Kernel debugger

Last updated February 17, 2020

A kernel debugger is a debugger present in some operating system kernels to ease debugging and kernel development by the kernel developers. A kernel debugger might be a stub implementing low-level operations, with a full-blown debugger such as GNU Debugger (gdb), running on another machine, sending commands to the stub over a serial line or a network connection, or it might provide a command line that can be used directly on the machine being debugged.

Operating systems and operating system kernels that contain a kernel debugger:

The Windows NT family includes a kernel debugger named KD,^[1] which can act as a local debugger with limited capabilities (reading and writing kernel memory, and setting breakpoints)^[2] and can attach to a remote machine over a serial line, IEEE 1394 connection, USB 2.0 or USB 3.0 connection.^[3] The WinDbg GUI debugger can also be used to debug kernels on local and remote machines.
BeOS and Haiku include a kernel debugger usable with either an on-screen console or over a serial line. It features various commands to inspect memory, threads, and other kernel structures. ^[4]
DragonFly BSD
Linux kernel; No kernel debugger was included in the mainline Linux tree prior to version 2.6.26-rc1 because Linus Torvalds didn't want a kernel debugger in the kernel.^[5]^[6]
- KDB (local)^[7]
- KGDB (remote)
- MDB (local/remote)^[8]^[9]^[10]
NetBSD (DDB for local, KGDB for remote)
macOS,^[11] Darwin which runs the XNU kernel using the Mach component
OpenBSD includes ddb which has a syntax is similar to GNU Debugger.^[12]

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References

↑ "Debugging Environments". Debugging Tools for Windows (WinDbg, KD, CDB, NTSD). Retrieved 16 February 2020.
↑ "Local Kernel-Mode Debugging" . Retrieved 16 February 2020.
↑ "Live Kernel-Mode Debugging Using KD" . Retrieved 16 January 2020.
↑ "Welcome to Kernel Debugging Land".
↑ "LWN.net" . Retrieved 29 May 2008.
↑ Torvalds, Linus (3 May 2008). "Linux 2.6.26-rc1". LWN. Retrieved 9 March 2015.
↑ Nellitheertha, Hariprasad. "Inside the Linux kernel debugger". Archived from the original on 21 June 2008. Retrieved 29 May 2008.
↑ "LWN Weekly Kernel News". 7 September 2008.
↑ "MDB Github Website". 1 January 2016. Archived from the original on 22 March 2016.
↑ "LWN Weekly Kernel News". 28 June 2010.
↑ Singh, Amit (December 2003). "XNU: The Kernel". What is Mac OS X?. Retrieved 25 May 2012. the built-in low-level kernel debugger, ddb, is part of XNU's Mach component, and so is kdp, a remote kernel debugging protocol implementation
↑ "ddb(4)". OpenBSD manual page server. 6 December 2019. Retrieved 13 December 2019. The ddb debugger provides a means for debugging the kernel, and analysing the kernel after a system crash ("panic"), with a gdb(1)-like syntax.

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[1] "Debugging Environments". Debugging Tools for Windows (WinDbg, KD, CDB, NTSD). Retrieved 16 February 2020.

[2] "Local Kernel-Mode Debugging" . Retrieved 16 February 2020.

[3] "Live Kernel-Mode Debugging Using KD" . Retrieved 16 January 2020.

[4] "Welcome to Kernel Debugging Land".

[linus-5] "LWN.net" . Retrieved 29 May 2008.

[6] Torvalds, Linus (3 May 2008). "Linux 2.6.26-rc1". LWN. Retrieved 9 March 2015.

[kdb-7] Nellitheertha, Hariprasad. "Inside the Linux kernel debugger". Archived from the original on 21 June 2008. Retrieved 29 May 2008.

[8] "LWN Weekly Kernel News". 7 September 2008.

[9] "MDB Github Website". 1 January 2016. Archived from the original on 22 March 2016.

[10] "LWN Weekly Kernel News". 28 June 2010.

[11] Singh, Amit (December 2003). "XNU: The Kernel". What is Mac OS X?. Retrieved 25 May 2012. the built-in low-level kernel debugger, ddb, is part of XNU's Mach component, and so is kdp, a remote kernel debugging protocol implementation

[12] "ddb(4)". OpenBSD manual page server. 6 December 2019. Retrieved 13 December 2019. The ddb debugger provides a means for debugging the kernel, and analysing the kernel after a system crash ("panic"), with a gdb(1)-like syntax.