On 12/10/18 1:04 PM, Peter Maydell wrote:
> Taking the address of a field in a packed struct is a bad idea, because
> it might not be actually aligned enough for that pointer type (and
> thus cause a crash on dereference on some host architectures). Newer
> versions of clang warn about this. Avoid the bug by not using the
> "modify in place" byte swapping functions.
>
> Patch produced with scripts/coccinelle/inplace-byteswaps.cocci
> (with a couple of long lines manually wrapped).
>
> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> s390 also has some warnings in hw/s390x/css.c which are going to
> be harder to fix, relating to taking the address of the 'pmcw' and
> 'scsw' fields in the SCHUB struct...
>
> hw/s390x/virtio-ccw.c | 42 ++++++++++++++++++++++--------------------
> 1 file changed, 22 insertions(+), 20 deletions(-)
>
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 212b3d3dead..c2b78c8e9b1 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -287,18 +287,18 @@ static int virtio_ccw_handle_set_vq(SubchDev *sch, CCW1
> ccw, bool check_len,
> }
> if (is_legacy) {
> ccw_dstream_read(&sch->cds, linfo);
> - be64_to_cpus(&linfo.queue);
> - be32_to_cpus(&linfo.align);
> - be16_to_cpus(&linfo.index);
> - be16_to_cpus(&linfo.num);
> + linfo.queue = be64_to_cpu(linfo.queue);
> + linfo.align = be32_to_cpu(linfo.align);
> + linfo.index = be16_to_cpu(linfo.index);
> + linfo.num = be16_to_cpu(linfo.num);
> ret = virtio_ccw_set_vqs(sch, NULL, &linfo);
> } else {
> ccw_dstream_read(&sch->cds, info);
> - be64_to_cpus(&info.desc);
> - be16_to_cpus(&info.index);
> - be16_to_cpus(&info.num);
> - be64_to_cpus(&info.avail);
> - be64_to_cpus(&info.used);
> + info.desc = be64_to_cpu(info.desc);
> + info.index = be16_to_cpu(info.index);
> + info.num = be16_to_cpu(info.num);
> + info.avail = be64_to_cpu(info.avail);
> + info.used = be64_to_cpu(info.used);
> ret = virtio_ccw_set_vqs(sch, &info, NULL);
> }
> sch->curr_status.scsw.count = 0;
> @@ -382,7 +382,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> features.features = 0;
> }
> ccw_dstream_rewind(&sch->cds);
> - cpu_to_le32s(&features.features);
> + features.features = cpu_to_le32(features.features);
> ccw_dstream_write(&sch->cds, features.features);
> sch->curr_status.scsw.count = ccw.count - sizeof(features);
> ret = 0;
> @@ -403,7 +403,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> ret = -EFAULT;
> } else {
> ccw_dstream_read(&sch->cds, features);
> - le32_to_cpus(&features.features);
> + features.features = le32_to_cpu(features.features);
> if (features.index == 0) {
> virtio_set_features(vdev,
> (vdev->guest_features &
> 0xffffffff00000000ULL) |
> @@ -546,7 +546,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> ret = -EFAULT;
> } else {
> ccw_dstream_read(&sch->cds, indicators);
> - be64_to_cpus(&indicators);
> + indicators = be64_to_cpu(indicators);
> dev->indicators = get_indicator(indicators, sizeof(uint64_t));
> sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
> ret = 0;
> @@ -567,7 +567,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> ret = -EFAULT;
> } else {
> ccw_dstream_read(&sch->cds, indicators);
> - be64_to_cpus(&indicators);
> + indicators = be64_to_cpu(indicators);
> dev->indicators2 = get_indicator(indicators, sizeof(uint64_t));
> sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
> ret = 0;
> @@ -588,14 +588,14 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> ret = -EFAULT;
> } else {
> ccw_dstream_read(&sch->cds, vq_config.index);
> - be16_to_cpus(&vq_config.index);
> + vq_config.index = be16_to_cpu(vq_config.index);
> if (vq_config.index >= VIRTIO_QUEUE_MAX) {
> ret = -EINVAL;
> break;
> }
> vq_config.num_max = virtio_queue_get_num(vdev,
> vq_config.index);
> - cpu_to_be16s(&vq_config.num_max);
> + vq_config.num_max = cpu_to_be16(vq_config.num_max);
> ccw_dstream_write(&sch->cds, vq_config.num_max);
> sch->curr_status.scsw.count = ccw.count - sizeof(vq_config);
> ret = 0;
> @@ -621,9 +621,11 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> if (ccw_dstream_read(&sch->cds, thinint)) {
> ret = -EFAULT;
> } else {
> - be64_to_cpus(&thinint.ind_bit);
> - be64_to_cpus(&thinint.summary_indicator);
> - be64_to_cpus(&thinint.device_indicator);
> + thinint.ind_bit = be64_to_cpu(thinint.ind_bit);
> + thinint.summary_indicator =
> + be64_to_cpu(thinint.summary_indicator);
> + thinint.device_indicator =
> + be64_to_cpu(thinint.device_indicator);
>
> dev->summary_indicator =
> get_indicator(thinint.summary_indicator,
> sizeof(uint8_t));
> @@ -654,8 +656,8 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
> break;
> }
> ccw_dstream_read_buf(&sch->cds, &revinfo, 4);
> - be16_to_cpus(&revinfo.revision);
> - be16_to_cpus(&revinfo.length);
> + revinfo.revision = be16_to_cpu(revinfo.revision);
> + revinfo.length = be16_to_cpu(revinfo.length);
> if (ccw.count < len + revinfo.length ||
> (check_len && ccw.count > len + revinfo.length)) {
> ret = -EINVAL;
>
