Re: [RFC][PATCH 6/8] mm: handle_speculative_fault()

From: Linus Torvalds
Date: Thu Jan 07 2010 - 19:40:05 EST




On Fri, 8 Jan 2010, KAMEZAWA Hiroyuki wrote:
>
> Hmm, do_brk() sometimes unmap conflicting mapping. Isn't it be a problem ?

No. For two reasons:

- sys_brk() doesn't actually do that (see the "find_vma_intersection()"
call). I'm not sure why do_brk() does, but it might have to do with
execve().

- the patch I sent out just falls back to the old code if it finds
something fishy, so it will do whatever do_brk() does regardless.

(Yes, brk() does unmap the old brk for the _shrinking_ case, of course.
Again, the patch I sent just falls back to the old behavior in that case)

Linus

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/