On Tue, 27 Aug 2024 14:45:37 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> When working on startup improvements, I noticed that the method handle >> returned by `MemoryLayout::offsetHandle` can overflow if the client calls >> the handle with a base offset that is too big. >> >> In other similar situations, the layout API always fails with >> `ArithmeticException` (see `MemoryLayout::scale`), so we should do the same >> here. >> >> The fix is to use a `Math::addExact(long, long)` for the outermost add >> operation in the computation of the offset method handle. That outermost >> computation in fact is the only one that can overflow: it is an addition >> between a user-provided base offset `B` and a layout offset `L`. `L` is >> guaranteed not to overflow, by construction (as `L` is derived from a layout >> path). But `B` + `L` might overflow, so the new logic checks for that. > > Maurizio Cimadamore has updated the pull request with a new target base due > to a merge or a rebase. The pull request now contains three commits: > > - Merge branch 'master' into offset_overflow > - Merge branch 'master' into offset_overflow > - Initial push Merge ok ;-) ------------- Marked as reviewed by pminborg (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/20662#pullrequestreview-2265544939
