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/

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Linux on Cavium CN23XX cards by tsbogend

Before Cavium switched to ARM64 CPUs they developed quite powerful MIPS based SOCs. The current upstream Linux kernel already supports some Octeon SOCs, but not the latest versions. Goal of this Hack Week project is to use the latest Cavium SDK to update the Linux kernel code to let it running on CN23XX network cards.

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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.

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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.

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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]

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Create a DRM driver for VGA video cards by tdz

Yes, those VGA video cards. The goal of this project is to implement a DRM graphics driver for such devices. While actual hardware is hard to obtain or even run today, qemu emulates VGA output.

VGA has a number of limitations, which make this project interesting.

• There are only 640x480 pixels (or less) on the screen. That resolution is also a soft lower limit imposed by DRM. It's mostly a problem for desktop environments though.
• Desktop environments assume 16 million colors, but there are only 16 colors with VGA. VGA's 256 color palette is not available at 640x480. We can choose those 16 colors freely. The interesting part is how to choose them. We have to build a palette for the displayed frame and map each color to one of the palette's 16 entries. This is called dithering, and VGA's limitations are a good opportunity to learn about dithering algorithms.
• VGA has an interesting memory layout. Most graphics devices use linear framebuffers, which store the pixels byte by byte. VGA uses 4 bitplanes instead. Plane 0 holds all bits 0 of all pixels. Plane 1 holds all bits 1 of all pixels, and so on.

The driver will probably not be useful to many people. But, if finished, it can serve as test environment for low-level hardware. There's some interest in supporting old Amiga and Atari framebuffers in DRM. Those systems have similar limitations as VGA, but are harder to obtain and test with. With qemu, the VGA driver could fill this gap.

Apart from the Wikipedia entry, good resources on VGA are at osdev.net and FreeVGA

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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.

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