Re: [PATCH] Extra check in grant table code for mapping of shared frame

[Tim Deegan <tim@xen.org>]

At 12:17 +0100 on 17 Sep (1347884247), Keir Fraser wrote:
> Probably needs Tim to comment on it. Assuming he's any wiser about this code
> than the rest of us. ;)

Looks OK to my limited understanding. :)

Tim.

> On 17/09/2012 12:00, "Andres Lagar-Cavilla" <andreslc@gridcentric.ca> wrote:
> 
> > pingŠ
> > Thanks,
> > Andres
> > On Sep 13, 2012, at 11:27 AM, Andres Lagar-Cavilla wrote:
> > 
> >> xen/common/grant_table.c |  9 ++++++---
> >> 1 files changed, 6 insertions(+), 3 deletions(-)
> >> 
> >> 
> >> Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
> >> 
> >> diff -r 5ce5b53ea68f -r 40b91bed1275 xen/common/grant_table.c
> >> --- a/xen/common/grant_table.c
> >> +++ b/xen/common/grant_table.c
> >> @@ -649,9 +649,12 @@ __gnttab_map_grant_ref(
> >>     }
> >>     else if ( owner == rd || owner == dom_cow )
> >>     {
> >> -        if ( gnttab_host_mapping_get_page_type(op, ld, rd) &&
> >> -             !get_page_type(pg, PGT_writable_page) )
> >> -            goto could_not_pin;
> >> +        if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
> >> +        {
> >> +            if ( (owner == dom_cow) ||
> >> +                 !get_page_type(pg, PGT_writable_page) )
> >> +                goto could_not_pin;
> >> +        }
> >> 
> >>         nr_gets++;
> >>         if ( op->flags & GNTMAP_host_map )
> > 
> 
>