[LTP] [PATCH] dio_sparse: prevent race between kill and signal

[Jan S. <jst...@re...>]

If child gets killed before it completes signal(SIGTERM, SIG_DFL),
then kill(childpid, SIGTERM) causes testcase to fail, because
it is caught by LTP def_handler.

For example:
dio_sparse    0  TINFO  :  Dirtying free blocks
dio_sparse    0  TINFO  :  Starting I/O tests
dio_sparse    1  TBROK  :  unexpected signal 15 received (pid = 10319).
dio_sparse    2  TBROK  :  Remaining cases broken
...

Fix this by adding semaphore to wait until all children complete
signal() before killing them.

Signed-off-by: Jan Stancek <jst...@re...>
---
 testcases/kernel/io/ltp-aiodio/dio_sparse.c |   43 +++++++++++++++++++++++++-
 1 files changed, 41 insertions(+), 2 deletions(-)