Althought, it is undefined behavior, there is no reason for segfault. Signed-off-by: Leonid Lisovskiy &lt;lly.dev(a)gmail.com&gt; --- libpthread/linuxthreads/mutex.c | 3 ++- test/pthread/ex8-mtx-odd.c | 56 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+), 1 deletion(-) create mode 100644 test/pthread/ex8-mtx-odd.c diff --git a/libpthread/linuxthreads/mutex.c b/libpthread/linuxthreads/mutex.c index 8908414..8cb779b 100644 --- a/libpthread/linuxthreads/mutex.c +++ b/libpthread/linuxthreads/mutex.c @@ -171,7 +171,8 @@ int attribute_hidden __pthread_mutex_unlock(pthread_mutex_t * mutex) { switch (mutex->__m_kind) { case PTHREAD_MUTEX_ADAPTIVE_NP: - __pthread_unlock(&mutex->__m_lock); + if (mutex->__m_lock.__status != 0) + __pthread_unlock(&mutex->__m_lock); return 0; case PTHREAD_MUTEX_RECURSIVE_NP: if (mutex->__m_owner != thread_self()) diff --git a/test/pthread/ex8-mtx-odd.c b/test/pthread/ex8-mtx-odd.c new file mode 100644 index 0000000..791b2c2 --- /dev/null +++ b/test/pthread/ex8-mtx-odd.c @@ -0,0 +1,56 @@ +/* Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper &lt;drepper(a)redhat.com&gt;om>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + + +static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; + +static int +do_test (void) +{ + + if (pthread_mutex_lock (&lock) != 0) + { + puts ("mutex_lock failed"); + exit (1); + } + + if (pthread_mutex_unlock (&lock) != 0) + { + puts ("1st mutex_unlock failed"); + exit (1); + } + + if (pthread_mutex_unlock (&lock) != 0) + { + puts ("2nd mutex_unlock failed"); + exit (1); + } + + return 0; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" -- 1.8.5.6