[Qemu-devel] [PATCH] virtio: do not take address of packed members

[Paolo Bonzini]

The address of a packed member is not packed, which may cause accesses
to unaligned pointers.  Avoid this by reading the packed value before
passing it to another function.

Cc: Jason Wang <address@hidden>
Cc: Peter Maydell <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Cc: address@hidden
Signed-off-by: Paolo Bonzini <address@hidden>
---
        Resubmission of the patch at 
https://patchwork.kernel.org/patch/10160229/
        The vhost part has since been fixed independently (commit
        69aff03064, "vhost-user: fix misaligned access to payload",
        2018-01-18).

 hw/char/virtio-serial-bus.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index d2dd8ab502..04e3ebe352 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -667,9 +667,9 @@ static void virtio_serial_save_device(VirtIODevice *vdev, 
QEMUFile *f)
 
     /* The config space (ignored on the far end in current versions) */
     get_config(vdev, (uint8_t *)&config);
-    qemu_put_be16s(f, &config.cols);
-    qemu_put_be16s(f, &config.rows);
-    qemu_put_be32s(f, &config.max_nr_ports);
+    qemu_put_be16(f, config.cols);
+    qemu_put_be16(f, config.rows);
+    qemu_put_be32(f, config.max_nr_ports);
 
     /* The ports map */
     max_nr_ports = s->serial.max_virtserial_ports;
-- 
2.17.1