4 ms·
It does exist in single user environments. What about a desktop/phone that runs untrusted code? e.g. every browser that supports JavaScript.
by als0 7y ago
It does exist in single user environments. What about a desktop/phone that runs untrusted code? e.g. every browser that supports JavaScript.
- atemerev 7y agoYes, and this code is contained within the Javascript engine. Mitigations could be enabled only there.
- danarmak 7y agoDisabling HT can't be done per-process. Since per-frame browser processes need to be protected from one another, you can't even run two browser processes on the same core in HT. And scheduling a browser process while leaving the second HT slot on the same core empty is even slower than turning HT off.
- gmueckl 7y agoSomebody please explain to me why ripping out the JS JIT wouldn't work.
- dfrage 7y agoIn the most recent discussion of this it was reported that is no longer an easy option with Firefox: https://news.ycombinator.com/item?id=20012750 https://news.ycombinator.com/item?id=20012750 There's also a general impression that would be too slow for many web pages, and that comment noted it took minutes for logins using JavaScript cryptography to execute.
- gpderetta 7y agoIt seems to me that most people will be willing to pay for slower js as opposed to an overall slower system.
- zzzcpan 7y agoDoes it even need to be slower? Almost every single website out there is not a javascript app and so side channel attacks can be mitigated by simply having an rlimit-style CPU time limit after say a user action on a tab.
- zzzcpan 7y agoBrowsers rely on kernel/hardware mitigations. Google people even claimed it's impossible to fully mitigate those vulnerabilities in existing Javascript implementation in Chrome.
- als0 7y agoIt's the job of the OS to make sure one process can't read the memory of another process. What you're saying is that should now be the responsibility of the JavaScript engine as well as the OS.