Correct, but 'geofft's criticism of it isn't great, in my opinion. Reading it makes it obvious what it does, and only a fool would disable security mitigations in a situation where it mattered. The link has significant value in being a quick and easy way to direct people to information, and it seems nonsensical to criticize it for things which don't particularly apply.
> only a fool would disable security mitigations in a situation where it mattered.
Are we reading the same HN threads on this page? I'm seeing people who I don't consider to be stupid, who obviously have some Linux knowledge, still advocating that user accounts are a waste of time for most desktops.
If anyone is smart enough and knows enough about Spectre/Meltdown to understand the risks they're taking, they are also smart enough to search online how to disable the kernel protections. The commands aren't hard to find.
If anyone is not smart enough find that information online for themselves, they also don't have enough knowledge to make an informed decision about whether or not it's safe for them to run.
In both cases, there is value in forcing users to display a modicum of knowledge about even just the fact that Spectre/Meltdown exist before we give them a command to run that turns off an important security setting. Anyone who knows anything about Spectre/Meltdown already knows that the mitigations affect performance. They should already know what to search for online without the aid of no-context commands being pasted at the top of HN.
Are we reading the same HN threads on this page? I'm seeing people who I don't consider to be stupid, who obviously have some Linux knowledge, still advocating that user accounts are a waste of time for most desktops.
A fool isn't necessarily stupid: plenty of people have knowledge yet terrible judgement.
If anyone is smart enough and knows enough about Spectre/Meltdown to understand the risks they're taking, they are also smart enough to search online how to disable the kernel protections. The commands aren't hard to find.
If anyone is not smart enough find that information online for themselves, they also don't have enough knowledge to make an informed decision about whether or not it's safe for them to run.
In both cases, there is value in forcing users to display a modicum of knowledge about even just the fact that Spectre/Meltdown exist before we give them a command to run that turns off an important security setting. Anyone who knows anything about Spectre/Meltdown already knows that the mitigations affect performance. They should already know what to search for online without the aid of no-context commands being pasted at the top of HN.
You're considering it as advice, when really it should be considered more like a doi.
> A fool isn't necessarily stupid: plenty of people have knowledge yet terrible judgement.
Then I'm not sure why you disagree with my criticism - I'm claiming that this page appeals to people who have knowledge in this matter but have not done the deep thinking to have wisdom in this matter. There are plenty of smart people who find "Make X Y again" for other values of X and Y appealing.
I'm claiming it functions more like a doi or other identifier than a sales pitch. I don't think there's a ton of deep thinking involved: there will always be someone who's willing to run a web browser as root on their main system; you can't stop people who are set on something foolish from doing it, but if you can make it more convenient for people who have valid reasons, why not?
This all might be a bit too much serious thought for what was intended as a joke initially (the site, not my comments), though.
Android differentiates between user processes and root processes. I'm pretty sure iOS does as well, although maybe they've coded it as something weird.
I'm not seeing people here arguing that Linux could get by with only supporting 1 user account. I'm seeing people argue that the biggest reason they avoid running as root is just because userland applications complain about it. It's very difficult to do sandboxing if there isn't some kind of differentiation between a privileged and unprivileged process.
Regardless, Linux also doesn't really have good sandboxing by default, so I'm not completely sure what you're getting at. It's still a bad idea for people to run a Linux system as root.
> Reading it makes it obvious what it does, and only a fool would disable security mitigations in a situation where it mattered.
I disagree. Most users do not understand how speculative side channels work or how they might be affected; many people's experience with Meltdown and Spectre is "my games got slower because of some magical speculative stuff that I don't really understand". Making an informed decision on this is hard.
The average Linux user will not understand the implications. Heck most don't even know the security trade-offs of X11 (which are relatively simple to discover and understand).
Leave the HN bubble and go to an average Linux forum. You would be surprised what kind of advise people give or what people are willing to copy and paste into their terminal ;).
This is not meant as a criticism. Most people, including many Linux users, just use their computer as a tool and will just do anything to get it running as they want.
Most offline systems, and many systems used only for using trusted code (which obviously bars anything with a web browser, and most internet-connected personal computing devices, among other things). Applications that equate roughly to "Scientific number-crunching" for example are generally systems where security doesn't matter much.
There's a case to be made for gaming, and the mitigations if I remember correctly definitely ding performance on quite a few games, but because most computers used for games have significant amounts of sensitive information on them, among other things, I don't think it really holds well.
Benchmarks (I really dislike linking to this site, but given it did a bunch of benchmarks, it's not the worst thing, I guess):
'Up to 50% performance loss!' is obviously clickbait, and I disagree with a lot of the wording & conclusions & so on, but there's definitely some workloads where the trade-off makes sense.
Warning about those benchmarks, though: they're of a rather old kernel version, I imagine they tank performance less now. However, given that 5x has been performing way worse to my knowledge than 4x, 4x is probably what most people would be using for these sorts of things.
Are systems used for "scientific number-crunching" really applicable in this case? While some departments may have those on a separate network, not connected to the internet at large, I have never heard of a system employed for research tasks being completely air gapped. Otherwise, accessing and working on data would be prohibitively harder. Would such a trade-off be worth the potential gains by deactivating mitigations?
Also, may I ask why you dislike Phoronix? I personally enjoy their articles and the benchmark suite they have developed seems very well-rounded and transparent. I wouldn't count the statement concerning the ~50% increase in time it takes to complete a certain task on 4.20 as clickbait, considering it was never used in the linked articles title to hock readers and gain clicks.
Honestly, I have yet to see a large and popular enough use-case that allows for a both completely air gapped system, whilst also heavily benefiting from disabling mitigation to such an extent, that an admin couldn't just lock up the flags required. If I, as an admin, made the conscious choice of going so far as to disable these patches, I would also want to at least re-read whether this is truly significantly advantageous, rather than copying a line from a website with no context or further information on the current state and impact on performance.
It'd be nice to be able to easily boot into, or toggle into, a performance optimized, disabled mitigations environment to do something while offline.. many computer uses don't require being connected to other computers. I've gotten into the habit of hotplugging my Ethernet connection, personally.
You can actually do that fairly easily, just add the parameters linked to a second boot entry in GRUB.
However, I would very much not advise doing so, as I still am unaware of any task that can both, be done without the need for a network connection, while also being significantly slowed down by the mitigations, after recent improvements to the kernel and software. Basically, the potential benefit is very low in a lot of tasks, whilst requiring additional security measures (ideally fully air-gapped) and that you reboot the system every time you'd do such a task.
Also note that, in theory, just being temporarily offline may not shield from being exploited fully.
As an example (the only case that I've identified personally), if your curious, I have a (windows; Intel q6600) box that I use for gaming occasionally. Single player game I like, Total War: Shogun 2, runs at about 55 fps (benchmark) pre-Meltdown/Spectre/etc. Now it gets ~22 fps. I can use https://www.grc.com/inspectre.htm to toggle some mitigations to get it playable again.
