[compiler-rt] [tsan] Hanging test

I am seeing the compiler-rt tsan test getline_nohang.cc hanging. Here's
the backtrace:

(gdb) bt
#0 0x00007fb3e26cd13b in __lll_lock_wait_private () from /lib64/libc.so.6
#1 0x00007fb3e264cdc2 in __GI__IO_flush_all () from /lib64/libc.so.6
#2 0x00007fb3e264cebf in _IO_cleanup () from /lib64/libc.so.6
#3 0x00007fb3e260e0eb in __run_exit_handlers () from /lib64/libc.so.6
#4 0x00007fb3e260e185 in exit () from /lib64/libc.so.6
#5 0x00007fb3e25f76ec in __libc_start_main () from /lib64/libc.so.6
#6 0x0000000000420639 in _start () at ../sysdeps/x86_64/start.S:118

So apparently it's waiting on a lock during an I/O flush. Has anyone
seen this before?

                         -David

David Greene via llvm-dev <llvm-dev@lists.llvm.org> writes:

So apparently it's waiting on a lock during an I/O flush. Has anyone
seen this before?

And the test is testing for exactly this behavior. It seems the fix
made for this test isn't enough for our environment (SLES 12). I've
marked it unsupported in our sources for now but thought someone should
be aware of the issue. I'll file a bug as well.

                            -David