RFR: 8313796: AsyncGetCallTrace crash on unreadable interpreter method pointer

[Richard Startin]

On Mon, 7 Aug 2023 20:26:06 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> We have observed invalid pointers to the interpreted method at Datadog. The fix is based on a discussion with and a code snippet from @parttimenerd.
>
> src/hotspot/cpu/ppc/frame_ppc.cpp line 332:
> 
>> 330:   }
>> 331:   Method* m = *m_addr;
>> 332: 
> 
> Wouldn't it make more sense to define a function which takes a pointer to a (possible) method pointer and returns true if the method is valid?

It's not clear to me how the proposed solution could make less sense than another solution - could you elaborate please? Are you concerned about code repetition? I must say this code is already rather repetitive across the different architectures and, while I don't want to make it any worse in that respect, I'm trying to make the smallest possible change to prevent the observed crash from recurring.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15178#discussion_r1286366611