[jdk17] RFR: 8269035: bug in monitor locking/unlocking on ARM32 C1 due to uninitialized BasicObjectLock::_displaced_header

[Boris Ulasevich]

Hi,

Could we have a review of this change?

The bug was discovered in ARM32 C1 monitor locking/unlocking: the
displaced header is not initialized to the non-zero value which results in deadlock.

The issue was fixed in jdk18, and I want to have this P3 fix in jdk17 as well.

Thanks,
Boris

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Commit messages:
 - 8267042: bug in monitor locking/unlocking on ARM32 C1 due to uninitialized BasicObjectLock::_displaced_header

Changes: https://git.openjdk.java.net/jdk17/pull/102/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=102&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8269035
  Stats: 176 lines in 3 files changed: 172 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/102.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/102/head:pull/102

PR: https://git.openjdk.java.net/jdk17/pull/102