On Fri, 24 Mar 2023 16:54:59 GMT, Thomas Stuefe <stu...@openjdk.org> wrote:
>> src/hotspot/share/runtime/lockStack.cpp line 42:
>>
>>> 40:
>>> 41: #ifndef PRODUCT
>>> 42: void LockStack::validate(const char* msg) const {
>>
>> Would you also like to check there are no `nullptr` elements on stack here?
>
> Please also verify against over- and underflow, and better than just null
> checks check that every oop really is an oop. I added this to my code:
>
> assert((_offset <= end_offset()), "lockstack overflow: _offset %d
> end_offset %d", _offset, end_offset());
> assert((_offset >= start_offset()), "lockstack underflow: _offset %d
> end_offset %d", _offset, start_offset());
> int end = to_index(_offset);
> for (int i = 0; i < end; i++) {
> assert(oopDesc::is_oop(_base[i]), "index %i: not an oop (" PTR_FORMAT
> ")", i, p2i(_base[i]));
> ...
Just realized that my proposal of oop-checking does not work since during GC
oop can be moved and will temporarily be invalid.
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PR Review Comment: https://git.openjdk.org/jdk/pull/10907#discussion_r1150847182
