In November 2012, we finished the libthreads (cthreads) to libpthread (POSIX Threads) conversion. Converting the Hurd libraries to the pthread interfaces allows linking them together with other libraries that use this standard threading interface themselves. This project once was begun by Vicente Hernando Ara, and later continued by Barry deFreese, Thomas DiModica, Thomas Schwinge, Samuel Thibault, Pino Toscano, and now brought to completion by Richard Braun, who could not be scared by having to resolve the last remaining tricky issues before the transition could be completed.

Cyril Roelandt shared a patch series to fix double mutex unlocking problems. He found these using a simple script for Coccinelle, which is a static code analysis tool. We hope to see more such changes in the future, and we're always interested in hearing people who have experience with similar tools, for example to resolve other locking issues.

Thomas Schwinge together with Richard Braun and Samuel Thibault debugged and fixed a deadlock related to signal delivery, resulting from a regression due to earlier changes.

Also Samuel Thibault provided new installation CDs and a new QEMU image. Additionally to using pthreads, these now offer keyboard layout configuration.

In glibc, Pino Toscano implemented syncfs which ensures that all data in the filesystem gets written to disk, as well as support in procfs for statfs.

Thomas Schwinge improved the hardware compatibility of the Hurd by identifying and backporting some changes contained in Linux 2.0.40, which prevents data corruption due to a miscalculation of the size of medium-sized disks reporting 15 heads instead of 16. This fix was part of an effort to get Hurd running using a solid-state disk. Samuel Thibault improved network card detection on busses other than 0 and 2.

Several people ported and fixed packages, further increasing the number of Debian packages that work on the Hurd: Svante Signell ported mlocate-0.25, gnat-gps, libpst, libetpan, spl, dovecot, xplc, parrot, x86info, atlas, rrdtool, gdb, yodl, and fixed ntpdate to work again and improved the error handling in pflocal. Pino Toscano added patches for procfs, ptrace, fsync on stdout, muntrace, ulimit, glibc which among others improve POSIX conformance, making it easier to write programs which work on GNU/Hurd and GNU/Linux. And he made the test pass for FIFO sockets with mknod and added a size parameter to tmpfs and a version suffix option for GNU Mach's configure script. Cyril Roelandt fixed a ps bug, a documentation typo in ps and a missing linker flag in procfs. Matthew Leach fixed a compilation error with older GCC versions due to duplicate type definition. Ole Streicher fixed a bug in the Makefile of ftools-fv which was exposed by testing on Hurd. Samuel Thibault removed the out-of-date floppy-warnings in the debian installer.

So if you want to test if your favorite packages work on the Hurd and contribute towards making the full GNU system usable for a wider range of people, please get in contact -- and maybe already grab the source code.

The GNU Hurd is the GNU project's replacement for the Unix kernel. It is a collection of servers that run on the Mach microkernel to implement file systems, network protocols, file access control, and other features that are implemented by the Unix kernel or similar kernels (such as Linux). More detailed.

GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism that the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides. More detailed.

Google Summer of Code

Jérémie Koenig released the final report on his Google Summer of Code project Java on Hurd along with a summary of his changes and the challenges he faced. In a similar track, Samuel Thibault merged the slab branch, concluding Maksym Planeta's Goggle Summer of Code project on an improved memory allocator.

Pino Toscano improved the Hurd implementations of nanosleep, ptsname_r, getlogin_r, getgroups, and sendto, for POSIX compliance.

Barrier of Entry

Samuel Thibault, Ludovic Courtès and Thomas Schwinge reduced the barrier of entry into hacking the Hurd.

As part of this, Samuel prepared DDE in incubator, making about half the Linux kernel 2.6.29.6's network drivers compile on the Hurd, together with a netdde debian package and testing notes.

Ludovic contributed a continuous testing framework using a Nix-based GNU QEMU image. Thanks to his work, we now have automatic tests (background).

Thomas on the other hand moved the translators cvsfs and smbfs into the incubator Git repository, as well as libfuse, reducing the barrier of entry to improving them, so integrating cvs and samba in the filesystem and using FUSE translators can be stabilized more easily. Also he improved the Hurd build system, removing automatically generated files from the source repository, as now running autoreconf is all you need to create them.

Roland McGrath merged many glibc changes for upstream inclusion, reducing the maintenance load for our regular glibc development work.

The Core of the Hurd

Ludovic Courtès, Maksym Planeta, Samuel Thibault and Richard Braun took a dive into the core of the Hurd. Ludovic fixed invalid port deallocation in `symlink' and made console-run resilient against missing /dev/console. Maksym tested the performance of tmpfs, showing a speedup for apt-get calls from 22 seconds with ramdisk and 32 seconds with ext2fs to 16 seconds with tmpfs for apt-get invocations, showing the possible wins due to going deep. An obvious use case for tmpfs are faster Hurd LiveCDs. Samuel made it easier to dive in by improving debugging in GNU Mach. The debugger is now aware of the difference between kernel space and user space. This should substantially reduce the development time for features in Mach by giving nicer stack traces. And in the deepest core of the Mach, Richard improved memory mapping with a red-black tree, which should speed up memory access.

Porting

As in the previous quarters, we also saw lots of ported packages, including Richard's work on libpcap which brought wireshark and pcap_inject for easier network testing, libtool thanks to Samuel Thibault and Peter O'Gorman, gnat by Svante Signell for Ada support (a language used in many mission-critical applications such as automotive and aerospace, offering features like strong typing, modularity, run-time checking and parallel processing), and iconx thanks to Samuel Thibault, which fulfills a requirement of tests for many packages, among them glib - and allowed Svante Signell to port the literate programming language noweb and ifupdown. Also Thomas DiModica merged the cthreads to pthreads patch and added a branch for it to make it easier to work on getting Hurd to use the more current pthreads.

With his Debian GNU/Hurd maintainer hat on, Samuel Thibault posted some new bits from the Debian GNU/Hurd porters.

And now, as a final note, we want to share a story about real-life debugging on a Hurd system; IRC, freenode, #hurd, 2012-03-02:

<youpi> yay GNU/Hurd  
<youpi> I have added i_translator check in e2fsck, it was missing  
<youpi> I had a volume that was keeping making ext2fs crash  
<youpi> with a reproductible scenario  
<youpi> could easily work out it was i_translator, then add a
  check to e2fsck, run it, which indeed fixed, them, and voilà,
  ext2fs was working again
<youpi> all that on the same machine with *no* system reboot  
<youpi> just ext2fs restart :)

So if you want to experience enjoyable debugging of code deep in the core of your system, please get in contact -- and maybe already grab the source code.

The GNU Hurd is the GNU project's replacement for the Unix kernel. It is a collection of servers that run on the Mach microkernel to implement file systems, network protocols, file access control, and other features that are implemented by the Unix kernel or similar kernels (such as Linux). More detailed.

GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism that the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides. More detailed.

This quarter, Ludovic Courtès contributed a continuously-built Nix-based QEMU image, raising the count of GNU/Hurd distributions to three: Debian GNU/Hurd, Arch Hurd, and now Nix. His build is still pretty basic, but a step into the right direction: continuous integration is a great facility for automated testing.

Samuel Thibault followed suit with a new Debian GNU/Hurd disk set as a christmas gift, and identified three easy porting cases with solutions:

• undefined reference to dl_*: add -ldl for building
• undefined reference to main: missing gnu* case in the linking part of configure.ac or .in
• undefined reference to clock_gettime or crypt: add -lrt or -lcrypt

These should help all those who want to help porting packages.

Maksym Planeta and Richard Braun finished integration of the slab allocator. From IRC, freenode, #hurd, 2011-11-14:

<braunr> there shouldn't be any noticeable difference [...]
<braunr> a bit less fragmentation  
<braunr> more memory can be reclaimed by the VM system  
<braunr> there are debugging features  
<braunr> it's SMP ready  
<braunr> and overall cleaner than the zone allocator  
<braunr> although a bit slower on the free path (because of
  what's performed to reduce fragmentation)  
<braunr> but even "slower" here is completely negligible

This also concludes our first FOSS Factory project -- one bounty has been redeemed, more are waiting.

Sergio Lopez documented his work on better memory management and memfs, making it easier for other hackers to join in working on that topic.

Our hackers also used the quarter for porting a good number of packages and fixing bugs. After fixing quirks in the Hurd's memory management system, Sergio Lopez reported success building webkitgtk+, whose build stresses the available memory resources on a 32-bit architecture to a large extent. Svante Signell was busy, too: pax, abiword, syslog-ng, ecl, fakeroot, daemon, and procps, e2fsprogs' quota. Samuel Thibault handled packagekit, evolution, emacs23, gcc-4.7, and iceweasel (firefox). Bouju Alain submitted a patch to support /proc/cpuinfo. Ludovic Courtès contributed a patch to allow for /hurd/init being symlink, made the Hurd build with glibc 2.14+, and worked with the GNU coreutils team on a few issues. Pino Toscano improved recvfrom with NULL address ports. Maksym Planeta continued working on tmpfs. Samuel Thibault turned /dev/random and /dev/urandom into native translators, modernized libtool's configuration, mknod's cleanup in error cases, fixed POSIX 2008 visibility, and fixed an issue in setresuid that broke sudo. Pino Toscano and Thomas Schwinge improved key handling in libpthread. Guillem Jover fixed Mach's int vs. long discrepancy, which takes us the first step towards porting the system to x86 64.

If you want to join us in our journey to realize more of the promises of the architecture of the Hurd, please get in contact -- and maybe already grab the source code and have fun hacking on Free Software!

The GNU Hurd is the GNU project's replacement for the Unix kernel. It is a collection of servers that run on the Mach microkernel to implement file systems, network protocols, file access control, and other features that are implemented by the Unix kernel or similar kernels (such as Linux). More detailed.

GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism that the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides. More detailed.