The fun part of this Bluetooth crash in an embedded ARM system was that a particular test bench doing a software update procedure on the ARM system had a Linux kernel crash in the Bluetooth RFCOMM sub-system but Bluetooth was not used or required for the software update procedure. The failure was only observed on this test bench.

It transpired that a previous tester had put a paired Bluetooth enabled smartphone in the desk draw underneath the test rig. The guy running the software update procedure was unaware of the presence of the other guy's smartphone that was still connected to the ARM system under test. The software update procedure was very CPU intensive and triggered the race condition in the Bluetooth stack.

Once we understood the failure scenario, we could trigger the failure case by adding a sleep in one of the Bluetooth threads so that kernel would always crash.

The morale of the story, do not blindly use reference counters for abrupt protocol disconnect handling. Meaning that immediate clean-up can take place, no need to delay the freeing via a reference counter.

I think that some bug scenarios are more complex than described in this article.

I recall working on a Bluetooth kernel crash more than 10 years ago. The crash was a race condition between 2 Bluetooth threads when the RFCOMM link was being disconnected. To trigger the crash, the execution order of the 2 threads had to be reversed from "normal" so that 1 thread freed the memory containing the reference counter that the other thread relied on to not free the memory! This was a case of inappropriate use of reference counters when an abrupt disconnect had to be handled.

The crash was observed under very heavy processor loading that caused CPU starvation to the Bluetooth threads resulting in an "abnormal" execution order. Static analysis suggested that the reference counter would provide lock protection because reference counters are used through-out the kernel's networking protocol implementations. However, the flaw is that the reference counter can momentarily go to zero to trigger memory freeing but a second thread can come along and add 1 to the reference counter despite the memory now being in a freed state.

Looking through the commit history revealed about 4 attempts to fix this issue by 4 individuals over a period of about 5 years. I had to remove these ineffective and misguided workarounds to implement a proper fix that completely removed the use of the reference counter and immediately delete the state memory as soon as the disconnect was detected. NULL pointer checks prevented any use-after-free scenarios.

Therefore, kernel bugs may go through several workaround fixes before the root cause is fully understood and fixed. So saying that a bug was resident for 5 years may not mean that no attempts had been made to resolve it during that period.

Sadly, some of your premises are false.

It is a well known fact that emissions from internal combustion engines cause air pollution. People commit suicide by breathing in the toxic fumes from their car parked in their closed garage with the engine running.

NOx air pollution is not from the fuel itself but from the atmospheric nitrogen and oxygen in the air-fuel mixture that is combusted. Synthetic fuel will also produce NOx air pollution in a combustion engine. Consequently, synthetic fuel will become banned in cities with Utra Low Emission Zones (ULEZ) such as London UK.

In China, the transition to BEVs is driven by the desire to reduce air pollution rather than reducing CO2 emissions. Note that China now has stricter vehicle emission regulations than Europe.

A Tesla Model S can do 400 miles on a battery charge. A typical combustion car has a fuel tank range of 600 miles. Your argument on battery energy density is flawed because BEVs have more mass than combustion cars due to the traction battery. In other words, the power to weight ratio is the better metric to analyse. Also, a combustion engine is about 25% efficient which means that 4 times the fuel is needed despite the higher energy density.

2025 is the first year that Norway has effectively banned the sale of new combustion cars. The surge in BEVs is spreading to Norway's neighboring countries such as Sweden, Netherlands, and Denmark. This trend is accelerating. By 2030, Northern Europe, including the UK will be selling more new BEVs than new combustion cars.

Synthetic fuel will fail because it does not resolve the air pollution issue.

The battery storage is not a big UPS. The battery storage provides load balancing and this helps to keep gas peaker plants off-line during peak power demand.

It is helpful to first research for hardware that is known to work well with Linux based operating systems. In particular, the graphical hardware can be a problem area due to the need for proprietary or closed source drivers. Meaning, that a successful installation and a crash free experience of a Linux distribution is dependent on avoiding certain hardware.

Linux based operating systems are a best effort solution and so there will be some hardware configurations that give trouble in being unreliable. Windows needs certified hardware in order to run reliably. However, the sets of suitable hardware for both operating systems overlap (Venn diagram) but there will be hardware that only works reliably for one of the two operating systems.

However, the status quo won't remain in place forever. Meaning that eventually, the criteria for being allowed to drive in a low emission zone will become more strict in future and there will be additional purges of now older vehicles. This will be a consequence of a ratcheting up of the minimum emission standards that a compliant vehicle has to comply with. In other words, if the minimum emission standard is currently EURO5 then there comes a point when EURO6 is declared the minimum standard. I think EURO7 is the current emission standard for new cars. I expect EURO8 to trigger low emission zones to perform a ratchet up.

But also the threshold in the UK for declaring a polluted area continues to decrease over time based on scientific data. Meaning that the goal posts have moved which caused more areas to be declared as polluted despite the actual recorded level of pollution being unchanged. The UK government was fined for breaching the pollution laws and had to take measures to reduce pollution including low emission zones.

But how many decades did it take before smoking bans were implemented? That lag in law making is common when the law is perceived as being controversial.

Another example is mandating that new cars have seat belts in 1965 in the UK, but then it took to 1983 before seat belt wearing became compulsory.

Governments have the right to ban things that harm their citizens but it can take decades getting scientific consensus and overcoming lobby groups with their vested interests.

So yes, governments can ban vehicles and take a hit on the social consequences.

In the UK, no new pure ICE cars after 2030, but there is the loophole of hybrids until 2035.

Anyway, new BEV car sales will be in the majority by 2030 so the discussion on new ICE car bans will become a moot point.

In the enterprise environment, Microsoft's core applications of Outlook, Teams and Office365 are available as cross-platform web based or PWA applications. I use Ubuntu 22.04 with a KDE Plasma desktop at work and I can access all the MS applications that I need to use on Linux. The days of the Microsoft lockin have dissolved away.

I don't have a MS Windows system for me to run WSL2 but I don't think that I am missing out. ;-)

Linux chrome browser and Linux Edge browser. I believe it also works in Linux Firefox but I have not tried that.

I thought vintage computers were built in the 1980s. I would not call a 2012-2014 computer, vintage.

I have 40 year old Sinclair ZX Spectrums that still work as intended.

I am still using a dual core PC built circa 2007 that runs Linux but I don't call it vintage. I did upgrade to using a Raspberry Pi 4 8GB RAM as my main desktop machine with a 250GB micro SD card.

My employer allows me to run Linux Ubuntu 24.04 and it is supported in the corporate Intranet. Ironically, Microsoft is one of our partners allowing Linux desktops to be integrated into the corporate Intranet. My Linux laptop does have some services running for compliance purposes so you are correct that only authorized operating systems and devices can be used. However, Microsoft themselves are supporting Linux desktops in the corporate environment. Therefore, the lockin to being forced to use MS windows is becoming weaker especially that Microsoft is supporting Linux.

Did you know that Microsoft is a member of the Linux Foundation and provides Linux kernel fixes ?

I use Linux Ubuntu 24.04 at work and I also use the MS PWA for Outlook, Office and Teams. It works well on Linux. I used to have a Win10 virtual machine for the rare occasions when something was too Windows centric for Linux to handle but now I no longer use the Win10 VM (also Broadcom broke my VMware environment).

Norway's oil company is state owned and therefore, Norway's citizens benefit from the sale of their own oil. The US and UK oil companies are not state owned and their citizens have to rely on taxing them to get any benefit. Obviously, giving the profits back to the people from a state owned oil company is more per capita than taxing the profits of a public company. This is one reason why Norway can have social policies for their citizens.