As far as I can tell, the following LTP test fails due to a timeout because it
is waiting to write to a locked FILE stream.
https://openqa.opensuse.org/tests/329595#step/run_ltp/565

The test locks stdout then forks and starts a new thread in the child. In the
new thread it tries to lock the file again. The expected behaviour is for this
to fail, but ftrylockfile returns success. The test then tries to print to
stdout which blocks until abort causes the child to exit. If the test is
modified to print to stderr then the test exits normally, but with a fail.

I am not sure if this is a problem with the Kernel or C stdlib. So far I have
tested it on 4.9.0-2-default and 4.9.0-1-default where it is present in both
cases.