On Thu, 2011-08-11 at 13:07 +0800, Liming Wang wrote: > If num_pages is negative, balloon will make kernel crash with > "out of memory". So we check this value to avoid it to be negative. > > Signed-off-by: Liming Wang <[email protected]> > --- > tools/kvm/virtio/balloon.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/tools/kvm/virtio/balloon.c b/tools/kvm/virtio/balloon.c > index 854d04b..0223ee4 100644 > --- a/tools/kvm/virtio/balloon.c > +++ b/tools/kvm/virtio/balloon.c > @@ -222,8 +222,13 @@ static void handle_sigmem(int sig) > { > if (sig == SIGKVMADDMEM) > bdev.config.num_pages += 256; > - else > + else { > bdev.config.num_pages -= 256; > + if ((s32)bdev.config.num_pages < 0){
imo it's worth doing this check before the decrement instead of casting to signed here. you also need to wrap the 'if ()' with parenthesis if you add them to the 'else' case. > + bdev.config.num_pages = 0; > + return; > + } > + } > > /* Notify that the configuration space has changed */ > bdev.isr = VIRTIO_PCI_ISR_CONFIG; -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
