hw: Fix error API violation around object_property_set_link()

The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

virtio_gpu_pci_base_realize(), virtio_vga_base_realize(),
sparc32_ledma_device_realize(), sparc32_dma_realize(),
sparc32_dma_realize() xilinx_axidma_realize(), mips_cps_realize(),
macio_realize_ide(), xilinx_enet_realize(), and
virtio_iommu_pci_realize() are wrong that way: they reuse the argument
they pass to object_property_set_link() for another call.

Harmless, because object_property_set_link() can't actually fail for
them: it fails when the property doesn't exist, is not settable, or
its .check() method fails.  Fix by passing &error_abort instead.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Alistair Francis <alistair@alistair23.me>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>
Cc: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200630090351.1247703-16-armbru@redhat.com>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

2 files changed, 5 insertions, 13 deletions

diff --git a/hw/dma/sparc32_dma.c b/hw/dma/sparc32_dma.c
index f02aca6..2d7dbbb 100644
--- a/hw/dma/sparc32_dma.c
+++ b/hw/dma/sparc32_dma.c
@@ -346,7 +346,7 @@ static void sparc32_ledma_device_realize(DeviceState *dev, Error **errp)
     d = qdev_new(TYPE_LANCE);
     object_property_add_child(OBJECT(dev), "lance", OBJECT(d));
     qdev_set_nic_properties(d, nd);
-    object_property_set_link(OBJECT(d), OBJECT(dev), "dma", errp);
+    object_property_set_link(OBJECT(d), OBJECT(dev), "dma", &error_abort);
     sysbus_realize_and_unref(SYS_BUS_DEVICE(d), &error_fatal);
 }
 
@@ -379,7 +379,7 @@ static void sparc32_dma_realize(DeviceState *dev, Error **errp)
     }
 
     espdma = qdev_new(TYPE_SPARC32_ESPDMA_DEVICE);
-    object_property_set_link(OBJECT(espdma), iommu, "iommu", errp);
+    object_property_set_link(OBJECT(espdma), iommu, "iommu", &error_abort);
     object_property_add_child(OBJECT(s), "espdma", OBJECT(espdma));
     sysbus_realize_and_unref(SYS_BUS_DEVICE(espdma), &error_fatal);
 
@@ -394,7 +394,7 @@ static void sparc32_dma_realize(DeviceState *dev, Error **errp)
                                 sysbus_mmio_get_region(sbd, 0));
 
     ledma = qdev_new(TYPE_SPARC32_LEDMA_DEVICE);
-    object_property_set_link(OBJECT(ledma), iommu, "iommu", errp);
+    object_property_set_link(OBJECT(ledma), iommu, "iommu", &error_abort);
     object_property_add_child(OBJECT(s), "ledma", OBJECT(ledma));
     sysbus_realize_and_unref(SYS_BUS_DEVICE(ledma), &error_fatal);
 
diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
index 6a9df2c..a069637 100644
--- a/hw/dma/xilinx_axidma.c
+++ b/hw/dma/xilinx_axidma.c
@@ -537,7 +537,6 @@ static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
     XilinxAXIDMAStreamSlave *ds = XILINX_AXI_DMA_DATA_STREAM(&s->rx_data_dev);
     XilinxAXIDMAStreamSlave *cs = XILINX_AXI_DMA_CONTROL_STREAM(
                                                             &s->rx_control_dev);
-    Error *local_err = NULL;
     int i;
 
     object_property_add_link(OBJECT(ds), "dma", TYPE_XILINX_AXI_DMA,
@@ -548,11 +547,8 @@ static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
                              (Object **)&cs->dma,
                              object_property_allow_set_link,
                              OBJ_PROP_LINK_STRONG);
-    object_property_set_link(OBJECT(ds), OBJECT(s), "dma", &local_err);
-    object_property_set_link(OBJECT(cs), OBJECT(s), "dma", &local_err);
-    if (local_err) {
-        goto xilinx_axidma_realize_fail;
-    }
+    object_property_set_link(OBJECT(ds), OBJECT(s), "dma", &error_abort);
+    object_property_set_link(OBJECT(cs), OBJECT(s), "dma", &error_abort);
 
     for (i = 0; i < 2; i++) {
         struct Stream *st = &s->streams[i];
@@ -567,10 +563,6 @@ static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
 
     address_space_init(&s->as,
                        s->dma_mr ? s->dma_mr : get_system_memory(), "dma");
-    return;
-
-xilinx_axidma_realize_fail:
-    error_propagate(errp, local_err);
 }
 
 static void xilinx_axidma_init(Object *obj)