Re: [ANNOUNCE] MDB Linux Kernel debugger kernels 2.6.19 through 4.3.0

From: Jeffrey Merkey
Date: Tue Dec 01 2015 - 18:01:31 EST

Correct website address for patches is:

http://jeffmerkey.github.io/linux
http://www.jeffmerkey.com


On 12/1/15, Jeffrey Merkey <jeffmerkey@xxxxxxxxx> wrote:
> I am in process of completing testing all the branches. If you find a
> bug or have a problem with a build, then feel free to push a change to
> the git repo on github.com at https://github.com/jeffmerkey/linux.
> See the logs in the git repo for info on changes.
>
> Patches are available from github. To download patches and diffs, go to:
>
> http://jeffmerkey.github.io
>
> MDB (The Minimal Kernel Debugger) was written in 1998 and was one of
> the earliest debuggers on Linux. It was originally developed for Linux
> kernel file system development on the 2.2 series Linux kernels. MDB is
> a tool I wrote for my own use and development since at the time, Linux
> had no kernel debugger. MDB was open sourced in 2000. Over the years,
> I shared this tool with friends and co-workers, and continued to
> enhance it. Linux has since grown up and has several debugging tools
> available including KGDB and KDB.
>
> MDB supports a lot of features and capabilities and enhances the range
> of tools for debugging kernel applications on Linux. If MDB is useful
> to you, please feel free to contribute any changes or enhancements
> back. Currently MDB supports x86 and x86_64, but can be easily ported
> to other architectures.
>
> MDB is fast, loads as a module, and supports complex conditional
> breakpoints and disassembly on the fly, and is extremely useful for
> debugging in the field. It's also a great example of how to write a
> self-contained modular debugger that can load as a kernel module on
> Linux. MDB has an open plug and play architecture and you can add
> custom commands easily to the code, or support for other
> architectures.
>
> MDB uses the Native Linux Breakpoint API, which is platform
> independent. The current architecture support module in the debugger
> has all the code stubs for disassembly across all gcc compiler
> supported platforms, and simply require the specific gdb disassembly
> code sections for each architecture added to support that particular
> processor. Anyone interested in doing so feel free to fork this repo
> and have fun!
> Download
>
> Linux 4.X Diffs and Patches
>
> Linux v4.3 : mdb-v4.3-x86_64.diff : mdb-v4.3-x86_64.patch
> Linux v4.2 : mdb-v4.2-x86_64.diff : mdb-v4.2-x86_64.patch
> Linux v4.1 : mdb-v4.1-x86_64.diff : mdb-v4.1-x86_64.patch
> Linux v4.0 : mdb-v4.0-x86_64.diff : mdb-v4.0-x86_64.patch
>
> Linux 3.X Diffs and Patches
>
> Linux v3.19 : mdb-v3.19-x86_64.diff : mdb-v3.19-x86_64.patch
> Linux v3.18 : mdb-v3.18-x86_64.diff : mdb-v3.18-x86_64.patch
> Linux v3.17 : mdb-v3.17-x86_64.diff : mdb-v3.17-x86_64.patch
> Linux v3.16 : mdb-v3.16-x86_64.diff : mdb-v3.16-x86_64.patch
> Linux v3.15 : mdb-v3.15-x86_64.diff : mdb-v3.15-x86_64.patch
> Linux v3.14 : mdb-v3.14-x86_64.diff : mdb-v3.14-x86_64.patch
> Linux v3.13 : mdb-v3.13-x86_64.diff : mdb-v3.13-x86_64.patch
> Linux v3.12 : mdb-v3.12-x86_64.diff : mdb-v3.12-x86_64.patch
> Linux v3.11 : mdb-v3.11-x86_64.diff : mdb-v3.11-x86_64.patch
> Linux v3.10 : mdb-v3.10-x86_64.diff : mdb-v3.10-x86_64.patch
> Linux v3.9 : mdb-v3.9-x86_64.diff : mdb-v3.9-x86_64.patch
> Linux v3.8 : mdb-v3.8-x86_64.diff : mdb-v3.8-x86_64.patch
> Linux v3.7 : mdb-v3.7-x86_64.diff : mdb-v3.7-x86_64.patch
> Linux v3.6 : mdb-v3.6-x86_64.diff : mdb-v3.6-x86_64.patch
> Linux v3.5 : mdb-v3.5-x86_64.diff : mdb-v3.5-x86_64.patch
> Linux v3.4 : mdb-v3.4-x86_64.diff : mdb-v3.4-x86_64.patch
> Linux v3.3 : mdb-v3.3-x86_64.diff : mdb-v3.3-x86_64.patch
> Linux v3.2 : mdb-v3.2-x86_64.diff : mdb-v3.2-x86_64.patch
> Linux v3.1 : mdb-v3.1-x86_64.diff : mdb-v3.1-x86_64.patch
> Linux v3.0 : mdb-v3.0-x86_64.diff : mdb-v3.0-x86_64.patch
>
> MDB Linux Kernel Debugger Branches
>
> Linux 4.X Branches
>
> Linux kernel v4.3 (https://github.com/jeffmerkey/linux/tree/mdb-v4.3)
> Linux kernel v4.2 (https://github.com/jeffmerkey/linux/tree/mdb-v4.2)
> Linux kernel v4.1 (https://github.com/jeffmerkey/linux/tree/mdb-v4.1)
> Linux kernel v4.0 (https://github.com/jeffmerkey/linux/tree/mdb-v4.0)
>
> Linux 3.X Branches
>
> Linux kernel v3.19 (https://github.com/jeffmerkey/linux/tree/mdb-v3.19)
> Linux kernel v3.18 (https://github.com/jeffmerkey/linux/tree/mdb-v3.18)
> Linux kernel v3.17 (https://github.com/jeffmerkey/linux/tree/mdb-v3.17)
> Linux kernel v3.16 (https://github.com/jeffmerkey/linux/tree/mdb-v3.16)
> Linux kernel v3.15 (https://github.com/jeffmerkey/linux/tree/mdb-v3.15)
> Linux kernel v3.14 (https://github.com/jeffmerkey/linux/tree/mdb-v3.14)
> Linux kernel v3.13 (https://github.com/jeffmerkey/linux/tree/mdb-v3.13)
> Linux kernel v3.12 (https://github.com/jeffmerkey/linux/tree/mdb-v3.12)
> Linux kernel v3.11 (https://github.com/jeffmerkey/linux/tree/mdb-v3.11)
> Linux kernel v3.10 (https://github.com/jeffmerkey/linux/tree/mdb-v3.10)
> Linux kernel v3.9 (https://github.com/jeffmerkey/linux/tree/mdb-v3.9)
> Linux kernel v3.8 (https://github.com/jeffmerkey/linux/tree/mdb-v3.8)
> Linux kernel v3.7 (https://github.com/jeffmerkey/linux/tree/mdb-v3.7)
> Linux kernel v3.6 (https://github.com/jeffmerkey/linux/tree/mdb-v3.6)
> Linux kernel v3.5 (https://github.com/jeffmerkey/linux/tree/mdb-v3.5)
> Linux kernel v3.4 (https://github.com/jeffmerkey/linux/tree/mdb-v3.4)
> Linux kernel v3.3 (https://github.com/jeffmerkey/linux/tree/mdb-v3.3)
> Linux kernel v3.2 (https://github.com/jeffmerkey/linux/tree/mdb-v3.2)
> Linux kernel v3.1 (https://github.com/jeffmerkey/linux/tree/mdb-v3.1)
> Linux kernel v3.0 (https://github.com/jeffmerkey/linux/tree/mdb-v3.0)
>
> Installation
>
> Download the diff which matches your particular linux version, then
> apply the patch from your linux build directory. To download the diff
> and convert it into a patch file, click on the link for your kernel
> version for your system, then the patch text will display in your
> browser window, use your mouse to right click, then save as and save
> the patch into any filename you wish. It does not matter what filename
> you save the file under, you can choose any filename you wish, so long
> as it matches the filename you specify when you run the patch utility.
> To patch the kernel, from the linux build directory, type:
>
> (linux build directory) patch -p1 < filename.diff
>
> then type
>
> make oldconfig
>
> make bzImage modules modules_install install
>
> You can also type "make menuconfig" to manually adjust kernel settings
> for your debugger under the section "Kernel Hacking". After the kernel
> rebuilds, reboot your system to the new kernel and you can load MDB as
> a module.
> Loading MDB
>
> To load MDB as a module, type:
>
> modprobe mdb
>
> To enter the debugger type:
>
> echo a > /proc/sysrq-trigger
>
> The debugger has excellent online help, just type 'h' or 'help' from
> the debugger console for a list of commands. For help with a specific
> command, just type 'help (command)' where (command) is the command you
> need help with.
> Disabling KDB/KGDB
>
> You need to check whether or not another kernel debugger is active on
> the system, and if so, disable it. Both the KGDB and KDB debuggers are
> available as default build options on Linux. Only one debugger can be
> running at a time on the system to function properly. Don't try to run
> MDB if KDB or KGDB are active, disable them first. If MDB is compiled
> as a module, during module loading MDB will attempt to disable
> KGDB/KDB if it detects either is active. You may see something like
> this in your /var/log/messages file after the module loads which
> indicates it detected and disabled KGDB or KDB:
>
> Nov 30 10:28:49 localhost kernel: KGDB: Registered I/O driver kgdboc
> Nov 30 10:28:52 localhost kernel: MDB: kgdb currently set to
> [kdb], attempting to disable.
> Nov 30 10:28:52 localhost kernel: KGDB: Unregistered I/O driver
> kgdboc, debugger disabled
> Nov 30 10:28:52 localhost kernel: MDB: kgdb/kdb set to disabled.
> MDB is enabled.
>
> By default, MDB will always compile as a module unless you select it
> to compile directly into the kernel. If MDB is compiled in the kernel
> directly, you may need to check whether KGDB/KDB have been enabled
> before activating the MDB debugger.
>
> To check whether kdb or kgdb are running on your system, type:
>
> cat /sys/module/kgdboc/parameters/kgdboc
>
> if the text string "kdb", "kbd", or "tty"(some numbers) show up
> disable this interface by typing:
>
> echo "" > /sys/module/kgdboc/parameters/kgdboc
>
> which will disable kgdb and kdb and allow MDB to function correctly.
> Using Git to pull remote MDB Branches
>
> You can also use git to pull any of the debugger branches into your
> local git tree of the default linux and linux-stable git trees from
> kernel.org and build MDB directly from your tree as each branch
> corresponds to a particular kernel build and revision. To pull a
> remote branch from your local repository type:
>
> git remote add mdb https://github.com/jeffmerkey/linux.git
>
> git fetch mdb mdb-(branch version) i.e. git fetch mdb mdb-v4.3
>
> make certain you create a local branch to merge to
>
> git checkout (kernel version) i.e. git checkout v4.3
>
> git branch (mdb branch) i.e. git branch mdb-v4.3
>
> git checkout (mdb branch) i.e. git checkout mdb-v4.3
>
> then if you wish to commit those changes, type:
>
> git merge mdb/(branch version) i.e. git merge mdb/mdb-v4.3
>
> you can also just pull directly and skip the fetch/merge steps just
> make certain you have created and switched to a local branch to commit
> your changes into.
>
> git pull mdb mdb-(branch version) i.e. git pull mdb mdb-v4.3
>
> After you have merged your changes into your local branch, switch to
> your local linux build directory then you can build your kernel by
> typing:
>
> make oldconfig
>
> make bzImage modules modules_install install
>
> then follow the instructions above for loading MDB from the linux command
> line.
> Legacy MDB Versions (X86_64 and IA32)
>
> Linux 2.6.X Patches and Diffs (X86_64)
>
> Linux v2.6.37 : mdb-v2.6.37-x86_64.diff : mdb-v2.6.37-x86_64.patch
> Linux v2.6.36 : mdb-v2.6.36-x86_64.diff : mdb-v2.6.36-x86_64.patch
> Linux v2.6.35 : mdb-v2.6.35-x86_64.diff : mdb-v2.6.35-x86_64.patch
> Linux v2.6.34 : mdb-v2.6.34-x86_64.diff : mdb-v2.6.34-x86_64.patch
> Linux v2.6.33 : mdb-v2.6.33-x86_64.diff : mdb-v2.6.33-x86_64.patch
> Linux v2.6.32 : mdb-v2.6.32-x86_64.diff : mdb-v2.6.32-x86_64.patch
> Linux v2.6.31 : mdb-v2.6.31-x86_64.diff : mdb-v2.6.31-x86_64.patch
> Linux v2.6.30 : mdb-v2.6.30-x86_64.diff : mdb-v2.6.30-x86_64.patch
> Linux v2.6.29 : mdb-v2.6.29-x86_64.diff : mdb-v2.6.29-x86_64.patch
> Linux v2.6.28 : mdb-v2.6.28-x86_64.diff : mdb-v2.6.28-x86_64.patch
>
> Linux 2.6.X Branches (X86_64)
>
> Linux kernel v2.6.37
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.37)
> Linux kernel v2.6.36
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.36)
> Linux kernel v2.6.35
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.35)
> Linux kernel v2.6.34
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.34)
> Linux kernel v2.6.33
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.33)
> Linux kernel v2.6.32
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.32)
> Linux kernel v2.6.31
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.31)
> Linux kernel v2.6.30
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.30)
> Linux kernel v2.6.29
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.29)
> Linux kernel v2.6.28
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.28)
>
> Legacy MDB Patches and Diffs (IA32 Only)
>
> These versions are for older kernels and support IA32 only. They do
> not support x86_64 based systems.
>
> mdb-v2.6.27-ia32.diff : mdb-v2.6.27-ia32.patch
> mdb-v2.6.26-ia32.diff : mdb-v2.6.26-ia32.patch
> mdb-v2.6.25-ia32.diff : mdb-v2.6.25-ia32.patch
> mdb-v2.6.24-ia32.diff : mdb-v2.6.24-ia32.patch
> mdb-v2.6.23-ia32.diff : mdb-v2.6.23-ia32.patch
> mdb-v2.6.22-ia32.diff : mdb-v2.6.22-ia32.patch
> mdb-v2.6.21-ia32.diff : mdb-v2.6.21-ia32.patch
> mdb-v2.6.20-ia32.diff : mdb-v2.6.20-ia32.patch
> mdb-v2.6.19-ia32.diff : mdb-v2.6.19-ia32.patch
> mdb-v2.6.18-ia32.diff : mdb-v2.6.18-ia32.patch
>
> Legacy MDB Branches (IA32 Only)
>
> Linux kernel v2.6.27
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.27)
> Linux kernel v2.6.26
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.26)
> Linux kernel v2.6.25
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.25)
> Linux kernel v2.6.24
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.24)
> Linux kernel v2.6.23
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.23)
> Linux kernel v2.6.22
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.22)
> Linux kernel v2.6.21
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.21)
> Linux kernel v2.6.20
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.20)
> Linux kernel v2.6.19
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.19)
> Linux kernel v2.6.18
> (https://github.com/jeffmerkey/linux/tree/mdb-v2.6.18)
>
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