Re: [Qemu-devel] [Qemu-arm] [PATCH] sd: Fix "info qtree" on boards with SD cards

[Thomas Hanson]

The patch looks good.

Would it also be good to update bus_add_child() so that it NULL-checks
its "bus" parameter before dereferencing it?

-Tom

On 15 March 2016 at 10:56, Peter Maydell <address@hidden> wrote:
> The SD card object is not a SysBusDevice, so don't create it with
> qdev_create() if we're not assigning it to a specific bus; use
> object_new() instead.
>
> This was causing 'info qtree' to segfault on boards with SD cards,
> because qdev_create(NULL, TYPE_FOO) puts the created object on the
> system bus, and then we may try to run functions like sysbus_dev_print()
> on it, which fail when casting the object to SysBusDevice.
>
> (This is the same mistake that we made with the NAND device
> and fixed in commit 6749695eaaf346c1.)
>
> Reported-by: hitmoon <address@hidden>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> I assume that using qdev_create() for non-SysBus devices is
> OK if we are passing in a specific bus pointer, because we do
> this already for various things including PCI devices. The
> various "properly QOMified" uses of TYPE_SD_CARD do that; only
> this sd_init() function for the legacy uses doesn't.
> ---
>  hw/sd/sd.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/hw/sd/sd.c b/hw/sd/sd.c
> index 00c320d..1568057 100644
> --- a/hw/sd/sd.c
> +++ b/hw/sd/sd.c
> @@ -563,17 +563,19 @@ static const VMStateDescription sd_vmstate = {
>  /* Legacy initialization function for use by non-qdevified callers */
>  SDState *sd_init(BlockBackend *blk, bool is_spi)
>  {
> +    Object *obj;
>      DeviceState *dev;
>      Error *err = NULL;
>
> -    dev = qdev_create(NULL, TYPE_SD_CARD);
> +    obj = object_new(TYPE_SD_CARD);
> +    dev = DEVICE(obj);
>      qdev_prop_set_drive(dev, "drive", blk, &err);
>      if (err) {
>          error_report("sd_init failed: %s", error_get_pretty(err));
>          return NULL;
>      }
>      qdev_prop_set_bit(dev, "spi", is_spi);
> -    object_property_set_bool(OBJECT(dev), true, "realized", &err);
> +    object_property_set_bool(obj, true, "realized", &err);
>      if (err) {
>          error_report("sd_init failed: %s", error_get_pretty(err));
>          return NULL;
> --
> 1.9.1
>
>