Integrated: 8329757: Crash with fatal error: DEBUG MESSAGE: Fast Unlock lock on stack

[Axel Boldt-Christmas]

On Wed, 10 Apr 2024 12:11:17 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

> `Deoptimization::relock_objects` may reorder locks within in the `LockStack` which are added inside the same vframe. This can be handled by the interpreter but if OSR has occurred C2 may observe this invalid order in the `LockStack`, which breaks its assumption leading to incorrect behaviour.
> 
> This patch functionally makes sure that the LockStack is always consistent by always inflating eliminated locks when `Deoptimization::relock_objects`  is called.
> 
> It also adds verification code which checks that the LockStack is consistent with the lock order observed inside the deoptimized vframes. 
> 
> Note: for leaf deoptimizations we have enough information to recreate a correct top of the LockStack with minimal inflations, however that should be a separate RFE. This only inflates eliminated locks so the worth of solving that may be minimal or even detrimental. 
> 
> Tests still running. Tier 1-7 done.

This pull request has now been integrated.

Changeset: e45fea5a
Author:    Axel Boldt-Christmas <aboldtch at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/e45fea5a801ac09c3d572ac07d6179e80c422942
Stats:     149 lines in 4 files changed: 148 ins; 0 del; 1 mod

8329757: Crash with fatal error: DEBUG MESSAGE: Fast Unlock lock on stack

Reviewed-by: pchilanomate, kvn

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PR: https://git.openjdk.org/jdk/pull/18715