krealloc()

A quick check of mm/util.c confirms this. Initially I had no idea what the network developers are thinking. If the new size will fit in the original allocation, then no locks will be taken, no sleeping, etc.

But then it occured to me that the code that needs to do the expansion may be holding locks and may be in interrupt context. Preparing to call krealloc may require releasing locks, etc, since it could take locks.