brk's zero-fill behavior on VAXen

[Mike Tilson]

Several people have mentioned that it is important to clear memory
newly allocated to a process, for security reasons (since otherwise
a program could continually allocate memory in the hope of finding
interesting or secret data left over from previous processes.)

I'd like to point out that there is another very good reason to
set newly allocated memory to a fixed value:  buggy programs are much
less likely to exhibit non-deterministic behavior, which makes it
much easier to fix problems.  If newly allocated memory were initialized
with random values, then tracking down wild pointers, etc., would be much
harder.

/Michael Tilson, HCR, {utzoo,decvax,...}!hcr!mike