StarDreamer

An alternative definition: a real-time system is a system where the correctness of the computation depends on a deadline. For example, if I have a drone checking “with my current location + velocity will I crash into the wall in 5 seconds?”, the answer will be worthless if the system responds 10 seconds later.

A real-time kernel is an operating system that makes it easier to build such systems. The main difference is that they offer lower latency than a usual OS for your one critical program. The OS will try to give that program as much priority as it wants (to the detriment of everything else) and immediately handle all signals ASAP (instead of coalescing/combining them to reduce overhead)

Linux has real-time priority scheduling as an optional feature. Lowering latency does not always result in reduced overhead or higher throughout. This allows system builders to design RT systems (such as audio processing systems, robots, drones, etc) to utilize these features without annoying the hell out of everyone else.

iirc the bad UA filter is bundled with either base-http-scenarios or nginx. That might help assuming they aren’t trying to mask that UA.

Pretty sure expiry is handled by the local crowdsec daemon, so it should automatically revoke rules once a set time is reached.

At least that’s the case with the iptables and nginx bouncers (4 hour ban for probing). I would assume that it’s the same for the cloudflare one.

Alternatively, maybe look into running two bouncers (1 local, 1 CF)? The CF one filters out most bot traffic, and if some still get through then you block them locally?

I’ve recently moved from fail2ban to crowdsec. It’s nice and modular and seems to fit your use case: set up a http 404/rate-limit filter and a cloudflare bouncer to ban the IP address at the cloudflare level (instead of IPtables). Though I’m not sure if the cloudflare tunnel would complicate things.

Another good thing about it is it has a crowd sourced IP reputation list. Too many blocks from other users = preemptive ban.

According to this post, the person involved exposed a different name at one point.

https://boehs.org/node/everything-i-know-about-the-xz-backdoor

Cheong is not a Pingyin name. It uses Romanization instead. Assuming that this isn’t a false trail (unlikely, why would you expose a fake name once instead of using it all the time?) that cuts out China (Mainland) and Singapore which use the Pingyin system. Or somebody has a time machine and grabbed this guy before 1956.

Likely sources of the name would be a country/Chinese administrative zone that uses Chinese and Romanization. Which gives us Taiwan, Macau, or Hong Kong, all of which are in GMT+8. Note that two of these are technically under PRC control.

Realistically I feel this is just a rogue attacker instead of a nation state. The probability of China 1. Hiring someone from these specific regions 2. Exposing a non-pinying full name once on purpose is extremely low. Why bother with this when you have plenty of graduates from Tsinghua in Beijing? Especially after so many people desperate for jobs after COVID.

Both Bluetooth and BLE are perfectly fine protocols. You won’t be able to design much for short distance with that much power savings otherwise. The main issue is that for any protocols like this you would most likely need to put it in the 2.4ghz unlicensed band. And that’s predominantly used by wifi these days.

My suggestion would be to try compiling the kernel locally.its highly likely the one packaged in your distro contains extensions that you don’t have. Doing a local native compile should rule that out pretty quickly without having to disable any additional features.

Look at the line with the asm_exc_invalid_op. That seems like a hardware fault caused by an invalid asm instruction to me. Either something wrong is being interpreted as an opcode (unlikely) or maybe the driver was compiled with extensions not available on the current machine.

OP, how old is your CPU? And how old is the nic you are using?

Edit: did you use a custom driver for the NIC? I’m looking at the Linux src and rt_mutex_schedule does not exist. Nevermind. Was checking 4.18 instead of 6.7. found it now. The bug is most likely inside a macro called preempt_disable(). Unfortunately most of the functions are pretty heavily inlined and architecture dependent so you won’t get much out of it. But it is likely any changes you made in terms of premption might also be causing the bug.

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I think we may be looking at these wrong. Yes there’s a visible throughput/latency improvement here but what about other factors? Power savings? Cache efficiency? CPU cycles saved for other co-running processes?

These are going to be pretty hard to measure without an x86_64 simulator. So I don’t fault them for not including such benches. But there might be more to the story here.

Out of curiosity, what’s preventing someone from making a regulatory db similar to tzdb other than the lack of maintainers?

This seems like the perfect use case for something like this: ship with a reasonable default, then load a specific profile after init to further tweak PM. If regulations change you can just update a package instead of having to update the entire kernel.

HDR

I would argue that this is something that should be taught in every undergraduate Operating Systems course. But if someone posting it here benefits teens, self-taught hobbyists, and old-timers getting back into the field so be it.

So let me get this straight, you want other people to work on a project that you yourself think is a hassle to maintain for free while also expecting the same level of professionalism of a 9to5 job?

Last time I checked, K-9 didn’t have OAUTH integration.

Granted, it’s been a few years, so that may have changed since then.

As much as I don’t like Gmail, I need it for work so it’s kinda important for productivity software to support that.

Edit: Nvm. Looks like they finally added OAUTH last year. Better late than never.

+1 for fairmail. Never have I seen an app so functional yet so ugly at the same time.

Having one program (process) talk to another is dangerous. Think of a stranger trying to come over to me and deliver a message. There’s no way I can guarantee that he isn’t planning to stab me as soon as he sees me.

That’s why we have special mechanisms for programs talking to other programs. Instead of having the stranger deliver the message directly to me, our mutual friend Bob (IPC Library, binder in this case) acts as an intermediary. This way at least I can’t be “directly” stabbed.

What’s preventing the stranger from convincing Bob to stab me? Not much (except for Bob’s own ethics/programming)

To work around this, we have designed programming languages (rust) that don’t work if there’s a possibility of it being corrupted (I would add “at least superficially”, but that’s not the main topic here). Bob was trained by the CIA in anti-brainwashing techniques. It’s really hard to convince Bob to stab me. That’s why it’s such a big deal. We now have a way of delivering messages between two programs that is much safer than before.

The only problem is that the CIA anti-brainwashing techniques (rust) tend to make people slow. So we deliver messages less efficiently than before. Good news is in this case we managed to make Bob almost as fast as before, so we don’t lose our own much while gaining additional security. The people who checked on Bob even made sure to have Bob do the exact same thing as before when delivering messages (using RB Trees), hence this evidence is most likely credible.

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Worked in IT, target disk mode is a life saver when you have to recover data from a laptop with a broken screen/keyboard/bad ribbon cable and don’t want to take apart something held together by glue.

I mean they’re not wrong…

This is why my next book will be titled “how to cook dinner without a compiler, GCC 4 to GCC 11 compatible!”