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Comment by archgrove | Hacker News Reader

It's just about not allowing 3rd party code to have writable code pages. In principle, this is good - most programs don't write code to memory, unless they're suffering a security problem. It's just unfortunate that the few legitimate uses of this are also culled.

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It's not good in principle. There are many legitimate uses of writeable code pages, and as long as they're not the default they are unlikely to cause security problems. Don't forget that these apps all run in a sandbox already, so an app exploit won't get you system access anyway. All the excuses Apple/Microsoft give are just that: excuses. The real reason interpreters and self-modifying code are prohibited is to prevent competition with the first-party browsers and app frameworks.

um, interpreters aren't prohibited.

They are prohibited by Apple to be even built with iOS SDK, if they interpret the code downloaded from the Web, which is naturally the case with browsers and JavaScript.

If they were serious about security, they'd do without JIT in their own browsers too. But that would be silly.

Exactly, that _would_ be silly.

I don't get this kind of arguments "if you are serious about X you should go all the way, else forget about it altogether".

You can both be serious about something AND reach some reasonable compromise.

In this case, it is enough that they only allow one JIT that they control and can update/revoke etc immediately.

But IE10, unlike competing browsers, isn't just a "browser" on Windows 8, it's one of the fundamental development platforms built into the OS, along with .NET, WinRT, and Win32. Of course it has special privileges

If it were a default prohibition that could be overridden for a project that really needs it, I wouldn't complain. But as it is it's an unreasonable cost for the benefit for everyone but the platform owner. (Cost: obvious. Benefit: some hacks get harder, but with no essential change to what's possible in the way that memory protection or high-level programming languages change the game. E.g. instead of native code your hack uses https://en.wikipedia.org/wiki/Return-oriented_programming .)

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