
Userland xnr jit - seryoiupfurds
http://www.tedunangst.com/flak/post/userland-xnr-jit
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jevinskie
Apple added XO (VM_PROT_EXECUTE_ONLY) in iOS 10 and uses it in JavaScriptCore
for JITing.

[https://opensource.apple.com/source/JavaScriptCore/JavaScrip...](https://opensource.apple.com/source/JavaScriptCore/JavaScriptCore-7603.1.30.0.34/jit/ExecutableAllocatorFixedVMPool.cpp.auto.html)

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_wmd
This doesn't seem any more practical a technique than printing the pages to
paper and OCRing them on each access.. one signal and two expensive syscalls
per randomly accessed page of memory is hardly cheap, especially in the
context of a JIT

