1. Optionally add random "canaries" to the end of an allocation. This
requires increasing the internal size of the allocation slightly, which
probably results in a large effective increase with current power of two
sizing. Therefore, this option is only enabled via 'C'.
2. When writing junk (0xdf) to freed chunks (current default behavior),
check that the junk is still intact when finally freeing the delayed chunk
to catch some potential use after free. This should be pretty cheap so
there's no option to control it separately.
ok deraadt tb