Re: [PATCH 4/4] Swap migration V3: sys_migrate_pages interface

From: Ray Bryant
Date: Fri Oct 21 2005 - 11:10:29 EST


On Friday 21 October 2005 10:47, Christoph Lameter wrote:
> On Fri, 21 Oct 2005, Paul Jackson wrote:
> > * Christoph - what is the permissions check on sys_migrate_pages()?
> > It would seem inappropriate for 'guest' to be able to move the
> > memory of 'root'.
>
> The check is missing.
>

That code used to be there. Basically the check was that if you could
legally send a signal to the process, you could migrate its memory.
Go back and look and my patches for this.

Why was this dropped, arbitrarily?

> Maybe we could add:
>
> if (!capable(CAP_SYS_RESOURCE))
> return -EPERM;
>
> Then we may also decide that root can move any process anywhere and drop
> the retrieval of the mems_allowed from the other task.
>
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--
Ray Bryant
AMD Performance Labs Austin, Tx
512-602-0038 (o) 512-507-7807 (c)

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