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Comment by mikeash | Hacker News Reader

Tesla’s infotainment and IT infrastructure is unrelated to their safety. If this guy worked on motor control or braking system firmware then that would be scary, but he didn’t.

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If the infotainment system caused the MCUs to reboot while someone traveling "130mph on San Mateo Bridge" and that caused the break system to segfault due to unconventional way of loading parts firmware, it might be a life&death situation, easily. Examples in that threads go on, literally hundreds!

I don't understand how that could happen. MCU reboots, ???, brake system segfaults? What goes in the middle?

Probably everything has access to everything on the CAN bus.

IIRC car manufactures are irresponsibly lazy and never properly air-gap infotainment from critical stuff.

There's a firewall between the CAN bus so it cannot be affected at all by the MCU.

Even if this were true (and as another commenter says, it's not) I don't see how that fills in this gap. It would make sense if the first step were "MCU goes crazy," but not with a simple reboot.

Well, you can reboot the system while driving(both console and dash), nothing special happens other than the AC turning off for a brief period of time. Brakes, wheel, throttle all respond normally.

Source: Done this a few times to clear bad map data or occasional glitch.

Doesn't surprise me -- a couple of times my new 3 has had nothing on the display but it's still happy to let me put it in gear and drive away, and the display pops up within a second or two.

To be sure, it's a bit unsettling, and I wouldn't be thrilled about it deciding to not work for a day or two, but, in a way, it makes me MORE comfortable that the vehicle control systems function as expected.

AC should be considered mission critical.

Definitely, I'd put it on the mission criticality list right below inflight wifi.

It's not mission critical, but it's important: in cold weather the windshield can fog up to the point of 0% visibility.

In hot weather it can become very uncomfortable or even impossible to drive without AC.

There’s a distinction between safety critical equipment and essential equipment. If the former fails, it could kill you. If the latter fails, you can’t drive anymore but you won’t die if it happens on the road. Brakes are in the former category, while things like HVAC and instruments are in the latter.

Safety equipment must not fail, but essential equipment can fail as much as your customers will tolerate.

You can steal a trick the motorcycle community discovered a long time ago, some water + soap on the windshield prevents condensation.

Our '83 Vanagon doesn't have AC, it can be uncomfortable but sure isn't the end of the world.

Seriously yes, at least ventilation. Anybody who don't believe this, try turn off your AC completely and see how quickly your wind screen is fogged up to the point you can't see out. (depending on which climate you live in)

There’s no concept of “reboot” with MCUs, since there’s usually no OS. Likewise there’s usually no concept of segfault, because segfault requires memory protection which is something most MCUs don’t use.

Tesla’s MCU runs Linux. Older ones use a 2012-era Nvidia mobile SoC, while newer ones use something from Intel.

Nah. No way the mcu responsible for braking would run an OS

Didn't they already do an Over-the-Air update to fix the braking time in response to a bad review?

You don’t need an OS for that.

This must be an acronym mixup. We’re talking about the Media Control Unit, i.e. the giant screen in the center of the dashboard responsible for zero safety-critical systems.

MCU in the case of braking and steering is “micro controller unit”.

Yeah, those definitely aren’t running Linux, and the guy here wasn’t working on them.

Yes, The infotainment stuff, like the screen, internal lights, speakers are connected via a low profile third bus system, certainly not the main CAN bus or profibus or firewire. Some, like in the BMW even via WiFi. These are the systems usually used with Linux or Windows or Android. On top of the important stuff.

s/reboot/reset/, s/segfault/bus-fault/

Ignoring the infotainment system for this argument (as they firewall it off from CANBUS and other life critical systems [1]), I argue that their IT infrastructure is safety related, as it governs Tesla's velocity in getting patches and security fixes out to vehicles in a timely manner.

Can you imagine a zero day being found in Windows with Windows Update being down?

[1] https://www.youtube.com/watch?v=KX_0c9R4Fng

There's no guarantee that any given car is connected and receives updates, so the safety-critical systems need to be good enough when the car ships. They might mess up, but then they'd at least be able to patch cars faster, while other manufacturers would have to do a recall.

1. According to this source, the infotainment system arbitrates flashing other ECUs.

2. Apparently people can ssh into the infotainment system.

1 + 2 => someone hacks into the infotainment system and flashes a safety-critical ECU. I guess/hope there's some protection in place to prevent that.

> Tesla’s infotainment and IT infrastructure is unrelated to their safety.

Only if it's deliberately isolated in the vehicle. It should be. Aaaand, it isn't: the firmware upgrades to all other car computing elements go through it.

Runtime isolation is distinct from compile/build-time isolation. You're citing the latter, but it's the former that matters. Tesla gets this right, e.g. an interrupt in the MCU does not have any effect on braking, drive-by-wire, or ADAS systems while a car is in operation.

Just to back this up: I have rebooted both my MCU and my instrument panel while driving. Critical systems are not affected.

Fair enough, but if those bits pass through the infotainment center on the way in, controlling one allows you to control the other.

Well, the model 3 lacks a normal speedometer, it's in the screen. For that car, it's related to safety.

>Tesla’s infotainment and IT infrastructure is unrelated to their safety

Because drivers can't get distracted and crash because of a failure in the infotainment and IT infrastructure?

If that's the standard, then almost everything becomes safety critical. Drivers can easily get distracted by malfunctioning smartphones or apps. (Or, for that matter, properly functioning smartphones or apps.) Yet the prior discussion was based on the idea that things like iPhones and Facebook aren't safety critical the way this is.

It is my understanding that two major reasons for various ugly UI and unintuitive UX in automotive infotainment systems are patents and safety certifications.

>If that's the standard, then almost everything becomes safety critical.

Almost everything in a cars front panel and dashboard can be. I've read somewhere that people have been killed even because of something as quaint as the wrong placement of car ashtray.

One time I pulled up at the red light behind a Tesla while I was on a bicycle. Straight through the rear window I could see the driver and front passenger being distracted by the massive flat touch screen. The traffic light turned green, and had I been beside the Tesla, I would have beaten it across the intersection despite all that electric motor tech in the car.

Anyway this little illustrated anecdote of mine aside, driver distraction is a genuine issue - even for drivers at red lights. The number of times I've seen this type of behaviour transcend into moving off while remaining distracted (whether that's heads down visually or just mentally) is too boringly frequent to detail. Sometimes the distracted drivers even creep forward unconsciously while traffic is flowing across them. Emergency vehicles can't get through, drivers end up splitting their attention, pressure mounts once proper movement starts again, and all the while they don't realise they don't have full attention in a changing environment.

It's almost like a hypoxia.

Tom Scott did a pretty good video on this: https://youtu.be/_-aDHxoblr4

I've missed the light turning green while just looking out the window (our car has no screen). As long as people are only distracted while waiting at a light I wouldn't worry too much.

Except they're not only distracted while looking at their screen when stopped. The distraction continues after they start rolling again - one thing directly leads to another here.

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