[Qemu-devel] [STABLE 1/3] Fix -usbdevice crash

[Luiz Capitulino <lcapitulino@redhat.com>]

From: Paul Brook <paul@codesourcery.com>

If -usbdevice is used on a machine with no USB busses, usb_create
will fail and return NULL.  Patch below handles this failure gracefully
rather than crashing when we try to init the device.

Signed-off-by: Paul Brook <paul@codesourcery.com>
(cherry picked from commit d44168fffa07fc57e61a37da65e9348661dec887)
---
 hw/usb-bus.c    |    3 +++
 hw/usb-msd.c    |    3 +++
 hw/usb-net.c    |    3 +++
 hw/usb-serial.c |    3 +++
 4 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index 54027df..7c82314 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -102,6 +102,9 @@ USBDevice *usb_create(USBBus *bus, const char *name)
 USBDevice *usb_create_simple(USBBus *bus, const char *name)
 {
     USBDevice *dev = usb_create(bus, name);
+    if (!dev) {
+        hw_error("Failed to create USB device '%s'\n", name);
+    }
     qdev_init_nofail(&dev->qdev);
     return dev;
 }
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 1fb62ad..9d8d044 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -592,6 +592,9 @@ static USBDevice *usb_msd_init(const char *filename)
 
     /* create guest device */
     dev = usb_create(NULL /* FIXME */, "usb-storage");
+    if (!dev) {
+        return NULL;
+    }
     qdev_prop_set_drive(&dev->qdev, "drive", dinfo);
     if (qdev_init(&dev->qdev) < 0)
         return NULL;
diff --git a/hw/usb-net.c b/hw/usb-net.c
index cfd2f62..6875f11 100644
--- a/hw/usb-net.c
+++ b/hw/usb-net.c
@@ -1491,6 +1491,9 @@ static USBDevice *usb_net_init(const char *cmdline)
     }
 
     dev = usb_create(NULL /* FIXME */, "usb-net");
+    if (!dev) {
+        return NULL;
+    }
     qdev_set_nic_properties(&dev->qdev, &nd_table[idx]);
     qdev_init_nofail(&dev->qdev);
     return dev;
diff --git a/hw/usb-serial.c b/hw/usb-serial.c
index c3f3401..1410b11 100644
--- a/hw/usb-serial.c
+++ b/hw/usb-serial.c
@@ -594,6 +594,9 @@ static USBDevice *usb_serial_init(const char *filename)
         return NULL;
 
     dev = usb_create(NULL /* FIXME */, "usb-serial");
+    if (!dev) {
+        return NULL;
+    }
     qdev_prop_set_chr(&dev->qdev, "chardev", cdrv);
     if (vendorid)
         qdev_prop_set_uint16(&dev->qdev, "vendorid", vendorid);
-- 
1.7.1.231.gd0b16