RFR: 8345296: AArch64: VM crashes with SIGILL when prctl is disallowed

[Andrew Haley]

On Mon, 2 Dec 2024 14:06:00 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> > Does this patch mean that a warning is printed unconditionally on systems where `prctl` is disabled?
> 
> Unfortunately, yes. On the other hand, I believe it is recognized that disabling "innocuous" `prctl` queries is not great, and sandboxes should actually allow them. We really just want a more graceful JVM behavior in these cases. Anything apart the VM crash would do better. The alternative is to exit the VM and ask users to `UseSVE=0` manually. Doing this automatically and proceeding with the warning looks like a sane middle ground.

I understand, but there are compatibility issues. As far as I can tell this issue is only likely to manifest on systems where the console isn't monitored, so I'm not sure I'd print the warning unconditionally, but your call.

Anyway, please print something like "Use -XX:UseSVE=0 to remove this warning."

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PR Comment: https://git.openjdk.org/jdk/pull/22479#issuecomment-2511782585