RFR: 8280601: ClhsdbThreadContext.java test is triggering codecache related assert in PointerFinder.find() [v2]

[Chris Plummer]

On Fri, 28 Jan 2022 04:07:40 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> It's possible for an address to be in the codecache but not in any CodeBlob. Don't assert in this case.
>> 
>> Also I ran into a couple of other asserts listed below. It looks like since dumping the threadcontext can result in using PointerFinder with fairly random addresses, it is doing a much better job of stress testing PointerFinder than is done by other tests. The root issue in all these asserts is that a random address in the codecache can either be outside of any CodeBlob, or can map to a CodeBlob that is not yet initialized or could even have been freed. PointerFinder and PointerLocation need to be prepared to handled these asserts, and any other exception thrown. 
>> 
>> sun.jvm.hotspot.utilities.AssertionFailure: found wrong CodeBlob
>> at jdk.hotspot.agent/sun.jvm.hotspot.utilities.Assert.that(Assert.java:32)
>> at jdk.hotspot.agent/sun.jvm.hotspot.code.CodeCache.findBlobUnsafe(CodeCache.java:140)
>> at jdk.hotspot.agent/sun.jvm.hotspot.utilities.PointerFinder.find(PointerFinder.java:138)
>> at jdk.hotspot.agent/sun.jvm.hotspot.runtime.JavaThread.printThreadContextOn(JavaThread.java:493)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor$46.doit(CommandProcessor.java:1702)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:2215)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:2185)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.run(CommandProcessor.java:2056)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.run(CLHSDB.java:112)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.main(CLHSDB.java:44)
>> at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runCLHSDB(SALauncher.java:281)
>> at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:500)
>> 
>> sun.jvm.hotspot.utilities.AssertionFailure: Should have found CodeBlob
>> at jdk.hotspot.agent/sun.jvm.hotspot.utilities.Assert.that(Assert.java:32)
>> at jdk.hotspot.agent/sun.jvm.hotspot.utilities.PointerFinder.find(PointerFinder.java:140)
>> at jdk.hotspot.agent/sun.jvm.hotspot.runtime.JavaThread.printThreadContextOn(JavaThread.java:493)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor$46.doit(CommandProcessor.java:1702)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:2215)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:2185)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.run(CommandProcessor.java:2056)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.run(CLHSDB.java:112)
>> at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.main(CLHSDB.java:44)
>> at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runCLHSDB(SALauncher.java:281)
>> at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:500)
>
> Chris Plummer has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Guard against invalid CodeBlobs that may throw exceptions.

Thanks Serguei and Kevin!

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PR: https://git.openjdk.java.net/jdk/pull/7217