nptl: Return EINVAL for pthread_mutex_clocklock/PI with CLOCK_MONOTONIC [BZ #26801]

Linux futex FUTEX_LOCK_PI operation only supports CLOCK_REALTIME,
so pthread_mutex_clocklock operation with priority aware mutexes
may fail depending of the input timeout.

Also, it is not possible to convert a CLOCK_MONOTONIC to a
CLOCK_REALTIME due the possible wall clock time change which might
invalid the requested timeout.

Checked on x86_64-linux-gnu and i686-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>

1 files changed, 68 insertions, 0 deletions

diff --git a/nptl/tst-mutexpi10.c b/nptl/tst-mutexpi10.c
new file mode 100644
index 0000000000..417322e991
--- /dev/null
+++ b/nptl/tst-mutexpi10.c
@@ -0,0 +1,68 @@
+/* Check if pthread_mutex_clocklock with PRIO_INHERIT fails with clock
+   different than CLOCK_REALTIME.
+   Copyright (C) 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 <errno.h>
+#include <array_length.h>
+
+#include <support/check.h>
+#include <support/xthread.h>
+#include <support/timespec.h>
+
+static int
+do_test (void)
+{
+  const int types[] = {
+    PTHREAD_MUTEX_NORMAL,
+    PTHREAD_MUTEX_ERRORCHECK,
+    PTHREAD_MUTEX_RECURSIVE,
+    PTHREAD_MUTEX_ADAPTIVE_NP
+  };
+  const int robust[] = {
+    PTHREAD_MUTEX_STALLED,
+    PTHREAD_MUTEX_ROBUST
+  };
+
+
+  for (int t = 0; t < array_length (types); t++)
+    for (int r = 0; r < array_length (robust); r++)
+      {
+	pthread_mutexattr_t attr;
+
+	xpthread_mutexattr_init (&attr);
+	xpthread_mutexattr_setprotocol (&attr, PTHREAD_PRIO_INHERIT);
+	xpthread_mutexattr_settype (&attr, types[t]);
+	xpthread_mutexattr_setrobust (&attr, robust[r]);
+
+	pthread_mutex_t mtx;
+	xpthread_mutex_init (&mtx, &attr);
+
+	struct timespec tmo = timespec_add (xclock_now (CLOCK_MONOTONIC),
+					    make_timespec (0, 100000000));
+
+	TEST_COMPARE (pthread_mutex_clocklock (&mtx, CLOCK_MONOTONIC, &tmo),
+		      EINVAL);
+
+	xpthread_mutex_destroy (&mtx);
+      }
+
+  return 0;
+}
+
+#include <support/test-driver.c>