[11u] RFR: 8247691: [aarch64] Incorrect handling of VM exceptions in C1 deopt stub/traps

[Andrew Haley]

On 20/01/2021 10:33, Doerr, Martin wrote:
> Hi,
> 
> JDK-8247691 is backported to 11.0.11-oracle. I'd like to backport it for parity.
> Change doesn't apply cleanly. I had to apply 2 parts manually:
> c1_Runtime1_aarch64.cpp: The code which gets replaced by this change contains differences. I've resolved it such that it matches the new version exactly. Note that aarch64 uses DEOPTIMIZE_WHEN_PATCHING so it always deoptimizes instead of performing the patching as done by other platforms.
> deoptimization.cpp: Integrated assertion manually due to unrelated context changes.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8247691
> 
> Original change:
> https://git.openjdk.java.net/jdk/commit/7817963c
> 
> 11u backport:
> http://cr.openjdk.java.net/~mdoerr/8247691_aarch64_11u/webrev.00/
> 
> Please review.

This is a tricky one. I wouldn't want to commit this unless I'd single-
stepped through the code to be sure that it worked correctly.

I think there's a less intrusive way to fix the bug by putting an
enter/leave around the BLR to target.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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