I compliled OpenBSC in linux kernel 4.2.* and all test was successful but when upgrade my linux to kernel v4.8.* , we face 2 failed test. logs attached

That has nothing to do with your kernel, your setup is just broken in some way :

/home/osmocom/openbsc/openbsc/tests/testsuite.dir/at-groups/3/test-source: line 27: 28496 Segmentation fault (core dumped) $abs_top_builddir/tests/db/db_test

/home/osmocom/openbsc/openbsc/tests/mgcp/mgcp_test: error while loading shared libraries: libosmonetif.so.3: cannot open shared object file: No such file or directory

First one is a crash, would need to see the actual backtrace to see what's up. Second is a linking issue, your library setup is broken somewhere.

Cheers,

Sylvain