On Wed, 2 Sep 2015 11:25:22 +0800
Jason Wang <jasow...@redhat.com> wrote:
> There's no need to adjust endianness for zero length eventfd since the
> data wrote was actually ignored by kernel. So skip the adjust in this
> case to fix a possible crash when trying to use wildcard mmio eventfd
> in ppc.
>
> Cc: Greg Kurz <gk...@linux.vnet.ibm.com>
> Cc: Peter Maydell <peter.mayd...@linaro.org>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Signed-off-by: Jason Wang <jasow...@redhat.com>
> ---
Indeed, this patch prevents the crash to occur on ppc64.
Acked-by: Greg Kurz <gk...@linux.vnet.ibm.com>
> memory.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/memory.c b/memory.c
> index 0d8b2d9..de2d999 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1653,7 +1653,9 @@ void memory_region_add_eventfd(MemoryRegion *mr,
> };
> unsigned i;
>
> - adjust_endianness(mr, &mrfd.data, size);
> + if (size) {
> + adjust_endianness(mr, &mrfd.data, size);
> + }
> memory_region_transaction_begin();
> for (i = 0; i < mr->ioeventfd_nb; ++i) {
> if (memory_region_ioeventfd_before(mrfd, mr->ioeventfds[i])) {
> @@ -1686,7 +1688,9 @@ void memory_region_del_eventfd(MemoryRegion *mr,
> };
> unsigned i;
>
> - adjust_endianness(mr, &mrfd.data, size);
> + if (size) {
> + adjust_endianness(mr, &mrfd.data, size);
> + }
> memory_region_transaction_begin();
> for (i = 0; i < mr->ioeventfd_nb; ++i) {
> if (memory_region_ioeventfd_equal(mrfd, mr->ioeventfds[i])) {
