I believe fans have provided a retroactive explanation that all our computer tech was based on reverse engineering the crashed alien ship, and thus the arch, and abis etc were compatible.

It's a movie, so whatever, but considering how easily a single project / vendor / chip / anything breaks compatibility, it's a laughable explanation.

Edit: phrasing

Still dumb but not as dumb as what we got.

If you mess with the logo, the console locks up during boot. If you don't, you're violating the trademark.

If you haven't already, give the Alvin Draft/Matic a try, imho it's up there along with them.

Depends on the boundary. I can give a non-Linux, microkernel example (but that was/is shipped on dozens of millions of devices):

- prior to 11.0, Nintendo 3DS kernel SVC (syscall) implementations did not clear output parameters, leading to extremely trivial leaks. Unprivileged processes could retrieve kernel-mode stack addresses easily and making exploit code much easier to write, example here: https://github.com/TuxSH/universal-otherapp/blob/master/sour...

- Nintendo started clearing all temporary registers on the Switch kernel at some point (iirc x0-x7 and some more); on the 3DS they never did that, and you can leak kernel object addresses quite easily (iirc by reading r2), this made an entire class of use-after-free and arbwrite bugs easier to exploit (call SvcCreateSemaphore 3 times, get sema kernel object address, use one of the now-patched exploit that can cause a double-decref on the KSemaphore, call SvcWaitSynchronization, profit)

more generally:

- unclearead padding in structures + copy to user = infoleak

so one at least ought to be careful where crossing privilege boundaries

You probably would not even need it in a lot of instances because the compiler would elide lots of dead stores (zeroing) even without hinting.

You might claim that that you can have both but bugs are more inevitable in the uninitialised by default scenario. I doubt that variable initialisation is the thing that would slow down HFT. I would posit is it things like network latency that would dominate.

As someone who works in the HFT space: it depends. How frequently and how bad are the bad-trade cases? Some slop happens. We make trade decisions with hardware _without even seeing an entire packet coming in on the network_. Mistakes/bad trades happen. Sometimes it results in trades that don't go our way or missed opportunities.

Just as important as "can we do better?" is "should we do better?". Queue priority at the exchange matters. Shaving nanoseconds is how you get a competitive edge.

> I would posit is it things like network latency that would dominate.

Everything matters. Everything is measured.

edit to add: I'm not saying we write software that either has or relies upon unitialized values. I'm just saying in such a hypothetical, it's not a cut and dry "do the right thing (correct according to the language spec)" decision.

Wait what????

Can you please educate me on high frequency trading... , like I don't understand what's the point of it & lets say one person has created a hft bot then why the need of other bot other than the fact of different trading strats and I don't think these are profitable / how they compare in the long run with the boglehead strategy??

HFT firms are (almost) always willing to buy or sell at or near the current market price. HFT firms basically race each other for trade volume from "retail" traders (and sometimes each other). HFTs make money off the spread - the difference between the bid & offer - typically only a cent. You don't make a lot of money on any individual trade (and some trades are losers), but you make money on doing a lot of volume. If done properly, it doesn't matter which direction the market moves for an HFT, they'll make money either way as long as there's sufficient trading volume to be had.

But honestly, if you want to learn about HFT, best do some actual research on it - I'm not a great source as I'm just the guy that keeps the stuff up and running; I'm not too involved in the business side of things. There's a lot of negative press about HFTs, some positive.

That is the usual fearmongering when security improvements are done to C and C++.