http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56159
Bug #: 56159
Summary: config/linux/ptrlock.c lacks acquire barrier
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: amo...@gmail.com
CC: ja...@gcc.gnu.org
Spotted while looking for another bug: gomp_ptrlock_get_slow lacks an acquire
barrier (and do_wait doesn't always provide one). Thus it's possible to exit
from gomp_ptrlock_get without proper synchronization. The (unnecessary)
MEMMODEL_ACQUIRE on failing __atomic_compare_exchange_n in gomp_ptrlock_get is
too early.
