Skip to content

8274944: AppCDS dump causes SEGV in VM thread while adjusting lambda proxy class info#6070

Closed
calvinccheung wants to merge 4 commits intoopenjdk:masterfrom
calvinccheung:8274944-adjusting-lambda-proxy-classes
Closed

8274944: AppCDS dump causes SEGV in VM thread while adjusting lambda proxy class info#6070
calvinccheung wants to merge 4 commits intoopenjdk:masterfrom
calvinccheung:8274944-adjusting-lambda-proxy-classes

Conversation

@calvinccheung
Copy link
Member

@calvinccheung calvinccheung commented Oct 21, 2021

During dumping of CDS archive, the ArchiveBuilder::gather_klass_and_symbol set the address of an object to null if the
object cannot be archived. Since the lambda proxy class in this scenario contains an old version (major version < 50) of
interface which has been linked, the class won't be archived and its address will be set to null. The SystemDictionaryShared::adjust_lambda_proxy_class_dictionary is called after
ArchiveBuilder::gather_klass_and_symbol and thus encountered the null pointer.

A fix is to add a function SystemDictionaryShared::cleanup_lambda_proxy_class_dictionary to cleanup the
_dumptime_lambda_proxy_class_dictionary at the beginning of the CDS dumping operation.

The proposed fix passed tiers 1 - 4 testing (including the new tests).


Progress

  • Change must not contain extraneous whitespace
  • Commit message must refer to an issue
  • Change must be properly reviewed

Issue

  • JDK-8274944: AppCDS dump causes SEGV in VM thread while adjusting lambda proxy class info

Reviewers

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/6070/head:pull/6070
$ git checkout pull/6070

Update a local copy of the PR:
$ git checkout pull/6070
$ git pull https://git.openjdk.java.net/jdk pull/6070/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 6070

View PR using the GUI difftool:
$ git pr show -t 6070

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/6070.diff

@calvinccheung
Copy link
Member Author

/label add hotspot-runtime

@bridgekeeper
Copy link

bridgekeeper bot commented Oct 21, 2021

👋 Welcome back ccheung! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

@openjdk openjdk bot added the hotspot-runtime hotspot-runtime-dev@openjdk.org label Oct 21, 2021
@openjdk
Copy link

openjdk bot commented Oct 21, 2021

@calvinccheung
The hotspot-runtime label was successfully added.

@calvinccheung calvinccheung marked this pull request as ready for review October 21, 2021 21:51
@openjdk openjdk bot added the rfr Pull request is ready for review label Oct 21, 2021
@mlbridge
Copy link

mlbridge bot commented Oct 21, 2021

Webrevs

Copy link
Contributor

@yminqi yminqi left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM.


class CleanupDumpTimeLambdaProxyClassTable: StackObj {
public:
CleanupDumpTimeLambdaProxyClassTable() {}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Why need a explicit public constructor for nothing?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for your review.
In a previous version of the fix, the _dumptime_lambda_proxy_class_dictionary was passed to the constructor but it is no longer needed. I've removed the constructor.

@openjdk
Copy link

openjdk bot commented Oct 22, 2021

@calvinccheung This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8274944: AppCDS dump causes SEGV in VM thread while adjusting lambda proxy class info

Reviewed-by: minqi, dholmes

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 161 new commits pushed to the master branch:

  • 82f4aac: 8259609: C2: optimize long range checks in long counted loops
  • 574f890: 8275720: CommonComponentAccessibility.createWithParent isWrapped causes mem leak
  • 7c88a59: 8275809: crash in [CommonComponentAccessibility getCAccessible:withEnv:]
  • c9dec2f: 8273299: Unnecessary Vector usage in java.security.jgss
  • b98ed55: 8275819: [TableRowAccessibility accessibilityChildren] method is ineffective
  • 71d593e: 8275162: Use varargs in 'def' macros in mutexLocker.cpp
  • 7ca053d: 8251904: vmTestbase/nsk/sysdict/vm/stress/btree/btree010/btree010.java fails with ClassNotFoundException: nsk.sysdict.share.BTree0LLRLRLRRLR
  • 4be88d5: 8275047: Optimize existing fill stubs for AVX-512 target
  • 63e0f34: 8275767: JDK source code contains redundant boolean operations in jdk.charsets
  • 4961373: 8275137: jdk.unsupported/sun.reflect.ReflectionFactory.readObjectNoDataForSerialization uses wrong signature
  • ... and 151 more: https://git.openjdk.java.net/jdk/compare/d9e03e42afbb2e5115b67accfffad4938b8314b1...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

@openjdk openjdk bot added the ready Pull request is ready to be integrated label Oct 22, 2021
void VM_PopulateDumpSharedSpace::doit() {
HeapShared::run_full_gc_in_vm_thread();

SystemDictionaryShared::start_dumping();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What is the significance of this? It seems unrelated to the bug being fixed.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It is for setting the _dump_in_progress flag to true so that no new entries will be added to the _dumptime_table.
The SystemDictionaryShared::start_dumping() is being called for the dynamic dumping case, it would be consistent
if it is also called for the static dumping case.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Perhaps but again that seems a different issue unrelated to this bug. Nor is it immediately obvious that the dynamic dumping and static dumping are equivalent in this regard. If the flag was only added for the dynamic case then apparently the static case does not need it - no?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I've reverted the change of calling SystemDictionaryShared::start_dumping() for the static dump case.
If the call is needed, it will be addressed via a separate bug.

Copy link
Member

@dholmes-ora dholmes-ora left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Seems fine.

Thanks,
David

Copy link
Contributor

@yminqi yminqi left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Still LGTM.

@calvinccheung
Copy link
Member Author

Thanks David and Yumin for the review.
/integrate

@openjdk
Copy link

openjdk bot commented Oct 26, 2021

Going to push as commit e5cd269.
Since your change was applied there have been 161 commits pushed to the master branch:

  • 82f4aac: 8259609: C2: optimize long range checks in long counted loops
  • 574f890: 8275720: CommonComponentAccessibility.createWithParent isWrapped causes mem leak
  • 7c88a59: 8275809: crash in [CommonComponentAccessibility getCAccessible:withEnv:]
  • c9dec2f: 8273299: Unnecessary Vector usage in java.security.jgss
  • b98ed55: 8275819: [TableRowAccessibility accessibilityChildren] method is ineffective
  • 71d593e: 8275162: Use varargs in 'def' macros in mutexLocker.cpp
  • 7ca053d: 8251904: vmTestbase/nsk/sysdict/vm/stress/btree/btree010/btree010.java fails with ClassNotFoundException: nsk.sysdict.share.BTree0LLRLRLRRLR
  • 4be88d5: 8275047: Optimize existing fill stubs for AVX-512 target
  • 63e0f34: 8275767: JDK source code contains redundant boolean operations in jdk.charsets
  • 4961373: 8275137: jdk.unsupported/sun.reflect.ReflectionFactory.readObjectNoDataForSerialization uses wrong signature
  • ... and 151 more: https://git.openjdk.java.net/jdk/compare/d9e03e42afbb2e5115b67accfffad4938b8314b1...master

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot closed this Oct 26, 2021
@openjdk openjdk bot added integrated Pull request has been integrated and removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Oct 26, 2021
@openjdk
Copy link

openjdk bot commented Oct 26, 2021

@calvinccheung Pushed as commit e5cd269.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

@calvinccheung calvinccheung deleted the 8274944-adjusting-lambda-proxy-classes branch October 26, 2021 16:29
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

hotspot-runtime hotspot-runtime-dev@openjdk.org integrated Pull request has been integrated

Development

Successfully merging this pull request may close these issues.

3 participants