Unplugging Logitech USB Receivers Has Been Causing The Linux Kernel To Crash

[Sethox]

Did anyone bother to read the diffstat on the patch? 1 deletion and 2 additions

Srsly Bro

When I read the entire Phoronix article and then looked at the patch to read the explanation by it's developer (and the explanation is much longer than the actual lines of code in the patch) I was struck by the question:

"Do the people that write this buggy code even bother to draw out and walk through functional block diagrams of the code design before they throw keystrokes at the wall to see what will stick/compile?"

Now you know part of the reason why Linus famous outrages are worded so colorful.

In my junior class in programming (C#, because of course it is), no student (besides me) went for the higher grades and that's a problem. The fundamentals of understanding code and structure of codes, hell even building functional functions that you can reuse was not learned. It was literally spaghetti code. And the worse offense was the comments or documentation, code was just copy and pasted (because stackoverflow and AI) without even look at how it works.
The only upside is that the students at least admitted they just wanted to pass and never code again, it's just sad that students do not take in the lessons (of any course) in their lives, so much knowledge lost to the void just to get that pass grade (fundamentals can be applied other places in life, philosophy).

[sobkas]

User mountable filesystems and user plug-able USB devices have a potential to be a good candidates to move some drivers out of kernel into userspace.

[Mike Frett]

Not just that. Every time I unplug my USB hauppauge capture device, the system refuses to reboot. If I plug in a microphone after I unplug it, trying to capture sound from that mic results in corrupt audio. Not really a killer bug unless you use it all the time.

[jacob]

I manage bugzilla.kernel.org and most if not all the crashes that you've just listed have been fatal so far. Maybe you could show examples when the Linux kernel does not crash because I've yet to see those. Oopses are not fatal, but panics are panics.

That's kind of a tautology, isn't it? On Windows kernel panics are panics too.

[avis]

That's kind of a tautology, isn't it? On Windows kernel panics are panics too.

Windows can normally (i.e. in most cases) reload a crashing GPU driver, Linux just dies. What tautology are you talking about?

[user1]

"Hybrid" kernel doesn't mean much. Some people use it in the sense of a kernel that allows loadable modules (which includes pretty much everything except OpenBSD). Some use it to denote a kernel that runs internal services as active processes in kernel space (both Windows and Linux are like that), some say it's a message-passing kernel in which the various services run in kernel space (that's DragonflyBSD, but neither Windows nor Linux fit that definition, except for some specific functionalities). Some say that Windows is hybrid because it runs some drivers in Ring 1, but that's only on x86. Another definition has it that Windows id hybrid because it runs some drivers in user space (but so does Linux)...

Correct me if I'm wrong, but afaiu the main difference between hybrid and monolithic kernels is in the way they're internally designed. Hybrid kernels have a layered design which comprises a basic kernel and the other kernel services on top of it, so that it more resembles a Microkernel OS design. Monolithic kernels aren't designed this way. However, when it comes to what runs in kernel space and user space, both hybrid and monolithic kernels aren't really different. At least that's how I understand it according to this wikipedia page. I mean, in some ways, Windows is even more monolithic because part of its GUI stack runs in kernel mode, while on Linux everything related to GUI runs in user mode.

[Slartifartblast]

it just has to many wholes.

Typo: holes.

PS not very up to date are you ?

http://www.pcworld.com/article/1529986/rare-amd-radeon-driver-bug-corrupt-windows-fix.html

[MorrisS.]

Since 6.2 or some patches there issues on some USB systems. In my case the problems deals with UVC.

[Weasel]

AFAIK Linux has very little hybrid in its architecture. Correct me if I'm wrong but only FUSE (filesystem modules in user space) looks like something which you could call "hybrid", everything else about the kernel is pretty much monolithic.

Windows on the other hand has partially moved certain features from kernel space into user space, i.e. GPU drivers and since Windows Vista a GPU driver crash has normally been recoverable (AFAIK it's not limited to GPU drivers, other classes of drivers are "fixable") which is not something that's possible under Linux where any driver crash is fatal.

That has nothing to do with monolithic. To use a userspace analogy, because people are more familiar with it, "monolithic" means that the kernel is a "single process" and all the modules/drivers it loads are "libraries" brought into its own address space. Same process.

Whereas Windows for example has services and device drivers run under different "processes", even though they run at the same privilege (or something like that), because they're kernel-mode drivers after all, so it doesn't really protect against malicious drivers, but it protects against bugs (such as memory corruption or crashes), because it will only take down that "process". Needless to say, Windows' model is slower and adds overhead due to "IPC", but is "safer".

Of course there's also userspace-mode drivers but you can find those on Linux as well, they're just not what typically one thinks of drivers. Wireguard can be implemented in userspace for example. Obviously it's going to be slower.

[Volta]

Exactly correct, it is a bug in a relatively minor subsystem (as in not critical to the function of the kernel) that brings the whole kernel down. This only happens in a monolithic arch.

In the Windows hybrid arch the USB stack would fail but the system would remain online and re-init the stack.

I think ReactOS has a beter desktop chance than Linux atm.

Windows is NOT bug free... but very few bring the system down these days.

Yeah, right sherlock. In windows USB crashes your entire crap OS. You have hybrid brain it seems, because you're not aware of obvious things.

https://tencomputer.com/fix-usb-3-0-crashes-on-windows-10/

https://windospc.com/fix-usb-flash-drive-freezes-computer-when-plugged-in-issue/