On 02/12/2012 11:31 AM, Michael S. Tsirkin wrote:
On Sun, Feb 12, 2012 at 07:07:43PM +0200, Michael S. Tsirkin wrote:
I got this assert when working on qemu: pci hotplug
callback failed so qdev_free was called.
(gdb) where
#0 0x00007ffff5fa1905 in raise () from /lib64/libc.so.6
#1 0x00007ffff5fa30e5 in abort () from /lib64/libc.so.6
#2 0x00007ffff7413a7f in g_assertion_message () from
/lib64/libglib-2.0.so.0
#3 0x00007ffff7414020 in g_assertion_message_expr () from
/lib64/libglib-2.0.so.0
#4 0x00007ffff7e452a9 in object_delete (obj=0x7ffff9124e60) at
qom/object.c:375
#5 0x00007ffff7e2f5d4 in qdev_free (dev=0x7ffff9124e60)
at /home/mst/scm/qemu/hw/qdev.c:250
#6 qdev_init (dev=0x7ffff9124e60) at /home/mst/scm/qemu/hw/qdev.c:149
#7 0x00007ffff7e2a7fe in qdev_device_add (opts=0x7ffff8b0d3a0)
at /home/mst/scm/qemu/hw/qdev-monitor.c:473
#8 0x00007ffff7e06da9 in device_init_func (opts=<value optimized out>,
opaque=<value optimized out>) at /home/mst/scm/qemu/vl.c:1754
#9 0x00007ffff7e3737a in qemu_opts_foreach (list=<value optimized out>,
func=
0x7ffff7e06d90<device_init_func>, opaque=0x0,
abort_on_failure=<value optimized out>) at qemu-option.c:1048
#10 0x00007ffff7e09cdb in main (argc=<value optimized out>, argv=<value
optimized out>,
envp=<value optimized out>) at /home/mst/scm/qemu/vl.c:3407
(gdb) frame 6
#6 qdev_init (dev=0x7ffff9124e60) at /home/mst/scm/qemu/hw/qdev.c:149
149 qdev_free(dev);
The problems seems to be that
pci_qdev_init calls do_pci_unregister_device on
hotplug error which will free the device twice?
Here's a reproducer to a similar error in property parsing:
qemu-system-x86_64 -enable-kvm -m 1G -drive file=/home/mst/rhel6.qcow2
-netdev user,id=bar -net
nic,netdev=bar,model=e1000,macaddr=52:54:00:12:34:57 -redir
tcp:8022::22 -device virtio-net-pci,netdev=foo,mac=5854:00:12:34:56
-netdev
tap,id=foo,ifname=msttap0,script=/home/mst/ifup,downscript=no,vhost=on
-vnc :1 -monitor stdio
Here's the fix. I need to do some regression testing and then I'll post as a
proper top-level patch.
Thanks for the report.
Regards,
Anthony Liguori
--
MST
>From b7fc6f1eb7c5e041eac7d610061a1be950707e5b Mon Sep 17 00:00:00 2001
From: Anthony Liguori <aligu...@us.ibm.com>
Date: Sun, 12 Feb 2012 11:36:24 -0600
Subject: [PATCH] device_add: don't add a /peripheral link until init is complete
Otherwise we end up with a dangling reference which causes qdev_free() to fail.
Reported-by: Michael Tsirkin <m...@redhat.com>
Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
hw/qdev-monitor.c | 18 ++++++++++--------
1 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 49f13ca..a310cc7 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -457,6 +457,16 @@ DeviceState *qdev_device_add(QemuOpts *opts)
id = qemu_opts_id(opts);
if (id) {
qdev->id = id;
+ }
+ if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) {
+ qdev_free(qdev);
+ return NULL;
+ }
+ if (qdev_init(qdev) < 0) {
+ qerror_report(QERR_DEVICE_INIT_FAILED, driver);
+ return NULL;
+ }
+ if (qdev->id) {
object_property_add_child(qdev_get_peripheral(), qdev->id,
OBJECT(qdev), NULL);
} else {
@@ -466,14 +476,6 @@ DeviceState *qdev_device_add(QemuOpts *opts)
OBJECT(qdev), NULL);
g_free(name);
}
- if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) {
- qdev_free(qdev);
- return NULL;
- }
- if (qdev_init(qdev) < 0) {
- qerror_report(QERR_DEVICE_INIT_FAILED, driver);
- return NULL;
- }
qdev->opts = opts;
return qdev;
}
--
1.7.4.1
