Re: [PATCH] nommu arch dont zero the anonymous mapping by addingUNINITIALIZE flag

[Alan Cox]

> I can't find mmap must give zeroed memory in the mmap manual.
> Is there any reason relying on anon mmap() giving zerod memory?

Its how all Unix/Linux like systems behave. You have to clear the memory
to something to deal with security on any kind of real system, and zero
is a good a value as any

> > Personally, I'd prefer to maintain compatibility with MMU-mode wherever
> > possible, but I'm happy with overrides like the MAP_UNINITIALISED flag
> > suggested.
> >
> Not necessary IMHO.

mmap() for anonymous memory pools should not normally be a hot path,
because the C library malloc is supposed to show some brains. If you need
special behaviour (eg for performance hacks) then create yourself
a /dev/zero like device which just maps uncleared pages. Its not much
code and it keeps special cases out of the core kernel.
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