gheap-jemalloc is a jemalloc plugin for gdb
gheap-jemalloc was/is being developed to aid in the debugging of heap related bugs in applications using jemalloc for linux, and also to aid in CTF challenges that focus on heap and jemalloc.
gheap-jemalloc requires that gdb be compiled with guile support
and also that jemalloc be compiled with debugging symbols.
(or at least, not stripped of symbols)
First clone the repository and then
Start gdb with the -x flag with the path to the .scm file.
> gdb /path/to/binary -x /path/to/repo/gheap-jemalloc.scm
Or from gdb itself
> gdb binary
(gdb) source /path/to/repo/gheap-jemalloc.scm
If you want to load this automatically upon gdb start up, add the
following line to your .gdbinit file:
source /path/to/repo/gheap-jemalloc.scm
where /path/to/repo is the path to the cloned git repository
After searching
the net for appropriate plugins or debuggers for heap related things
I came across quite a few but none of them worked properly. Some
were designed for firefox specifically or for android. shadow
for example, is targeted for debugging of jemalloc but somehow it
simply doesnt work with jemalloc 5.3.0 from my experience.
The goal of this project is to provide a consitent interface to inspecting, testing and debugging of the heap for applications using the linux jemalloc standalone binary.
The ultimate goal is to provide a top-notch state-of-the-art debugging exprience and tools to aid in heap debugging. Many bugs go simply unnoticed because there simply isnt a good way to visualize or inspect the heap of a running application during development.
The pwndbg project provides a great experience in aiding of debugging
heap related bugs.
Once gheap-jemalloc is considered feature complete I will move on
to implementing something simmilar for glibc as well.
There are quite a few versions of jemalloc so this project provides a gdb plugin for the standalone version of jemalloc for linux, version 5.3.0 (and up, hopefuly)
Current features are limited and only provide some basic commands, such
as jeslabs and je_narenas_total and je_nbins_total which show the slabs, number
of arenas and number of bins respectivelly.
guile was chosen for this module, because it is a scheme programming
language and because most python scripts and plugins are terrible, unreliable and slow.
This wont change so don't even ask. Python related pull-request will be rejected.
As an added bonus, guile is GNU software, so I think it fits better into the Free Software
ecosystem than python which is MIT licensed.
gheap-jemalloc provides mostly just basic features for inspecting the heap. In case you'd like support to be added for other jemalloc versions, open an issue of the format
[Linux standalone] Version request for jemalloc X.Y.Z
Where X.Y.Z is the version you'd like supported. and Linux standalone is
the OS flavor. Right now though, only the linux standalone versions are considered.
But Windows, FreeBSD and MacOS support might be added in the future.
For feature requests, open an issue of the format
[Feature request] Brief text describing the feature
For bugs:
[Bug] Brief bug description
Try to provide as much information as you can gather in your bug and feature reports (not the brief title description).
This software is licensed under the GNU GPL version 3+ license. See COPYING file for more information.
