Re: [PATCH][RFC][0/4] InfiniBand userspace verbs implementation

Troy Benjegerdes
2005-04-11T18:02:51Z

On Mon, Apr 11, 2005 at 09:56:53AM -0700, Roland Dreier wrote:
> Troy> Is there a check in the kernel that the memory is actually
> Troy> mlock()ed?
>
> No.
>
> Troy> What if a malicious (or broken) application does
> Troy> ibv_reg_mr() but doesn't lock the memory? Does the IB card
> Troy> get a physical address for a page that might get swapped
> Troy> out?
>
> No, the kernel does get_user_pages(). So the pages that the HCA gets
> will not be swapped or used for anything else. The only thing a
> malicious userspace app can do is screw itself up.
>
> - R.

Do we even need the mlock in userspace then?