Hi, On free, chunks (the pieces of a pages used for smaller allocations) are junked and then validated after they leave the delayed free list. So after free, a chunk always contains junk bytes. This means that if we start with the right contents for a new page of chunks, we can *validate* instead of *write* junk bytes when (re)-using a chunk.
Wiht this, we can detect write-after-free when a chunk is recycled, not justy when a chunk is in the delayed free list. We do a little bit more work on initial allocation of a page of chunks and when re-using (as I validate now even on junk level 1), so some performance validation is needed. In my tests I did not see negative effects, even some slight improvemt (likely because validating junk bytes is cheaper than writing). But this needs tests to see if that is true in more cases than my tests. Also: some extra consistency checks for recallocaray(3) and fixes in error messages to make them more consistent, with man page bits. Plus regress additions. Please test and review! Thanks, -Otto