RFR: 8277100: Dynamic dump can inadvertently overwrite default CDS archive

[David Holmes]

On Mon, 20 Dec 2021 18:14:05 GMT, Calvin Cheung <ccheung at openjdk.org> wrote:

> Please review this small fix for preventing the default CDS archive from being overwritten via the
> -XX:ArchiveClassesAtExit VM option.
> 
> If the user sets the -XX:ArchiveClassesAtExit option pointing to the default CDS archive, VM will
> exit with the following message:
> 
> `Cannot specify the default CDS archive for -XX:ArchiveClassesAtExit: <path to classes.jsa>`
> 
> Passed CI tiers 1 and 2 tests.

Hi Calvin,

Fix is good, but I have to query whether this is just a P4? I suppose anyone who can overwrite the default archive this way can also restore it with -Xdump, but still this seems a bit of a usability issue worthy of a P3 and fixing in 18.

Thanks,
David

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Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/6896