perfect antidote but the one there as well as elsewhere were all bleh. What was interesting though, was the coffee caller besides it. It looked like a simple circuit mounted on a PCB board with lights, vibrations and RFID and it worked exactly like that. I am guessing as and when the order is ready, there is an interrupt signal sent via radio waves which causes the buzzer to light and vibrate. Here s the back panel if somebody wants to take inspiration and try it as a fun project Once we were somewhat strengthened by the snacks, chai, coffee etc. we made our move to seeing the mountain. The only way to describe it is that it s similar to Raigad Fort but the plateau seemed to be bigger. The wikipedia page of Table Mountain attempts to share but I guess it s more clearly envisioned by one of the pictures shared therein. I have to say while Table Mountain is beautiful and haunting as it has scenes like these There is something there which pulls you, which reminds you of a long lost past. I could have simply sat there for hours together but as was part of the group had to keep with them. Not that I minded. The moment I was watching this, I was transported to some memories of the Himalayas about 20 odd years or so. In that previous life, I had the opportunity to be with some of the most beautiful women and also been in the most happening places, the Himalayas. I had shared years before some of my experiences I had in the Himalayas. I discontinued it as I didn t have a decent camera at that point in time. While I don t wanna digress, I would challenge anybody to experience the Himalayas and then compare. It is just something inexplicable. The beauty and the rawness that Himalayas shows makes you feel insignificant and yet part of the whole cosmos. What Paulo Cohello expressed in The Valkyries is something that could be felt in the Himalayas. Leh, Ladakh, Himachal , Garwhal, Kumaon. The list will go on forever as there are so many places, each more beautiful than the other. Most places are also extremely backpacker-friendly so if you ask around you can get some awesome deals if you want to spend more than a few days in one place. Moving on, while making small talk @olasd or Nicolas Dandrimont , the headmaster of our trip made small talk to each of us and eked out from all of us that we wanted to have Pollito as our DPL (Debian Project Leader) for 2017. Few pictures being shared below as supporting evidence as well While I do not know who further up than Nicolas was on the coup which would take place. The idea was this If the current DPL steps down, we would take all and any necessary actions to make Pollito our DPL. This has been taken from Pollito s adventure Being a responsible journalist, I also enquired about Pollito s true history as it would not have been complete without one. This is the e-mail I got from Gunnar Wolf, a friend and DD from Mexico

Turns out, Valessio has just spent a week staying at my house And
in any case, if somebody in Debian knows about Pollito s
childhood That is me. Pollito came to our lives when we went to Congreso Internacional de
Software Libre (CISOL) in Zacatecas city. I was strolling around the
very beautiful city with my wife Regina and our friend Alejandro
Miranda, and at a shop at either Ram n L pez Velarde or Vicente
Guerrero, we found a flock of pollitos. http://www.openstreetmap.org/#map=17/22.77111/-102.57145 Even if this was comparable to a slave market, we bought one from
them, and adopted it as our own. Back then, we were a young couple Well, we were not that young
anymore. I mean, we didn t have children. Anyway, we took Pollito with
us on several road trips, such as the only time I have crossed an
international border driving: We went to Encuentro Centroamericano de
Software Libre at Guatemala city in 2012 (again with Alejandro), and
you can see several Pollito pics at: http://gwolf.org/album/road-trip-ecsl-2012-guatemala-0 Pollito likes travelling. Of course, when we were to Nicaragua for
DebConf, Pollito tagged along. It was his first flight as a passenger
(we never asked about his previous life in slavery; remember, Pollito
trust no one). Pollito felt much welcome with the DebConf crowd. Of course, as
Pollito is a free spirit, we never even thought about forcing him to
come back with us. Pollito went to Switzerland, and we agreed to meet
again every year or two. It s always nice to have a chat with him. Hugs!

So with that backdrop I would urge fellow Debianities to take up the slogans LONG LIVE THE DPL ! LONG LIVE POLLITO ! LONG LIVE POLLITO THE DPL ! The first step to make Pollito the DPL is to ensure he has a @debian.org (pollito@debian.org) We also need him to be made a DD because only then can he become a DPL. In solidarity and in peace
Filed under: Miscellenous Tagged: #caller, #confession, #Debconf16, #debian, #Fiction, #history, #Pollito, #Pollito as DPL, #Table Mountain, Cabal, memories, south africa

I attended this year's Linux Kernel Summit in Santa Fe, NM, USA and made notes on some of the sessions that were relevant to Debian. LWN also reported many of the discussions. This is the second and last part of my notes; part 1 is here. Kernel Hardening Kees Cook presented the ongoing work on upstream kernel hardening, also known as the Kernel Self-Protection Project or KSPP. GCC plugins The kernel build system can now build and use GCC plugins to implement some protections. This requires gcc 4.5 and the plugin headers installed. It has been tested on x86, arm, and arm64. It is disabled by CONFIG_COMPILE_TEST because CI systems using allmodconfig/allyesconfig probably don't have those installed, but this ought to be changed at some point. There was a question as to how plugin headers should be installed for cross-compilers or custom compilers, but I didn't hear a clear answer to this. Kees has been prodding distribution gcc maintainers to package them. Mark Brown mentioned the Linaro toolchain being widely used; Kees has not talked to its maintainers yet. Probabilistic protections These protections are based on hidden state that an attacker will need to discover in order to make an effective attack; they reduce the probability of success but don't prevent it entirely. Kernel address space layout randomisation (KASLR) has now been implemented on x86, arm64, and mips for the kernel image. (Debian enables this.) However there are still lots of information leaks that defeat this. This could theoretically be improved by relocating different sections or smaller parts of the kernel independently, but this requires re-linking at boot. Aside from software information leaks, the branch target predictor on (common implementations of) x86 provides a side channel to find addresses of branches in the kernel. Page and heap allocation, etc., is still quite predictable. struct randomisation (RANDSTRUCT plugin from grsecurity) reorders members in (a) structures containing only function pointers (b) explicitly marked structures. This makes it very hard to attack custom kernels where the kernel image is not readable. But even for distribution kernels, it increases the maintenance burden for attackers. Deterministic protections These protections block a class of attacks completely. Read-only protection of kernel memory is either mandatory or enabled by default on x86, arm, and arm64. (Debian enables this.) Protections against execution of user memory in kernel mode are now implemented in hardware on x86 (SMEP, in Intel processors from Skylake onward) and on arm64 (PXN, from ARMv8.1). But Skylake is not available for servers and ARMv8.1 is not yet implemented at all! s390 always had this protection. It may be possible to 'emulate' this using other hardware protections. arm (v7) and arm64 now have this, but x86 doesn't. Linus doesn't like the overhead of previously proposed implementations for x86. It is possible to do this using PCID (in Intel processors from Sandy Bridge onward), which has already been done in PaX - and this should be fast enough. Virtually mapped stacks protect against stack overflow attacks. They were implemented as an option for x86 only in 4.9. (Debian enables this.) Copies to or from user memory sometimes use a user-controlled size that is not properly bounded. Hardened usercopy, implemented as an option in 4.8 for many architectures, protects against this. (Debian enables this.) Memory wiping (zero on free) protects against some information leaks and use-after-free bugs. It was already implemented as debug feature with non-zero poison value, but at some performance cost. Zeroing can be cheaper since it allows allocator to skip zeroing on reallocation. That was implemented as an option in 4.6. (Debian does not currently enable this but we might do if the performance cost is low enough.) Constification (with the CONSTIFY gcc plugin) reduces the amount of static data that can be written to. As with RANDSTRUCT, this is applied to function pointer tables and explicitly marked structures. Instances of some types need to be modified very occasionally. In PaX/Grsecurity this is done with pax_ open,close _kernel() which globally disable write protection temporarily. It would be preferable to override write protection in a more directed way, so that the permission to write doesn't leak into any other code that interrupts this process. The feature is not in mainline yet. Atomic wrap detction protects against reference-counting bugs which can result in a use-after-free. Overflow and underflow are trapped and result in an 'oops'. There is no measurable performance impact. It would be applied to all operations on the atomic_t type, but there needs to be an opt-out for atomics that are not ref-counters - probably by adding an atomic_wrap_t type for them. This has been implemented for x86, arm, and arm64 but is not in mainline yet. Kernel Freezer Hell For the second year running, Jiri Kosina raised the problem of 'freezing' kthreads (kernel-mode threads) in preparation for system suspend (suspend to RAM, or hibernation). What are the semantics? What invariants should be met when a kthread gets frozen? They are not defined anywhere. Most freezable threads don't actually need to be quiesced. Also many non-freezable threads are pointlessly calling try_to_freeze() (probably due to copying code without understanding it)). At a system level, what we actually need is I/O and filesystem consistency. This should be achieved by:

• Telling mounted filesystems to freeze. They can quiesce any kthreads they created.
• Device drivers quiescing any kthreads they created, from their PM suspend implementation.

The system suspend code should not need to directly freeze threads. Kernel Documentation Jon Corbet and Mauro Carvalho presented the recent work on kernel documentation. The kernel's documentation system was a house of cards involving DocBook and a lot of custom scripting. Both the DocBook templates and plain text files are gradually being converted to reStructuredText format, processed by Sphinx. However, manual page generation is currently 'broken' for documents processed by Sphinx. There are about 150 files at the top level of the documentation tree, that are being gradually moved into subdirectories. The most popular files, that are likely to be referenced in external documentation, have been replaced by placeholders. Sphinx is highly extensible and this has been used to integrate kernel-doc. It would be possible to add extensions that parse and include the MAINTAINERS file and Documentation/ABI/ files, which have their own formats, but the documentation maintainers would prefer not to add extensions that can't be pushed to Sphinx upstream. There is lots of obsolete documentation, and patches to remove those would be welcome. Linus objected to PDF files recently added under the Documentation/media directory - they are not the source format so should not be there! They should be generated from the corresponding SVG or image files at build time. Issues around Tracepoints Steve Rostedt and Shuah Khan led a discussion about tracepoints. Currently each maintainer decides which tracepoints to create. The cost of each added tracepoint is minimal, but the cost of very many tracepoints is more substantial. So there is such a thing as too many tracepoints, and we need a policy to decide when they are justified. They advised not to create tracepoints just in case, since kprobes can be used for tracing (almost) anywhere dynamically. There was some support for requiring documentation of each new tracepoint. That may dissuade introduction of obscure tracepoints, but also creates a higher expectation of stability. Tools such as bcc and IOVisor are now being created that depend on specific tracepoints or even function names (through kprobes). Should we care about breaking them? Linus said that we should strive to be polite to developers and users relying on tracepoints, but if it's too painful to maintain a tracepoint then we should go ahead and change it. Where the end users of the tool are themselves developers it's more reasonable to expect them to upgrade the tool and we should care less about changing it. In some cases tracepoints could provide dummy data for compatibility (as is done in some places in procfs).

Categories:

• Debian-Blog
• Computing
• Tools

Keywords:

• LIO
• scsi
• Storage
• migration

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Categories:

• Debian-Blog
• Computing
• Tools

Keywords:

• SAN
• Storage
• iscsi
• multipath
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I m at an airport, about to board the first of three flights across the world, from timezone +8 to timezone -8. I ll be in transit 27 hours to get to Seattle, Washington state. I m leaving my wife and two young children behind. My work has given me a days worth of leave under the Corporate Social Responsibility program, and I m taking three days annual leave, to do this. 27 hours each way in transit, for 3 days on the ground. Why? Backstory I started playing in technology as a kid in the 1980s; my first PC was a clone (as they were called) 286 running MS-DOS. It was clunky, and the most I could do to extend it was to write batch scripts. As a child I had no funds for commercial compilers, no network connections (this was pre Internet in Australia), no access to documentation, and no idea where to start programming properly. It was a closed world. I hit university in the summer of 1994 to study Computer Science and French. I d heard of Linux, and soon found myself installing the Linux distributions of the day. The Freedom of the licensing, the encouragement to use, modify, share, was in stark contrast to the world of consumer PCs of the late 1980 s. It was there at the UCC at UWA I discovered Debian. Some of the kind network/system admins at the University maintained a Debian mirror on the campus LAN, updated regularly and always online. It was fast, and more importantly, free for me to access. Back in the 1990s, bandwidth in Australia was incredibly expensive. The vast distances of the country mean that bandwidth was scarce. Telcos were in races to put fiber between Perth and the Eastern States, and without that in place, IP connectivity was constrained, and thus costly. Over many long days and nights I huddled down, learning window managers, protocols, programming and scripting languages. I became a system/network administrator, web developer, dev ops engineer, etc. My official degree workload, algorithmic complexity, protocol stacks, were interesting, but fiddling with Linux based implementations was practical. Volunteer After years of consuming the output of Debian and running many services with it I decided to put my hand up and volunteer as a Debian Developer: it was time to give back. I had benefited from Debian, and I saw others benefit from it as well. As the 2000 s started, I had my PGP key in the Debian key ring. I had adopted a package and was maintaining it load balancing Apache web servers. The web was yet to expand to the traffic levels you see today; most web sites were served from one physical web server. Site Reliability Engineering was a term not yet dreamed of. What became more apparent was the applicability of Linux, Open Source, and in my line-of-sight Debian to a wider community beyond myself and my university peers. Debain was being used to revive recycled computers that were being donated to charities; in some cases, unable to transfer commercial software licenses with the hardware that was no longer required by organisations that had upgraded. It appeared that Debian was being used as a baseline above which society in general had access to fundamental capability of computing and network services. The removal of subscriptions, registrations, and the encouragement of distribution meant this occurred at rates that could never be tracked, and more importantly, the consensus was that it should not be automatically tracked. The privacy of the user is paramount more important than some statistics for the Developer to ponder. When the Bosnia-Herzegovina war ended in 1995, I recall an email from academics there, having found some connectivity, writing to ask if they would be able to use Debian as part of their re-deployment of services for the Tertiary institutions in the region. This was an unnecessary request as Debian GNU/Linux is freely available, but it was a reminder that, for the country to have tried to procure commercial solutions at that time would have been difficult. Instead, those that could do the task just got on with it. There s been many similar project where the grass-roots organisations non profits, NGOs, and even just loose collectives of individuals have turned to Linux, Open Source, and sometimes Debian to solve their problems. Many fine projects have been established to make technology accessible to all, regardless of race, gender, nationality, class, or any other label society has used to divide humans. Big hat tip to Humanitarian Open Street Map, Serval Project. I ve always loved Debian s position on being the Universal operating system. Its vast range of packages and wide range of computing architectures supported means that quite often a litmus test of is project X a good project? was met with is it packaged for Debian? . That wide range of architectures has meant that administrators of systems had fewer surprises and a faster adoption cycle when changing platforms, such as the switch from x86 32 bit to x86 64 bit. Enter the Cloud I first laid eyes on the AWS Cloud in 2008. It was nothing like the rich environment you see today. The first thing I looked for was my favourite operating system, so that what I already knew and was familiar with was available in this environment to minimise the learning curve. However there were no official images, which was disconcerting. In 2012 I joined AWS as an employee. Living in Australia they hired me into the field sales team as a Solution Architect a sort of pre-sales tech with a customer focused depth in security. It was a wonderful opportunity, and I learnt a great deal. It also made sense (to me, at least) to do something about getting Debian s images blessed. It turned out, that I had to almost define what that was: images endorsed by a Debian Developer, handed to the AWS Marketplace team. And so since 2013 I have done so, keeping track of Debian s releases across the AWS regions, collaborating with other Debian folk on other cloud platforms to attempt a unified approach to generating and maintaining these images. This included (for a stint) generating them into the AWS GovCloud Region, and still into the AWS China (Beijing) Region the other side of the so-called Great Firewall of China. So why the trip? We ve had focus groups at the Debconf (Debian conference) around the world, but its often difficult to get the right group of people in the same rooms at the same time. So the proposal was to hold a focused Debian Cloud Sprint. Google was good enough to host this, for all the volunteers across all the cloud providers. Furthermore, donated funds were found to secure the travel for a set of people to attend who otherwise could not. I was lucky enough to be given a flight. So here I am, in the terminal in Australia: my kids are tucked up in bed, dreaming of the candy they just collected for Halloween. It will be a draining week I am sure, but if it helps set and improve the state of Debian then its worth it.

It all started last June when my son had his Janoi (Yagnopavita) ceremony -- the ritual by which a Brahmana boy becomes "twice-born" and eligible to study the Vedas. As well as a profound religious experience, it is also an important social occasion with a reception for as many friends and family as can attend. (I think our final guest total was ~250.) This meant new outfits for everyone which might be exciting for some people but not me. I still don't know why I couldn't just keep wearing the khes and pitambar from the puja but no, apparently that's a faux pas. So I relented and agreed to wear my "darbari" suit from my wedding. And it didn't fit. I knew I had gained some weight in the intermediate 17 years but the thing was sitcom levels of too small. I ended up having to purchase a new one, a snazzy (and shiny!) maroon number with gold stripes (or were they black stripes?) Problem having been solved, much was eaten, more weight was gained and then I forgot about the whole thing. Tip 1: Actually Do Something. I have over the years tried to improve my physical condition but it has never gotten very far. For instance I have a treadmill/coatrack and a couple of years ago I began using it in earnest. I got to the point where I actually ran a 10K race without dying. But I did not train systematically and I ended up in some pain which caused me to stop working out for a while and then I never got around to restarting. Diets have also failed because I don't have a clear idea of what and how much I am eating. All I know is that women go into the kitchen and when they come out they have food. By what eldritch process this occurs is a mystery, I just eat whats given to me thankful that the magic happens. Once I was moved to try and help but quickly fell afoul of the lack of well-defined algorithms in Gujarati home cooking.

"How much saffron should I add?"

"this much."

"How much is this much in SI units?"

"You're annoying me. Get out."

Fast forward to March of this year. For my birthday, my wife got me a Fitbit fitness tracker. This is what I had needed all this time. It measure heart rate, distance travelled, time slept and several other pieces of info you can use to really plan a fitness regimen rationally. For example, I was chagrined to learn that sometimes when I'm at the computer, I am so immobile that the fitbit thought I was asleep. So I started planning to taken more frequent breaks. (A recent firmware upgrade has added the ability to nudge to walk atleast 250 paces each daytime hour which is handy for this.) Also by checking my heart rate I discovered that I went on the treadmill I ran too fast thereby stressing my body for little gain and ending up going too slow to get much aerobic effect. Now I can pace myself appropriately for maximum cardiac efficiency without ending up injuring myself and giving up. I also get a little more activity each day by simple changes such as taking the stairs instead of the lift and instead of getting off at the 14th street PATH I go all the way to 34th street and walk down. Tip 2: You must have data in order to see what you did right or wrong and to plan what you need to do moving forward. One caveat about these fitness trackers. They are not anywhere as accurate as a proper checkup from a doctor who specializes in such things. If you want to do any kind of pro or amateur athletics you probably should not rely on them but for the average shlub who just wants to avoid appearing on the news being winched off his sofa by the fire brigade they are good enough. Another practice I began was keeping a food diary. It can be a real eye-opener to see how much you are actually eating. It is probably much more than you thought. I am fortunate that my diet is pretty good to begin with. Vegetarian, (not vegan, Hindus eat dairy products,) mostly home-cooked with fresh ingredients, not fried or processed, and I don't drink alcohol. However there were a few optimizations I could make. I drink a lot of soda; atleast two cans a day. I really ought to stop altogether but in lieu of that I have atleast switched from Coke to Coke Zero thereby saving a lot of empty calories. I now eat 4 rotlis with my dinner instead of six. We as a family eat more green vegetables instead of potatos, skim milk instead of whole fat, canola oil instead of corn oil, and less rice and don't slather ghee on everything quite so much. One entirely new practice I've adopted that may seem faddish but works for me is intermittent fasting. The idea is to steadily train your body to need less food by eating all your days allowed amount pf calories during a 6-8 hour window and not eating at all during the remaining time. It's hard to get used to for many people but I fast atleast 2-3 times a month for religious reasons anyway so I adapted pretty quickly. The fitbit tells me how many calories I am expending and how many I can eat to maintain a healthy level of weight loss but other than that I don't bother with "food groups" or specific diets such as paleo, or low-carb etc. As long as what you eat is reasonably balanced and you are burning more calories than you are adding, it should be enough for weight loss. Indeed from the end of March to now, I've lost 3 stones (20Kg) even with the occasional "cheat" day. Tip 3: All published diets are bullshit without scientifically proven efficacy. Don't bother with them. Experiment instead and see what works for you and your metabolism. As long as you are getting all the proper nutrients (you shouldn't need a supplement unless you have an actual medical condition.) and you have a net calorie deficit, it's all good. If you eat food you enjoy, you are more likely to stick to your diet. The proper amount of sleep is one area of a healthy lifestyle I am still doing poorly in and the reasons are not all raven-related. I have always had problems with insomnia and was once actually diagnosed with sleep apnea. Losing weight has helped a lot but the fitbit is still reporting that I toss and turn a lot during the night. And that's when I'm in bed in the first place. I stay up much too late which can also lead to subsidiary bad behaviours such as midnight snacking. It's something I need to work on. Tip 4: Stop blogging at all hours of the night, It's not doing you any good. So that's what I'm doing. Moving forward, I need to deal with the sleep thing and I would also like to start some program of strength-training, I'm doing ok in terms of aerobic exercise but from what I've read, you also have to build up muscles to keep weight loss permanent. The difficulty is that it would involve joining a gym and then actually going to that gym so I've put it off for now. The immediate threat is Diwali (and Thanksgiving and Christmas...) My wife bought 4 lbs of sweets today and I can feel their presence in the fridge calling to me.

Previously: v4.7. Here are a bunch of security things I m excited about in Linux v4.8: SLUB freelist ASLR Thomas Garnier continued his freelist randomization work by adding SLUB support. x86_64 KASLR text base offset physical/virtual decoupling On x86_64, to implement the KASLR text base offset, the physical memory location of the kernel was randomized, which resulted in the virtual address being offset as well. Due to how the kernel s -2GB addressing works (gcc s -mcmodel=kernel ), it wasn t possible to randomize the physical location beyond the 2GB limit, leaving any additional physical memory unused as a randomization target. In order to decouple the physical and virtual location of the kernel (to make physical address exposures less valuable to attackers), the physical location of the kernel needed to be randomized separately from the virtual location. This required a lot of work for handling very large addresses spanning terabytes of address space. Yinghai Lu, Baoquan He, and I landed a series of patches that ultimately did this (and in the process fixed some other bugs too). This expands the physical offset entropy to roughly $physical_memory_size_of_system / 2MB bits. x86_64 KASLR memory base offset Thomas Garnier rolled out KASLR to the kernel s various statically located memory ranges, randomizing their locations with CONFIG_RANDOMIZE_MEMORY. One of the more notable things randomized is the physical memory mapping, which is a known target for attacks. Also randomized is the vmalloc area, which makes attacks against targets vmalloced during boot (which tend to always end up in the same location on a given system) are now harder to locate. (The vmemmap region randomization accidentally missed the v4.8 window and will appear in v4.9.) x86_64 KASLR with hibernation Rafael Wysocki (with Thomas Garnier, Borislav Petkov, Yinghai Lu, Logan Gunthorpe, and myself) worked on a number of fixes to hibernation code that, even without KASLR, were coincidentally exposed by the earlier W^X fix. With that original problem fixed, then memory KASLR exposed more problems. I m very grateful everyone was able to help out fixing these, especially Rafael and Thomas. It s a hard place to debug. The bottom line, now, is that hibernation and KASLR are no longer mutually exclusive. gcc plugin infrastructure Emese Revfy ported the PaX/Grsecurity gcc plugin infrastructure to upstream. If you want to perform compiler-based magic on kernel builds, now it s much easier with CONFIG_GCC_PLUGINS! The plugins live in scripts/gcc-plugins/. Current plugins are a short example called Cyclic Complexity which just emits the complexity of functions as they re compiled, and Sanitizer Coverage which provides the same functionality as gcc s recent -fsanitize-coverage=trace-pc but back through gcc 4.5. Another notable detail about this work is that it was the first Linux kernel security work funded by Linux Foundation s Core Infrastructure Initiative. I m looking forward to more plugins! If you re on Debian or Ubuntu, the required gcc plugin headers are available via the gcc-$N-plugin-dev package (and similarly for all cross-compiler packages). hardened usercopy Along with work from Rik van Riel, Laura Abbott, Casey Schaufler, and many other folks doing testing on the KSPP mailing list, I ported part of PAX_USERCOPY (the basic runtime bounds checking) to upstream as CONFIG_HARDENED_USERCOPY. One of the interface boundaries between the kernel and user-space are the copy_to_user()/copy_from_user() family of functions. Frequently, the size of a copy is known at compile-time ( built-in constant ), so there s not much benefit in checking those sizes (hardened usercopy avoids these cases). In the case of dynamic sizes, hardened usercopy checks for 3 areas of memory: slab allocations, stack allocations, and kernel text. Direct kernel text copying is simply disallowed. Stack copying is allowed as long as it is entirely contained by the current stack memory range (and on x86, only if it does not include the saved stack frame and instruction pointers). For slab allocations (e.g. those allocated through kmem_cache_alloc() and the kmalloc()-family of functions), the copy size is compared against the size of the object being copied. For example, if copy_from_user() is writing to a structure that was allocated as size 64, but the copy gets tricked into trying to write 65 bytes, hardened usercopy will catch it and kill the process. For testing hardened usercopy, lkdtm gained several new tests: USERCOPY_HEAP_SIZE_TO, USERCOPY_HEAP_SIZE_FROM, USERCOPY_STACK_FRAME_TO,
USERCOPY_STACK_FRAME_FROM, USERCOPY_STACK_BEYOND, and USERCOPY_KERNEL. Additionally, USERCOPY_HEAP_FLAG_TO and USERCOPY_HEAP_FLAG_FROM were added to test what will be coming next for hardened usercopy: flagging slab memory as safe for copy to/from user-space , effectively whitelisting certainly slab caches, as done by PAX_USERCOPY. This further reduces the scope of what s allowed to be copied to/from, since most kernel memory is not intended to ever be exposed to user-space. Adding this logic will require some reorganization of usercopy code to add some new APIs, as PAX_USERCOPY s approach to handling special-cases is to add bounce-copies (copy from slab to stack, then copy to userspace) as needed, which is unlikely to be acceptable upstream. seccomp reordered after ptrace By its original design, seccomp filtering happened before ptrace so that seccomp-based ptracers (i.e. SECCOMP_RET_TRACE) could explicitly bypass seccomp filtering and force a desired syscall. Nothing actually used this feature, and as it turns out, it s not compatible with process launchers that install seccomp filters (e.g. systemd, lxc) since as long as the ptrace and fork syscalls are allowed (and fork is needed for any sensible container environment), a process could spawn a tracer to help bypass a filter by injecting syscalls. After Andy Lutomirski convinced me that ordering ptrace first does not change the attack surface of a running process (unless all syscalls are blacklisted, the entire ptrace attack surface will always be exposed), I rearranged things. Now there is no (expected) way to bypass seccomp filters, and containers with seccomp filters can allow ptrace again. That s it for v4.8! The merge window is open for v4.9

2016, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.

When I gave my State of the Kernel Self-Protection Project presentation at the 2016 Linux Security Summit, I included some slides covering some quick bullet points on things I found of interest in recent Linux kernel releases. Since there wasn t a lot of time to talk about them all, I figured I d make some short blog posts here about the stuff I was paying attention to, along with links to more information. This certainly isn t everything security-related or generally of interest, but they re the things I thought needed to be pointed out. If there s something security-related you think I should cover from v4.3, please mention it in the comments. I m sure I haven t caught everything. :) A note on timing and context: the momentum for starting the Kernel Self Protection Project got rolling well before it was officially announced on November 5th last year. To that end, I included stuff from v4.3 (which was developed in the months leading up to November) under the umbrella of the project, since the goals of KSPP aren t unique to the project nor must the goals be met by people that are explicitly participating in it. Additionally, not everything I think worth mentioning here technically falls under the kernel self-protection ideal anyway some things are just really interesting userspace-facing features. So, to that end, here are things I found interesting in v4.3: CONFIG_CPU_SW_DOMAIN_PAN Russell King implemented this feature for ARM which provides emulated segregation of user-space memory when running in kernel mode, by using the ARM Domain access control feature. This is similar to a combination of Privileged eXecute Never (PXN, in later ARMv7 CPUs) and Privileged Access Never (PAN, coming in future ARMv8.1 CPUs): the kernel cannot execute user-space memory, and cannot read/write user-space memory unless it was explicitly prepared to do so. This stops a huge set of common kernel exploitation methods, where either a malicious executable payload has been built in user-space memory and the kernel was redirected to run it, or where malicious data structures have been built in user-space memory and the kernel was tricked into dereferencing the memory, ultimately leading to a redirection of execution flow. This raises the bar for attackers since they can no longer trivially build code or structures in user-space where they control the memory layout, locations, etc. Instead, an attacker must find areas in kernel memory that are writable (and in the case of code, executable), where they can discover the location as well. For an attacker, there are vastly fewer places where this is possible in kernel memory as opposed to user-space memory. And as we continue to reduce the attack surface of the kernel, these opportunities will continue to shrink. While hardware support for this kind of segregation exists in s390 (natively separate memory spaces), ARM (PXN and PAN as mentioned above), and very recent x86 (SMEP since Ivy-Bridge, SMAP since Skylake), ARM is the first upstream architecture to provide this emulation for existing hardware. Everyone running ARMv7 CPUs with this kernel feature enabled suddenly gains the protection. Similar emulation protections (PAX_MEMORY_UDEREF) have been available in PaX/Grsecurity for a while, and I m delighted to see a form of this land in upstream finally. To test this kernel protection, the ACCESS_USERSPACE and EXEC_USERSPACE triggers for lkdtm have existed since Linux v3.13, when they were introduced in anticipation of the x86 SMEP and SMAP features. Ambient Capabilities Andy Lutomirski (with Christoph Lameter and Serge Hallyn) implemented a way for processes to pass capabilities across exec() in a sensible manner. Until Ambient Capabilities, any capabilities available to a process would only be passed to a child process if the new executable was correctly marked with filesystem capability bits. This turns out to be a real headache for anyone trying to build an even marginally complex least privilege execution environment. The case that Chrome OS ran into was having a network service daemon responsible for calling out to helper tools that would perform various networking operations. Keeping the daemon not running as root and retaining the needed capabilities in children required conflicting or crazy filesystem capabilities organized across all the binaries in the expected tree of privileged processes. (For example you may need to set filesystem capabilities on bash!) By being able to explicitly pass capabilities at runtime (instead of based on filesystem markings), this becomes much easier. For more details, the commit message is well-written, almost twice as long as than the code changes, and contains a test case. If that isn t enough, there is a self-test available in tools/testing/selftests/capabilities/ too. PowerPC and Tile support for seccomp filter Michael Ellerman added support for seccomp to PowerPC, and Chris Metcalf added support to Tile. As the seccomp maintainer, I get excited when an architecture adds support, so here we are with two. Also included were updates to the seccomp self-tests (in tools/testing/selftests/seccomp), to help make sure everything continues working correctly. That s it for v4.3. If I missed stuff you found interesting, please let me know! I m going to try to get more per-version posts out in time to catch up to v4.8, which appears to be tentatively scheduled for release this coming weekend.

2016, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.

Around a week ago, I started to play with programmatically controlling Azure. I needed to create and destroy a bunch of VMs over and over again, and this seemed like something I would want to automate once instead of doing manually and repeatedly. I started to look into the azure-sdk-for-python and mentioned that I wanted to look into this in #debian-python. ardumont from Software Heritage noticed me, and was planning to package azure-storage-python. We joined forces and started a packaging team for Azure-related software. I spoke with the upstream developer of the azure-sdk-for-python and he pointed me towards azure-cli. It looked to me that this fit my use case better than the SDK alone, as it had the high level commands I was looking for. Between me and ardumont, in the space of just under a week, we have now packaged: python-msrest (#838121), python-msrestazure (#838122), python-azure (#838101), python-azure-storage (#838135), python-adal (#838716), python-applicationinsights (#838717) and finally azure-cli (#838708). Some of these packages are still in the NEW queue at the time I m writing this, but I don t foresee any issues with these packages entering unstable. azure-cli, as we have packaged, is the new Python-based CLI for Azure. The Microsoft developers gave it the tagline of our next generation multi-platform command line experience for Azure . In the short time I ve been using it I ve been very impressed with it. In order to set it up initially, you have to configure a couple of of defaults using az configure. After that, you need to az login which again is an entirely painless process as long as you have a web browser handy in order to perform the login. After those two steps, you re only two commands away from deploying a Debian virtual machine:

az resource group create -n testgroup -l "West US"
az vm create -n testvm -g testgroup --image credativ:Debian:8:latest --authentication-type ssh

This will create a resource group, and then create a VM within that resource group with a user automatically created with your current username and with your SSH public key (~/.ssh/id_rsa.pub) automatically installed. Once it returns you the IP address, you can SSH in straight away. Looking forward to some next steps for Debian on Azure, I d like to get images built for Azure using vmdebootstrap and I ll be exploring this in the lead up to, and at, the upcoming vmdebootstrap sprint in Cambridge, UK later in the year (still being organised).

A few weeks ago, I hacked up go-wmata, some golang bindings to the WMATA API. This is super handy if you are in the DC area, and want to interface to the WMATA data. As a proof of concept, I wrote a yo bot called @WMATA, where it returns the closest station if you Yo it your location. For hilarity, feel free to Yo it from outside DC. For added fun, and puns, I wrote a dbus proxy for the API as weel, at wmata-dbus, so you can query the next train over dbus. One thought was to make a GNOME Shell extension to tell me when the next train is. I d love help with this (or pointers on how to learn how to do this right).

A while ago, it occurred to me that querying Debian Code Search seemed slow, which surprised me because I previously spent quite some effort on making it faster, see Debian Code Search Instant and Taming the latency tail for the most recent substantial architecture overhaul and related optimizations. Upon taking a closer look, I realized that while performing the search query on the server side was pretty fast, the perceived slowness was due to the client side being slow. By being slow , I mean that it took a long time until something was drawn on the screen (high latency) and that what was happening on the screen was janky (stuttering, not smooth). Part of that slowness was due to historical reasons: the client-side architecture was optimized for the use-case where users open Debian Code Search s index page and then submit a search query, but I was using Chrome s address bar to send a search query (type codesearch , then hit the TAB key). Further, we only added a non-JavaScript version after we launched the JavaScript version. Hence, the redirects and progressive enhancements we implemented are more of a kludge than a well thought out design. After this bit of original investigation, I opened GitHub issue #69 to track the work on making Debian Code Search faster. In that issue, I captured how Chrome s network inspector visualizes the work necessary to render the page: A couple of quick wins There are a couple of little fixes and improvements on which I m not going to spend too much time on, but which I list for completeness anyway just in case they come in handy for a similar project of yours:

• Remove css @import, unnecessary because we minify the two stylesheets together already.
• Compress assets using the gzip-compatible Z pfli algorithm (saves 3KB).
• Run SVG files through the svgo optimizer (saves 8KB).
• Use highly compressed/post-processed woff/woff2 webfont versions (gains such as 57KB 14KB for Roboto-Bold).
• Enabled HTTP/2 in nginx not a win by itself, but avoids further round trips in combination with the EventSource API (see below).

Bigger changes The URL pattern has changed. Previously, we had 2 areas of the website, one for JavaScript-compatible clients and one for the rest. When you hit the wrong one, you were redirected. In some areas, we couldn t tell which area is the correct one for you, so you would always incur a redirect: one example for this is the search bar. With the new URL pattern, we deliver both versions under the same URL: the elements only used by the JavaScript code are hidden using CSS by default, then made visible by JavaScript code. The elements only used by the non-JavaScript code are wrapped in a <noscript> tag. All CSS which is required for the initial page rendering is now inlined in the responses, allowing the browser to immediately render a response without requiring any additional round trips. All non-essential CSS has been moved into a separate CSS file which is loaded asynchronously. This is done using a pattern like <link rel="preload" href="foo.css" as="style" onload="this.rel='stylesheet'">, see also filamentgroup/loadCSS. We switched from WebSockets to the EventSource API because the former is not compatible with HTTP/2, whereas the latter is. This removes a round trip and some custom code for WebSocket reconnecting, because EventSource does that for you. The progress bar animation used to animate the background-position property. It turns out that browsers can only animate the position, scale, rotation and opacity properties smoothly, because such animations can be off-loaded to the GPU. Hence, we have re-implemented the progress bar animation using the position property. The biggest win for improving client-side latency from the Chrome address bar was introducing Service Workers (see commit 7f31aef402cb782056e290a797f224171f4af270). Our Service Worker caches static assets and a placeholder results page. The placeholder page is presented immediately when you start a search (e.g. from the address bar), making the first response immediate, i.e. rendered within 100ms. Having assets and the result page out of the way, the first round trip is used for actually doing the search, removing all unnecessary overhead. With all of these improvements in place, rendering latency goes down from half a second to well under 100 ms, and this is what the Chrome network inspector looks like:

I bought a new laptop E200HA, because my previous was a MacBook and It broke after a fall into the ground. I let it boot first in Win10 to check if everything was OK and because I could not found the way to enter in the UEFI/BIOS. It is F2 and is edge triggered. It boots fast into Win10, but I got the feeling of being a little slow. No worries because I it bought for running Debian and because of the autonomy of the battery, 14hours playing music according to Asus. A little research if the new laptop could run Linux almost return no hits, but one very valuable link on how to setup the Wifi. So I got the feeling that I needed a Debian stretch CD for installation. So I download the first installation DVD from here. Run a trial of the DVD image using kvm

kvm -m 2047 -cdrom debian-stretch-DI-alpha7-amd64-DVD-1.iso

Found that the installer DVD now have the functionality of Live CD. This will be useful. Copy the image to a USB stick using dd command. I turned on the E200HA, entered into the UEFI/BIOS by pressing and releasing the F2 key. Turned off the secure boot and select USB storage for boot. The E200HA happily boot the Linux and I select the rescue mode. Using another USB stick of 32GB that was formatted in xfs, because of the lower slack for storing the inodes than ext3/4. In this USB stick I put a raw image of the internal storage of the E200HA, preserving this way the Win10. Another reboot, this time for installation of Debian stretch. It detected the lack of firmware files, for the WiFi adaptor. This link come very handy. The instructions are for an older Linux kernel. So I recommend doing something similar to the following commands:

git clone https://github.com/ajaybhatia/Qualcomm-Atheros-QCA9377-Wifi-Linux
cd Qualcomm-Atheros-QCA9377-Wifi-Linux/firmware-only
tar cvf QCA9377.tar QCA9377

Copy the tar file to a a second USB stick and connect it to the other USB port. This tar is not the files the Debian installer are expecting, so you need to change to the second console "Alt-F2", press enter to activate a shell, and do the following commands:

cd /lib/firmware
mkdir ath10k
mount /dev/sdb1 /mnt
cd ath10k
tar xf /mnt/QCA9377.tar

Return to the first console "Alt-F1" and continue with the installation. The list of missing firmware files is reduced and the WiFi can work. I had problems with the WiFI, but was because a neighbor router was on the same channel, since I changed the channel of my router the WiFi is working as a charm. The following links maybe useful in the future or as a reference: kvalo/ath10k-firmware kernel/git/firmware/linux-firmware.git

I'm glad to announce that we have the current release of Theano (0.8.2) in Debian unstable now, it's on its way into the testing branch and the Debian derivatives, heading for Debian 9. The Debian package is maintained in behalf of the Debian Science Team. We have a binary package with the modules in the Python 2.7 import path (python-theano), if you want or need to stick to that branch a little longer (as a matter of fact, in the current popcon stats it's the most installed package), and a package running on the default Python 3 version (python3-theano). The comprehensive documentation is available for offline usage in another binary package (theano-doc). Although Theano builds its extensions on run time and therefore all binary packages contain the same code, the source package generates arch specific packages¹ for the reason that the exhaustive test suite could run over all the architectures to detect if there are problems somewhere (#824116). what's this? In a nutshell, Theano is a computer algebra system (CAS) and expression compiler, which is implemented in Python as a library. It is named after a Classical Greek female mathematician and it's developed at the LISA lab (located at MILA, the Montreal Institute for Learning Algorithms) at the Universit de Montr al. Theano tightly integrates multi-dimensional arrays (N-dimensional, ND-array) from NumPy (numpy.ndarray), which are broadly used in Scientific Python for the representation of numeric data. It features a declarative Python based language with symbolic operations for the functional definition of mathematical expressions, which allows to create functions that compute values for them. Internally the expressions are represented as directed graphs with nodes for variables and operations. The internal compiler then optimizes those graphs for stability and speed and then generates high-performance native machine code to evaluate resp. compute these mathematical expressions². One of the main features of Theano is that it's capable to compute also on GPU processors (graphical processor unit), like on custom graphic cards (e.g. the developers are using a GeForce GTX Titan X for benchmarks). Today's GPUs became very powerful parallel floating point devices which can be employed also for scientific computations instead of 3D video games³. The acronym "GPGPU" (general purpose graphical processor unit) refers to special cards like NVIDIA's Tesla⁴, which could be used alike (more on that below). Thus, Theano is a high-performance number cruncher with an own computing engine which could be used for large-scale scientific computations. If you haven't came across Theano as a Pythonistic professional mathematician, it's also one of the most prevalent frameworks for implementing deep learning applications (training multi-layered, "deep" artificial neural networks, DNN) around⁵, and has been developed with a focus on machine learning from the ground up. There are several higher level user interfaces build in the top of Theano (for DNN, Keras, Lasagne, Blocks, and others, or for Python probalistic programming, PyMC3). I'll seek for some of them also becoming available in Debian, too. helper scripts Both binary packages ship three convenience scripts, theano-cache, theano-test, and theano-nose. Instead of them being copied into /usr/bin, which would result into a binaries-have-conflict violation, the scripts are to be found in /usr/share/python-theano (python3-theano respectively), so that both module packages of Theano can be installed at the same time. The scripts could be run directly from these folders, e.g. do $ python /usr/share/python-theano/theano-nose to achieve that. If you're going to heavy use them, you could add the directory of the flavour you prefer (Python 2 or Python 3) to the $PATH environment variable manually by either typing e.g. $ export PATH=/usr/share/python-theano:$PATH on the prompt, or save that line into ~/.bashrc. Manpages aren't available for these little helper scripts⁶, but you could always get info on what they do and which arguments they accept by invoking them with the -h (for theano-nose) resp. help flag (for theano-cache). running the tests On some occasions you might want to run the testsuite of the installed library, like to check over if everything runs fine on your GPU hardware. There are two different ways to run the tests (anyway you need to have python ,3 -nose installed). One is, you could launch the test suite by doing $ python -c 'import theano; theano.test() (or the same with python3 to test the other flavour), that's the same what the helper script theano-test does. However, by doing it that way some particular tests might fail by raising errors also for the group of known failures. Known failures are excluded from being errors if you run the tests by theano-nose, which is a wrapper around nosetests, so this might be always the better choice. You can run this convenience script with the option --theano on the installed library, or from the source package root, which you could pull by $ sudo apt-get source theano (there you have also the option to use bin/theano-nose). The script accept options for nosetests, so you might run it with -v to increase verbosity. For the tests the configuration switch config.device must be set to cpu. This will also include the GPU tests when a proper accessible device is detected, so that's a little misleading in the sense of it doesn't mean "run everything on the CPU". You're on the safe side if you run it always like this: $ THEANO_FLAGS=device=cpu theano-nose, if you've set config.device to gpu in your ~/.theanorc. Depending on the available hardware and the used BLAS implementation (see below) it could take quite a long time to run the whole test suite through, on the Core-i5 in my laptop that takes around an hour even excluded the GPU related tests (which perform pretty fast, though). Theano features a couple of switches to manipulate the default configuration for optimization and compilation. There is a rivalry between optimization and compilation costs against performance of the test suite, and it turned out the test suite performs a quicker with lesser graph optimization. There are two different switches available to control config.optimizer, the fast_run toggles maximal optimization, while fast_compile runs only a minimal set of graph optimization features. These settings are used by the general mode switches for config.mode, which is either FAST_RUN by default, or FAST_COMPILE. The default mode FAST_RUN (optimizer=fast_run, linker=cvm) needs around 72 minutes on my lower mid-level machine (on un-optimized BLAS). To set mode=FAST_COMPILE (optimizer=fast_compile, linker=py) brings some boost for the performance of the test suite because it runs the whole suite in 46 minutes. The downside of that is that C code compilation is disabled in this mode by using the linker py, and also the GPU related tests are not included. I've played around with using the optimizer fast_compile with some of the other linkers (c py and cvm, and their versions without garbage collection) as alternative to FAST_COMPILE with minimal optimization but also machine code compilation incl. GPU testing. But to my experience, fast_compile without another than the linker py results in some new errors and failures of some tests on amd64, and this might the case also on other architectures, too. By the way, another useful feature is DebugMode for config.mode, which verifies the correctness of all optimizations and compares the C to Python results. If you want to have detailed info on the configuration settings of Theano, do $ python -c 'import theano; print theano.config' less, and check out the chapter config in the library documentation in the documentation. cache maintenance Theano isn't a JIT (just-in-time) compiler like Numba, which generates native machine code in the memory and executes it immediately, but it saves the generated native machine code into compiledirs. The reason for doing it that way is quite practical like the docs explain, the persistent cache on disk makes it possible to avoid generating code for the same operation, and to avoid compiling again when different operations generate the same code. The compiledirs by default are located within $(HOME)/.theano/. After some time the folder becomes quite large, and might look something like this: If the used Python version changed like in this example you might to want to purge obsolete cache. For working with the cache resp. the compiledirs, the helper theano-cache comes in handy. If you invoke it without any arguments the current cache location is put out like ~/.theano/compiledir_Linux-4.5--amd64-x86_64-with-debian-stretch-sid--2.7.12-64 (the script is run from /usr/share/python-theano). So, the compiledirs for the old Python versions in this example (11+ and 12rc1) can be removed to free the space they occupy. All compiledirs resp. cache directories meaning the whole cache could be erased by $ theano-cache basecompiledir purge, the effect is the same as by performing $ rm -rf ~/.theano. You might want to do that e.g. if you're using different hardware, like when you got yourself another graphics card. Or habitual from time to time when the compiledirs fill up so much that it slows down processing with the harddisk being very busy all the time, if you don't have an SSD drive available. For example, the disk space of build chroots carrying (mainly) the tests completely compiled through on default Python 2 and Python 3 consumes around 1.3 GB (see here). BLAS implementations Theano needs a level 3 implementation of BLAS (Basic Linear Algebra Subprograms) for operations between vectors (one-dimensional mathematical objects) and matrices (two-dimensional objects) carried out on the CPU. NumPy is already build on BLAS and pulls the standard implementation (libblas3, soure package: lapack), but Theano links directly to it instead of using NumPy as intermediate layer to reduce the computational overhead. For this, Theano needs development headers and the binary packages pull libblas-dev by default, if any other development package of another BLAS implementation (like OpenBLAS or ATLAS) isn't already installed, or pulled with them (providing the virtual package libblas.so). The linker flags could be manipulated directly through the configuration switch config.blas.ldflags, which is by default set to -L/usr/lib -lblas -lblas. By the way, if you set it to an empty value, Theano falls back to using BLAS through NumPy, if you want to have that for some reason. On Debian, there is a very convenient way to switch between BLAS implementations by the alternatives mechanism. If you have several alternative implementations installed at the same time, you can switch from one to another easily by just doing: The implementations are performing differently on different hardware, so you might want to take the time to compare which one does it best on your processor (the other packages are libatlas-base-dev and libopenblas-dev), and choose that to optimize your system. If you want to squeeze out all which is in there for carrying out Theano's computations on the CPU, another option is to compile an optimized version of a BLAS library especially for your processor. I'm going to write another blog posting on this issue. The binary packages of Theano ship the script check_blas.py to check over how well a BLAS implementation performs with it, and if everything works right. That script is located in the misc subfolder of the library, you could locate it by doing $ dpkg -L python-theano grep check_blas (or for the package python3-theano accordingly), and run it with the Python interpreter. By default the scripts puts out a lot of info like a huge perfomance comparison reference table, the current setting of blas.ldflags, the compiledir, the setting of floatX, OS information, the GCC version, the current NumPy config towards BLAS, NumPy location and version, if Theano linked directly or has used the NumPy binding, and finally and most important, the execution time. If just the execution time for quick perfomance comparisons is needed this script could be invoked with -q. Theano on CUDA The function compiler of Theano works with alternative backends to carry out the computations, like the ones for graphics cards. Currently, there are two different backends for GPU processing available, one docks onto NVIDIA's CUDA (Compute Unified Device Architecture) technology⁷, and another one for libgpuarray, which is also developed by the Theano developers in parallel. The libgpuarray library is an interesting alternative for Theano, it's a GPU tensor (multi-dimensional mathematical object) array written in C with Python bindings based on Cython, which has the advantage of running also on OpenCL⁸. OpenCL, unlike CUDA⁹, is full free software, vendor neutral and overcomes the limitation of the CUDA toolkit being only available for amd64 and the ppc64el port (see here). I've opened an ITP on libgpuarray and we'll see if and how this works out. Another reason for it would be great to have it available is that it looks like CUDA currently runs into problems with GCC 6¹⁰. More on that, soon. Here's a litle checklist for setting up your CUDA device so that you don't have to experience something like this: hardware check For running Theano on CUDA you need an NVIDIA graphics card which is capable of doing that. You can recheck if your device is supported by CUDA here. When the hardware isn't too old (CUDA support started with GeForce 8 and Quadro X series) or too strange I think it isn't working only in exceptional cases. You can check your model and if the device is present in the system on the bare hardware level by doing this: If a line like this doesn't get returned, your device most probably is broken, or not properly connected (ouch). If rev ff appears at the end of the line that means the device is off meaning powered down. This might be happening if you have a laptop with Optimus graphics hardware, and the related drivers have switched off the unoccupied device to safe energy¹¹. kernel module Running CUDA applications requires the proprietary NVIDIA driver kernel module to be loaded into the kernel and working. If you haven't already installed it for another purpose, the NVIDIA driver and the CUDA toolkit are both in the non-free section of the Debian archive, which is not enabled by default. To get non-free packages you have to add non-free (and it's better to do so, also contrib) to your package source in /etc/apt/sources.list, which might then look like this: After doing that, perform $ apt-cache update to update the package lists, and there you go with the non-free packages. The headers of the running kernel are needed to compile modules, you can get them together with the NVIDIA kernel module package by running: DKMS will then build the NVIDIA module for the kernel and does some other things on the system. When the installation has finished, it's generally advised to reboot the system completely. troubleshooting If you have problems with the CUDA device, it's advised to verify if the following things concerning the NVIDIA driver resp. kernel module are in order: blacklist nouveau Check if the default Nouveau kernel module driver (which blocks the NVIDIA module) for some reason still gets loaded by doing $ lsmod grep nouveau. If nothing gets returned, that's right. If it's still in the kernel, just add blacklist nouveau to /etc/modprobe.d/blacklist.conf, and update the booting ramdisk with sudo update-initramfs -u afterwards. Then reboot once more, this shouldn't be the case then anymore. rebuild kernel module To fix it when the module haven't been properly compiled for some reason you could trigger a rebuild of the NVIDIA kernel module with $ sudo dpkg-reconfigure nvidia-kernel-dkms. When you're about to send your hardware in to repair because everything looks all right but the device just isn't working, that really could help (own experience). After the rebuild of the module or modules (if you have a few kernel packages installed) has completed, you could recheck if the module really is available by running: It should be something similiar to this when everything is all right. reload kernel module When there are problems with the GPU, maybe the kernel module isn't properly loaded. You could recheck if the module has been properly loaded by doing The kernel module could be loaded resp. reloaded with $ sudo nvidia-modprobe (that tool is from the package nvidia-modprobe). unsupported graphics card Be sure that you graphics cards is supported by the current driver kernel module. If you have bought new hardware, that's quite possible to come out being a problem. You can get the version of the current NVIDIA driver with: Then, google the version number like nvidia 352.79, this should get you onto an official driver download page like this. There, check for what's to be found under "Supported Products". I you're stuck with that there are two options, to wait until the driver in Debian got updated, or replace it with the latest driver package from NVIDIA. That's possible to do, but something more for experienced users. occupied graphics card The CUDA driver cannot work while the graphical interface is busy like by processing the graphical display of your X.Org server. Which kernel driver actually is used to process the desktop could be examined by this command:¹² This example shows that the rendering of the desktop is performed by the graphical device of the Intel CPU, which is just like it's needed for running CUDA applications on your NVIDIA graphics card, if you don't have another one. nvidia-cuda-toolkit With the Debian package of the CUDA toolkit everything pretty much runs out of the box for Theano. Just install it with apt-get, and you're ready to go, the CUDA backend is the default one. Pycuda is also a suggested dependency of the binary packages, it could be pulled together with the CUDA toolkit. The up-to-date CUDA release 7.5 is of course available, with that you have Maxwell architecture support so that you can run Theano on e.g. a GeForce GTX Titan X with 6,2 TFLOPS on single precision¹³ at an affordable price. CUDA 8¹⁴ is around the corner with support for the new Pascal architecture¹⁵. Like the GeForce GTX 1080 high-end gaming graphics card already has 8,23 TFLOPS¹⁶. When it comes to professional GPGPU hardware like the Tesla P100 there is much more computational power available, scalable by multiplication of cores resp. cards up to genuine little supercomputers which fit on a desk, like the DGX-1¹⁷. Theano can use multiple GPUs for calculations to work with highly scaled hardware, I'll write another blog post on this issue. Theano on the GPU It's not difficult to run Theano on the GPU. Only single precision floating point numbers (float32) are supported on the GPU, but that is sufficient for deep learning applications. Theano uses double precision floats (float64) by default, so you have to set the configuration variable config.floatX to float32, like written on above, either with the THEANO_FLAGS environment variable or better in your .theanorc file, if you're going to use the GPU a lot. Switching to the GPU actually happens with the config.device configuration variable, which must be set to either gpu or gpu0, gpu1 etc., to choose a particular one if multiple devices are available. Here's is a little test script check1.py, it's taken from the docs and slightly altered. You can run that script either with python or python3 (there was a single test failure on the Python 3 package, so the Python 2 library might be a little more stable currently). For comparison, here's an example on how it perfoms on my hardware, one time on the CPU, one more time on the GPU: If you got a result like this you're ready to go with Theano on Debian, training computer vision classifiers or whatever you want to do with it. I'll write more on for what Theano could be used, soon.

Yesterday, I tried to unlock a HTC Desire HD phone, and it proved to be a slight challenge. Here is the recipe if I ever need to do it again. It all started by me wanting to try the recipe to set up an hardened Android installation from the Tor project blog on a device I had access to. It is a old mobile phone with a broken microphone The initial idea had been to just install CyanogenMod on it, but did not quite find time to start on it until a few days ago. The unlock process is supposed to be simple: (1) Boot into the boot loader (press volume down and power at the same time), (2) select 'fastboot' before (3) connecting the device via USB to a Linux machine, (4) request the device identifier token by running 'fastboot oem get_identifier_token', (5) request the device unlocking key using the HTC developer web site and unlock the phone using the key file emailed to you. Unfortunately, this only work fi you have hboot version 2.00.0029 or newer, and the device I was working on had 2.00.0027. This apparently can be easily fixed by downloading a Windows program and running it on your Windows machine, if you accept the terms Microsoft require you to accept to use Windows - which I do not. So I had to come up with a different approach. I got a lot of help from AndyCap on #nuug, and would not have been able to get this working without him. First I needed to extract the hboot firmware from the windows binary for HTC Desire HD downloaded as 'the RUU' from HTC. For this there is is a github project named unruu using libunshield. The unshield tool did not recognise the file format, but unruu worked and extracted rom.zip, containing the new hboot firmware and a text file describing which devices it would work for. Next, I needed to get the new firmware into the device. For this I followed some instructions available from HTC1Guru.com, and ran these commands as root on a Linux machine with Debian testing:

adb reboot-bootloader
fastboot oem rebootRUU
fastboot flash zip rom.zip
fastboot flash zip rom.zip
fastboot reboot

The flash command apparently need to be done twice to take effect, as the first is just preparations and the second one do the flashing. The adb command is just to get to the boot loader menu, so turning the device on while holding volume down and the power button should work too. With the new hboot version in place I could start following the instructions on the HTC developer web site. I got the device token like this:

fastboot oem get_identifier_token 2>&1   sed 's/(bootloader) //'

And once I got the unlock code via email, I could use it like this:

fastboot flash unlocktoken Unlock_code.bin

And with that final step in place, the phone was unlocked and I could start stuffing the software of my own choosing into the device. So far I only inserted a replacement recovery image to wipe the phone before I start. We will see what happen next. Perhaps I should install Debian on it. :)

Today was day one of the DebConf16 Open Festival and I attended the open hardware panel, part of the talk about Code For South Africa, shirish's experiences and the DebConf new folks session. The open hardware panel was a wide ranging discussion between bdale, Andy and indiebio. bdate talked about the experiences he has had with his rocketry hardware. bdale said "Make concious decisions about what you are buying", referencing a case where he investigated, found a GPL violation and didn't buy. Various people care about openness of different layers of the hardware. Off-the-shelf products are very strongly integrated, which is great for makers but means that people who care about lower layers like CPU micro-architecture aren't able to participate. Andy said "We are just beginning to come out of the shareware stage [of open hardware]". bdale mentioned the companies who do hardware production as a service from design files. Later in the pub some folks mentioned j-core, an open re-implementation of SuperH processors. I missed most of the code4sa talk unfortunately, but it was about government services and open data. shirish covered his journey through life to Debian. His youth, how satellite TV and knowledge of the outside world came to India around the time of the Iraq war. His experience accessing the Internet for the first time, uncensored vs the usual censorship in India's media. His experiences of Windows 95 viruses and crashes. He learned of PCTwist Linux through a magazine cover. His initial install was not a success but eventually managed to break through and install a desktop, but experienced network and other issues. Eventually he encountered Ubuntu and began contributing bug reports. His experiences there led him to Debian. He began blogging about Debian. In the last few years he and others have been going around the country doing mini-DebConfs at institutes around India. The first question was predictably about having a DebConf in India and how shirish might like to get more involved. DebConf in India sounds like a possibility some day and shirish was thinking about getting involved in publicity, marketting and the Debian installer. The DebConf new folks session was a great intro to DebConf for folks new to the community. There were some quite excellent touches added to this year's version of the event by indiebio and Rhonda. I also got some things done. Usual spam reporting. Reviewed wiki RecentChanges. Talked to the chromium-bsu/MacPorts maintainer about AX_CHECK_GL brokenness. Filed Debian wishlist bug #829292 asking to update autoconf-archive. Redirected a Hurd porterbox request to the exodar admin and quickly found out I was wrong to do that, rectified. Then we found out the LDAP sync to exodar was broken. Replied to someone who intends to sell Debian pre-installs. Thanked BunsenLabs folks for joining the derivatives list. Applied reproducible builds patch for cats from Chris Lamb. Heard about awesome new terminal-mode screensaver. Moo! Prepared a blog post about check-all-the-things.