Bug 1907554

Summary:	Fix racy update of Shenandoah code roots
Product:	Red Hat Enterprise Linux 8	Reporter:	Mike Millson <mmillson>
Component:	java-1.8.0-openjdk	Assignee:	Roman Kennke <rkennke>
Status:	CLOSED ERRATA	QA Contact:	OpenJDK QA <java-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	8.0	CC:	ahughes, dkutalek, jvanek, jwboyer, lmiksik, rkennke, zzambers
Target Milestone:	rc	Keywords:	Triaged
Target Release:	8.0	Flags:	pm-rhel: mirror+
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	java-1.8.0-openjdk-1.8.0.282.b02-0.1.ea.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1940511 (view as bug list)		Environment:
Last Closed:	2021-05-18 15:31:49 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1940511

Description Mike Millson 2020-12-14 17:28:18 UTC

There is a race condition in ShenadoahRootUpdater. Threads go into threads::oops_do() with a CodeBlobClosure and then they also go into ShenandoahCodeRoots::oops_do(). This leads to visiting nmethods concurrently, which is problematic because fix_relocations() is not MT-safe and will mess up oops in nmethods.

Comment 1 Mike Millson 2020-12-14 17:28:46 UTC

Fix already committed upstream:
https://mail.openjdk.java.net/pipermail/shenandoah-dev/2020-December/014082.html

Comment 16 errata-xmlrpc 2021-05-18 15:31:49 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (java-1.8.0-openjdk bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2021:1795