RFR: 8340212: -Xshare:off -XX:CompressedClassSpaceBaseAddress=0x40001000000 crashes on macos-aarch64 [v10]

[Coleen Phillimore]

On Mon, 9 Dec 2024 17:51:44 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> If this is a log-error or fatal, then maybe we should give an error for an invalid SharedBaseAddress, as with Thomas's suggested patch.  We generally try to get SharedBaseAddress and that fails, let the OS code pick one.  If we want to give an error for invalid SharedBaseAddress, I could fix the test that fails to not try for an invalid address.  But the validity of the address is only for aarch64 so I don't know if we want to do this.
>
> `base_address` here is not from user input. It is something produced by the JVM after validity checks. So if we have an error it, we JVM has done something wrong. I think a fatal() would be apropriate.
> 
> In contract, SharedBaseAddress can be specified by the user, and we usually do not use fatal() to report such errors.

SharedBaseAddress comes through here also.  It was valid at one point but UseCompactObjectHeaders forces the shift to be 10 so on using the shared archive, it might not be correct.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21695#discussion_r1876734231