[PATCH] cr_tests: Fix hang when robust futex lists are not restored during restart

[Serge E. Hallyn]

Quoting Matt Helsley (matthltc at us.ibm.com):
> The robust futex test can hang if the kernel fails to properly set the robust
> list pointer. This currently happens during restart. The test should not
> hang and instead should report failure.
> 
> Use a timeout to ensure that hangs are caught and reported as failure.
> The timeout should return ETIMEDOUT. This limits the total amount of time
> checkpoint/restart can take so a suitable timeout is essential here.
> 
> Signed-off-by: Matt Helsley <matthltc at us.ibm.com>
> Reported-by: Serge Hallyn <serue at linux.vnet.ibm.com>

Hey Matt,

last month you sent out a (short) kernel patch for robust futexes.
Was that supposed to be enough to fully support c/r of robust futexes?

-serge