On Wed, Oct 31, 2012 at 01:08:16PM +0200, Orit Wasserman wrote:
> On 10/31/2012 05:43 AM, David Gibson wrote:
> > The code for migrating (or savevm-ing) memory pages starts off by creating
> > a dirty bitmap and filling it with 1s. Except, actually, because bit
> > addresses are 0-based it fills every bit except bit 0 with 1s and puts an
> > extra 1 beyond the end of the bitmap, potentially corrupting unrelated
> > memory. Oops. This patch fixes it.
> >
> > Signed-off-by: David Gibson <[email protected]>
> > ---
> > arch_init.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch_init.c b/arch_init.c
> > index e6effe8..b75a4c5 100644
> > --- a/arch_init.c
> > +++ b/arch_init.c
> > @@ -568,7 +568,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> > int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
> >
> > migration_bitmap = bitmap_new(ram_pages);
> > - bitmap_set(migration_bitmap, 1, ram_pages);
> > + bitmap_set(migration_bitmap, 0, ram_pages);
> > migration_dirty_pages = ram_pages;
> >
> > bytes_transferred = 0;
> >
> You are correct, good catch.
> Reviewed-by: Orit Wasserman <[email protected]>
Juan,
Sorry, forgot to CC you on the original mailing here, which I should
have done. This is a serious bug in the migration code and we should
apply to mainline ASAP.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
