Re: [PATCH] hw/display/xenfb: Replace unreachable code by abort()

[Markus Armbruster <armbru@redhat.com>]

Bernhard Beschow <shentey@gmail.com> writes:

> Am 13. Oktober 2025 11:10:45 UTC schrieb Markus Armbruster <armbru@redhat.com>:
>>Ping?
>>
>>Markus Armbruster <armbru@redhat.com> writes:
>>
>>> xenfb_mouse_event() has a switch statement whose controlling
>>> expression move->axis is an enum InputAxis.  The enum values are
>>> INPUT_AXIS_X and INPUT_AXIS_Y, encoded as 0 and 1.  The switch has a
>>> case for both axes.  In addition, it has an unreachable default label.
>>> This convinces Coverity that move->axis can be greater than 1.  It
>>> duly reports a buffer overrun when it is used to subscript an array
>>> with two elements.
>>>
>>> Replace the unreachable code by abort().
>>>
>>> Resolves: Coverity CID 1613906
>>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>>> ---
>>>  hw/display/xenfb.c | 3 +--
>>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c
>>> index 22822fecea..5e6c691779 100644
>>> --- a/hw/display/xenfb.c
>>> +++ b/hw/display/xenfb.c
>>> @@ -283,8 +283,7 @@ static void xenfb_mouse_event(DeviceState *dev, QemuConsole *src,
>>>                  scale = surface_height(surface) - 1;
>>>                  break;
>>>              default:
>>> -                scale = 0x8000;
>>> -                break;
>>> +                abort();
>
> Don't we prefer g_assert_not_reached() these days, for more expressiveness?

See https://lore.kernel.org/qemu-devel/87v7nbdwfx.fsf@pond.sub.org/

[...]