Welcome to the KGDB and KDB wiki, the official home of kgdb and kdb for kernel.org.

Quick History

• 2.6.26 - KGDB was merged
• 2.6.35 - KDB was merged, and uses the same backend as KGDB.
• 2.6.36 - The atomic kernel mode setting (KMS) API was merged (currently on the Intel i915 class of video cards are supported)
• 2.6.37 - Radeon and Nouveau atomic KMS support merged along with improved KDB keyboard support

KGDB Mailing list & TODO List

Subscribe: https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport

KGDB Mail archives

TO DO:

• Create a to do list on a separate page and elaborate on the debugger wish list
• x86/perf - Close the race window where kgdb and perf can both write to hw breakpoint registers at the same time when switching from early to late debugging.

KGDB Development

The git branch is organized into the pieces that are not in the main line kernel. The top level link to the development git archive is here:

http://git.kernel.org/?p=linux/kernel/git/jwessel/kgdb.git

There is a branch head for each kernel release starting with 2.6.21. Starting in 2.6.24 the kgdb internals were completely changed. The kgdb core was merged to the mainline kernel in 2.6.26.

There is also a directory with a quilt series corresponding to the kgdb development git archive which is periodically updated. It can be found at: http://kernel.org/pub/linux/kernel/people/jwessel/branches

KGDB kernel documentation (2.6.26 -> 2.6.34)

http://kernel.org/pub/linux/kernel/people/jwessel/kgdb/

The new KDB and KGDB documentation (kernel >= 2.6.35)

http://kernel.org/pub/linux/kernel/people/jwessel/kdb/

• The new KDB FAQ: http://kgdb.wiki.kernel.org/index.php/KDB_FAQ

Presentations about kernel debugging

Linux Plumbers Conference presentation 2009

Merging KGDB KDB and Kernel Mode Setting

This presentation used kdb_prototype8 from the kgdb git repository. This was an intermediate build of the 2.6.32 development kernel however while the KMS core was in flux, so it is not terribly useful to anyone except as a demonstration.

The kdb_prototype9 branch was created after the KMS core changes stabilized and will form the basis for the cleanup and initial post to lkml.

The kdb_prototype10 branch will be the first posted to lkml since the initial RFC. Ideally this code base will get merged into the 2.6.34 kernel.

Kernel Debugging Webinar June 23, 2010

The materials from the presentation can be found at:

Directory of webinar materials

State of Kernel Debugging - LinuxCon - Aug 12, 2010

LinuxCon2010 State of Kernel Debugging Presentation

State of Kernel Debugging - LinuxCon - Aug 20, 2014

LinuxCon2014 State of Kernel Debugging Presentation