diff --git a/include/pthread.h b/include/pthread.h
index d8a9f4ab..9f6daf79 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -252,6 +252,27 @@ void pthread_cleanup_push(void (*routine)(void *), void *arg);
 void pthread_cleanup_pop(int execute);
 
 
+int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
+
+
+int pthread_rwlock_init(pthread_rwlock_t *__restrict__ rwlock, const pthread_rwlockattr_t *__restrict__ attr);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/sys/types.h b/include/sys/types.h
index dd7b12e1..0a3d5534 100644
--- a/include/sys/types.h
+++ b/include/sys/types.h
@@ -54,6 +54,11 @@ typedef struct {
 	volatile int initialized;
 } pthread_mutex_t;
 
+/* TODO */
+typedef int pthread_rwlock_t;
+
+typedef int pthread_rwlockattr_t;
+
 
 typedef struct lockAttr pthread_mutexattr_t;
 
diff --git a/include/unistd.h b/include/unistd.h
index dca551d7..a8082174 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -259,6 +259,9 @@ extern int ttyname_r(int fildes, char *name, size_t namesize);
 extern int pause(void);
 
 
+int chroot(const char *path);
+
+
 extern char *optarg;
 
 
diff --git a/pthread/pthread.c b/pthread/pthread.c
index ff0381a3..5139229e 100644
--- a/pthread/pthread.c
+++ b/pthread/pthread.c
@@ -1340,6 +1340,57 @@ void pthread_cleanup_pop(int execute)
 }
 
 
+/* FIXME: rwlocks are yet to be implemented, that breaks shared_mutex in cpp. */
+int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
+{
+	(void)rwlock;
+	return ENOSYS;
+}
+
+
+int pthread_rwlock_init(pthread_rwlock_t *__restrict__ rwlock, const pthread_rwlockattr_t *__restrict__ attr)
+{
+	(void)rwlock;
+	(void)attr;
+	return ENOSYS;
+}
+
+
 void _pthread_init(void)
 {
 	mutexCreate(&pthread_common.pthread_key_lock);
diff --git a/string/string.c b/string/string.c
index bdd61f26..983040a5 100644
--- a/string/string.c
+++ b/string/string.c
@@ -179,7 +179,9 @@ int memcmp(const void *s1, const void *s2, size_t count)
 
 #ifndef __STRLEN
 #define __STRLEN
-size_t strlen(const char *s)
+/* FIXME: long-standing bug in gcc https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102725
+ *        it occurs in strlen causing inf loop, can be avoided if all platform implement strlen in asm. */
+__attribute__((optimize("-fno-tree-loop-distribute-patterns")))  size_t strlen(const char *s)
 {
 	unsigned int k;
 
diff --git a/sys/socket.c b/sys/socket.c
index 26b70f66..c3594618 100644
--- a/sys/socket.c
+++ b/sys/socket.c
@@ -42,7 +42,7 @@ WRAP_ERRNO_DEF(int, listen, (int socket, int backlog), (socket, backlog))
 WRAP_ERRNO_DEF(ssize_t, recvfrom, (int socket, void *message, size_t length, int flags, struct sockaddr *src_addr, socklen_t *src_len), (socket, message, length, flags, src_addr, src_len))
 WRAP_ERRNO_DEF(ssize_t, sendto, (int socket, const void *message, size_t length, int flags, const struct sockaddr *dest_addr, socklen_t dest_len), (socket, message, length, flags, dest_addr, dest_len))
 WRAP_ERRNO_DEF(int, socket, (int domain, int type, int protocol), (domain, type, protocol))
-WRAP_ERRNO_DEF(int, socketpair, (int domain, int type, int protocol, int *sv), (domain, type, protocol, sv))
+WRAP_ERRNO_DEF(int, socketpair, (int domain, int type, int protocol, int sv[2]), (domain, type, protocol, sv))
 WRAP_ERRNO_DEF(int, shutdown, (int socket, int how), (socket, how))
 WRAP_ERRNO_DEF(int, setsockopt, (int socket, int level, int optname, const void *optval, socklen_t optlen), (socket, level, optname, optval, optlen))