RFR: 8277204: Implementation of JEP 8264130: PAC-RET protection for Linux/AArch64 [v14]

[Alan Hayward]

On Wed, 2 Feb 2022 09:29:21 GMT, Alan Hayward <duke at openjdk.java.net> wrote:

>> Given that the implementation has now changed so much that it's no longer NOP based, I'll go with @dholmes-ora .
>> One other thing, though: it might be better to say here "but this VM was built without ROP-protection support." That's more informative, IMO.
>
> Ok, I'll fix up as suggested.
> 
> The beginning part of that message needs fixing too - UseROPProtection is no longer the name of the flag. I'll switch to:
> "ROP-protection specified, but this VM was built without ROP-protection support."

And this change will keep ROP protection enabled if we fall into the "this VM was built without ROP-protection support.". In that case we'll be protecting generated code, but the VM itself won't be protected. This will run without crashing.

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PR: https://git.openjdk.java.net/jdk/pull/6334