Some skins, such as helgrind, use VG_(describe_addr)() as part of their error reporting. VG_(describe_addr)() looks at the VCPU state (in the base-block) to try to work out a symbolic description for a particular address in memory. At present, the codegen doesn't keep the baseblock up to date before calling a helper, so describe_addr is working with useless values. Since saving the VCPU state could be quite expensive, there should be a mechanism which allows skins to indicate what state they need saved before which calls. Note that this is an generalization of the current policy, which always saves %ESP to the baseblock before a helper call.
If the origin Members still active on this or have an Ticket, MR or PR (as in Invent or on the Kanban), can you insert it to the Bug Report? Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with either Plasma 5.27 (the current LTS version) or Plasma 6.3 (the latest released version). Regards, [Tizen](https://invent.kde.org/tizen)
Valgrind is a guest in the KDE bug tracker but it does not use KDE development processes so please ignore that last comment.