[hurd,commited,1/3] htl: Report missing mutex lock on pthread_cond_*wait

diff --git a/htl/Makefile b/htl/Makefile
index bb9ef5deba..b2dc797ee4 100644
--- a/htl/Makefile
+++ b/htl/Makefile
@@ -68,7 +68,7 @@  libpthread-routines := pt-attr pt-attr-destroy pt-attr-getdetachstate	    \
 	pt-mutexattr-setpshared pt-mutexattr-settype			    \
 	pt-mutexattr-getrobust pt-mutexattr-setrobust			    \
 									    \
-	pt-mutex-init pt-mutex-destroy					    \
+	pt-mutex-init pt-mutex-destroy pt-mutex-checklocked		    \
 	pt-mutex-lock pt-mutex-trylock pt-mutex-timedlock		    \
 	pt-mutex-unlock							    \
 	pt-mutex-transfer-np						    \
diff --git a/htl/pt-internal.h b/htl/pt-internal.h
index 064e795157..8ffe1bd970 100644
--- a/htl/pt-internal.h
+++ b/htl/pt-internal.h
@@ -301,6 +301,9 @@  extern error_t __pthread_sigstate (struct __pthread *__restrict thread, int how,
 				   const sigset_t *__restrict set,
 				   sigset_t *__restrict oset,
 				   int clear_pending);
+
+/* If supported, check that MUTEX is locked by the caller.  */
+extern int __pthread_mutex_checklocked (pthread_mutex_t *mtx);
 
 
 /* Default thread attributes.  */
diff --git a/sysdeps/htl/pt-cond-timedwait.c b/sysdeps/htl/pt-cond-timedwait.c
index d9ce23b682..3a11e016d7 100644
--- a/sysdeps/htl/pt-cond-timedwait.c
+++ b/sysdeps/htl/pt-cond-timedwait.c
@@ -78,6 +78,10 @@  __pthread_cond_timedwait_internal (pthread_cond_t *cond,
   if (abstime && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
+  err = __pthread_mutex_checklocked (mutex);
+  if (err)
+    return err;
+
   struct __pthread *self = _pthread_self ();
   struct cancel_ctx ctx;
   ctx.wakeup = self;
diff --git a/sysdeps/mach/hurd/htl/pt-mutex-checklocked.c b/sysdeps/mach/hurd/htl/pt-mutex-checklocked.c
new file mode 100644
index 0000000000..dea580fa04
--- /dev/null
+++ b/sysdeps/mach/hurd/htl/pt-mutex-checklocked.c
@@ -0,0 +1,51 @@ 
+/* __pthread_mutex_checklocked.  Hurd version.
+   Copyright (C) 2016-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <pt-internal.h>
+#include "pt-mutex.h"
+#include <hurdlock.h>
+
+int
+__pthread_mutex_checklocked (pthread_mutex_t *mtxp)
+{
+  int ret = 0;
+
+  switch (MTX_TYPE (mtxp))
+    {
+    case PT_MTX_NORMAL:
+      break;
+
+    case PT_MTX_RECURSIVE:
+    case PT_MTX_ERRORCHECK:
+    case PT_MTX_NORMAL | PTHREAD_MUTEX_ROBUST:
+    case PT_MTX_RECURSIVE | PTHREAD_MUTEX_ROBUST:
+    case PT_MTX_ERRORCHECK | PTHREAD_MUTEX_ROBUST:
+      if (!mtx_owned_p (mtxp, _pthread_self (), mtxp->__flags))
+	ret = EPERM;
+      break;
+
+    default:
+      ret = EINVAL;
+      break;
+    }
+
+  return ret;
+}