Hi David, On 01/23/20 15:46 pm, David Holmes wrote: > > So on 32-bit size_t is 32-bit and so may have ~half the capacity allowed > for by the jlong size variable. On 64-bit overflow is not possible > because jlong is signed and size_t is not. > > So we only need an overflow check on 32-bit.
OK. So wrap the check in #ifndef _LP64? > > But your checks don't look correct to me. If size is already aligned to > HeapWordSize then "sz < (size_t)size" won't be true but you already have > a completely bogus value for sz when you truncated size to 32-bits. > On a 32-bit system we already know the upper 32-bits of `size' are zero because Unsafe.checkSize() checks this prior to calling the native function, so I think the cast is OK. Thanks, Nick
