Over on [1], Tom mentioned that we might want to rethink the decision to not protect chunk headers with Valgrind. That thread fixed a bug that was accessing array element -1, which effectively was reading the MemoryChunk at the start of the allocated chunk as an array element.
I wrote a patch to adjust the Valgrind macros to mark the MemoryChunks as NOACCESS and that finds the bug reported on that thread (with the fix for it reverted). I didn't quite get a clear run at committing the changes during the v16 cycle, but wondering since they're really just Valgrind macro changes if anyone would object to doing it now? I know there are a few people out there running sqlsmith and/or sqlancer under Valgrind. It would be good to have this in so we could address any new issues the attached patch might help them highlight. Any objections? (Copying in Tom and Richard same as original thread. Reposting for more visibility of this change) David
protect_MemoryChunks_with_Valgrind.patch
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