On 3/30/07, David Howells <[EMAIL PROTECTED]> wrote:
Aubrey Li <[EMAIL PROTECTED]> wrote:
> malloc() allocates size bytes and returns a pointer to the allocated memory.
> ****The memory is not cleared.****
But this is *not* malloc(). It's mmap(). Are you prepared to guarantee that
there are no applications out there that don't rely on anon mmap() giving
zeroed memory?
I can't find mmap must give zeroed memory in the mmap manual.
Is there any reason relying on anon mmap() giving zerod memory?
Can you show me an example?
The MMU-mode clearing is done for security reasons - there shouldn't be any
leakage between processes, and because the zero page can just be faulted in.
NO-MMU can't do this clearing. Performance is down.
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.
-Aubrey
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
