Re: [Qemu-devel] [PATCH v2] qemu-thread: fix qemu_thread_set_name() race in qemu_thread_create()

[Paolo Bonzini <pbonzini@redhat.com>]

On 05/01/2017 09:36, Hailiang Zhang wrote:
> On 2017/1/4 19:59, Paolo Bonzini wrote:
>> On 04/01/2017 02:32, zhanghailiang wrote:
>>> From: Caoxinhua <caoxinhua@huawei.com>
>>>
>>> QEMU will crash with the follow backtrace if the new created thread
>>> exited before
>>> we call qemu_thread_set_name() for it.
>>>
>>>    (gdb) bt
>>>    #0 0x00007f9a68b095d7 in __GI_raise (sig=sig@entry=6) at
>>> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
>>>    #1 0x00007f9a68b0acc8 in __GI_abort () at abort.c:90
>>>    #2 0x00007f9a69cda389 in PAT_abort () from
>>> /usr/lib64/libuvpuserhotfix.so
>>>    #3 0x00007f9a69cdda0d in patchIllInsHandler () from
>>> /usr/lib64/libuvpuserhotfix.so
>>>    #4 <signal handler called>
>>>    #5 pthread_setname_np (th=140298470549248,
>>> name=name@entry=0x8cc74a "io-task-worker") at
>>> ../nptl/sysdeps/unix/sysv/linux/pthread_setname.c:49
>>>    #6 0x00000000007f5f20 in qemu_thread_set_name
>>> (thread=thread@entry=0x7ffd2ac09680, name=name@entry=0x8cc74a
>>> "io-task-worker") at util/qemu_thread_posix.c:459
>>>    #7 0x00000000007f679e in qemu_thread_create
>>> (thread=thread@entry=0x7ffd2ac09680, name=name@entry=0x8cc74a
>>> "io-task-worker",start_routine=start_routine@entry=0x7c1300
>>> <qio_task_thread_worker>, arg=arg@entry=0x7f99b8001720,
>>> mode=mode@entry=1) at util/qemu_thread_posix.c:498
>>>    #8 0x00000000007c15b6 in qio_task_run_in_thread
>>> (task=task@entry=0x7f99b80033d0, worker=worker@entry=0x7bd920
>>> <qio_channel_socket_connect_worker>, opaque=0x7f99b8003370,
>>> destroy=0x7c6220 <qapi_free_SocketAddress>) at io/task.c:133
>>>    #9 0x00000000007bda04 in qio_channel_socket_connect_async
>>> (ioc=0x7f99b80014c0, addr=0x37235d0, callback=callback@entry=0x54ad00
>>> <qemu_chr_socket_connected>, opaque=opaque@entry=0x38118b0,
>>> destroy=destroy@entry=0x0) at io/channel_socket.c:191
>>>    #10 0x00000000005487f6 in socket_reconnect_timeout
>>> (opaque=0x38118b0) at qemu_char.c:4402
>>>    #11 0x00007f9a6a1533b3 in g_timeout_dispatch () from
>>> /usr/lib64/libglib-2.0.so.0
>>>    #12 0x00007f9a6a15299a in g_main_context_dispatch () from
>>> /usr/lib64/libglib-2.0.so.0
>>>    #13 0x0000000000747386 in glib_pollfds_poll () at main_loop.c:227
>>>    #14 0x0000000000747424 in os_host_main_loop_wait
>>> (timeout=404000000) at main_loop.c:272
>>>    #15 0x0000000000747575 in main_loop_wait
>>> (nonblocking=nonblocking@entry=0) at main_loop.c:520
>>>    #16 0x0000000000557d31 in main_loop () at vl.c:2170
>>>    #17 0x000000000041c8b7 in main (argc=<optimized out>,
>>> argv=<optimized out>, envp=<optimized out>) at vl.c:5083
>>>
>>> Let's detach the new thread after calling qemu_thread_set_name().
>>>
>>> Signed-off-by: Caoxinhua <caoxinhua@huawei.com>
>>
>> Please reply with your own Signed-off-by too, not just Xinhua's.
>>
> 
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> 
> OK, thanks, would you please help merge this patch ?

Sure.

Paolo