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[PATCH] Fix robust mutex daedlock [BZ #20263]
- From: Jiyoung Yun <t2wish at gmail dot com>
- To: libc-alpha at sourceware dot org
- Cc: jy910 dot yun at samsung dot com, Jiyoung Yun <t2wish at gmail dot com>
- Date: Fri, 24 Jun 2016 04:26:22 +0900
- Subject: [PATCH] Fix robust mutex daedlock [BZ #20263]
- Authentication-results: sourceware.org; auth=none
In Linux/ARM environment, a robust mutex can't catch the timeout result
when it is already owned by other thread and requests to try lock with
a specific time value(pthread_mutex_timedlock). The futex already returns
the ETIMEDOUT result but there is no check the return value and it makes
a deadlock.
* nptl/lowlevelrobustlock.c: Implement ETIMEDOUT logic.
Signed-off-by: Jiyoung Yun <t2wish@gmail.com>
---
ChangeLog | 5 +++++
nptl/lowlevelrobustlock.c | 9 +++++++--
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 4bfee94..7b95767 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-06-24 Jiyoung Yun <t2wish@gmail.com>
+
+ [BZ #20263]
+ * nptl/lowlevelrobustlock.c: Implement ETIMEDOUT logic.
+
2016-06-23 Florian Weimer <fweimer@redhat.com>
* test-skeleton.c (xrealloc): Support deallocation with n == 0.
diff --git a/nptl/lowlevelrobustlock.c b/nptl/lowlevelrobustlock.c
index 3b988b2..8842032 100644
--- a/nptl/lowlevelrobustlock.c
+++ b/nptl/lowlevelrobustlock.c
@@ -113,15 +113,20 @@ __lll_robust_timedlock_wait (int *futex, const struct timespec *abstime,
&& atomic_compare_and_exchange_bool_acq (futex, newval, oldval))
continue;
+ int err;
/* If *futex == 2, wait until woken or timeout. */
#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \
|| !defined lll_futex_timed_wait_bitset)
- lll_futex_timed_wait (futex, newval, &rt, private);
+ err = lll_futex_timed_wait (futex, newval, &rt, private);
#else
- lll_futex_timed_wait_bitset (futex, newval, abstime,
+ err = lll_futex_timed_wait_bitset (futex, newval, abstime,
FUTEX_CLOCK_REALTIME, private);
#endif
+ /* the futex call time out */
+ if (err == -ETIMEDOUT)
+ return ETIMEDOUT;
+
try:
;
}
--
1.9.1