On 08/08/2017 01:30 PM, Hailiang Zhang wrote:

Did you test this branch https://github.com/coloft/qemu/tree/colo-for-qemu-2.10-2017-4-22 ?

This seems to be an already known problem, I'm not quite sure, it may be fixed by this patch

It's not :( Using your branch I don't see the assert() error anymore, but the segfault remains and apparently in the same place:

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x00007ffff30ec79e in pthread_join () from /lib64/libpthread.so.0
(gdb) bt
#0  0x00007ffff30ec79e in pthread_join () at /lib64/libpthread.so.0
#1 0x0000555555c0b807 in qemu_thread_join (thread=0x7ffff7ff5130) at util/qemu-thread-posix.c:504 #2 0x0000555555ac96c2 in colo_compare_finalize (obj=0x7ffff7fd3010) at net/colo-compare.c:873 #3 0x0000555555b12f90 in object_deinit (obj=0x7ffff7fd3010, type=0x5555566e4c70) at qom/object.c:454 #4 0x0000555555b13002 in object_finalize (data=0x7ffff7fd3010) at qom/object.c:468 #5 0x0000555555b13f92 in object_unref (obj=0x7ffff7fd3010) at qom/object.c:903 #6 0x0000555555b17a3e in user_creatable_add_type (type=0x5555566eb270 "colo-compare", id=0x5555566eb230 "test-object", qdict=0x555556781bc0, v=0x5555567798f0, errp=0x7fffffffde58) at qom/object_interfaces.c:104 #7 0x0000555555b17b9b in user_creatable_add_opts (opts=0x5555566eb1e0, errp=0x7fffffffde58) at qom/object_interfaces.c:134 #8 0x0000555555b17c96 in user_creatable_add_opts_foreach (opaque=0x5555558e3562 <object_create_delayed>, opts=0x5555566eb1e0, errp=0x0) at qom/object_interfaces.c:158 #9 0x0000555555c1e634 in qemu_opts_foreach (list=0x5555561077a0 <qemu_object_opts>, func=0x555555b17c08 <user_creatable_add_opts_foreach>, opaque=0x5555558e3562 <object_create_delayed>, errp=0x0) at util/qemu-option.c:1114 #10 0x00005555558e7441 in main (argc=6, argv=0x7fffffffe2d8, envp=0x7fffffffe310) at vl.c:4455

So, from what you're saying, this is *not* caused by the lack of parameter on the command line. Right?

char: Fix removing wrong GSource that be found by fd_in_tag
We use fd_in_tag to find a GSource, fd_in_tag is return value of g_source_attach(GSource *source, GMainContext *context), the return value is unique only in the same context, so we may get the same values with different 'context' parameters. It is no problem to find the right fd_in_tag by using g_main_context_find_source_by_id(GMainContext *context, guint source_id) while there is only one default main context. But colo-compare tries to create/use its own context, and if we pass wrong 'context' parameter with right fd_in_tag, we will find a wrong GSource to handle. We tried to fix the related codes in commit b43decb015a6efeb9e3cdbdb80f6547ad7248a4c, but it didn't fix the bug completely, because we still have some codes didn't pass *right* context parameter for remove_fd_in_watch(). Let's fix it by record the GSource directly instead of fd_in_tag. Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> Message-Id: <1492564532-91680-1-git-send-email-zhang.zhanghaili...@huawei.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Actually, we have already re-writed this part, and please follow the later series. Thanks, Hailiang

On 2017/8/8 0:39, Eduardo Otubo wrote:
(please ignore my last email, looks like mutt wants play games lately)

Hi all,

I have found a problem on colo-compare that leads to segmentation fault
when calling qemu like this:

   $ qemu-system-x86_64 -S -machine pc -object colo-compare,id=test-object

First I got an assert failed:

   (qemu-system-x86_64:7887): GLib-CRITICAL **: g_main_loop_quit:
assertion 'loop != NULL' failed

  From this looks like s->compare_loop is NULL on the function
colo_compare_finalize(), then I just added a check there and the assert
went away. But then there's the segfault:

   Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
   0x00007ffff333f79e in pthread_join () from /lib64/libpthread.so.0
   (gdb) bt
   #0  0x00007ffff333f79e in pthread_join () at /lib64/libpthread.so.0
   #1  0x0000555555c379d2 in qemu_thread_join (thread=0x7ffff7ff5160) at
   #2  0x0000555555adfc1a in colo_compare_finalize (obj=0x7ffff7fd3010)
at net/colo-compare.c:867
   #3  0x0000555555b2cd87 in object_deinit (obj=0x7ffff7fd3010,
type=0x5555567432e0) at qom/object.c:453
   #4  0x0000555555b2cdf9 in object_finalize (data=0x7ffff7fd3010) at
   #5  0x0000555555b2dd80 in object_unref (obj=0x7ffff7fd3010) at
   #6  0x0000555555b319a5 in user_creatable_add_type (type=0x5555567499a0
"colo-compare", id=0x555556749960 "test-object", qdict=0x555556835750,
v=0x55555681a3f0, errp=0x7fffffffde58) at qom/object_interfaces.c:105
   #7  0x0000555555b31b02 in user_creatable_add_opts
(opts=0x555556749910, errp=0x7fffffffde58) at qom/object_interfaces.c:135
   #8  0x0000555555b31bfd in user_creatable_add_opts_foreach
(opaque=0x5555558e9c39 <object_create_delayed>, opts=0x555556749910,
errp=0x0) at qom/object_interfaces.c:159
   #9  0x0000555555c4aecf in qemu_opts_foreach (list=0x555556157ac0
<qemu_object_opts>, func=0x555555b31b6f
<user_creatable_add_opts_foreach>, opaque=0x5555558e9c39
<object_create_delayed>, errp=0x0) at util/qemu-option.c:1104
   #10 0x00005555558edb75 in main (argc=6, argv=0x7fffffffe2d8,
envp=0x7fffffffe310) at vl.c:4520

At this point '&s->thread' is '0'. Is this segfault and the above
mentioned assert trigged because I'm creating a colo-compare object
without any other parameter? In a positive case, a simple workaround and
error check should do it. Otherwise I'll debug a little more.

Best regards,

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