lockup in socket_wrapper?

[Volker Lendecke]

Hi!

Trying a

make test TESTS=smbclient_ntlm.plain

in master (d4f7d9e08ca690b8278b35690dfb9e4673c19e00) on a debian
stretch leads to a hung python process:

vlendec at vl-vm1:~/git/scratch$ ps uww 28795
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
vlendec  28795  0.0  0.1  40892  7308 pts/25   S    16:45   0:00 /usr/bin/python /data/vlendec/git/scratch/selftest/tests.py

with this stack trace:

#0  __lll_lock_wait () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1  0x00007f8461af4b95 in __GI___pthread_mutex_lock (mutex=0x7f846295a148 <libc_symbol_binding_mutex>) at ../nptl/pthread_mutex_lock.c:80
#2  0x00007f84627504d9 in swrap_thread_prepare () at ../third_party/socket_wrapper/socket_wrapper.c:5909
#3  0x00007f8460edf2f5 in __libc_fork () at ../sysdeps/nptl/fork.c:96
#4  0x00005566defcfb6b in ?? ()
#5  0x00005566deef6dff in PyEval_EvalFrameEx ()
#6  0x00005566deeefd45 in PyEval_EvalCodeEx ()
#7  0x00005566deef7f15 in PyEval_EvalFrameEx ()
#8  0x00005566deeefd45 in PyEval_EvalCodeEx ()
#9  0x00005566def0cc38 in ?? ()
#10 0x00005566deede413 in PyObject_Call ()
#11 0x00005566def2335e in ?? ()
#12 0x00005566deede413 in PyObject_Call ()
#13 0x00005566def23097 in ?? ()
#14 0x00005566deee3f34 in ?? ()
#15 0x00005566deede413 in PyObject_Call ()
#16 0x00005566deef8998 in PyEval_EvalFrameEx ()
#17 0x00005566deeefd45 in PyEval_EvalCodeEx ()
#18 0x00005566deef7f15 in PyEval_EvalFrameEx ()
#19 0x00005566deeefd45 in PyEval_EvalCodeEx ()
#20 0x00005566deeefb09 in PyEval_EvalCode ()
#21 0x00005566deeedc1e in PyImport_ExecCodeModuleEx ()
#22 0x00005566deeeaa9a in ?? ()
#23 0x00005566deedc967 in PyImport_ImportModuleLevel ()
#24 0x00005566deede6d8 in ?? ()
#25 0x00005566deede413 in PyObject_Call ()
#26 0x00005566deefbec0 in PyEval_CallObjectWithKeywords ()
#27 0x00005566deef4690 in PyEval_EvalFrameEx ()
#28 0x00005566deeefd45 in PyEval_EvalCodeEx ()
#29 0x00005566deeefb09 in PyEval_EvalCode ()
#30 0x00005566def2014f in ?? ()
#31 0x00005566def1afc2 in PyRun_FileExFlags ()
#32 0x00005566def1ab0e in PyRun_SimpleFileExFlags ()
#33 0x00005566deecbaa1 in Py_Main ()
#34 0x00007f8460e472b1 in __libc_start_main (main=0x5566deecb3d0 <main>, argc=2, argv=0x7ffd4a79e098, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffd4a79e088) at ../csu/libc-start.c:291
#35 0x00005566deecb2ca in _start ()

The mutex already seems locked and socket wrapper seems to try to
reacquire the lock:

(gdb) p libc_symbol_binding_mutex
$1 = {__data = {__lock = 2, __count = 0, __owner = 28795, __nusers =
1, __kind = 0, __spins = 0, __elision = 0, __list = {__prev = 0x0,
__next = 0x0}},
  __size = "\002\000\000\000\000\000\000\000{p\000\000\001", '\000'
<repeats 26 times>, __align = 2}

What am I doing wrong?

Thanks, Volker

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