1 files changed, 126 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/tst-clone2-internal.c b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
new file mode 100644
index 0000000000..fd3a55158c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
@@ -0,0 +1,126 @@
+/* Test if CLONE_VM does not change pthread pid/tid field (BZ #19957)
+   Copyright (C) 2021 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 <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/syscall.h>
+#include <clone_internal.h>
+#include <support/xunistd.h>
+#include <support/check.h>
+
+static int sig;
+static int pipefd[2];
+
+static int
+f (void *a)
+{
+  close (pipefd[0]);
+
+  pid_t ppid = getppid ();
+  pid_t pid = getpid ();
+  pid_t tid = gettid ();
+
+  if (write (pipefd[1], &ppid, sizeof ppid) != sizeof (ppid))
+    FAIL_EXIT1 ("write ppid failed\n");
+  if (write (pipefd[1], &pid, sizeof pid) != sizeof (pid))
+    FAIL_EXIT1 ("write pid failed\n");
+  if (write (pipefd[1], &tid, sizeof tid) != sizeof (tid))
+    FAIL_EXIT1 ("write tid failed\n");
+
+  return 0;
+}
+
+
+static int
+do_test (void)
+{
+  sig = SIGRTMIN;
+  sigset_t ss;
+  sigemptyset (&ss);
+  sigaddset (&ss, sig);
+  if (sigprocmask (SIG_BLOCK, &ss, NULL) != 0)
+    FAIL_EXIT1 ("sigprocmask failed: %m");
+
+  if (pipe2 (pipefd, O_CLOEXEC))
+    FAIL_EXIT1 ("pipe failed: %m");
+
+#ifdef __ia64__
+# define STACK_SIZE 256 * 1024
+#else
+# define STACK_SIZE 128 * 1024
+#endif
+  char st[STACK_SIZE] __attribute__ ((aligned));
+  struct clone_args clone_args =
+    {
+      .stack = (uintptr_t) st,
+      .stack_size = sizeof (st),
+    };
+  pid_t p = __clone_internal (&clone_args, f, 0);
+
+  close (pipefd[1]);
+
+  if (p == -1)
+    FAIL_EXIT1("clone failed: %m");
+
+  pid_t ppid, pid, tid;
+  if (read (pipefd[0], &ppid, sizeof pid) != sizeof pid)
+    {
+      kill (p, SIGKILL);
+      FAIL_EXIT1 ("read ppid failed: %m");
+    }
+  if (read (pipefd[0], &pid, sizeof pid) != sizeof pid)
+    {
+      kill (p, SIGKILL);
+      FAIL_EXIT1 ("read pid failed: %m");
+    }
+  if (read (pipefd[0], &tid, sizeof tid) != sizeof tid)
+    {
+      kill (p, SIGKILL);
+      FAIL_EXIT1 ("read tid failed: %m");
+    }
+
+  close (pipefd[0]);
+
+  pid_t own_pid = getpid ();
+  pid_t own_tid = syscall (__NR_gettid);
+
+  /* Some sanity checks for clone syscall: returned ppid should be current
+     pid and both returned tid/pid should be different from current one.  */
+  if ((ppid != own_pid) || (pid == own_pid) || (tid == own_tid))
+    FAIL_RET ("ppid=%i pid=%i tid=%i | own_pid=%i own_tid=%i",
+	      (int)ppid, (int)pid, (int)tid, (int)own_pid, (int)own_tid);
+
+  int e;
+  xwaitpid (p, &e, __WCLONE);
+  TEST_VERIFY (WIFEXITED (e));
+  TEST_COMPARE (WEXITSTATUS (e), 0);
+  return 0;
+}
+
+#include <support/test-driver.c>