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-rw-r--r--nptl/tst-robust-fork.c184
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diff --git a/nptl/tst-robust-fork.c b/nptl/tst-robust-fork.c
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+/* Test the interaction of fork and robust mutexes.
+ Copyright (C) 2017 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/test-driver.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <sys/mman.h>
+
+/* Data shared between processes. */
+struct shared
+{
+ pthread_mutex_t parent_mutex;
+ pthread_mutex_t child_mutex;
+};
+
+/* These flags control which mutex settings are enabled in the parent
+ and child (separately). */
+enum mutex_bits
+ {
+ mutex_pshared = 1,
+ mutex_robust = 2,
+ mutex_pi = 4,
+ mutex_check = 8,
+
+ /* All bits combined. */
+ mutex_all_bits = 15,
+ };
+
+static void
+mutex_init (pthread_mutex_t *mutex, int bits)
+{
+ pthread_mutexattr_t attr;
+ xpthread_mutexattr_init (&attr);
+ if (bits & mutex_pshared)
+ xpthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED);
+ if (bits & mutex_robust)
+ xpthread_mutexattr_setrobust (&attr, PTHREAD_MUTEX_ROBUST);
+ if (bits & mutex_pi)
+ xpthread_mutexattr_setprotocol (&attr, PTHREAD_PRIO_INHERIT);
+ if (bits & mutex_check)
+ xpthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ERRORCHECK);
+ xpthread_mutex_init (mutex, &attr);
+ xpthread_mutexattr_destroy (&attr);
+}
+
+static void
+one_test (int parent_bits, int child_bits, int nonshared_bits,
+ bool lock_nonshared, bool lock_child)
+{
+
+ struct shared *shared = xmmap (NULL, sizeof (*shared),
+ PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_SHARED, -1);
+ mutex_init (&shared->parent_mutex, parent_bits);
+ mutex_init (&shared->child_mutex, child_bits);
+
+ /* Acquire the parent mutex in the parent. */
+ xpthread_mutex_lock (&shared->parent_mutex);
+
+ pthread_mutex_t nonshared_mutex;
+ mutex_init (&nonshared_mutex, nonshared_bits);
+ if (lock_nonshared)
+ xpthread_mutex_lock (&nonshared_mutex);
+
+ pid_t pid = xfork ();
+ if (pid == 0)
+ {
+ /* Child process. */
+ if (lock_child)
+ xpthread_mutex_lock (&shared->child_mutex);
+ else
+ xmunmap (shared, sizeof (*shared));
+ if (lock_nonshared)
+ /* Reinitialize the non-shared mutex if it was locked in the
+ parent. */
+ mutex_init (&nonshared_mutex, nonshared_bits);
+ xpthread_mutex_lock (&nonshared_mutex);
+ /* For robust mutexes, the _exit call will perform the unlock
+ instead. */
+ if (lock_child && !(child_bits & mutex_robust))
+ xpthread_mutex_unlock (&shared->child_mutex);
+ _exit (0);
+ }
+ /* Parent process. */
+ {
+ int status;
+ xwaitpid (pid, &status, 0);
+ TEST_VERIFY (status == 0);
+ }
+
+ if (parent_bits & mutex_check)
+ /* Test for expected self-deadlock. This is only possible to
+ detect if the mutex is error-checking. */
+ TEST_VERIFY_EXIT (pthread_mutex_lock (&shared->parent_mutex) == EDEADLK);
+
+ pid = xfork ();
+ if (pid == 0)
+ {
+ /* Child process. We can perform some checks only if we are
+ dealing with process-shared mutexes. */
+ if (parent_bits & mutex_pshared)
+ /* It must not be possible to acquire the parent mutex.
+
+ NB: This check touches a mutex which has been acquired in
+ the parent at fork time, so it might be deemed undefined
+ behavior, pending the resolution of Austin Groups issue
+ 1112. */
+ TEST_VERIFY_EXIT (pthread_mutex_trylock (&shared->parent_mutex)
+ == EBUSY);
+ if (lock_child && (child_bits & mutex_robust))
+ {
+ if (!(child_bits & mutex_pshared))
+ /* No further tests possible. */
+ _exit (0);
+ TEST_VERIFY_EXIT (pthread_mutex_lock (&shared->child_mutex)
+ == EOWNERDEAD);
+ xpthread_mutex_consistent (&shared->child_mutex);
+ }
+ else
+ /* We did not acquire the lock in the first child process, or
+ we unlocked the mutex again because the mutex is not a
+ robust mutex. */
+ xpthread_mutex_lock (&shared->child_mutex);
+ xpthread_mutex_unlock (&shared->child_mutex);
+ _exit (0);
+ }
+ /* Parent process. */
+ {
+ int status;
+ xwaitpid (pid, &status, 0);
+ TEST_VERIFY (status == 0);
+ }
+
+ if (lock_nonshared)
+ xpthread_mutex_unlock (&nonshared_mutex);
+ xpthread_mutex_unlock (&shared->parent_mutex);
+ xpthread_mutex_destroy (&shared->parent_mutex);
+ xpthread_mutex_destroy (&shared->child_mutex);
+ xpthread_mutex_destroy (&nonshared_mutex);
+ xmunmap (shared, sizeof (*shared));
+}
+
+static int
+do_test (void)
+{
+ for (int parent_bits = 0; parent_bits <= mutex_all_bits; ++parent_bits)
+ for (int child_bits = 0; child_bits <= mutex_all_bits; ++child_bits)
+ for (int nonshared_bits = 0; nonshared_bits <= mutex_all_bits;
+ ++nonshared_bits)
+ for (int lock_nonshared = 0; lock_nonshared < 2; ++lock_nonshared)
+ for (int lock_child = 0; lock_child < 2; ++lock_child)
+ {
+ if (test_verbose)
+ printf ("info: parent_bits=0x%x child_bits=0x%x"
+ " nonshared_bits=0x%x%s%s\n",
+ parent_bits, child_bits, nonshared_bits,
+ lock_nonshared ? " lock_nonshared" : "",
+ lock_child ? " lock_child" : "");
+ one_test (parent_bits, child_bits, nonshared_bits,
+ lock_nonshared, lock_child);
+ }
+ return 0;
+}
+
+#include <support/test-driver.c>