From: Michael Neumann <mneumann@ntecs.de>
Date: Thu, 8 Jan 2015 23:40:06 +0000 (+0100)
Subject: Make pthread_*_destroy() more standards compliant
X-Git-Tag: v4.2.0rc~1129
X-Git-Url: https://gitweb.dragonflybsd.org/~tuxillo/dragonfly.git/commitdiff_plain/146da5fcd4be3d6b3e74514ab38418637b600540

Make pthread_*_destroy() more standards compliant

Function pthread_{mutex,cond,rwlock}_destroy() returned EINVAL when the
mutex/cond/rwlock was initialized statically via one of the
PTHREAD_*_INITIALIZER macros and not being used before destruction. We now
return success (0) instead, as it would have been the case when the *_init()
function were used for initialization. This is also the behaviour Linux
exhibits.

Note that we now can no longer detect multiple calls to *_destroy(). Multiple
calls will do no harm, but return success.

While there, fix some potential null pointer derefs in cond and rwlock.

Fixes: #2763
---

diff --git a/lib/libthread_xu/thread/thr_cond.c b/lib/libthread_xu/thread/thr_cond.c
index 0dbda34ba2..da403c4cf1 100644
--- a/lib/libthread_xu/thread/thr_cond.c
+++ b/lib/libthread_xu/thread/thr_cond.c
@@ -111,8 +111,10 @@ _pthread_cond_destroy(pthread_cond_t *cond)
 	struct pthread		*curthread = tls_get_curthread();
 	int			rval = 0;
 
-	if (*cond == NULL)
+	if (cond == NULL)
 		rval = EINVAL;
+	else if (*cond == NULL)
+		rval = 0;
 	else {
 		/* Lock the condition variable structure: */
 		THR_LOCK_ACQUIRE(curthread, &(*cond)->c_lock);
diff --git a/lib/libthread_xu/thread/thr_mutex.c b/lib/libthread_xu/thread/thr_mutex.c
index 3ddfacc115..617d8219a1 100644
--- a/lib/libthread_xu/thread/thr_mutex.c
+++ b/lib/libthread_xu/thread/thr_mutex.c
@@ -213,8 +213,10 @@ _pthread_mutex_destroy(pthread_mutex_t *mutex)
 	pthread_mutex_t m;
 	int ret = 0;
 
-	if (mutex == NULL || *mutex == NULL)
+	if (mutex == NULL)
 		ret = EINVAL;
+	else if (*mutex == NULL)
+		ret = 0;
 	else {
 		/*
 		 * Try to lock the mutex structure, we only need to
diff --git a/lib/libthread_xu/thread/thr_rwlock.c b/lib/libthread_xu/thread/thr_rwlock.c
index 385174d346..6761ef735a 100644
--- a/lib/libthread_xu/thread/thr_rwlock.c
+++ b/lib/libthread_xu/thread/thr_rwlock.c
@@ -92,6 +92,8 @@ _pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
 
 	if (rwlock == NULL)
 		ret = EINVAL;
+	else if (*rwlock == NULL)
+		ret = 0;
 	else {
 		pthread_rwlock_t prwlock;