Re: QEMU v5.2.0: object_new_with_type: assertion failed: (type != NULL)

[Paolo Bonzini]

On 05/02/21 14:03, Philippe Mathieu-Daudé wrote:
> On 2/5/21 12:48 PM, Bharat Bhushan wrote:
> > Hi All,
> >
> > I am using QEMU version "v5.2.0" and getting below error when running on arm64
> >
> > $ qemu-system-aarch64 --version
> >
> > ERROR:../qom/object.c:711:object_new_with_type: assertion failed: (type != NULL)
> > Bail out! ERROR:../qom/object.c:711:object_new_with_type: assertion failed: 
> > (type != NULL)
> >
> > Running GDB give below information.
> > Is this something known.
> >
> > (gdb) run
> > Starting program: /root/qemu-system-aarch64
> > [Thread debugging using libthread_db enabled]
> > Using host libthread_db library "/lib64/libthread_db.so.1".
> > [New Thread 0xfffff703ed90 (LWP 5212)]
> > **
> > ERROR:../qom/object.c:711:object_new_with_type: assertion failed: (type != NULL)
> > Bail out! ERROR:../qom/object.c:711:object_new_with_type: assertion failed: 
> > (type != NULL)
> >
> > Thread 1 "qemu-system-aar" received signal SIGABRT, Aborted.
> > 0x0000fffff73e380c in raise () from /lib64/libc.so.6
> > (gdb) bt
> > #0  0x0000fffff73e380c in raise () from /lib64/libc.so.6
> > #1  0x0000fffff73d0bcc in abort () from /lib64/libc.so.6
> > #2  0x0000fffff7b7c058 in g_assertion_message () from /lib64/libglib-2.0.so.0
> > #3  0x0000fffff7b7c0b8 in g_assertion_message_expr () from 
> > /lib64/libglib-2.0.so.0
> > #4  0x0000aaaaab2b880c in object_new_with_type (type=<optimized out>) at 
> > ../qom/object.c:711
> > #5  0x0000aaaaab2b8870 in object_new (typename=typename@entry=0xaaaaab50a668 
> > "container") at ../qom/object.c:744
>
> How can you not have "container" registered? libqom is a core part
> of QEMU... Cc'ing Gerd for the module initialization.

The problem seems to be that chardev/chardev-sysemu.c's register_types 
is not exactly a QOM hook, it calls qemu_add_machine_init_done_notifier. 
 And for some weird reason machine_init_done is already true when it is 
called.

Bharat, you could try to set a watchpoint on machine_init_done and see 
who sets it to true.  Alternatively you can try to backport 
5a1ee6077b89ee9a803aaf8d1c98004701f63684, which gets rid of the code 
that is involved here.

Paolo

> > #6  0x0000aaaaab2b9ec4 in object_get_root () at ../qom/object.c:1674
> > #7  0x0000aaaaab2a4c0c in get_chardevs_root () at ../chardev/char.c:50
> > #8  0x0000aaaaaaf9f2b4 in chardev_machine_done_hook (notifier=<optimized out>, 
> > unused=<optimized out>)
> >      at ../chardev/chardev-sysemu.c:45
> > #9  0x0000aaaaab3d4ae8 in module_call_init (type=type@entry=MODULE_INIT_QOM) at 
> > ../util/module.c:106
> > #10 0x0000aaaaab235000 in qemu_init (argc=1, argv=0xfffffffffcb8, envp=<optimized 
> > out>) at ../softmmu/vl.c:2916
> > #11 0x0000aaaaaad9e084 in main (argc=<optimized out>, argv=<optimized out>, 
> > envp=<optimized out>) at ../softmmu/main.c:49
> > (gdb)
> >
> > Thanks
> > -Bharat