Re: [PATCH v2] hw/nubus/nubus-virtio-mmio: Fix missing ERRP_GUARD() in nubus_virtio_mmio_realize()

[Philippe Mathieu-Daudé]

On 23/7/24 18:10, Philippe Mathieu-Daudé wrote:
> On 23/7/24 18:18, Zhao Liu wrote:
> > According to the comment in qapi/error.h, dereferencing @errp requires
> > ERRP_GUARD():
> >
> > * = Why, when and how to use ERRP_GUARD() =
> > *
> > * Without ERRP_GUARD(), use of the @errp parameter is restricted:
> > * - It must not be dereferenced, because it may be null.
> > ...
> > * ERRP_GUARD() lifts these restrictions.
> > *
> > * To use ERRP_GUARD(), add it right at the beginning of the function.
> > * @errp can then be used without worrying about the argument being
> > * NULL or &error_fatal.
> > *
> > * Using it when it's not needed is safe, but please avoid cluttering
> > * the source with useless code.
> >
> > In nubus_virtio_mmio_realize(), @errp is dereferenced without
> > ERRP_GUARD().
> >
> > Although nubus_virtio_mmio_realize() - as a DeviceClass.realize()
> > method - is never passed a null @errp argument, it should follow the
> > rules on @errp usage.  Add the ERRP_GUARD() there.
> >
> > Reviewed-by: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
> > ---
> > v2: Used Markus' words in commit message and added his r/b tag.
> > ---
> >   hw/nubus/nubus-virtio-mmio.c | 1 +
> >   1 file changed, 1 insertion(+)
>
> Patch queued, thanks!

Squashing:

-- >8 --
diff --git a/hw/nubus/nubus-virtio-mmio.c b/hw/nubus/nubus-virtio-mmio.c
index a5558d3ec28..7a98731c451 100644
--- a/hw/nubus/nubus-virtio-mmio.c
+++ b/hw/nubus/nubus-virtio-mmio.c
@@ -7,6 +7,7 @@
  */

 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "hw/nubus/nubus-virtio-mmio.h"

---

to avoid:

../hw/nubus/nubus-virtio-mmio.c:26:5: error: call to undeclared function 
'ERRP_GUARD'; ISO C99 and later do not support implicit function 
declarations [-Wimplicit-function-declaration]
    ERRP_GUARD();
    ^
1 error generated.

Better to test your patches ;)

Regards,

Phil.