RFR: 8352112: [ubsan] hotspot/share/code/relocInfo.cpp:130:37: runtime error: applying non-zero offset 18446744073709551614 to null pointer

[Boris Ulasevich]

On Tue, 18 Mar 2025 21:49:53 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> So why not do that by setting valid address to _mutable_data and done?

Yes. We already have _immutable_data set to blob_end(). By setting _mutable_data to the same value, we align code with _immutable_data and eliminate the UBSAN error, and there's no need to modify RelocIterator.

> Actually I can do this (in both constructors):
> |   -  _mutable_data(nullptr), 
> |   +  _mutable_data(header_begin() + size), // default value is blob_end()
> |
> |    -    _mutable_data = blob_end();
> |    +    assert(_mutable_data == blob_end(), "sanity");
>
> What do you think?

Good. It seems correct. Thank you!

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PR Comment: https://git.openjdk.org/jdk/pull/24102#issuecomment-2734958828