RFR: 8374807: Crash in MethodData::extra_data_lock()+0x0 when running -XX:+TraceDeoptimization -XX:-ProfileTraps -XX:-TieredCompilation -Xcomp -version [v4]

[Guanqiang Han]

> Please review this change. Thanks!
> 
> Description:
> 
> This change fixes a crash in Deoptimization::uncommon_trap_inner when running with -XX:+TraceDeoptimization -XX:-ProfileTraps -XX:-TieredCompilation -Xcomp.
> 
> With -XX:-ProfileTraps, create_if_missing is set to false.
> https://github.com/openjdk/jdk/blob/74faf033127ab3a5e28be75b91e662c589f81084/src/hotspot/share/runtime/deoptimization.cpp#L2121-L2122
> 
> When create_if_missing is false, new mdo can not be created when m()->method_data() return null, so get_method_data() may return null .
> https://github.com/openjdk/jdk/blob/74faf033127ab3a5e28be75b91e662c589f81084/src/hotspot/share/runtime/deoptimization.cpp#L1911-L1912
> 
> and trap_mdo can be null as a result
> https://github.com/openjdk/jdk/blob/74faf033127ab3a5e28be75b91e662c589f81084/src/hotspot/share/runtime/deoptimization.cpp#L2134-L2136
> 
> The crash happens here because trap_mdo is null
> https://github.com/openjdk/jdk/blob/74faf033127ab3a5e28be75b91e662c589f81084/src/hotspot/share/runtime/deoptimization.cpp#L2157
> 
> Fix:
> 
> The fix makes acquisition of extra_data_lock conditional on trap_mdo being non-null, preserving the required lock ordering (extra_data_lock before ttyLocker) when an MDO exists.
> 
> Test:
> 
> GHA

Guanqiang Han has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - revert
 - Merge remote-tracking branch 'upstream/master' into 8374807
 - narrow lock scope
 - Merge remote-tracking branch 'upstream/master' into 8374807
 - split long line
 - Merge remote-tracking branch 'upstream/master' into 8374807
 - fix 8374807

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/29147/files
  - new: https://git.openjdk.org/jdk/pull/29147/files/cdc88af1..e065ae56

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29147&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29147&range=02-03

  Stats: 4227 lines in 70 files changed: 2638 ins; 859 del; 730 mod
  Patch: https://git.openjdk.org/jdk/pull/29147.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29147/head:pull/29147

PR: https://git.openjdk.org/jdk/pull/29147