Re: [RFC][PATCH] Cross Memory Attach

[Peter Zijlstra]

On Thu, 2010-09-16 at 09:54 -0700, Linus Torvalds wrote:
> On Thu, Sep 16, 2010 at 9:27 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > On Wed, 2010-09-15 at 08:11 -0700, Linus Torvalds wrote:
> >
> >>    if (copy_to)
> >>       ret = copy_from_user(..);
> >>    else
> >>       ret = copy_to_user(..);
> >>    kunmap(process_pages[i]);
> >>    if (ret)
> >>       goto out;
> >
> > Shouldn't we be using kmap_atomic()
> 
> Over a copy_to/from_user? Not bloody likely.

Gah, indeed. OK, since its not nested kmap() should indeed work. The
alternative is using get_user_pages() on both address spaces, but I
guess that makes things unnecessarily complex.


--
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/