.
Thread 2 (Thread 0x7f4c0281f700 (LWP 2094)):
#0  0x00007f4c09f1fbb7 in epoll_wait (epfd=37, events=0x7f4c0281df10, maxevents=256, timeout=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
        resultvar = 18446744073709551612
        sc_cancel_oldtype = 0
        sc_ret = <optimized out>
#1  0x0000559c1029c027 in ?? ()
No symbol table info available.
#2  0x0000559c102997be in ?? ()
No symbol table info available.
#3  0x00007f4c0a1f66db in start_thread (arg=0x7f4c0281f700) at pthread_create.c:463
        pd = 0x7f4c0281f700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139964436313856, 1550416284993647645, 139964436311232, 0, 0, 140733368277488, -1505281556648365027, -1505262911872633827}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#4  0x00007f4c09f1f88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
No locals.
.
Thread 1 (Thread 0x7f4c0cb0d580 (LWP 2089)):
#0  0x0000559c102a4060 in ErrorFSigSafe ()
No symbol table info available.
#1  0x0000559c102977e2 in xorg_backtrace ()
No symbol table info available.
#2  0x0000559c1029b599 in ?? ()
No symbol table info available.
#3  <signal handler called>
No locals.
#4  _dl_fixup (l=0x559c10faa5a0, reloc_arg=<optimized out>) at ../elf/dl-runtime.c:84
        symtab = <optimized out>
        strtab = 0x7f4c03c13e78 ""
        reloc = 0x7f4c03c15eb0
        sym = 0x7f4c03c13008
        refsym = 0x7f4c03c13008
        rel_addr = 0x7f4c03e3d270
        result = <optimized out>
        value = <optimized out>
        __PRETTY_FUNCTION__ = "_dl_fixup"
#5  0x00007f4c0c9317ca in _dl_runtime_resolve_xsavec () at ../sysdeps/x86_64/dl-trampoline.h:125
No locals.
#6  0x00007f4c03c31592 in ?? () from /usr/lib/xorg/modules/libwfb.so
No symbol table info available.
#7  0x00007f4c03c31b4c in wfbComposite () from /usr/lib/xorg/modules/libwfb.so
No symbol table info available.
#8  0x00007f4c050c94b7 in ?? () from /usr/lib/x86_64-linux-gnu/nvidia/xorg/nvidia_drv.so
No symbol table info available.
#9  0x0000000000000000 in ?? ()
No symbol table info available.