RFR: 8345569: [ubsan] filemap.cpp:2215:47: runtime error: applying non-zero offset 34358689792 to null pointer [v2]

[Matthias Baesken]

On Tue, 10 Dec 2024 05:10:32 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   address addition in FileMapInfo::heap_region_dumptime_address
>
> src/hotspot/share/memory/virtualspace.cpp line 439:
> 
>> 437: }
>> 438: 
>> 439: ATTRIBUTE_NO_UBSAN
> 
> So it complains about line 462:
> 
>   (_base < aligned_heap_base_min_address || _base + size > upper_bound))) {
> 
> and I presume the issue is `_base + size` could theoretically wrap to zero, which seems fixable via `size > upper_bound - _base` (though this pointer arithmetic should probably be converted to unsigned integer arithmetic to avoid UB).

Thanks for the hint,  I adjusted the coding the removed the ubsan-disable attribute/macro .

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PR Review Comment: https://git.openjdk.org/jdk/pull/22603#discussion_r1882351183