http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51296
--- Comment #24 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> 2012-01-13 10:25:34 UTC --- I've done some more digging and found that the EINVAL error is generated inside libpthread.so, by a function called __thdIsAddrInStack. And in fact, if I make M m static, the test passes. While I do have Tru64 UNIX V5.1 sources, some parts are missing, libpthread sources unfortunately among them, so I cannot determine why this is done or suggest another workaround. Rainer