unitialized memory is all zeros...why not garbage instead?

[Dag-Erling Smørgrav]

Mike Hunter <mhunter at ack.berkeley.edu> writes:
> I have a feeling that I'm missing something really obvious, but I'm having
> trouble understanding why the following program:
> [...]
> Never prints anything but "0"'s.

Because the kernel always hands processes pre-zeroed pages.

> I ran less up to my hw.physmem by feeding it /dev/random and watching
> top, and then ran the program, so I "know" there was tons of non-zero
> bits in memory.

If your program had been able to see leftovers from less in its own
address space, we'd have a huge security hole on our hands.

> I'm curious because I am worried about information leaks between processes
> on the same machine...did somebody decide to solve this problem while I
> wasn't paying attention?  :)

It's always been this way.

DES
-- 
Dag-Erling Smørgrav - des at des.no