I hypothesize it could have come down to "well, we made this type of decision this way before, and the world didn't fall down, so we can probably make it that way again, right?" Since these aren't formally proven systems, to some extent deciding whether an optimization is safe is going to be a judgment call - and if you go for "well, if this assumption is false, we're already doomed because we did X elsewhere...", the results could look like this.
Or maybe not, I've never worked for a chip design house.
why would cache performance be considered a cheat?
Consider that local privilege escalations are generally (and I'd say correctly) treated as critical severity issues. Any general purpose process memory read-isolation leak is a quick route to a local privilege escalation, so how could isolation be anything other than a security feature? In its absence, you might as well run everything as root and there would be no point whatsoever to caring about privilege escalations.
> In its absence, you might as well run everything as root
this is what 99% of people with a home computer did until windows XP (and even then most people today run under an admin account of some sorts on their computers)
isolation between users is only relevant for clusters, it's a super minority usecase versus what is the main thing that matters, home computers which only have one human user anyways. But I guess you'd disagree with Stallman's paragraph at the end here: https://ftp.gnu.org/old-gnu/Manuals/coreutils-4.5.4/html_nod...
The XKCD argument misses the point entirely; if someone p0wns your browser, they p0wn your browser, but what we're talking about is allowing every VSCode extension and Docker image someone installs to read your GMail. It's an absolute dipshit idea that would make every current security problem with computing orders of magnitude worse.
I don't understand, this is already the status quo today. Any vscode extension can access your filesystem and connect to a socket, so it can just pipe your ~/.cache/mozilla to some server in russia, and even read the memory of any of your processes through /proc/$PID/maps. Ditto for any shell script you run, any build script for any software you clone from github before building it, unless you are running Qubes OS.
Also let’s stop here and admire just how far you’ve shifted the goal posts: we’ve gone from “memory isolation isn’t a security measure it’s actually just for reliability” to “ok sure it’s obviously a security critical measure, but check out this boneheaded RMS rant and also what about the lower threat value data that gets cached, what about that. And do we even need security or can we just go back to the 1980s with our Amigas when everything was cool and advanced persistent threats didn’t exist, man”.
Pick a coherent point you’re trying to argue and some kind of intelligible threat model, at least. If we’re concerned about leaking filesystem data, there’s more aggressive sandboxing measures which several OSes employ, but they even more strongly rely on memory isolation, not less.
The point, which you seem to have conceded several posts ago, remains: Memory isolation is a security measure, not just or even primarily a reliability issue.
Also you don’t seem to understand what you’re trying to talk about, because:
> and even read the memory of any of your processes through /proc/$PID/maps
This requires root permissions (or for you to have explicitly changed /proc/sys/kernel/yama/ptrace_scope to a non-default value to allow processes to PTRACE_ATTACH to arbitrary non-child processes, which you shouldn’t do on a general purpose internet-facing machine unless you are a clinically insane person) for the obvious reason that this would be incredibly dangerous otherwise. Proving once again my entire point:
Memory isolation is a security measure.
Whether happening organically or through the magic of reputation management, that's pretty alarming, actually. Give it another few years and nobody will even remember.
But hey, we love our corporate overlords, they only want what's best for us, the shareholders.
(Not actually a shareholder of anything)
More or less, yes, they all did.
As an European I'd say it's a shared blame, though, as in the officials around Europe (both at national and at the EU level) who had very strongly pushed for diesel for the previous two to three decades (mostly through taxation/pricing policies) also deserve a very big part of this blame.
The Americans got it right (especially states like California) when relegating diesel to mostly commercial/truck/public transport use, but the hybris and the "we know better than the silly Americans when it comes to the environment" prevailed in the end, that's why it took Dieselgate and at least a couple of decades for those officials to reverse their past mistakes.
Edit: it was Volkswagen not Volvo.