SUSE Hack Week: Out-of-the-box SPD support

In order to see the SPD (detailed memory information) data, the user currently has to manually load the needed kernel driver. Which driver to load depends on the memory type. Depending on the driver user, the devices may even have to be instantiated manually and this is a non-trivial multi-step task. Plus you need to be root to do it.

I would like to attempt to automatize all this at least in the most common and simple cases like Intel x86 desktop. The idea would be to figure out the memory type and the I2C address of the SPD EEPROMs based on DMI data. If the DMI data is of good quality then it should be possible to automatically figure out which driver to use and to instantiate the devices at boot time.

If this works then running "decode-dimms" (or any other equivalent tool) should just work after boot without any preparatory work, for all users.

I plan to start implementing this for DDR3 memory and the i2c-i801 SMBus controller driver because that's what I have on my workstation. If it works, doing the same for DDR4 shouldn't be too difficult. Once this works for the i2c-i801, it should be pretty trivial to do the same with other SMBus controller drivers, for example i2c-piix4.

Excluded from the scope are large server systems with multiple SMBus controllers or multiplexed SMBus. Also excluded are OF/DT systems as I would expect SPD EEPROMs to be declared in the device tree so they would already be instantiated without further effort.

Looking for hackers with the skills:

i2c-tools kernel smbus dmi

This project is part of:

Hack Week 18

Activity

almost 5 years ago: jdelvare started this project.

over 5 years ago: a_faerber liked this project.

over 5 years ago: jdelvare added keyword "i2c-tools" to this project.

over 5 years ago: jdelvare added keyword "kernel" to this project.

over 5 years ago: jdelvare added keyword "smbus" to this project.

over 5 years ago: jdelvare added keyword "dmi" to this project.

over 5 years ago: jdelvare originated this project.

Comments

over 3 years ago by jdelvare | Reply

For the record, this hack week project was successful. Relevant upstream kernel commits:

commit 9e0afe3910ff7e5493c5d8ebe3b499994b5e0272
Author: Jean Delvare 
Date:   Tue Dec 3 11:20:37 2019 +0100

    firmware: dmi: Remember the memory type

commit 7c2378800cf7ac87e2663afa7f39d102871f0c28
Author: Jean Delvare 
Date:   Tue Dec 3 11:20:37 2019 +0100

    firmware: dmi: Add dmi_memdev_handle

commit 5ace60859e84113b7a185c117fbf2c429d381b59
Author: Jean Delvare 
Date:   Mon Mar 16 11:22:24 2020 +0100

    i2c: smbus: Add a way to instantiate SPD EEPROMs automatically

commit 01590f361e94a01e9b9868fa81d4079d255c681f
Author: Jean Delvare 
Date:   Mon Mar 16 11:24:48 2020 +0100

    i2c: i801: Instantiate SPD EEPROMs automatically

So the feature is supported since kernel v5.8. Next step is to extend support to systems with 5-8 memory slots (still on a single SMBus segment), and to add support to other SMBus controller drivers.

For the record, this hack week project was successful. Relevant upstream kernel commits:

commit 9e0afe3910ff7e5493c5d8ebe3b499994b5e0272
Author: Jean Delvare 
Date:   Tue Dec 3 11:20:37 2019 +0100

    firmware: dmi: Remember the memory type

commit 7c2378800cf7ac87e2663afa7f39d102871f0c28
Author: Jean Delvare 
Date:   Tue Dec 3 11:20:37 2019 +0100

    firmware: dmi: Add dmi_memdev_handle

commit 5ace60859e84113b7a185c117fbf2c429d381b59
Author: Jean Delvare 
Date:   Mon Mar 16 11:22:24 2020 +0100

    i2c: smbus: Add a way to instantiate SPD EEPROMs automatically

commit 01590f361e94a01e9b9868fa81d4079d255c681f
Author: Jean Delvare 
Date:   Mon Mar 16 11:24:48 2020 +0100

    i2c: i801: Instantiate SPD EEPROMs automatically

So the feature is supported since kernel v5.8. Next step is to extend support to systems with 5-8 memory slots (still on a single SMBus segment), and to add support to other SMBus controller drivers.

# A First Level Header
## A Second Level Header

Use one asterisk to *emphasize*

Use two asterisks for **strong emphasis**

- Use hyphens
- for unordereed
- lists

This is an [link to example.com](http://example.com/)

This is an image ![an openSUSE geeko icon](https://en.opensuse.org/images/d/d0/Icon-distribution.png)

This is a user link @hans

This is a project link hw#some-cool-title

More Complex Markdown Help

Formatting Help

Similar Projects

kernel

Modularization and Modernization of cifs.ko for Enhanced SMB Protocol Support by hcarvalho

Creator:
Enzo Matsumiya ematsumiya@suse.de @ SUSE Samba team
Members:
Henrique Carvalho henrique.carvalho@suse.com @ SUSE Samba team

Description

Split cifs.ko in 2 separate modules; one for SMB 1.0 and 2.0.x, and another for SMB 2.1, 3.0, and 3.1.1.

Goals

Primary

Start phasing out/deprecation of older SMB versions

Secondary

Clean up of the code (with focus on the newer versions)
Update cifs-utils
Update documentation
Improve backport workflow (see below)

Technical details

Ideas for the implementation.

fs/smb/client/{old,new}.c to generate the respective modules
- Maybe don't create separate folders? (re-evaluate as things progresses!)
Remove server->{ops,vals} if possible
Clean up fs_context.* -- merge duplicate options into one, handle them in userspace utils
Reduce code in smb2pdu.c -- tons of functions with very similar init/setup -> send/recv -> handle/free flow
Restructure multichannel
- Treat initial connection as "channel 0" regardless of multichannel enabled/negotiated status, proceed with extra channels accordingly
- Extra channel just point to "channel 0" as the primary server, no need to allocate an extra TCPServerInfo for each one
Authentication mechanisms
- Modernize algorithms (references: himmelblau, IAKERB/Local KDC, SCRAM, oauth2 (Azure), etc.

Model checking the BPF verifier by shunghsiyu

Project Description

BPF verifier plays a crucial role in securing the system (though less so now that unprivileged BPF is disabled by default in both upstream and SLES), and bugs in the verifier has lead to privilege escalation vulnerabilities in the past (e.g. CVE-2021-3490).

One way to check whether the verifer has bugs to use model checking (a formal verification technique), in other words, build a abstract model of how the verifier operates, and then see if certain condition can occur (e.g. incorrect calculation during value tracking of registers) by giving both the model and condition to a solver.

For the solver I will be using the Z3 SMT solver to do the checking since it provide a Python binding that's relatively easy to use.

Goal for this Hackweek

Learn how to use the Z3 Python binding (i.e. Z3Py) to build a model of (part of) the BPF verifier, probably the part that's related to value tracking using tristate numbers (aka tnum), and then check that the algorithm work as intended.

Resources

Formal Methods for the Informal Engineer: Tutorial #1 - The Z3 Theorem Prover and its accompanying notebook is a great introduction into Z3
- Has a section specifically on model checking
Software Verification and Analysis Using Z3 a great example of using Z3 for model checking
Sound, Precise, and Fast Abstract Interpretation with Tristate Numbers - existing work that use formal verification to prove that the multiplication helper used for value tracking work as intended
[PATCH v5 net-next 00/12] bpf: rewrite value tracking in verifier - initial patch set that adds tristate number to the verifier

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

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

Resources

The dashboard

The serie of blog posts by Gustavo Silva inspiring this project.

An email with some quick "where to start" instructions The patchset philosophy

Create DRM drivers for VESA and EFI framebuffers by tdz

Description

We already have simpledrm for firmware framebuffers. But the driver is originally for ARM boards, not PCs. It is already overloaded with code to support both use cases. At the same time it is missing possible features for VESA and EFI, such as palette modes or EDID support. We should have DRM drivers for VESA and EFI interfaces. The infrastructure exists already and initial drivers can be forked from simpledrm.

Goals

Initially, a bare driver for VESA or EFI should be created. It can take functionality from simpledrm.
Then we can begin to add additional features. The boot loader can provide EDID data. With VGA hardware, VESA can support paletted modes or color management. Example code exists in vesafb.