drgn

April 6, 2026 · View on GitHub

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.. |ci badge| image:: https://github.com/osandov/drgn/workflows/CI/badge.svg :target: https://github.com/osandov/drgn/actions :alt: CI Status

.. |docs badge| image:: https://readthedocs.org/projects/drgn/badge/?version=latest :target: https://drgn.readthedocs.io/en/latest/?badge=latest :alt: Documentation Status

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.. start-introduction

drgn (pronounced "dragon") is a debugger with an emphasis on programmability. drgn exposes the types and variables in a program for easy, expressive scripting in Python. For example, you can debug the Linux kernel:

.. code-block:: pycon

>>> from drgn.helpers.linux import list_for_each_entry
>>> for mod in list_for_each_entry('struct module',
...                                prog['modules'].address_of_(),
...                                'list'):
...    if mod.refcnt.counter > 10:
...        print(mod.name)
...
(char [56])"snd"
(char [56])"evdev"
(char [56])"i915"

Although other debuggers like GDB <https://www.gnu.org/software/gdb/>_ have scripting support, drgn aims to make scripting as natural as possible so that debugging feels like coding. This makes it well-suited for introspecting the complex, inter-connected state in large programs.

Additionally, drgn is designed as a library that can be used to build debugging and introspection tools; see the official tools <https://github.com/osandov/drgn/tree/main/tools>_.

drgn was developed at Meta <https://opensource.fb.com/>_ for debugging the Linux kernel (as an alternative to the crash <https://crash-utility.github.io/>_ utility), but it can also debug userspace programs written in C. C++ support is in progress.

.. end-introduction

Documentation can be found at drgn.readthedocs.io <https://drgn.readthedocs.io>_.

.. start-installation

Installation

Package Manager ^^^^^^^^^^^^^^^

drgn can be installed using the package manager on some Linux distributions.

.. image:: https://repology.org/badge/vertical-allrepos/drgn.svg?exclude_unsupported=1 :target: https://repology.org/project/drgn/versions :alt: Packaging Status

Fedora, RHEL/CentOS Stream >= 9

.. code-block:: console
```
$ sudo dnf install drgn
```
RHEL/CentOS < 9

Enable EPEL <https://docs.fedoraproject.org/en-US/epel/#_quickstart>_. Then:

.. code-block:: console
```
$ sudo dnf install drgn
```
Oracle Linux >= 8

Enable the ol8_addons or ol9_addons repository. Then:

.. code-block:: console
```
$ sudo dnf config-manager --enable ol8_addons  # OR: ol9_addons
$ sudo dnf install drgn
```
drgn is also available for Python versions in application streams. For example, use dnf install python3.12-drgn to install drgn for Python 3.12. See the documentation for drgn in Oracle Linux 9 <https://docs.oracle.com/en/operating-systems/oracle-linux/9/drgn/how_to_install_drgn.html>_ and Oracle Linux 8 <https://docs.oracle.com/en/operating-systems/oracle-linux/8/drgn/how_to_install_drgn.html>_ for more information.
Debian >= 12 (Bookworm)/Ubuntu >= 24.04 (Noble Numbat)

.. code-block:: console
```
$ sudo apt install python3-drgn
```
To get the latest version on Ubuntu, enable the michel-slm/kernel-utils PPA <https://launchpad.net/~michel-slm/+archive/ubuntu/kernel-utils>_ first.
Arch Linux

.. code-block:: console
```
$ sudo pacman -S drgn
```
Gentoo

.. code-block:: console
```
$ sudo emerge dev-debug/drgn
```
openSUSE

.. code-block:: console
```
$ sudo zypper install python3-drgn
```

pip ^^^

If your Linux distribution doesn't package the latest release of drgn, you can install it with pip <https://pip.pypa.io/>_.

First, install pip <https://packaging.python.org/guides/installing-using-linux-tools/#installing-pip-setuptools-wheel-with-linux-package-managers>_. Then, run:

.. code-block:: console

$ sudo pip3 install drgn

This will install a binary wheel by default. If you get a build error, then pip wasn't able to use the binary wheel. Install the dependencies listed below <#from-source>_ and try again.

Note that RHEL/CentOS 7, Debian 10 ("buster"), and Ubuntu 18.04 ("Bionic Beaver") (and older) ship Python versions which are too old. Python 3.8 or newer must be installed.

.. _installation-from-source:

From Source ^^^^^^^^^^^

To get the development version of drgn, you will need to build it from source. First, install dependencies:

Fedora, RHEL/CentOS Stream >= 9

.. code-block:: console

$ sudo dnf install autoconf automake check-devel elfutils-debuginfod-client-devel elfutils-devel gcc git json-c-devel libkdumpfile-devel libtool make pcre2-devel pkgconf python3 python3-devel python3-pip python3-setuptools xz-devel

RHEL/CentOS < 9, Oracle Linux

.. code-block:: console
```
$ sudo dnf install autoconf automake check-devel elfutils-devel gcc git json-c-devel libtool make pcre2-devel pkgconf python3 python3-devel python3-pip python3-setuptools xz-devel
```
Optionally, install libkdumpfile-devel from EPEL on RHEL/CentOS >= 8 or install libkdumpfile <https://github.com/ptesarik/libkdumpfile>_ from source if you want support for the makedumpfile format. For Oracle Linux >= 7, libkdumpfile-devel can be installed directly from the corresponding addons repository (e.g. ol9_addons).

Replace dnf with yum for RHEL/CentOS/Oracle Linux < 8.

When building on RHEL/CentOS/Oracle Linux < 8, you may need to use a newer version of GCC, for example, using the devtoolset-12 developer toolset. Check your distribution's documentation for information on installing and using these newer toolchains.

Debian/Ubuntu

.. code-block:: console

$ sudo apt install autoconf automake check gcc git libdebuginfod-dev libjson-c-dev libkdumpfile-dev liblzma-dev libelf-dev libdw-dev libpcre2-dev libtool make pkgconf python3 python3-dev python3-pip python3-setuptools zlib1g-dev

On Debian <= 11 (Bullseye) and Ubuntu <= 22.04 (Jammy Jellyfish), libkdumpfile-dev is not available, so you must install libkdumpfile from source if you want support for the makedumpfile format.

Arch Linux

.. code-block:: console

$ sudo pacman -S --needed autoconf automake check gcc git json-c libelf libkdumpfile libtool make pcre2 pkgconf python python-pip python-setuptools xz

Gentoo

.. code-block:: console

$ sudo emerge --noreplace --oneshot dev-build/autoconf dev-build/automake dev-libs/check dev-libs/elfutils dev-libs/json-c dev-libs/libpcre2 sys-devel/gcc dev-vcs/git dev-libs/libkdumpfile dev-build/libtool dev-build/make dev-python/pip virtual/pkgconfig dev-lang/python dev-python/setuptools app-arch/xz-utils

openSUSE

.. code-block:: console

$ sudo zypper install autoconf automake check-devel gcc git libdebuginfod-devel libdw-devel libelf-devel libjson-c-devel libkdumpfile-devel libtool make pcre2-devel pkgconf python3 python3-devel python3-pip python3-setuptools xz-devel

Then, run:

.. code-block:: console

$ git clone https://github.com/osandov/drgn.git
$ cd drgn
$ python3 setup.py build
$ sudo python3 setup.py install

.. end-installation

See the installation documentation <https://drgn.readthedocs.io/en/latest/installation.html>_ for more options.

Quick Start

.. start-quick-start

drgn debugs the running kernel by default; simply run drgn. To debug a running program, run drgn -p $PID. To debug a core dump (either a kernel vmcore or a userspace core dump), run drgn -c $PATH. Make sure to install debugging symbols <https://drgn.readthedocs.io/en/latest/getting_debugging_symbols.html>_ for whatever you are debugging.

Then, you can access variables in the program with prog["name"] and access structure members with .:

.. code-block:: pycon

$ drgn
>>> prog["init_task"].comm
(char [16])"swapper/0"

You can use various predefined helpers:

.. code-block:: pycon

>>> len(list(bpf_prog_for_each()))
11
>>> task = find_task(115)
>>> cmdline(task)
[b'findmnt', b'-p']

You can get stack traces with stack_trace() and access parameters or local variables with trace["name"]:

.. code-block:: pycon

>>> trace = stack_trace(task)
>>> trace[5]
#5 at 0xffffffff8a5a32d0 (do_sys_poll+0x400/0x578) in do_poll at ./fs/select.c:961:8 (inlined)
>>> poll_list = trace[5]["list"]
>>> file = fget(task, poll_list.entries[0].fd)
>>> d_path(file.f_path.address_of_())
b'/proc/115/mountinfo'

.. end-quick-start

See the user guide <https://drgn.readthedocs.io/en/latest/user_guide.html>_ for more details and features.

.. start-for-index

Getting Help

The GitHub issue tracker <https://github.com/osandov/drgn/issues>_ is the preferred method to report issues.
There is also a Linux Kernel Debuggers Matrix room <https://matrix.to/#/#linux-debuggers:matrix.org>_ and a linux-debuggers mailing list <https://lore.kernel.org/linux-debuggers/>_ on vger <https://subspace.kernel.org/vger.kernel.org.html>_.

License

drgn is licensed under the LGPLv2.1 <https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html>_ or later.

.. end-for-index