+2007-05-07 Ulrich Drepper <drepper@redhat.com>
+
+ * sysdeps/unix/sysv/linux/lowlevelrobustlock.c
+ (__lll_robust_lock_wait): Fix race caused by reloading of futex value.
+ (__lll_robust_timedlock_wait): Likewise.
+ Reported by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>.
+
2007-05-06 Mike Frysinger <vapier@gentoo.org>
[BZ #4465]
-/* Copyright (C) 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2006, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.
int oldval = *futex;
int tid = THREAD_GETMEM (THREAD_SELF, tid);
+ /* If the futex changed meanwhile try locking again. */
+ if (oldval == 0)
+ goto try;
+
do
{
if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
continue;
lll_futex_wait (futex, newval);
+
+ try:
+ ;
}
while ((oldval = atomic_compare_and_exchange_val_acq (futex,
tid | FUTEX_WAITERS,
return EINVAL;
int tid = THREAD_GETMEM (THREAD_SELF, tid);
+ int oldval = *futex;
+
+ /* If the futex changed meanwhile try locking again. */
+ if (oldval == 0)
+ goto try;
do
{
return ETIMEDOUT;
/* Wait. */
- int oldval = *futex;
if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
return oldval;
continue;
lll_futex_timed_wait (futex, newval, &rt);
+
+ try:
+ ;
}
- while (atomic_compare_and_exchange_bool_acq (futex, tid | FUTEX_WAITERS, 0));
+ while ((oldval = atomic_compare_and_exchange_val_acq (futex,
+ tid | FUTEX_WAITERS,
+ 0)) != 0);
return 0;
}