[stjohnswarts]

I doubt that. The number of ARM processors is far greater in reality than in x86 if we clarify it by saying “in operation” rather than historically and these stories will become more common but certainly won't see a “sharp increase”.

[codeflo]

This sort of bug only happens when running a multithreaded program (with shared memory) on a multicore processor.

You do need both for the problem to happen: Without shared memory, there’s nothing to exploit. And with a single core only, you get time-sliced multithreading, which orders all operations.

My point is, that combination was a lot rarer in ARM land before people started doing serious server or desktop computing with those chips.

[retrac]

Of course. Any such flaws in the Linux kernel or any library used by Android should have been found by now, for example. But the number of ARM processors running developer/server/desktop stacks has been tiny until recently. In my experience, quite a lot of Linux on desktop software fails to even build on non x86_64 machines.

[stjohnswarts]

Are you kidding? Arm computers are by far the most common over the past 10 years. Computers are everywhere and servers and home computers account for at most 10% of the market for cpus and microcontrollers.

[masklinn]

The vast majority of those are not running multitheaded workloads written by complete randos.

[SavantIdiot]

The dominant Arm core in the world is a Cortex-M (or Cortex-R) which are single-core. They are 99% of the time on a die with far less <512K SRAM, and run an RToS or baremetal.

These outnumber x86+Cortex-A by probably a factor of 1,000.

[rsynnott]

There are almost certainly more multi-core ARM chips than x86 chips around, too, tho.

[SavantIdiot]

That's a good question. I guess we would need to compare all the arm multi-core in smartphones & some laptops, vs all the intel laptops/desktops/servers. Hmmm... tough one.

[rsynnott]

Virtually all modern (last five years, for the low end) smartphones have multicore chips. It's estimated that there are around _7 billion_ smartphones worldwide, with another 1.5bn sold every year. So I don't think it's a very tough one.