This will greatly enhance the usefulness of QEMU virtual serial ports, because the Linux kernel interprets a break on the serial console as a SysRq, but there is currently no way to pass this signal over a pseudo-terminal.
This project is part of:
Hack Week 11
Activity
Comments
Similar Projects
Add a machine-readable output to dmidecode by jdelvare
Description
There have been repeated requests for a machine-friendly dmidecode output over the last decade. During Hack Week 19, 5 years ago, I prepared the code to support alternative output formats, but didn't have the time to go further. Last year, Jiri Hnidek from Red Hat Linux posted a proof-of-concept implementation to add JSON output support. This is a fairly large pull request which needs to be carefully reviewed and tested.
Goals
Review Jiri's work and provide constructive feedback. Merge the code if acceptable. Evaluate the costs and benefits of using a library such as json-c.
FastFileCheck work by pstivanin
Description
FastFileCheck is a high-performance, multithreaded file integrity checker for Linux. Designed for speed and efficiency, it utilizes parallel processing and a lightweight database to quickly hash and verify large volumes of files, ensuring their integrity over time.
https://github.com/paolostivanin/FastFileCheck
Goals
- Release v1.0.0
Design overwiew:
- Main thread (producer): traverses directories and feeds the queue (one thread is more than enough for most use cases)
- Dedicated consumer thread: manages queue and distributes work to threadpool
- Worker threads: compute hashes in parallel
This separation of concerns is efficient because:
- Directory traversal is I/O bound and works well in a single thread
- Queue management is centralized, preventing race conditions
- Hash computation is CPU-intensive and properly parallelized
FizzBuzz OS by mssola
Project Description
FizzBuzz OS (or just fbos
) is an idea I've had in order to better grasp the fundamentals of the low level of a RISC-V machine. In practice, I'd like to build a small Operating System kernel that is able to launch three processes: one that simply prints "Fizz", another that prints "Buzz", and the third which prints "FizzBuzz". These processes are unaware of each other and it's up to the kernel to schedule them by using the timer interrupts as given on openSBI (fizz on % 3 seconds, buzz on % 5 seconds, and fizzbuzz on % 15 seconds).
This kernel provides just one system call, write
, which allows any program to pass the string to be written into stdout.
This project is free software and you can find it here.
Goal for this Hackweek
- Better understand the RISC-V SBI interface.
- Better understand RISC-V in privileged mode.
- Have fun.
Resources
Results
The project was a resounding success Lots of learning, and the initial target was met.
ESETv2 Emulator / interpreter by m.crivellari
Description
ESETv2 is an intriguing challenge developed by ESET, available on their website under the "Challenge" menu.
The challenge involves an "assembly-like" language and a Python compiler that generates .evm
binary files.
This is an example using one of their samples (it prints N Fibonacci numbers):
.dataSize 0
.code
loadConst 0, r1 # first
loadConst 1, r2 # second
loadConst 1, r14 # loop helper
consoleRead r3
loop:
jumpEqual end, r3, r15
add r1, r2, r4
mov r2, r1
mov r4, r2
consoleWrite r1
sub r3, r14, r3
jump loop
end:
hlt
This language also supports multi-threading. It includes instructions such as createThread
to start a new thread, joinThread
to wait until a thread completes, and lock
/unlock
to facilitate synchronization between threads.
Goals
- create a full interpreter able to run all the available samples provided by ESET.
- improve / optimize memory (eg. using bitfields where needed as well as avoid unnecessary memory allocations)
Resources
- Challenge URL: https://join.eset.com/en/challenges/core-software-engineer
- My github project: https://github.com/DispatchCode/eset_vm2 (not 100% complete)
Achivements
Project still not complete. Added lock / unlock instruction implementation but further debug is needed; there is a bug somewhere. Actually the code it works for almost all the examples in the samples folder. 1 of them is not yet runnable (due to a missing "write" opcode implementation), another will cause the bug to show up; still not investigated, anyhow.
Improve UML page fault handler by ptesarik
Description
Improve UML handling of segmentation faults in kernel mode. Although such page faults are generally caused by a kernel bug, it is annoying if they cause an infinite loop, or panic the kernel. More importantly, a robust implementation allows to write KUnit tests for various guard pages, preventing potential kernel self-protection regressions.
Goals
Convert the UML page fault handler to use oops_* helpers, go through a few review rounds and finally get my patch series merged in 6.14.
Resources
Wrong initial attempt: https://lore.kernel.org/lkml/20231215121431.680-1-petrtesarik@huaweicloud.com/T/
Hacking on sched_ext by flonnegren
Description
Sched_ext upstream has some interesting issues open for grabs:
Goals
Send patches to sched_ext upstream
Also set up perfetto to trace some of the example schedulers.
Resources
https://github.com/sched-ext/scx
Contributing to Linux Kernel security by pperego
Description
A couple of weeks ago, I found this blog post by Gustavo Silva, a Linux Kernel contributor.
I always strived to start again into hacking the Linux Kernel, so I asked Coverity scan dashboard access and I want to contribute to Linux Kernel by fixing some minor issues.
I want also to create a Linux Kernel fuzzing lab using qemu and syzkaller
Goals
- Fix at least 2 security bugs
- Create the fuzzing lab and having it running
The story so far
- Day 1: setting up a virtual machine for kernel development using Tumbleweed. Reading a lot of documentation, taking confidence with Coverity dashboard and with procedures to submit a kernel patch
- Day 2: I read really a lot of documentation and I triaged some findings on Coverity SAST dashboard. I have to confirm that SAST tool are great false positives generator, even for low hanging fruits.
- Day 3: Working on trivial changes after I read this blog post:
https://www.toblux.com/posts/2024/02/linux-kernel-patches.html. I have to take confidence
with the patch preparation and submit process yet.
- First trivial patch sent: using strtruefalse() macro instead of hard-coded strings in a staging driver for a lcd display
- Fix for a dereference before null check issue discovered by Coverity (CID 1601566) https://scan7.scan.coverity.com/#/project-view/52110/11354?selectedIssue=1601566
- Day 4: Triaging more issues found by Coverity.
- The patch for CID 1601566 was refused. The check against the NULL pointer was pointless so I prepared a version 2 of the patch removing the check.
- Fixed another dereference before NULL check in iwlmvmparsewowlaninfo_notif() routine (CID 1601547). This one was already submitted by another kernel hacker :(
- Day 5: Wrapping up. I had to do some minor rework on patch for CID 1601566. I found a stalker bothering me in private emails and people I interacted with me, advised he is a well known bothering person. Markus Elfring for the record.
Wrapping up: being back doing kernel hacking is amazing and I don't want to stop it. My battery pack is completely drained but changing the scope gave me a great twist and I really want to feel this energy not doing a single task for months.
I failed in setting up a fuzzing lab but I was too optimistic for the patch submission process.
The patches
RISC-V emulator in GLSL capable of running Linux by favogt
Description
There are already numerous ways to run Linux and some programs through emulation in a web browser (e.g. x86 and riscv64 on https://bellard.org/jslinux/), but none use WebGL/WebGPU to run the emulation on the GPU.
I already made a PoC of an AArch64 (64-bit Arm) emulator in OpenCL which is unfortunately hindered by a multitude of OpenCL compiler bugs on all platforms (Intel with beignet or the new compute runtime and AMD with Mesa Clover and rusticl). With more widespread and thus less broken GLSL vs. OpenCL and the less complex implementation requirements for RV32 (especially 32bit integers instead of 64bit), that should not be a major problem anymore.
Goals
Write an RISC-V system emulator in GLSL that is capable of booting Linux and run some userspace programs interactively. Ideally it is small enough to work on online test platforms like Shaderoo with a custom texture that contains bootstrap code, kernel and initrd.
Minimum:
riscv32 without FPU (RV32 IMA) and MMU (µClinux), running Linux in M-mode and userspace in U-mode.
Stretch goals:
FPU support, S-Mode support with MMU, SMP. Custom web frontend with more possibilities for I/O (disk image, network?).
Resources
RISC-V ISA Specifications
Shaderoo
OpenGL 4.5 Quick Reference Card
Result as of Hackweek 2024
WebGL turned out to be insufficient, it only supports OpenGL ES 3.0 but imageLoad/imageStore needs ES 3.1. So we switched directions and had to write a native C++ host for the shaders.
As of Hackweek Friday, the kernel attempts to boot and outputs messages, but panics due to missing memory regions.
Since then, some bugs were fixed and enough hardware emulation implemented, so that now Linux boots with framebuffer support and it's possible to log in and run programs!
The repo with a demo video is available at https://github.com/Vogtinator/risky-v
Officially Become a Kernel Hacker! by m.crivellari
Description
My studies as well my spare time are dedicated to the Linux Kernel. Currently I'm focusing on interrupts on x86_64, but my interests are not restricted to one specific topic, for now.
I also "played" a little bit with kernel modules (ie lantern, a toy packet analyzer) and I've added a new syscall in order read from a task A, the memory of a task B.
Maybe this will be a good chance to...
Goals
- create my first kernel patch
Resources
- https://www.kernel.org/doc/html/latest/process/submitting-patches.html
- https://git-send-email.io/ (mentioned also in the kernel doc)
- https://javiercarrascocruz.github.io/kernel-contributor-1
Achivements
- found while working on a bug, this is the 1st patch: cifs: avoid deadlocks while updating iface [✅ has been merged]